Manuka Honey

The market for Manuka honey has recently exploded, thanks to the perceived benefits of its natural antibacterial properties. But what evidence is there to support the claims?

In this article, we explore what Manuka honey is, what its properties are, and how it differs from other types of honey.

We also look at the evidence available to assess whether Manuka honey really is the next great superfood.

Historical use of honey

Honey has been used to treat wounds since ancient times, as detailed in a document dating back to 1392. It was believed to help in the fight against infection, but the practice fell out of favor with the advent of antibiotics.

As we face the challenge of a growing worldwide resistance to antibiotics, scientists are examining the properties and potential of honey.

Qualities of Manuka honey

The leaves of the Manuka tree, also known as a tea tree, have been known for centuries among the indigenous tribes of New Zealand and southern Australia for their healing powers.

Bees that collect nectar from this tree make Manuka honey, which harbors some of the healing properties.

All Honey contains antimicrobial properties, but Manuka honey also contains non-hydrogen peroxide, which gives it an even greater antibacterial power.

Some studies have found Manuka honey can also help to boost production of the growth factors white blood cells need to fight infection and to heal tissue.

Manuka honey contains a number of natural chemicals that make it different:

  • Methylglyoxal (MGO): This has been shown to be effective against several bacteria, including Proteus mirabilis and Enterobacter cloacae.
  • Dihydroxyacetone (DHA): This is found in the nectar of Manuka flowers and converts into MGO during the honey production process.
  • Leptosperin: This is a naturally occurring chemical found in the nectar of Manuka plants and a few close relatives.

Manuka honey and wound care

Medical grade honey, used by healthcare professionals as part of a wound dressing, can help some kinds of wounds to heal.

Experts believe that because Manuka honey has added antibacterial and healing properties, it may be even more effective. At the moment, however, there is little evidence to support the theory.

A Cochrane Review looked at all the evidence available to support the use of honey in wound care. Published in 2015, the study said the differences in wound types made it impossible to draw overall conclusions about the effects of honey on healing.

The study found strong evidence that honey heals partial thickness burns around 4 to 5 days more quickly than conventional dressings. There is also evidence indicating that honey is more effective than antiseptic and gauze for healing infected surgical wounds.

Another study concluded that honey has rapid diabetic wound healing properties, but recommended more research to confirm that honey can be used as the first line of treatment for these types of wounds.

While some research does show that honey can help improve certain conditions, more studies are needed to confirm honey’s benefits for:

  • mixed acute and chronic wounds
  • pressure ulcers
  • Fournier’s gangrene
  • venous leg ulcers
  • minor acute wounds
  • Leishmaniasis

Manuka honey and bacteria

Antibiotics are used to prevent and treat bacterial infections all over the world. However, the bacteria the drugs are deployed to kill can adapt and become resistant.
Manuka honey has antibacterial properties and may be able to fight superbugs resistant to most standard antibiotics.

This resistance is currently happening all over the world, and a growing number of infections are becoming harder to treat. This leads to longer hospital stays, higher medical costs, and ultimately, more deaths.

The World Health Organization (WHO) has listed resistance to antibiotics as the one of the biggest threats to global health, food security, and development.

The natural antibacterial properties of honey may be useful in this fight. In the lab, Manuka honey has been shown to be able to inhibit around 60 species of bacteria. These include Escherichia coli (E. coli) and salmonella.

Some studies have shown that Manuka honey can fight so-called superbugs that have become resistant to antibiotics. These include Staphylococcus aureus (MRSA-15) and Pseudomonas aeruginosin.

This line of investigation is still in its infancy. These have been small, lab-based tests which combined medical grade Manuka honey with antibiotics.

There is still a lot of work to be done before scientists can come to a conclusion.

Other health benefits

There are many other potential health benefits of Manuka honey. These include:

  • reducing high cholesterol
  • reducing inflammation
  • reducing acid reflux
  • treating acne

There is, however, limited evidence for its use in these areas.

Using Manuka honey

The medical grade honey used to dress wounds is very different from the honey sold in stores.

Medical grade honey is sterilized, with all impurities removed, and prepared as a dressing. Wounds and infections should always be seen and treated by a healthcare professional.

Store-bought Manuka honey can be used in the same manner as any other honey: on toast, on porridge, or to sweeten drinks.

There is no clear evidence that people who consume Manuka honey in this way will notice any benefit to their health. It is not clear how the active ingredients that provide Manuka honey with its healing properties survive in the gut.


Honey is usually around 80 percent sugar, mainly supplied by glucose, fructose, and sucrose, so moderate intake is recommended. This is particularly true if you have diabetes.

Due to the recent trend for Manuka honey, it can be expensive, so it is important to make sure you know what you are looking for.

When buying Manuka honey from the store, look for the Unique Manuka Factor (UMF) mark. This means the honey has been produced by one of the 100+ beekeepers, producers, and exporters licensed by the UMF Honey Association.

The number displayed next to the UMF mark represents the quantity of Manuka key markers, leptosperin, DHA, and MGO. Consumers are advised to choose UMF 10+ and above.

Building Your Immune System {Part 1}

Did you know that when it comes to boosting your immune system, there’s a lot of misinformation circulating on the net?  Yes, everyone is selling magic bullet immune boosters, but do you know why, when it comes to the immune system, magic bullets can’t work?  Were you aware that it’s actually possible to fool your immune system into being more vigilant?  But most important of all, did you know that studies have shown that some immune enhancing herbs can actually boost T-cell production 30% more than the most powerful pharmaceutical drugs your doctor can prescribe–and a lot more safely at that?

If you want to maintain your health, increase your longevity, and minimize your risk of many illnesses, you must boost your immune system. It is not important to build your immune system just to protect yourself from cancer, age-related diseases, or autoimmune disorders either. Your garden variety flu is responsible for some 250,000 to 500,000 deaths worldwide each and every year–about 36,000 in the US alone–each and every year. In fact, of some 1,700 bacteria and viruses known to cause disease, historically, the flu virus has been the leading cause of death — only recently being surpassed by the HIV virus and the resulting AIDS!

The bottom line is if you’re looking to stay healthy–it’s worth optimizing your immune system. Scientists have known for years that it is possible to improve the functioning of your immune system. The conventional medical approach has been to use expensive, proprietary drugs, including concentrated cytokines such as interleukin and interferon. Holistic healers, on the other hand, have adopted a more nuanced approach using natural substances to:

  • Stimulate and strengthen the immune system
  • Fight infection
  • Strengthen tissue against assault by invading microorganisms
  • Stimulate macrophage capability
  • Increase T-cell production and protect helper T-cells
  • Complement the action of interferon and interleukin-1
  • Promote increased production of cytokines
  • Assist the cell-mediated immune response

With that in mind, let’s take a look at some natural immune boosters. Not only are they safer than their pharmaceutical counterparts, but they have fewer side effects and are, surprisingly, often more powerful– at least up to this point in time. First, we’ll look at the ingredients I use in my own immune system support formula. As a formula, they are designed to complement each and boost your immune system across the board. After that, we’ll take a look at some other useful immune enhancers that can be taken separately. The reason they are not included in the formula is that, although they are very powerful, they need to be taken in larger amounts–sometimes one or two capsules of just that one ingredient–to be effective and are, therefore, not suitable for inclusion in a multi-part formula.

A Multi-Part Formula for Building the Immune System

Under normal circumstances, your immune system responds to foreign organisms by producing antibodies and stimulating specialized cells which destroy the organisms or neutralize their toxic byproducts. A second major function of your immune system, though, is to watch over all of the cells of your body to ensure that they are not abnormal–in other words, cancerous. A properly functioning immune system is actually your first line of defense against cancer.

The secret to a good immune tonic is to:

  • Select complementary herbal immune enhancers that build immunity across the board, in multiple ways.
  • Use meaningful doses of a select number of herbs, not minuscule doses of a large number of herbs. You want efficacy from each herb you use, not a large number of herbs on a label used at insignificant doses.
  • Use only the highest quality herbs, not the cheapest. Formulators can buy ginseng for $5.00 a pound or $400-$600 a pound for high-quality wildcrafted or organic. Which do you think actually work? When it comes to your health and your immune system, you want only high-quality ingredients used in any formula you use.

With that said, let’s take a look at what actually goes into a good multi-part immune building formula.


There are several different ways that immune boosters can power up your immune system. One of the simplest is by presenting your immune system with what it perceives as a non-specific threat — a foreign antigen — that in actuality offers no real threat to the body. This false threat causes your immune system to “power up” its defenses. However, since the immune booster presents no actual threat to the body, the immune system has nothing to use its new-found readiness against. And thus it waits, charged up, primed for some/any threat to manifest so that it can jump on it with a vengeance. One thing to keep in mind about this kind of immune booster is that the immune system can be fooled by a false threat for only so long before it says to itself, “Ah, you’re just yanking my chain. I’m onto what’s happening here — time to stand down.” And thus the effectiveness of the supplement begins to wane. When using immune boosters of this type, it’s best to take regular breaks so your body forgets the false threat presented to the immune system. This works because since the threat is false, your immune system never actually gets to take the final step of “attacking” the immune booster, which is required for the cells of your immune system to memorize a response to an invader. Thus, you can pull your immune system’s leg again and again, while keeping your immune system on high alert indefinitely. For Echinacea, it’s best to use it for three weeks on and one week off.

Note: if someone is highly sensitive to the antigens presented by this type of immune booster, their immune systems can actually “kick over” into an actual allergic response to the immune booster and produce symptoms such as sneezing and watery eyes, for example. For sensitive people, then, this type of immune booster is not useful. It should also be noted that this type of response can plant part dependent. With Echinacea, for example, more people are sensitive to supplements made with Echinacea flowers as opposed to Echinacea seeds and roots. Fortunately, the strongest bioactives are in the seeds and roots, not the flowers.

Echinacea (purple coneflower) was “discovered” in the late 1800’s by a traveling salesman named Joseph Meyer, who learned about it from the Plains Indians while roaming out West. He brewed it up as an alcohol tincture and sold it as a cure all — demonstrating its effectiveness by drinking his tonic and letting rattlesnakes bite him. Needless to say, he never got sick, from whence comes the phrase “snake oil.”

How does Echinacea work? In addition to tricking the immune system to ramp up, Echinacea has a number of bioactives that help in several other ways. First, E. angustifolia and E. pallida roots contain echinacoside, a natural antibiotic comparable to penicillin in effect, which can kill a broad range of viruses, bacteria, fungi, and protozoa.3  And all three varieties contain cichoric and chlorogenic acids, as well as cynarin, which all work to charge up the immune system by stimulating phagocytosis. In addition, Echinacea contains high molecular weight polysaccharides such as heteroxylan, arabinogalactan, and fucogalactoxyloglucan, which stimulate macrophages and possess anti-inflammatory activity.

As a result, Echinacea is invaluable in wound healing and in the treatment of infectious diseases. Research has also reported Echinacea’s efficacy in treating colds, flu, bronchitis, and tuberculosis. And Echinacea contains echinacein, which along with echinacoside protects against germ attack by neutralizing the tissue-dissolving enzyme hyaluronidase, produced by many germs. Among the many pharmacological properties reported for Echinacea, the one demonstrated most convincingly is macrophage activation — by increasing production of interferon gamma. In addition, one study showed that Echinacea extracts can boost T-cell production by up to 30 percent more than pharmaceutical immune boosting drugs. And finally, Echinacea also increases production of the chemokines interleukin-8 and MCP-1, which enhance the migration of immune cells to the site of infection.

There are two primary varieties of Echinacea: purpurea and angustifolia. And depending on the country you’re in, you may also find E. pallida used in your formula. They are similar, but also have complementary properties. Formulas that use at least two of them (especially purpurea and angustifolia) are more likely to be effective. It’s also worth noting that potency runs from seed to root to leaf to least in the flower. And of course, herb quality is paramount.

Over the last few years, there have been several studies that claimed to debunk Echinacea’s ability to boost the immune system and fight colds. Suffice it to say that the studies were either flawed in design (reviews of previously flawed studies), used the wrong parts of the Echinacea plant (flowers and leaves rather than roots and seeds), or used it at the wrong strength. More disturbingly, a more recent study (2010), conducted using good quality Echinacea at a significant dose, found little benefit to using Echinacea in terms of reducing the length of a cold. Not surprisingly, the press jumped all over it, proclaiming Echinacea was now proven to be little more than a placebo. However, two aspects of the study’s protocol negate the results.

  • Dosing with Echinacea commenced at the onset of symptoms. This is too late to capitalize on Echinacea’s primary ability to ramp up the immune system in preparation for any pathogenic invasion. Once symptoms start, your immune system is going to be responding to the antigens presented by the cold virus itself so adding Echinacea will provide little added immune benefit at that point. (Remember, the key to Echinacea is ramping up the immune system “before” the invader arrives. And studies have shown that when used in that way, Echinacea can decrease your odds of getting a cold by 58%.)  After that, any benefit will come from its germ killing properties, which although real, are secondary. And even at that, the study showed that Echinacea did indeed shorten the duration of colds — just not by that much. Once again, the major benefit of Echinacea is in ramping up your defenses before an invader attacks–not shortening the duration of an illness after an attack. For that, you need an anti-pathogenic formula.
  • If you are going to wait until the last second, you have to intervene during the incubation phase at the latest, before symptoms fully manifest. And, at least with Echinacea, you have to use a liquid extract for quicker absorption. Once you hit the incubation phase, it’s only a matter of hours before the virus kicks into full gear. Waiting for an Echinacea pill to dissolve and make its way through the digestive tract takes too long.

Forget the negative studies. Echinacea still stands as a powerful immune booster. And as an interesting side note, a study published just a few weeks ago found that echinacoside protects against beta amyloid fibril-induced neuronal cell death. For those of you who don’t remember, beta amyloid protein depositions play a crucial role in a variety of degenerative disorders, especially Alzheimer’s.

Pau d’arco

Pau d’arco (Tabebuia impetiginosa) is a broad-leaf evergreen tree that comes from the rain forests of Brazil and other areas of South America. It is the inner bark of the tree that provides the medicinal function.

Like Echinacea, this amazing herb both stimulates the body’s defense system and actively attacks pathogenic organisms, especially bacteria and fungi. It has been used for centuries to improve immune function, detoxify, and reduce pain throughout the body, especially in the joints. Research has shown that it contains lapachol, a natural antibacterial agent that has a healing effect on the entire body, cleanses the blood, and kills viruses. Pau d’arco has been used as a treatment for AIDS, allergies, infections and inflammations, anemia, asthma, arthritis and rheumatism, arteriosclerosis, bronchitis, cancer, candidiasis, colitis, cystitis, diabetes, eczema, fistulas, gastritis, gonorrhea, hemorrhages, Hodgkin’s disease, liver disease, leukemia, lupus, multiple sclerosis, osteomyelitis, Parkinson’s disease, prostatitis, psoriasis, skin sores, snake bites, ulcers, varicose veins, warts, and wounds.

The primary active biochemicals in Pau d’arco are the naphthoquinones: lapachol and beta-lapachone. Researchers have shown that lapacholhas antitumorous, antiedemic, anti-inflammatory, antiseptic, antiviral, bactericidal (even against MRSA), and antifungal activity–not to mention being anti-parasitic.


Natives of the Amazon jungle have used suma root (Pfaffia paniculata) for at least the last 300 years. It wasn’t until 1975, however, that Suma was first tested at the University Of São Paulo, Brazil. The studies concluded that although it was not a cure, suma nevertheless brought significant relief for cancer, diabetes, and gout sufferers, with no undesirable side effects. Since then, studies at the American College of the Healing Arts have indicated that consistent use of suma may help combat fatigue (including treatment of chronic fatigue and low-energy conditions), prevent colds and flu, speed healing, regulate blood sugar, and stimulate the sex drive. In general, suma is considered an energizing adaptogen, an herb used to normalize and regulate the systems of the body when the body is under severe stress or attack from pathogens. Specifically, it is used to boost the immune system. In fact, it is suma’s ability to enhance non-specific immune and/or cellular immune systems that likely accounts for its anticancer abilities.

The key working ingredients in suma are pfaffic acid (prevents the spread of various cell disorders), pfaffocides and other saponins (help stop diseases already in progress), the plant hormones sitosterol and stigmasterol (prevent cholesterol absorption and improve blood circulation), allantoin (helps accelerate healing), and germanium. Suma has one of the highest concentrations of organic germanium sesquioxide (Ge-132) of any plant known. Discovered about thirty years ago, Ge-132 works much like Pau d’arco in that it stimulates the production of interferon gamma, while at the same time activating cytotoxic natural killer cells and macrophages. The net result is that it can invigorate the body, restore sexual function, protect against miscarriages, heal burns, reduce pain, treat circulatory disorders, and shrink cancers, in addition to being a powerful immunostimulant.

Astragalus Membranaceus

Astragalus has been a foundational herb in Traditional Chinese Medicine for hundreds of years. It is one of the important “Qi tonifying” adaptogenic herbs from the Chinese materia medica. Current research on Astragalus focuses on the immune stimulating capacity of its polysaccharides and saponins. It also appears to be useful in dealing with cancer, and in increasing stamina. First and foremost, though, it is an immunostimulant used in the treatment of chronic viral infections, hepatitis, edema, common cold, and flu. Astragalus increases the interferon response to viral infection and works synergistically with interferon. It also increases phagocytic activity and antibody levels and improves the functioning of natural killer cells.


Cordyceps Sinensis has properties similar to those of ginseng and has been used to strengthen and rebuild the body after exhaustion or long-term illness. It is one of the most valued medicinal fungi in Chinese medicine and has also been used traditionally for impotence, neurasthenia, and backache. Recent research with extracts of Cordyceps has yielded a protein-bound polysaccharide with activity against tumors, as well as being capable of up-regulating macrophage activity,  and inducing the apoptosis (cell death) of human leukemia cells, while at the same time moderating overactive T-cell activation.  In other words, Cordyceps functions as an immunomodulator–up-regulating depressed immune systems, but throttling back out of control immune systems. (More on this later.) Cordyceps is widely employed to treat upper respiratory problems, impotence, and weakened immune systems, and also by athletes to increase endurance.

Other Immune Boosters

Medicinal Mushrooms

Cordyceps is not the only immune-boosting mushroom of note. In fact, compounds found in mushrooms such as reishi and maitake, as in cordyceps, are classified as host defense potentiators. It is believed that combinations of these compounds target and strengthen the human immune system, as well as aid in neuron transmission, metabolism, hormonal balance, and the transport of nutrients and oxygen. Through a host-mediated (T-cell) immune mechanism, they help the body regulate the development of lymphoid stem cells and other important defense responses.

The anti-cancer and immune-enhancing effects of the reishi mushroom (Ganoderma lucidumi) are thought to be largely due to its mucopolysaccharides, which the body incorporates into cellular membranes, making them resistant to viruses and pathogenic bacteria and the triterpenes, which induce tumor necrosis factor production. The polysaccharides also appear to activate macrophages that “consume” viruses, bacteria, and other large particulate matter.

Maitake mushrooms (Grifola frondosa, also known as Sheep’s Head and Hen of the Woods) have a very high concentration of a unique polysaccharide compound called beta-1,6-glucan, which researchers consider to be one of the most powerful immune stimulants and adaptogens known. One study showed that maitake produced a 64 percent inhibition of breast cancer and tumor activity and a 75 percent inhibition of skin cancer and tumor activity. Also, laboratory studies conducted at the U.S. National Cancer Institute (NCI) and the Japanese National Institute of Health showed that maitake extract kills the human immunodeficiency virus (HIV) and enhances the activity of helper T-cells. In fact, the NCI researchers reported that the maitake extract was as powerful as AZT (a commonly prescribed AIDS drug) but without the toxic side effects.

Research has demonstrated that maitake stimulates the production of a variety of immune cells, including macrophages, NK cells, and T-cells, and it increases their effectiveness by increasing the production of interleukin-l, interleukin-2, and lymphokines. It also stimulates the bone marrow to produce stem cells and granulocytes by stimulating the production of the cytokine granulocyte colony stimulating factor. Further, maitake has been confirmed to have a multifaceted benefit for treating cancer and tumors: it protects healthy cells from becoming cancerous, helps prevent the spread of cancer (metastasis), and slows or stops the growth of tumors. Maitake works in conjunction with chemotherapy by lessening the negative side effects (by as much as 90 percent).

Incidentally, maitake is not the only source of beta glucan. Beta-glucan is a natural complex carbohydrate (polysaccharide) found in cereal grains such as oats and barley. But it is found in its greatest concentration in medicinal mushrooms as described above and in the cell walls of yeast. Beta glucan as a purified supplement, particularly Beta- 1,3/1,6 Glucan extracted from yeast cell walls, is a potent and proven immune response potentiator and modulator. It has been shown to stimulate anti-tumor and antimicrobial activity by binding to receptors on macrophages and other white blood cells and activating them, while at the same time throttling back overactive parts of the immune system.


AHCC (Active Hexose Correlated Compound) is a proprietary dietary supplement derived from mushrooms that are rich in polysaccharides and fiber. Some 20 human clinical studies and more than 100 pre-clinical and in vitro studies have shown that it can be effective in stimulating the production of NK cells, killer T-cells, and cytokines (interferon, interleukin-12, and TNF-alpha). In Japan, it is used extensively in hospitals in combination with chemotherapy treatments to reduce the adverse side effects of those treatments.

Aloe Vera

The polysaccharide component of aloe vera, acemannan, possesses significant immune-enhancing and antiviral activity. Supplementing with acemannan has been proven to increase lymphocyte response to antigens by enhancing the release of interleukin-I. In addition, Acemannan has been shown to increase macrophage levels and have a positive effect on T-cell activity and dendritic cell maturation. In addition, acemannan has various medicinal properties such as being osteogenic (promotes bone repair), anti-inflammatory, and antibacterial, which accelerate the healing of lesions. Also, in vivo studies have shown that acemannan has antiviral and antitumor activities through activation of immune responses. Look for whole leaf aloe extract, which is two to three times more potent than gel/juice. Why? The greatest concentration of active ingredients is at the interface of the rind and the inner gel. If your extract doesn’t come from the whole leaf, you lose half to two-thirds of the active biochemicals.


Alkylglycerols (AKGs) are lipids naturally manufactured in the body and found in mother’s milk, the liver and spleen, and bone marrow. They play a major role in the production and stimulation of white blood cells. They also help to normalize bone marrow function. The immune-supportive effect of AKGs helps our bodies protect against bacterial, fungal, and viral infections through enhanced phagocytosis (eating up the bad guys) and antibody production. The most potent source of AKGs in the world is shark liver oil.

Colostrum and Lactoferrin

Colostrum is the clear, yellowish, pre-milk fluid produced from the mother’s mammary glands during the first seventy-two hours after birth. It provides both immune and growth factors essential for the health and vitality of the newborn. Obviously, supplementation with human colostrum is not an option, but researchers have found that bovine colostrum (from cows) is virtually identical, except that the immune factors are actually several times more concentrated.

The immune factors in colostrum have been shown to help the body resist pathogens such as viruses, bacteria, yeast, and fungi. In addition, colostrum contains a number of antibodies to specific pathogens, including E. coli, salmonella, rotavirus, Candida, streptococcus, staphylococcus, H. pylori, and cryptosporidia. In addition, proline-rich-polypeptide, a component of colostrum, works as an immunomodulator, boosting a low immune system and balancing an overactive one. Another key component of colostrum is transferred factors, small molecules that transfer immunity information from one entity to another. In effect, they transfer immunity “memory,” thereby giving you instant resistance to a number of diseases.

Colostrum is a potent source of lactoferrin, a globular iron-binding protein produced in the body. It is found anywhere that is especially vulnerable to attack, such as in the gut, eyes, ears, nose, throat, and urinary tract. Lactoferrin has been shown to inhibit virus replication (including AIDS and herpes viruses), limit tumor growth and metastasis, directly kill both bacteria and yeast (including Candida), and activate neutrophils. Supplementation with lactoferrin can significantly boost the immune system and help the body recover from any existing infection. Maintaining healthy levels of intestinal flora through the use of probiotic supplements allows the body to produce its own lactoferrin.

Look for colostrum obtained from organic, grass-fed dairy cows and standardized to 40% Immunoglobulins.


Glutathione is a tripeptide molecule found in human cells. In addition to being a powerful antioxidant, glutathione works to support the active functioning of the immune system and is a key component of all lymphocytes. In fact, all lymphocytes require sufficient levels of intracellular glutathione to function properly. It also plays a major protective role against the damaging effects of the whole range of pathogens and carcinogens. For many people, glutathione supplements are upsetting to the stomach, and for that matter, it has been assumed for years that very little actually makes it out of the digestive tract when taken as a supplement, although at least one study may contradict that. Either way, it is possible to boost your body’s levels of glutathione by supplementing with the glutathione precursors L-cysteine and L-glutamate and specially formulated whey products.


Mangosteen (Garcinia mangostana) is a tropical evergreen tree whose fruit (and especially the hull of the fruit) contains a unique group of antioxidants called xanthones. Xanthones, particularly beta and gamma mangostin, work to maintain the immune system, support cardiovascular health, optimize joint flexibility, are naturally antibiotic, antiviral, and anti-inflammatory, and are some of the most powerful antioxidants found in nature. In addition, recent studies have confirmed that gamma mangostin is a potent COX inhibitor, an important factor in reducing inflammation, pain, and fever. Other studies have shown that alpha-mangostin can enhance the body’s innate responses to viral infection. And as has been true with most of the other immune boosters we’ve looked at so far, mangosteen has also shown the ability to work as an anticancer agent. Specifically, the antimetastatic activity of alpha-mangostin has been demonstrated in clinical studies on breast cancer.

Ascorbic Acid

Vitamin C is currently being pushed online as an Ebola solution. That may be a bit of a stretch. That vitamin C helps boost the immune system is pretty much a given. And it certainly has strong antiviral qualities in a test tube. But in real life, the results are more mixed. Forget Ebola or the flu, even when it comes to the common cold, results are mixed. As a 2013 Cochrane Report says, “Trials of high doses of vitamin C administered therapeutically, starting after the onset of symptoms, showed no consistent effect on the duration or severity of common cold symptoms.”

However, the story doesn’t end there. What most studies evaluate as “high doses” is not even close to what Linus Pauling recommended. For most studies, we’re talking about 1-3 grams a day. Pauling himself took 18 g a day. At these levels, ascorbate has been shown to have specific antiviral effects in which it inactivates the RNA or DNA of viruses or in the assembly of the virus. But it should be noted that even in these studies, the beneficial effect of vitamin C was moderate—not a cure-all.

The bottom line on vitamin C is that large doses are used as an immune booster but are unlikely to prove to be a cure-all for Ebola.

Colloidal Silver

Colloidal silver is not an immune booster, but rather, an anti-pathogen. However, since it’s currently being promoted as a cure for Ebola, we’ll make mention of it here.

I like colloidal silver as an antibacterial agent, and studies support its effectiveness in this regard. However, studies do not consistently support its effectiveness against viruses.  If you come down with Ebola, it certainly wouldn’t hurt to take colloidal silver; it just may not perform as promised. Note: when using colloidal silver, argyria(the permanent blue/graying of your skin) is always a back of the mind concern. The risk is extremely low and is almost always the result of foolishly high doses used over a long time, but it does happen. It should be noted that new versions of silver products, such as Silver Sol, claim to have eliminated the potential for argyria, but that claim has not been tested over time. That said, for anything other than very occasional use, I prefer ionic zinc, which has similar efficacy without the skin discoloration issues.


As we’ve mentioned several times so far, optimizing your immune system isn’t just about boosting it. An over-amped immune system can be just as problematic as an underperforming one. Many autoimmune disorders are the result of your immune system doing too much, eventually attacking healthy cells and tissue in your body. In medical terminology, an immunomodulator is a drug or natural substance that adjusts the immune response to the desired level, through either immunopotentiation, immunosuppression, or induction of immunological tolerance (stopping it from attacking a particular antigen). In other words, as with most medical thinking, immunomodulation is not about balancing the immune system, but about forcing it to behave in certain ways.

In contrast, in the world of natural healing, immunomodulators are thought of as nutraceuticals that can “intelligently” regulate your immune system, boosting a weak system or calming down an overactive one. If a person with low immune function takes an immunomodulator, it will help raise their immunity. Likewise, if a person with a hyperactive immune system takes the same immunomodulator, it will tend to calm their immune system down and normalize it. It appears that natural immunomodulators accomplish this, at least to some degree, by naturally increasing the body’s production of messenger molecules to regulate and correct defects in memory T-cells. In that sense, true immunoregulators are adaptogenic — capable of modifying the immune system, either up or down, as needed. By using natural immunomodulators, you can retrain the immune system to respond more efficiently and to not overreact (as happens in the case of people with autoimmune disorders). Some of the better immunomodulators include:


  • L-carnosine54
  • Cetyl myristoleate (CMO)
  • Colostrum
  • Ginseng
  • Astragalus
  • Rhodiola

Immune System Memory

Something to keep in mind is that your immune system has memory. If you are exposed to a pathogen (virus, bacteria, etc.), your immune system has a memory of that pathogen and the defense it mounted to defeat it. Thus, it can protect you against it (and its close cousins) for years–and possibly for the rest of your life. That means that some people who never seem to get sick were exposed to cold and flu germs previously that are similar to those currently circulating about. This gives them the appearance of invincibility. However, when exposed to a new pathogen, they quite likely will get sick as quickly as the next person.

Cytokine storm

There is a caveat to boosting your immune system. Under certain circumstances, having a maximized immune can be a two-edged sword. Some viruses actually use your immune system to kill you through a condition called acute respiratory distress syndrome in which the victim’s own immune system unleashes a cytokine storm that literally chews up their lung tissue, ultimately causing the victim to suffocate. In a cytokine storm, the immune system sees a virus that it has never seen before, and it goes nuts, whipping itself into a frenzy in response to the invading virus. A biochemical cascade of immune cells and immune system bio-chemicals such as interferon, interleukin, monokines and cytokines literally pour into the lungs. The subsequent damage to the lung tissue caused by these cells and biochemicals leads to the condition mentioned above called acute respiratory distress syndrome (ARDS). The net result is that the victim suffocates as a result of their own disease-fighting chemistry.

Most common cases of flu do not produce cytokine storms. Most cases of flu kill people who have weak immune systems by eventually opening the door for pneumonia, which is what actually kills them. That’s why health authorities specify that the very old and very young and those with weak immune systems are prime candidates for annual flu vaccines (even though they don’t work very well). But swine flu, avian flu, and most notably, the great flu pandemic of 1918 are different animals. They don’t kill through pneumonia. They kill you by unleashing a cytokine storm, which means that it is your own immune system that kills you. And this means that the most vulnerable are not the very old and the very young but healthy adults and pregnant women, people who have very strong immune systems. And that means that the stronger your immune system, the greater the danger — the exact opposite of standard flu strains.

Does that mean that you should weaken your immune system to protect against these special viruses? Not at all! That would be silly. Strong immune systems are good for many, many reasons. However, it does mean that you want natural antipathogens on hand in your medicine cabinet to use at the first sign of a cold or flu. It will protect you against standard flu, and if you perchance catch a rogue strain of avian or swine flu, the anti-pathogens will kill enough of the virus to take your viral load down to the point that your immune system can do its job with no risk of being forced into a cytokine storm. You get the best of all possible worlds.

One thing to keep in mind is that there is likely to be a run on natural antipathogens at the first hint of a viral pandemic. We saw just such a run on Tamiflu during the avian and swine flu scares — even though they provide little protection. And we saw a similar run on iodine tablets after the meltdown at the Fukushima Daiichi nuclear plant in Japan. In other words, you might want to stock your medicine cabinet before you actually need the anti-pathogens.


We’ve talked a lot about building your immune system, modulating it, and complementing it with anti-pathogens, but there’s an elephant in the room: what about all the other factors that impact your immune system indirectly?

  • For instance, how good can your immune system be (taking all the supplements in the world) if your colon is packed with pounds of old fecal matter? There are skeptics who deny it and doctors who say they’ve never seen it, but the math is irrefutable: a significant percentage of people on a typical Western diet store pounds of old fecal matter in their colons. A substantial portion of your immune system then has to combat the effects of self-toxicity. Clean up your intestinal tract, and you free up your immune system.
  • And then there are the beneficial bacteria that manufacture potent immune boosters such as transfer factor and lactoferrin (which we talked about earlier) right in your intestinal tract — if those beneficial bacteria are actually present in your intestinal tract. In other words, using a good probiotic can substantially boost your immune system by increasing internal production of a number of powerful immune factors.
  • Taking systemic/proteolytic enzymes between meals relieves stress on the immune system by helping to eliminate Circulating Immune Complexes from the body.
  • Proper diet and nourishment boost your immune system. Each and every immune cell in your body is manufactured from the food you eat. A nutritionally deficient diet means functionally deficient immune cells. You can’t build the same immune cells from chips and beer that you can from a balanced healthy diet.
  • Full spectrum antioxidant formulas boost the immune system in multiple ways. Just one example is curcumin. A study published in Immunological Investigations proves that curcumin can increase white blood cell count by some 50% in just 12 days — not to mention circulating antibodies by some 512 times in the same timeframe.
  • Cleaning out the liver with a good liver detox program improves your liver’s ability to produce immune factors and remove bacteria from the blood. Cleaning out the blood with a good blood cleansing formula and balancing your blood’s pH with alkalinizing formulas or high pH water also helps to improve immune function.
  • And of course, as we’ve already discussed, along with immune boosting formulas, you’ll want to use natural pathogen destroying formulas that are specifically designed to improve immune function and directly destroy invading pathogens.
  • As explained in Lessons from the Miracle Doctors, what you think matters too. Negative thoughts can kill you. Likewise, practicing some mental relaxation techniques and visualizations can result in a dramatic increase in immune function — virtually overnight.
  • And finally, one of the primary benefits of regular exercise is an optimized immune system.

The bottom line is that if you want your immune system running at peak level, you need to think holistically. Supplements are good and often necessary, but equally important is having all your body systems working in the background to move your immunity up or down as needed. No other program in the world works to enhance the immune system in as many ways as the Baseline of Health Program. It also works in the most targeted and efficient manner possible so that you don’t have to take 100 supplements to get a result — just deal with the major systems in the body. The bottom line is that you don’t have to chase the next hot “magic bullet” to build your immunity as long as you have optimized all of your major body systems.

Food as Medicine: Sorrel (Rumex acetosa, Polygonaceae)

History and Traditional Use

Garden sorrel (Rumex acetosa, Polygonaceae) is a wild, perennial herb characterized by slender stems supporting bright green, spear-shaped leaves, with distinctive backward-reaching lobes.1,2 Sorrel grows in patches that average in height from 20-36” and produce small red-brown flowers, which bloom in early summer and produce tiny, hard fruits.3 Sorrel is easy to cultivate and grows best in cool, temperate climates, as well as grasslands, coastal dunes, and cliffs.1 In addition to R. acetosa, another species of sorrel, French sorrel (R. scutatus), is used for culinary purposes.4 This article will profile the history, uses, and components of R. acetosa.

Sorrel is native to Europe and northern Asia, and evidence of cultivation dates back to 4,000 BCE.2 In the Middle Ages, sorrel was a prominent vegetable throughout Europe and was also cultivated by ancient Egyptians, Greeks, and Romans. Often referred to as the lemon of the leaf crops, the sour-tasting leaves are the most commonly consumed part of the plant.2,5 Sorrel’s stem and flower were also used in medicinal applications.2 Sorrel’s species name, acetosa, is Latin for “vinegary,” indicating the plant’s acidic taste.6

Phytochemicals and Constituents

Sorrel is a nutrient-dense green, containing important vitamins and minerals, such as vitamin A, vitamin C, sodium, potassium, magnesium, calcium, and iron.2Vitamin A is a fat-soluble vitamin that supports healthy vision, bone growth, and a strong immune system.7Vitamin C is a water-soluble vitamin, essential for its role in collagen synthesis and its antioxidant properties. Sodium, potassium, and magnesium are the most abundant minerals within human cells, and each plays a role in electrolyte and fluid balance. Calcium is a structural component of the skeletal matrix, and Iron is necessary for oxygen delivery and DNA synthesis.

Flavan-3-ols and other phenolic compounds in sorrel leaves provide additional benefits.8-10 Phenolic compounds have protective effects against inflammation and cell damage and interfere with tumor and estrogen receptor activities.10 The main phenolic compounds present in R. acetosa include resveratrol (41.27 µg/g), vanillic acid (130.29 µg/g), sinapic acid (5,708.48 µg/g), and catechin (75.46 µg/g). Sorrel leaves also contain beta-carotene, though not in therapeutic levels.11

Historical and Commercial Uses

Documented uses of sorrel include domestic remedies, and extend to complex medicinal therapies.2 Sorrel leaf juice has been used in fragrances and for stain removal, and sorrel leaves are a popular ingredient in French cuisine.

Sorrel leaves are considered acidic, astringent, and cooling.6 Sorrel has been used as a laxative and a topical treatment for skin disorders, sore throats, and warts.11 Sorrel leaf also was used for its diuretic properties to induce water excretion and to manage fevers.1,5,12 Due to its high concentration of vitamin C, sorrel has been used as a therapeutic food for conditions caused by vitamin C deficiencies, such as scurvy.1Furthermore, common garden sorrel was used as a treatment for constipation, cramping, and diarrhea since the plant demonstrates soothing effects on the stomach and intestines.8,9 The astringent properties of the seeds were used to treat hemorrhages.12

Currently, sorrel is used as an ingredient in herbal medicinal remedies, such as Sinupret (Bionorica SE; Neumarkt, Germany), a proprietary blend of botanicals, indicated for sinusitis and bronchitis.7 Tablets contain 18-36mg of sorrel leaf and stem extract, in addition to four other herbs: elder flower (Sambucus nigra, Adoxaceae), primrose flower and calyx (Primula veris, Primulaceae), European vervain leaf and stem (Verbena Officinalis, Verbenaceae), and yellow gentian root (Gentiana lutea, Gentianaceae).

Modern Research

Currently, studies on sorrel offer promising results in the areas of digestion, infection prevention, topical skin treatments, and anti-proliferative activity.10,12,13

A recent in vivo and in vitro study evaluated the traditional use of R. acetosa to treat stomach discomforts and distress in animal models.12 A 70% methanol extract from sorrel leaves was found to have a high acute toxicity dosage (i.e., large amounts were well tolerated and exhibited no adverse effects), relaxed the gastrointestinal tract or produced gastrointestinal contractions depending on the dose, and exhibited anti-emetic properties. These findings support the traditional use of sorrel as a constipation aid that stimulates a bowel movement.

Anti-diarrheal properties may be linked to the presence of calcium-binding components and tannins in sorrel.8,9,12Oxalic acid binds with and thereby reduces available free calcium for receptor stimulation. This leads to reduced muscle contraction and may alleviate diarrhea.12Tannins exert an astringent effect, which may help alleviate not only conditions such as diarrhea but also chronic upper respiratory infections, by reducing excess fluid.9

Phytochemical extracts from other buckwheat families (Polygonaceae) members exhibit antiviral and anticancer effects, specifically extracts from R. acetosella or sheep sorrel. Sheep sorrel has a history of use as an ingredient in the formula known as Essiac tea, which purportedly is based on the traditions of the indigenous Ojibwa Native American tribe.11 Garden sorrel shows similar antiviral and anticancer effects. An in vivo trial discovered that an extract of R. acetosa reduced influenza A viral invasion of host cells, and further reduced viral growth.14 Antiviral reactions are primary effects of rich polyphenol concentration. In sorrel, these polyphenols mainly include flavonols, proanthocyanidins, and hydrolysable tannins. These compounds may prevent the assembly and maturation (growth and development) of certain viruses, an important step in infection control.

Additional documentation supports anti-proliferative (tumor cell growth preventing) activities seen with R.acetosa preparations.10,13 Prevention of cell growth, specifically tumor cells, was found at concentrations of 75 and 100 µg/mL of a 90% aqueous methanol extract.10

In vitro and in vivo trials displayed antimicrobial and antiviral properties. Sinupret was able to reduce viscosity, or thickness, of mucus in animal models and produce an anti-inflammatory response. Sorrel’s contributions to anti-inflammation are credited to an increased response by immune cells. Few adverse side effects related to sorrel have been reported, and include gastrointestinal disorders and correlated allergic reactions.7
Consumer Considerations

Oxalic acid within sorrel produces a bitter taste, which makes sorrel a valuable ingredient for adding a tart, lemony flavor to various dishes. However, oxalic acid is a potential cause for concern in regard to renal function.11 Crystalized calcium oxalate (which forms when oxalic acid combines with calcium) can lead to the formation of kidney stones and may also accumulate in the heart, circulatory vessels, and lungs.15 In addition, oxalic acid’s ability to bind to micronutrients, such as iron and calcium, decreases its absorption.11,13 Furthermore, oxalates may irritate the digestive system when consumed in large amounts.16 For these reasons, consumption of sorrel should be monitored for special populations affected by renal and arthritic conditions, as well as those with gastrointestinal disorders.1,11

Oxalic acid is concentrated at 300mg per 100 grams of sorrel.11 The majority is found within the leaves, followed by marginal amounts in stems.13 The concentration of oxalates depends on the plant’s growing conditions, such as soil and climate.8 Moreover, tannins in sorrel leaves are concentrated between 7-15%.11When consumed in large amounts, tannins may cause stomach upset and/or kidney and liver damage.

Fortunately, the oxalic acid concentration decreases to negligible amounts with light cooking.11 For example, sorrel soup has a lower oxalic acid concentration compared to pesto made with fresh sorrel leaves.13 Also, the oxalic acid concentration increases proportionately to the size and length of the leaf, making young, tender leaves a better choice for those people affected by these conditions.

Nutrient Profile17

Macronutrient Profile: (Per 1 cup chopped raw sorrel)

29 calories
3 g protein
4 g carbohydrate
1 g fat

Secondary Metabolites: (Per 1 cup chopped raw sorrel)

Excellent source of:
Vitamin A: 5320 IU (106.4% DV)
Vitamin C: 63.8 mg (106.3% DV)
Magnesium: 137 mg (34.3% DV)
Manganese: 0.5 mg (25% DV)

Very good source of:
Iron: 3.2 mg (17.8% DV)
Dietary Fiber: 4 g (16% DV)
Potassium: 519 mg (14.8% DV)
Vitamin B6: 0.2 mg (10% DV)

Good source of:
Phosphorus: 83.8 mg (8.4% DV)
Thiamin: 0.1 mg (6.7% DV)
Calcium: 58.5 mg (5.9% DV)
Riboflavin: 0.1 mg (5.9% DV)

Also, provides:
Folate: 17.3 mcg (4.3% DV)
Niacin: 0.7 mg (3.5% DV)

DV = Daily Value as established by the US Food and Drug Administration (FDA), based on a 2,000-calorie diet.

Recipe: Green Potato Salad

Adapted from Blue Apron18


  • 2 pounds yellow potatoes, such as Yukon Gold, diced into bite-sized pieces
  • 6 ounces fresh spinach
  • 6 ounces fresh sorrel leaves
  • 2 green onions, thinly sliced
  • 2 stalks celery, thinly sliced
  • 1/2 cup sour cream or Greek yogurt
  • 1 tablespoon prepared horseradish (or to taste)
  • Salt and pepper to taste


  1. Place the potatoes in a saucepan and cover with water. Bring to a boil, salt the water, then cook until potatoes are tender and easily pierced with a fork, approximately 15 minutes.

  2. Lift the potatoes out, reserving the water, and set aside in a bowl. Add the greens to the boiling water and cook for 30 seconds to a minute, or until wilted. Drain the spinach into a strainer, pressing to release as much water as possible.

  3. Roughly chop the greens, then add to the potatoes.

  4. Add remaining ingredients to the bowl and toss thoroughly to combine. Season with salt and pepper. Salad may be served warm, at room temperature, or after chilling.


  1. Rumex acetosa (common sorrel). Kew Royal Botanic Gardens website. Available here. Accessed April 28, 2016.
  2. Van Wyk B-E. Food Plants of the World: An Illustrated Guide. Portland, Oregon: Timber Press, Inc.; 2006.
  3. Bown D. The Herb Society of America: New Encyclopedia of Herbs and Their Uses. London, UK: Dorling Kindersley Ltd.; 2001.
  4. Real Food Right Now and How to Cook It: Sorrel. Grace Communications Foundation website. Available here. Accessed April 28, 2016.
  5. Felter HW, Lloyd JU. King’s American Dispensatory. 18th edition. Cincinnati, OH: Ohio Valley Co.; 1898. Available here. Accessed April 28, 2016.
  6. Onstad D. Whole Foods Companion: A Guide for Adventurous Cooks, Curious Shoppers & Lovers of Natural Foods. White River Junction, VT: Chelsea Green Publishing Company; 1996.
  7. Oliff HS, Blumenthal M. Scientific and Clinical Monograph for Sinupret. Austin, TX: American Botanical Council; 2009.
  8. Kemper KJ. Sorrel (Rumex acetosa L.). Boston, MA: The Longwood Herbal Task Force; 1999.
  9. Bicker J, Petereit F, Hensel A. Proanthocyanidins and a phloroglucinol derivative from Rumex acetosaL. Fitoterapia. 2009;80(8):483-495.
  10. Kucekova Z, Mlcek J, Humpolicek P, Rop O, Valasek P, Saha P. Phenolic compounds from Allium schoenoprasumTragopogon pratensis and Rumex acetosa and their antiproliferative effects. Molecules. 2011;16(11):9207-9217.
  11. Vasas A, Orbán-Gyapai O, Hohmann J. The Genus Rumex: Review of traditional uses, phytochemistry, and pharmacology. J Ethnopharmacol. 2015;175:198-228.
  12. Hussain M, Raza SM, Janbaz KH. A pharmacologically mechanistic basis for the traditional uses of Rumex acetosa in gut motility disorders and emesis. Bangladesh J Pharmacol. 2015;10(3):548.
  13. Tuazon-Nartea J, Savage G. Investigation of oxalate levels in sorrel plant parts and sorrel-based products. Food Nutr Sci. 2013;4(8):838-843.
  14. Derksen A, Hensel A, Hafezi W, et al. 3-O-galloylated procyanidins from Rumex acetosa L. inhibit the attachment of influenza A virus. PLoS One. 2014;9(10).
  15. Oxalic acid. J.R. Organics website. Available here. Accessed May 5, 2016.
  16. Elpel T. Botany in a Day: The Patterns Method of Plant Identification. Pony, MT: HOPS Press, LLC; 2013.
  17. Basic report: 11616 Dock, raw. Agricultural Research Service, United States Department of Agriculture website. Available here. Accessed April 28, 2016.
  18. Seared Salmon and “Green” Potato Salad with Pickled Mustard Seeds. Blue Apron website. Available here. Accessed April 28, 2016.

Food as Medicine: Caper (Capparis spinosa, Capparaceae)

The caper (Capparis spinosa, Capparaceae) bush is a small, salt-tolerant shrub with trailing, thorny branches, and thick, fleshy leaves. Caper has a deep root system and trailing vines that grow seven to 10 feet tall.1 The semi-prostrate branches have ovate, petiolate leaves arranged opposite of each other. The flowers are pink or white with three petals and numerous stamens. Caper is a deciduous, dicotyledonous plant that produces distinctive flower buds, which have a lifespan of 24 to 36 hours after opening.1,2

Caper’s edible shoots are considered a vegetable, and its processed buds are considered a culinary herb.1The tender shoots emerge in the spring, while the flower buds are harvested from mid-May to mid-August. Each plant produces hundreds of flowers each season. When pickled in vinegar or brine, the immature flower buds form capric acid, which is responsible for caper’s unique, salty-sour flavor.2,3 Once the flower blooms and is pollinated, it produces a fruit two to three inches in length and one-half to three-quarters of an inch in diameter. Caper fruits start out green but turn purple when ripe. Each fruit contains 200 to 300 seeds.1 The fruit of the caper bush is also harvested, but not commonly used.2

capersCurrently, capers are cultivated commercially in northern Africa, Spain, and Italy. Caper plants in Cyprus, Greece, and Turkey are grown for domestic use and not for export. The United States imports more than $20 million of processed capers annually.1 Caper plants that are two to three years old produce about two pounds of buds in a year, while plants older than four years may produce more than 20 pounds of buds annually.1

Phytochemicals and Constituents

Macronutrients are found in capers in very small amounts. One tablespoon (8.6 grams) of pickled capers has two calories, half a gram of carbohydrates, and minute amounts of protein and fat. An important micronutrient to consider when eating capers is sodium. One tablespoon of capers contains 202 milligrams of sodium, which is 8.5% of the recommended daily intake for a healthy adult.4,5 The flower bud also contains trace amounts of vitamins C and E. The concentration of vitamins can vary from plant to plant. The vitamin C content in capers cultivated in different regions in Tunisia, for example, ranged from 0.3 to 0.5 milligrams per 100 grams of capers.6

A number of bioactive compounds have been isolated from the flower buds of the caper bush. The pickling process has varying effects on the bioavailability of compounds due to different fermentation methods.7 Among the most investigated of these phytochemicals are flavonoids and antioxidants.

Flavonoids from Capers reportedly have cytotoxic, anti-inflammatory, antidiabetic, and antiparasitic properties.7,8 Rutin (quercetin-3-O-rutinoside) is the most abundant flavonoid in fresh and pickled caper buds.7 Simple water extractions high in rutin have been shown to reduce inflammation and arrest cell growth in cancer cells, as well as kill intestinal parasites in animals.8,9 Caper flower buds also contain quercetin-3-O-rhamnosylrutinoside, a derivative of quercetin.6

Quercetin, another well-studied flavonoid, is formed from rutin during the pickling process.7 Quercetin can inhibit inflammation and cancer cell growth in the same way as rutin.9 Quercetin has also shown immune health benefits. Kaempferol 3-O-rhamnosylrutinoside, another flavonoid identified in an aqueous extract, has proven antiparasitic properties.8

The flower bud of the caper bush also contains antioxidants such as carotenoids, tocopherols, ascorbic acid, and a newly identified antioxidant, cappariside, a small organic acid.6,10 Antioxidants eliminate free radicals that cause damage to body tissues and DNA and have been implicated in the prevention of cancer, kidney damage, and heart disease, as well as protection against prescription drug-induced toxicity.11 The antioxidant effects of flower bud preparations have been shown to be more potent than those of the antioxidants in isolation.8

Historical and Commercial Uses

The unopened flower buds of the caper bush are commercially known as capers.2 Capers are used as a condiment in salads and sauces, or with meat or fish. They are also used in cosmetics and medicines.

Archeological evidence for the historical use of capers as a food and medicine exists among many ancient cultures.12 The earliest known evidence of caper consumption was found in the Mesolithic soil layer of an excavation site in Syria, potentially dating back to 9000 BCE. Nearby ancient peoples may have been using capers in 7500 BCE as evidenced by mineralised seeds found in the Franchthi cave, a Stone Age cave in the Greek Peloponnesian peninsula. Dried seeds found in the Nahal Hemar cave in Israel may have been used as early as 6000 BCE. In China, fresh clumps of capers and plant parts were preserved in entombed containers that are almost 3,000 years old. There is also evidence of Egyptian consumption of capers from 275 BCE to 600 CE.

Historical medicinal uses of capers ranged from expelling bad odor spirits in ancient Arabic cultures to treating paralysis in ancient Xinjiang, China.12 In addition to the buds, the root bark, fruit, and aerial parts of the caper bush were used in traditional remedies. Countries in the native range of caper, including Iran, Iraq, and Syria, used every part of the caper bush for a variety of ailments. As the cultivation and use of capers spread, the Greeks, Egyptians, and Chinese incorporated the caper bush into their traditional medicine practices.

Capers contain phytochemicals that can inhibit inflammation, which supports caper’s usages as a cleanser and pain reliever.9,12 In ancient Chinese, Greek, and Arabic cultures, the root bark was mixed with vinegar or honey and applied topically to treat skin conditions such as ulcers and white spots associated with vitiligo.12 Similarly, the root was consumed as a treatment for inflammation and lacerations of the mouth, spleen, stomach, and intestines. In ancient Egypt, the root was used to reduce the pain of a scorpion sting.

In ancient Greece and China, the caper bush was regarded for its drying properties and was used as an expectorant in treating wet cough and asthma.12 Ancient Romans boiled caper root and root bark in oil and used it as an anthelmintic (digestive tract parasitic worm expeller). Likewise, in the 12th century, the Egyptians used the root to cleanse and dry the stomach.

Current medicinal usages are a testament to caper’s efficacy for treating different ailments. In the Middle East, indigenous groups still use capers as a so-called “blood purifier” and diuretic, to relieve stomach discomfort, treat kidney stones, improve liver function, and treat eczema.13 In Ayurveda, one of the traditional medicine systems of India, caper is used to treat paralysis and tremors, as well as edema, gout, and rheumatism.14 The root bark is still used to stimulate the menstrual cycle, as an expectorant, and to treat paralysis, rheumatism, spleen conditions, and toothaches.15

Modern Research

Commercial capers are not frequently studied for their medicinal properties. However, some research has been conducted on the bioactive compounds in the flower buds.

A recent study investigated the antiparasitic effect of a caper bud extract against Haemonchus contortus, a common parasite in cows and sheep. A large number of eggs and short lifespan of H. contortus allows the parasite to adapt quickly to its environment.16 Parasite infestations can result in large economic losses in the animal production industry, and current treatments include chemotherapy and vaccinations, which pose a safety concern.17 Researchers compared the caper extract to a commonly prescribed antiparasitic drug albendazole. The flower bud extract (50 mg/mL) was almost twice as effective as albendazole (1 mg/mL) at killing parasites in sheep and inhibited  the hatching of parasitic eggs more than the leaf extract.8

The caper bud has also been studied for its anti-inflammatory and cytotoxic properties. A recent study investigated the potential of capers to inhibit nuclear factor-kappa B (NF-κB), a transcription factor that controls inflammation and cell growth. Mutations that impact its activation may lead to uncontrolled cell growth, one of the conditions that can cause a proliferation of cancer cells.18 For this reason, NF-κB is a therapeutic target for pancreatic, renal, and thyroid cancer treatments.18-20 In one in vitro study, researchers tested an aqueous extract of the flower bud and leaves, which were selected for their high levels of phenolic compounds, on human adenocarcinoma cells. The caper extract successfully inhibited the inflammation mechanism and arrested cell growth in a dose-dependent manner.9

Additionally, a caper flower bud extract has been studied for its ability to treat liver toxicity in animals. Rats were exposed to two different liver toxins: carbon tetrachloride, a known carcinogen that has been used as a commercial refrigerant, propellant, and solvent; and paracetamol, also known as acetaminophen, a pain-relieving drug that can induce liver failure in sufficiently high doses.21 Compared to control, the caper extract resulted in a significant reduction in carbon tetrachloride-induced and paracetamol-induced liver toxicity.

Nutrient Profile4

Macronutrient Profile: (Per 1 tablespoon pickled capers, drained)

2 calories

0.2 g protein

0.4 g carbohydrate

0.1 g fat

Secondary Metabolites: (Per 1 tablespoon pickled capers, drained)

Provides small amounts of:

Vitamin K: 2.1 mcg (2.6% DV)

Dietary Fiber: 0.3 g (1.2% DV)

Provides trace amounts of:

Magnesium: 3 mg (0.8% DV)

Vitamin C: 0.4 mg (0.7% DV)

Iron: 0.1 mg (0.6% DV)

Riboflavin: 0.01 mg (0.6% DV)

Folate: 2 mcg (0.5% DV)

Vitamin E: 0.1 mg (0.5% DV)

Manganese: 0.007 mg (0.4% DV)

Calcium: 3 mg (0.3% DV)

Niacin: 0.06 mg (0.3% DV)

Vitamin A: 12 IU (0.2% DV)

Phosphorus: 1 mg (0.1% DV)

Potassium: 3 mg (0.1% DV)

Thiamin: 0.002 mg (0.1% DV)

Vitamin B6: 0.002 mg (0.1% DV)

DV = Daily Value as established by the US Food and Drug Administration, based on a 2,000-calorie diet.

Recipe: Lemon Capellini with Capers

Adapted from Ina Garten22


  • 1 pound dried capellini pasta
  • 1/3 cup of extra virgin olive oil
  • Zest and juice of two lemons
  • 1/4 cup capers, drained
  • Salt and pepper to taste


  1. Cook pasta according to package directions. Before draining, reserve 1/4 cup of pasta cooking water. Drain pasta and return to pot off the heat.

  2. Toss the cooked pasta with olive oil, lemon juice, salt, and pepper, adding pasta water a tablespoon at a time until

    a thin sauce forms

    . Discard any remaining pasta water.

  3. Add capers and lemon zest and toss once more to combine. Serve immediately.


  1. Kontaxis DG. Specialty Crop: Capers. Davis, CA: University of California Cooperative Extension; 2012. Available at: Accessed April 17, 2017.
  2. Van Wyk, BE. Food Plants of the World: An Illustrated Guide. Portland, OR: Timber Press; 2005.
  3. National Geographic Society. Edible: An Illustrated Reference to the World’s Food Plants. Washington DC: National Geographic Society; 2008.
  4. Basic Report: 02054, Capers, canned. United States Department of Agriculture Agricultural Research Service website. Available at: Accessed April 6, 2017.
  5. Appendix 7. Nutritional Goals for Age-Sex Groups Based on Dietary Reference Intakes and Dietary Guidelines Recommendations. In: Dietary Guidelines for Americans 2015-2020. 8th ed. Washington DC: US Department of Health and Human Services and US Department of Agriculture; 2015.
  6. Tlili N, Khaldi A, Triki S, Munné-Bosch S. Phenolic compounds and vitamin antioxidants of caper (Capparis spinosa). Plant Foods Hum Nutr. 2010;65(3):260-265.
  7. Nabavi SF, Maggi F, Daglia M, Habtemariam S, Rastrelli L, Nabavi SM. Pharmacological effects of Capparis spinosa L. Phyother Res. 2016;30:1733-1744.
  8. Akkari H, B’chir F, Hajaji S, et al. Potential anthelmintic effect of Capparis spinosa (Capparidaceae) as related to its polyphenolic content and antioxidant activity. Veterinární Medicína. 2016;61(6):308-316.
  9. Kulisic-Bilusic T, Schmöller I, Schnäbele K, Siracusa L, Ruberto G. The anticarcinogenic potential of essential oil and aqueous infusion from caper (Capparis spinosa L.). Food Chem. 2012;132(1):261-267.
  10. Yang T, Wang C, Liu H, Chou G, Cheng X, Wang Z. A new antioxidant compound from Capparis spinosaPharm Biol. 2010;48(5):589-594.
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Food as Medicine: Spinach (Spinacia oleracea, Chenopodiaceae)

Spinach (Spinacia oleracea, Chenopodiaceae) is an annual plant that grows up to 23 inches tall (60 cm). Spinach plants produce an edible rosette and toothed fleshy leaves. There are two main types of spinach: crinkled savory leaf spinach and smooth or flat-leaf spinach. Spinach leaves are fleshy, deep green, and rich in essential nutrients and phytochemicals. Spinach requires deep and nitrogen-rich soil to grow, and prefers a cool climate, with spring and autumn being optimal growth seasons for the leaves. The hot weather of summer may cause the spinach to bolt quickly, which causes the leaves to deteriorate. The plant produces greenish-yellow flowers when ready to set seed.

Spinach is native to southwest Asia, in the area of present-day Iran. Spinach cultivation spread to China in 647 BCE and spread across Europe by the 12th century CE. Now, spinach is cultivated throughout the world in temperate climate zones. In the United States, California is the largest producer of spinach, followed by Arizona and New Jersey. The annual per capita consumption of spinach in the United States was estimated to be 1.7 pounds in 2014.

Phytochemicals and Constituents

Spinach is one of the most nutritious leafy vegetables and ranks second behind kale (Brassica oleracea var. acephela, Brassicaceae) in total carotenoids and folate content. Spinach is high in protein and low in carbohydrates and fat.

The plant is a nutrient-dense source of vitamins and minerals and maintains its nutritional value well after cooking. Spinach provides an array of B vitamins, which are important for carbohydrate metabolism, the nervous system, and the brain. Spinach contains other important minerals including calcium, magnesium, zinc, and selenium, and is a significant source of potassium, copper, iodine, and iron. It also contains abundant amounts of vitamins A, K, and C.

The flavonoid, phenolic acid, and carotenoid content of spinach make it a healthy, therapeutic food. These compounds are effective at neutralizing free radicals in the body and are able to protect the body from damage and disease by reducing inflammation.

The two major carotenoids present in spinach leaves are lutein and beta-carotene, and they compose more than 65% of the total carotenoids content. Lutein may help prevent vision loss from age-related degenerative disorders such as macular degeneration and cataracts. A yellow pigment, lutein is found in high amounts in the retina and absorbs blue light emitted by back-lit devices such as smartphones and computer screens. Other carotenoids in spinach include violaxanthin and neoxanthin.

The carotenoids in spinach are very delicate and highly susceptible to degradation over time. Post-harvest handling of spinach from a field to freezer does alter the phytochemical profile of the leaves. In one study, storing fresh spinach leaves for 24 hours at 39°F (4°C) did not impact the carotenoids content in fresh spinach. However, storing fresh spinach for 72 hours at the same temperature resulted in a reduction of the carotenoids content by almost 15%. Blanching fresh leaves for two minutes at 212°F (100°C) followed by freezing effectively preserved the carotenoid content of spinach.

Historical and Commercial Uses

Historically, spinach leaves have been used as a laxative, diuretic, antidote against poison or infection, and as a treatment for asthma and other breathing difficulties, sore throat, and kidney stones. Spinach also has potential effects against hyperglycemia and inflammation. The seeds were used to control fever, to address back pain, and as a diuretic. In the Indian traditional medicine, the plant is known as palak and was used to treat liver injury or infection and jaundice. Spinach was prescribed and used in traditional Iranian medicine as an antidepressant. Due to its high iron and chlorophyll content, spinach often is used as a therapeutic food for patients with anemia.

Spinach leaves are available commercially fresh, frozen, or canned. Depending on the spinach cultivar and method of preservation, the nutrients and phytochemical profile of spinach may vary. Spinach leaves can be eaten fresh or cooked. Several popular spinach-based dishes are said to be prepared “a la Florentine,” supposedly in honor of Catherine de Medici (1519-1589), who was born in Florence and introduced the vegetable to the French court upon her marriage to King Henry II.

Modern Research

There are limited data regarding the effect of whole spinach leaves on diseases, metabolic pathways, and conditions. Most of the available literature reports the effects of leaf extracts or specific isolated phytonutrient components.

Oxidative Damage and Inflammation

The antioxidant content of spinach leaf, which contains high amounts of vitamins A and C, suggests protective effects against damage from cellular oxidation. A mouse study found that supplementation with 1,100 mg/kg per day of methanolic spinach leaf extract significantly decreased radiation-induced lipid peroxidation in the liver. This study further demonstrated that the leaf extract decreased the negative impact of radiation on glutathione levels.

A 2017 rat study used a different methanolic spinach leaf extract with high levels of lutein, luteolin, quercetin, and coumarin. High-performance liquid chromatography analysis of the extract confirmed the presence of these compounds in active amounts. The study reported that intraperitoneal injection of the extract showed a protective anti-inflammatory effect in mice that were given isoproterenol to induce a heart attack. Spinach extract intake led to changes in activities of multiple enzymes, including paraoxonase, lecithin-cholesterol acyltransferase, C-reactive protein, myeloperoxidase, and caspase-3. Furthermore, the levels of pro-inflammatory cytokines in the heart tissue were significantly lower in mice pretreated with spinach extract than the control group. These results indicate the potential protective effects of spinach against inflammation and atherogenesis (the formation of abnormal fatty masses in arterial walls) when used as a concentrated leaf extract.

Cancer Chemoprevention

An in vitro study demonstrated that neoxanthin significantly suppressed inflammation and proliferation of prostate cancer cells. Additionally, in a bacteria-based model, flavonoids found in spinach leaves showed antimutagenic potential.

A study in mice reported that the antioxidants extracted from spinach leaves have protective effects against benign epithelial tumors. The potential mechanism of action was linked to the direct and indirect abilities of antioxidant compounds in spinach leaves to act as free-radical scavengers that inhibit the progression of carcinogenesis.

The abundant glycolipids in spinach leaves were found to possess inhibitory effects on the gastric cancer cell and promyelocytic leukemia cell proliferation in vitro. These findings are considered positive, but preliminary, results of the potential therapeutic effects of spinach glycolipids to prevent cancer proliferation.

Cardiovascular Disease

In a semi-randomized crossover study in humans, the consumption of a fortified spinach beverage resulted in a significant increase in plasma nitrate concentration, which correlated with lower diastolic blood pressure within 150 minutes post-consumption and persisted for five hours thereafter. This study suggests the possible therapeutic uses of spinach as a safe alternative and effective carrier for nitrate medications.


Spinach, like most dark, leafy greens, contains a high amount of folate: 100 grams of raw spinach provides almost half of an average person’s daily recommended intake. Daily intake of spinach for three weeks showed a significant increase in plasma folate concentrations, and processing spinach leaves did not affect the bioavailability of folate when compared to fresh whole-leaf spinach. Frozen whole-leaf spinach, minced spinach, and liquefied spinach have similar effects in terms of increasing plasma folate concentration.

Researchers currently are examining the potential benefits of fortifying flour with dehydrated spinach, with a goal to improve total folate content in bread.21 Fortification of white bread and whole grain bread with spinach (40 g spinach per 100 g of other ingredients) increased the total folate content, despite the effect of processing factors such as kneading and baking.


Spinach leaves contain many beneficial compounds such as vitamin C, iron, zinc, folic acid, polyphenols, and fatty acids. These compounds have protective effects topically as well as internally. In a study, diabetic rats were fed an aqueous spinach leaf extract to determine its effects on wound healing. The results showed that the spinach group had better wound-healing outcomes as indicated by significant improvements in epithelial and granulation tissue formation and blood vessels. These results indicate the potential beneficial effects of supplementation with spinach juice or other types of spinach extracts to treat wounds and ulcers in patients with diabetes.

Consumer Considerations

In August 2008, The US Food and Drug Administration (FDA) announced that it would allow the irradiation of spinach in order to kill the harmful bacteria Escherichia coli and Salmonella after numerous outbreaks of foodborne illness. Strains of E. coli have the ability to survive and multiply in the absence of an animal host when soil, water, and plants become contaminated. Pathogenic bacteria can grow inside the leaf tissues of spinach, rendering typical antimicrobial surface treatments ineffective. Uniformity of crop management practices as well as environmental factors not only impact the vegetable quality, but also the survival rate of E. coli in the soil and on the leaf crops. There are concerns, however, about the irradiation of food crops. Research indicates that the process generates harmful reactive oxygen species and decreases the phytonutrient content of the food in the process of eliminating foodborne pathogens.

The primary source of spinach leaf contamination with heavy metals is from pesticides containing lead arsenate, environmental pollution, contaminated irrigation water and rainwater, and runoff from nearby areas treated with plant pesticides and fertilizers. Leaf crops are most sensitive to lead contamination and bioaccumulation. Commercially farmed spinach is most susceptible to heavy metal and pathogen contamination due to the reliance on pesticides and poor land management techniques such as continual replanting in contaminated soil.

Caution with spinach consumption may be warranted in populations susceptible to kidney stones. Spinach is one of a number of foods that naturally contains oxalates. The oxalate content in spinach is estimated to be about 0.77 mg/100 g. Oxalates bind to many minerals, including calcium, zinc, and magnesium, inhibiting their absorption. Approximately 80% of kidney stones contain calcium and predominately consist of calcium oxalate. High levels of urinary oxalate are a major risk factor and precursor to the formation of calcium oxalate kidney stones. Observational data indicate an inverse relationship between dietary calcium and the risk of kidney stone formation, since dietary calcium may bind to oxalates in the gut, and thereby limit the absorption of intestinal oxalates and subsequent excretion of urinary oxalates. However, a study of three diverse populations noted only a small association between oxalate and spinach consumption and the risk of kidney stone formation.

Nutrient Profile

Macronutrient Profile: (Per 100 grams raw spinach)

23 calories

2.9 g protein

3.6 g carbohydrate

0.4 g fat

Secondary Metabolites: (Per 100 grams raw spinach)

Excellent source of:

Vitamin K: 482.9 mcg (603.6% DV)

Vitamin A: 9377 IU (187.5% DV)

Folate: 194 mcg (48.5% DV)

Vitamin C: 28.1 mg (46.8% DV)

Manganese: 0.9 mg (45% DV)

Magnesium: 79 mg (19.8% DV)

Potassium: 558 mg (15.9% DV)

Iron: 2.7 mg (15% DV)

Very good source of:

Riboflavin: 0.19 mg (11.2% DV)

Vitamin E: 2.03 mg (10.1% DV)

Vitamin B6: 0.2 mg (10% DV)

Calcium: 99 mg (9.9% DV)

Dietary Fiber: 2.2 g (8.8% DV)

Good source of:

Thiamin: 0.08 mg (5.3% DV)

Also, provides:

Phosphorus: 49 mg (4.9% DV)

Niacin: 0.72 mg (3.6% DV)

DV = Daily Value as established by the US Food and Drug Administration, based on a 2,000-calorie diet.

Recipe: Savory Spinach-Onion Pastry

Courtesy of Mariam Alhado


  • 3 cups frozen chopped spinach, thawed
  • 1 yellow onion, thinly sliced
  • 1/4 cup freshly-squeezed lemon juice
  • 1 tablespoon extra-virgin olive oil
  • 1 tablespoon ground sumac or za’atar spice blend
  • Salt to taste
  • 1 package frozen puff pastry


  1. Heat oven to 350°F. Using several layers of paper towels, squeeze as much excess water from the frozen spinach as possible.
  2. In a large bowl, combine spinach, onion, lemon juice, olive oil, sumac, and salt and form a uniform mixture.
  3. Roll out the pastry until it is smooth and of even thickness. Divide into three-inch squares. Add a few tablespoons of the spinach mixture into the center of each square, then fold the corners in and press to seal.
  4. Arrange the pastries on a baking sheet and bake for 15-20 minutes, until golden brown and heated through.