Is Vegetarianism the Natural Option?

In the world of nutrition, there’s no debate as fiery and fierce as the one between meat eaters and vegetarians. In this Spotlight feature, we ask whether or not humans were designed to be vegetarian.

Some people choose a plant-based diet for health reasons, while others do so with more ethical concerns in mind. On the other side of the dinner plate, some meat lovers put little thought into whether they should or shouldn’t eat meat, while others will defend their right to chow down on animal muscles until the end of time.

Passions can run surprisingly high when it comes to dietary decisions. Food is a matter of survival, and deep down in our primate brain, we still feel that we need to defend our food sources.

Today, we are not concerned with the ethics of the meat industry; it’s not that they aren’t important, but that we are more focused on the biology involved. Similarly, we tend not to dabble in the debate surrounding the environmental impact of meat rearing; we will leave that for others to chew over.

This article will be served in two courses. First, we ask whether or not humans are “designed” to eat meat — did we evolve to consume it? Then, we will ask which option is best for our health.

So, are we carnivores?

This is the first question to answer, and, anatomically, it seems to be a simple one. We don’t look like carnivores; our teeth are no good for ripping flesh, and our guts are too long. Are we herbivores, then? No; our guts aren’t long enough, and our teeth don’t quite fit the bill.

We are, it seems, omnivores; our bodies can handle both meat and plant matter pretty well. It’s not quite that simple, though. Just looking at an animal’s teeth and gut is no surefire way to distinguish its diet. The panda — with killer canines and a bamboo diet — is an excellent example.

That being said, it is true that most creatures have a gut suited to the diet that they consume. Lions, for instance, have huge, smooth-walled stomachs for holding hunks of animal. Many herbivores, meanwhile, have massive, plant-destroying factories in their abdomens, where bacteria smash apart the tough constituents of plant matter.

We, humans, like to think of ourselves as special, and, in many ways, you could argue that we are. But when it comes to our internal tubing, we are monumentally average.

Rather boringly, the human gut is very similar to that of our closest relatives: monkeys and apes. It follows that, if we are looking to work in harmony with our guts’ design, our diet should be at least similar to our cousins’.

When we examine the diet of virtually all monkeys and apes, it’s nuts, fruits, leaves, insects, and the occasional snack of flesh. You may have seen rather shocking footage of adult chimpanzees killing and eating baby ones, but that’s a relative rarity compared with the quantities of non-meat products consumed.

From these observations, we can perhaps conclude that evolutionarily speaking, we shouldn’t necessarily be vegetarian and evolved to eat only the occasional tidbit of animal matter.

Meat eating and human evolution

Eating meat, according to some evolutionary scientists, gave early humans a vital head start. Meat is packed with energy and protein that may have helped us to develop and nurture the over-sized bundle of cabling between our ears.

Human evolution illustration
Can human evolution help to settle the debate?

The expensive tissue hypothesis states that to have a larger brain, we need to save metabolic energy elsewhere. To do this, our guts were shortened.

But this brought another issue: having a shorter gut meant that our diet had to be of a higher quality to provide enough nutrients. Enter the animal-based diet. It is worth noting that this theory is not roundly supported.

Some researchers believe that hunting prey contributed to our bipedal stance and that planning and conducting a hunt could have assisted the development of language, communication, and complex societies.

But, just because something has been done for eons, it doesn’t mean that we necessarily need to continue down the same path.

Modern life is different; the options that lie on the dinner table are much more varied. Our forebears did not have access to tofu, for instance, and a human living in colder climes would struggle to find cashew nuts on her daily forage.

Once we’ve adapted, we can still go back

Evolution is endless, adaptation ongoing. Animals don’t continue to drink milk after weaning. If they tried it, it would make them sick. The enzyme that mammals need to break down lactose in milk — lactase — is not produced into adulthood. But now, entire populations of humans produce lactase long after they have stopped drinking their mother’s milk (known as lactase persistence).

At some point, a group of humans began making this change, and, because it gave them access to more calories and other nutritional goodies, they survived in favor of those who couldn’t stomach cow (or goat) juice. We have adapted to make use of an energy-rich source of protein, vitamins, and minerals. So, is it natural to drink milk? If not, does that mean that we shouldn’t drink it?

Our bodies are layered with a range of evolutionary changes: from a shift to meat millions of years ago, to microbiome shifts when we started eating wheat, barley, and other crops. We are a now mishmash of compensations and add-ons that have helped us to survive over the years.

If we say that we want to eat as our ancestors did, do we mean Homo erectus, Neanderthals (who may well have eaten more plants than is often imagined), Australopithecus (who walked the earth around 4 million years ago), the earliest primates (around 50–55 million years ago), or something in-between?

If the preceding ramblings mean anything, it is that we should only eat meat if it benefits us now. The important question is how it impacts our bodies today.

Meat: In sickness and in health

Whether eating meat is natural or not doesn’t make a lot of difference. Nobody realistically thinks that we should meticulously go back to what our earliest ancestors ate simply because it was a long time ago.

From a medical point of view, we should only eat meat if it is healthful to do so. Over recent years, there has been a growing mountain of evidence in support of the health benefits of a vegetarian diet and the health risks of pounding too many burgers into our bodies.

A large-scale meta-analysis carried out in 2016 reported “a significant protective effect of a vegetarian diet versus the incidence and/or mortality from ischemic heart disease (25 percent) and incidence from total cancer (8 percent). Vegan diet conferred a significantly reduced risk (15 percent) of incidence from total cancer.”

Vegetarian diets are also tied to a lower risk of metabolic syndromediabetescancer (again), and lower blood pressure, and they may fend off childhood obesity. On this matter, at least, the jury is well and truly in.

Health benefits of eating meat?

Meat is rich in protein and vitamin B-12 and is also a good source of iron, so it’s easy to see how incorporating meat into their diet might have helped our ancestors to survive.

Today, however, protein is much easier to come by — in nuts and beans, for example. Vitamin B-12 can be found adequately in cheese, eggs, milk, and artificially fortified products, and iron can be picked up from legumes, grains, nuts, and a range of vegetables.

With this in mind, rather than asking, “Should we eat meat?” we should probably be asking, “Is there a safe level of meat?” and, “Which types are worst?” In short, we can split meat into four types: white, red, processed, and fish.

Fish and white meat are roundly considered fairly healthful — as long as you aren’t deep frying them or wrapping them in bacon. For red meat and processed meats, though, it’s the reverse.

Red and processed meats are associated with colon cancer and heart disease. The majority of studies conclude that eating more of this meat is a bad idea. But how much is too much, and what levels are safe, are harder to quantify.

Dr. William Kormos, editor in chief of Harvard Men’s Health Watch, writes, “As for how much meat consumption is ‘safe,’ many studies show a small rise in the risk of disease at levels of 50–100 grams (1.8–3.5 ounces) of red meat consumed daily.”

Processed meats (salted, smoked, or cured) are also associated with a higher risk. In contrast, there does not appear to be a measurable risk from eating red meat once or twice a week.”

Dr. William Kormos

So, should we be vegetarians? Well, when the burger hits the fan and the kebab lady sings, there will still be no clear answer. Humans have eaten meat for a really long time, but a diet with minimal meat is much more healthful. And today, we don’t need meat nutritionally. I can’t make your choice for you though — sorry.

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Inulin 101

A prebiotic fiber with powerful health benefits:

If you’ve been reading up on gut health, then you may have heard of inulin.

Inulin is a fiber that has been linked to several health benefits and is added to many foods.

However, some people have concerns about its side effects and how well it works.

This article takes a detailed look at inulin and its health effects.

What is inulin?

Inulin is a type of soluble fiber found in many plants.

It is a “fructan” – meaning that it is made up of chains of fructose molecules that are linked together in a way that cannot be digested by your small intestine.

Instead, it travels to the lower gut, where it functions as a prebiotic, or food source for the beneficial bacteria that live there.

Your gut bacteria convert inulin and other prebiotics into short-chain fatty acids, which nourish colon cells and provide various other health benefits.

Inulin is relatively low in calories, providing 1.5 calories per gram.

Plants containing inulin have been around for a very long time, and some early humans consumed much more inulin than we do today.

Inulin.
While inulin is found in many plants, it also comes in supplement form, generally as a powder. This is what it looks like.

Bottom line: Inulin is a soluble fiber found in many plants. Your gut bacteria convert it into short-chain fatty acids, which provide several health benefits.

Where does inulin come from?

Inulin is naturally found in many plants, but can also be modified for commercial use.

Natural Sources of Inulin

Although many plants contain only small amounts of inulin, others are excellent sources. Here’s how much inulin is in 3.5 oz, or 100 grams, of the following foods:

  • Asparagus: 2-3 grams.
  • Chicory root: 36-48 grams.
  • Garlic: 9-16 grams.
  • Jerusalem artichoke: 16-20 grams.
  • Jicama: 10-13 grams.
  • Onions: 1-8 grams.
  • Yacon root: 7-8 grams

Manufactured sources of inulin

Inulin is also available in supplement form or as an ingredient in protein bars, cereal bars, yogurt and other products. Manufactured inulin comes in several forms:

  • Native chicory: Extracted from chicory root.
  • Oligofructose: Made by removing the longer molecules from inulin.
  • HP: High-performance (HP) inulin is created by removing the shorter molecules from it.
  • FOS: Fructooligosaccharides (FOS) consist of short inulin molecules synthesized from table sugar.

 Inulin is found naturally in several foods. It’s also modified for commercial use, and there are several varieties.

Health benefits of inulin

People take inulin for a variety of reasons. It may improve digestive health, relieve constipation, promote weight loss and help control diabetes.

Improves digestive health

The gut microbiota is the population of bacteria and other microbes that live in your gut. This community is highly complex and contains both good and bad bacteria.

Having the right balance of bacteria is essential for keeping your gut healthy and protecting you from disease.

Inulin can help promote this balance. In fact, studies have shown that inulin can help stimulate the growth of beneficial bacteria. Increasing the amounts of these bacteria can help improve digestion, immunity and overall health.

Bottom line: Inulin supports the growth of beneficial gut bacteria. This keeps the gut bacteria balanced and may have various health benefits.

Relieves constipation

For many people, inulin may also help relieve symptoms of constipation.

One analysis found that people taking inulin experienced more frequent bowel movements and improved stool consistency.

In another 4-week study, older adults who were given 15 grams of inulin per day reported less constipation and better digestion.

That being said, several studies have found no effects on bowel frequency.

For many people, inulin can help relieve constipation by causing more frequent bowel movements and better stool consistency.

Promotes weight loss

Several studies indicate that inulin can also help with weight loss.

When overweight and obese adults took 21 grams of inulin per day, their hunger hormone levels decreased and their fullness hormone levels increased.

On average, the people taking inulin lost over 2 lbs (0.9 kg), while the control group gained about 1 lb (0.45 kg) during the 12-week study.

In another weight loss study, people with prediabetes took inulin or another fiber called cellulose for 18 weeks. Those taking inulin lost 7.6% of their body weight, while the cellulose group lost only 4.9%.

However, in studies of overweight and obese children, oligofructose and inulin have not been effective in reducing calorie intake.

Bottom line: Inulin and oligofructose supplements may help regulate appetite in adults, leading to weight loss.

Helps control diabetes

Several studies suggest that inulin may improve blood sugar control in people with diabetes and prediabetes.

However, this may depend on the type of inulin, and the high-performance (HP) type may be especially beneficial. For example, one study found that HP inulin decreased fat in the livers of people with prediabetes.

This is significant, as reducing fat in the liver can help reduce insulin resistance and potentially reverse type 2 diabetes.

In another study, women with type 2 diabetes were given 10 grams of HP inulin per day. Their fasting blood sugar decreased by an average of 8.5%, while hemoglobin A1c (a marker for long-term blood sugar control) fell by an average of 10.5%.

However, although HP inulin has been shown to benefit diabetes and prediabetes, results from studies using some other types are less consistent.

HP inulin has been shown to reduce blood sugar levels in people with diabetes, but other forms may not be as beneficial.

Other potential benefits

There is some evidence that inulin supplements may help other conditions, although the evidence is not as strong.

This includes benefits for heart health, mineral absorption, colon cancer and inflammatory bowel disease.

May support heart health

Inulin may improve several markers for heart health. Mouse studies have found that it reduces blood triglycerides and cholesterol.

A human study found that women given 10 grams of HP inulin for 8 weeks experienced significant decreases in both triglycerides and LDL cholesterol.

However, other human studies reported fewer reductions in triglycerides, and no improvements in other markers.

Bottom line: Several studies indicate that inulin may improve certain risk factors for heart disease, but the evidence is mixed.

May improve mineral absorption and bone health

Animal studies have found that inulin improves calcium and magnesium absorption, resulting in improved bone density.

Human studies have found that boys and girls, aged 9-13, had significantly better calcium absorption and bone mineralization when taking inulin.

A few studies show that inulin may increase absorption of calcium and magnesium, and improve bone mineralization in children.

May help prevent colon cancer

It’s thought that the fermentation of inulin into butyrate protects colon cells. For this reason, several studies have looked into the effects on colon health.

One review looked at 12 animal studies and found that 88% of the groups given inulin saw a reduction in precancerous colon growths.

In another study, inulin-fed rats showed fewer precancerous cell changes and less inflammation than the control group.

A human study found that it caused the colon environment to be less favorable for cancer development, which is promising.

Animal studies have found that inulin can reduce gut inflammation and reduce the growth of precancerous cells. This may lead to a reduced risk of colon cancer, but more research is needed.

May help treat inflammatory bowel disease

Several animal studies suggest that inulin supplements may have benefits against inflammatory bowel disease (IBD).

A few small, human studies have also found reduced symptoms of ulcerative colitis, and a reduction in inflammatory markers in Crohn’s disease.

Nevertheless, researchers are not yet ready to recommend the use of inulin in treating IBD.

Inulin may also have benefits against inflammatory bowel diseases, including ulcerative colitis and Crohn’s disease.

Safety and side effects

The different forms of inulin have been studied extensively, and appear to be safe for most people when consumed in small doses.

However, people who are intolerant to FODMAPs are likely to experience significant side effects.

Those who are allergic to ragweed may also have worsened symptoms after taking it. Additionally – and very rarely – people with a food allergy to inulin may experience an anaphylactic reaction, which can be dangerous.

If you take more than a small amount, then you’re likely to experience some side effects in the beginning.

The most common side effects are:

  • Flatulence (gas)
  • Bloating
  • Abdominal discomfort
  • Loose stools and diarrhea

For example, oligofructose (a type of inulin) has been shown to cause significant flatulence and bloating for people taking 10 grams per day.

Inulin from chicory root can generally be taken at higher dosages, but some people reported slight stomach discomfort at 7.5 grams a day.

You can minimize your risk of discomfort by slowly increasing your intake over time, which helps your body adjust.

 Although inulin is safe for most people when taken at recommended dosages, people with certain allergies or a FODMAP intolerance should avoid it.

Dosage and how to take

Although all types of inulin are safe for most people, some are more likely to cause side effects.

Therefore, it’s best to start slow. Begin by adding some inulin-rich foods to your diet on a regular basis.

If you decide to supplement, begin with no more than 2-3 grams a day for at least 1-2 weeks.

Then, slowly increase your intake by 1-2 grams at a time, until you’re taking 5-10 grams a day. Most of the studies used 10-30 grams per day, gradually increasing over time.

The side effects should also improve with continued use. However, not everyone may be able to tolerate the amounts listed here.

Start by taking 2-3 grams a day for at least 1-2 weeks. Then gradually increase your dosage.

Should you take inulin?

Inulin has several important health benefits. It may promote gut health, help you lose weight and help manage diabetes.

However, while it is safe for most people, you should be careful if you have a FODMAP intolerance or certain allergies.

Additionally, start with a low dose of inulin and gradually increase your intake over the course of a few weeks.

Remember that if a little of something is good, more is not always better.

What is Konjac?

What are the benefits of konjac?

Konjac is a plant that is used to make high-fiber dietary supplements, jellies, and flour. It is used traditionally in both Japanese cuisine and Chinese medicine. But does konjac have any proven health benefits?

The proper name for the konjac plant is Amorphophallus, but it is also sometimes called konjaku, elephant yam, devil’s tongue, snake palm, and voodoo lily.

This article explores the potential health benefits of konjac as supported by scientific evidence. It also looks at how to use konjac and whether there are any risks to consider before taking it.

What is konjac?

Konjac root
Konjac is traditionally used in Japanese cuisine and Chinese medicine.

The konjac plant has a starchy root called a corm, which is high in a dietary fiber called glucomannan. This is the part of the plant that is used as a dietary supplement and to make high-fiber flour and jellies.

A range of different products can be made from the konjac corm, including:

  • Konjac flour: This is made by grinding down dry konjac corms to make flour that can be used to make noodles.
  • Konjac jelly: After further processing, konjac flour can be used to make a jelly or gum. This can be used instead of gelatin to thicken food.
  • Konjac soluble fiber: When konjac jelly is purified further, it can be made into a soluble fiber that is used as a dietary supplement.

Six health benefits of konjac

Konjac has a number of health potential benefits that are explored below. Many of these benefits relate to the high content of glucomannan, the soluble dietary fiber that is in the konjac plant.

1. Diabetes management

Research has shown that consuming a mix of glucomannan and American ginseng indicated a moderate improvement in type 2 diabetes management.

2015 review also noted glucomannan made people with diabetes less likely to eat foods that could increase their blood sugar levels. This is because it made them feel fuller for longer.

2. Weight loss

Glucomannan made from konjac may be beneficial for people who are looking to lose weight.

2005 study found that the soluble dietary fiber supplement helped people who were overweight to reduce their body weight. The people took the supplement as part of a balanced, calorie-controlled diet. This type of fiber helps a person feel full longer by slowing gastric emptying.

Researchers compared the effects of the glucomannan supplement with a guar gum supplement. They found that the glucomannan supplement increased weight loss whereas the guar gum supplement did not.

There are numerous studies that show the health benefits of higher fiber diets, including using konjac, for weight loss.

3. Cholesterol

hyperlipiedmia cholesterol
Glucomannan may have a beneficial effect on cholesterol levels.

Having high cholesterol means that people are more likely to experience heart disease or have a stroke. Water-soluble fibers are recommended to aid in cholesterol and weight management.

Glucomannan supplements may help people to keep their cholesterol levels in check. A 2008 study found that glucomannan had a beneficial effect on overall cholesterol levels.

A further study in 2017 looked at what dose of glucomannan was needed to improve cholesterol levels. Researchers found 3 grams per day to be a beneficial dose.

4. Constipation

Taking a glucomannan supplement may help to regulate a person’s bowel movements and prevent them from becoming constipated.

2006 study found that a modest dose glucomannan improved bowel movements in adults by 30 percent. Researchers also found the soluble dietary fiber supplement helped to improve gut health in people experiencing constipation.

A recent review from 2017 found that taking glucomannan improved the frequency of bowel movements in children with constipation.

However, researchers noted that taking glucomannan did not always improve stool consistency or the overall success rate of treatment.

5. Healthy skin

Glucomannan may also help people looking to improve the health of their skin.

2013 study found that glucomannan may be beneficial as a topical therapy for acne and that it improves overall skin health.

6. Wound healing

As well as supporting skin health, glucomannan may also help the body to heal wounds more quickly.

2015 study in mice found that glucomannan supplements may encourage wound healing because of the way they support the immune system. However, more research is needed to conclude that glucomannan is effective for wound healing in humans.

How to use konjac

woman in supermarket shopping for vitamins and supplements and checking the labels of different brands
Konjac may be used in glucomannan dietary supplements.

Glucomannan dietary supplements made from konjac are available in most health food stores. The precise dose of konjac a person should take depends on the reason they are taking it, as well as their age and overall health.

The United States Food & Drug Administration (FDA) does not regulate konjac supplements, so it is essential to purchase them from a reputable retailer.

Powder made from konjac corms is sometimes used as an alternative to seafood in vegan food.

Konjac is also used to make facial sponges for people looking to take advantage of the health benefits it has for the skin.

Other konjac products include:

  • fruit jelly
  • flour
  • noodles

Risks and considerations

When eaten as a fruit jelly, konjac may pose a choking risk, especially in children. This is because it absorbs a lot of water and does not dissolve readily. It is important to chew konjac jelly thoroughly to make sure it can be swallowed easily.

Konjac supplements can have an impact on blood sugar levels, so people with diabetes should talk to a doctor before using them.

Due to the way konjac affects the gut and reduces constipation, some people may experience diarrhea when they take konjac supplements.

Also,

Konjac products have a number of health benefits. They may help keep blood sugar and cholesterol levels low, improve skin and gut health, help heal wounds, and promote weight loss.

As with all unregulated dietary supplements, it is best to speak to a doctor before taking konjac. A person should also discuss konjac with a doctor before giving it to a child for constipation or other problems. Konjac should always be consumed with water to avoid a choking hazard.

Food as Medicine: Chia (Salvia hispanica, Lamiaceae)

Chia (Salvia hispanica, Lamiaceae) is an annual herb native to Mexico and Guatemala that requires fertile, well-drained soil and subtropical climate conditions to set seed in the late summer months of July and August.1-4 Chia is the most common name for this plant, but it is also sometimes called Spanish sage, lime-leaf sage, Mexican chia, and black chia.2,4 The plant grows to three feet (0.9 meters) tall when mature, and has opposite, serrated leaves that are 1.5-3 inches (3.8-7.6 cm) long and 1-2 inches (2.5-5 cm) wide, and produces small white or purple flowers on the tips of its terminal stems.2,4,5 Chia’s leaves contain essential oil that acts as a defense mechanism to repel insects.2 The edible part of the chia plant is the seeds,5-7which are small (2 mm in length), flat, and oval-shaped.2 Although dark chia seeds are predominantly gray with dark spots,7 they can also appear white, black, black spotted, or dark brown, and may differ slightly in size and weight.2,5

Phytochemicals and Constituents

Chia seed has high levels of protein, omega-3 fatty acids, fiber, and specific vitamins and minerals.2,7 The seed also contains all essential amino acids and is high in antioxidants.8 A gram of chia seeds contains about 0.28 g fiber, 0.21 g protein, and 0.6 g/g of the omega-3 fatty acid alpha-linolenic acid (ALA), which is the highest proportion of ALA of any known plant source.9 Chia seed and its oil have an abundance of polyunsaturated fatty acids (PUFAs). ALA is the most predominant fatty acid found in chia, followed by the omega-6 fatty acids linoleic acid and oleic acid.

Omega-6 fatty acids have pro-inflammatory, hypertensive, and prothrombotic properties.5Omega-3 fatty acids, however, are associated with numerous health benefits and have anti-inflammatory, anti-diabetic, lipid-lowering, cardioprotective, and hepatoprotective properties. For maintenance of good health, omega-3 fatty acids should be incorporated in the diet at higher amounts than omega-6 fatty acids. The omega-3:omega-6 ratio found in chia seeds is about 3:1.6,7 The amount of oil within chia seed ranges from 25-40%.2,5

In comparable serving sizes, the protein content of chia seeds exceeds that of seeds such as amaranth (Amaranthus spp., Amaranthaceae) and quinoa (Chenopodium quinoa, Chenopodiaceae).2 The primary determinant of a high-quality protein is its digestibility or the amount of protein absorbed by the body relative to the amount consumed. For chia seed flour, protein digestibility is nearly 80%, which is comparable to processed cereal grains such as wheat (Triticum aestivum, Poaceae) and oats (Avena sativa, Poaceae); however, chia contains a much higher percentage of protein per serving than these grains.10Furthermore, chia seed contains high levels of the amino acids glutamic acid, arginine, and aspartic acid.2In addition to an abundance of these non-essential amino acids, chia seed contains all nine essential amino acids that the body is unable to produce and is therefore considered a complete protein, unlike other plant protein sources such as chickpeas (Cicer arietinum, Fabaceae). Chia seed contains low concentrations of prolamins (< 15%), which suggests that it can be safely incorporated into the diet of patients with celiac disease.2,10

Approximately two tablespoons (one ounce or about 28 grams) of chia seed provides almost 40% of an average person’s daily fiber intake, as recommended by the US Food and Drug Administration (FDA). Total dietary fiber includes both soluble and insoluble forms that are important for reducing the risk of cardiovascular disease, diabetes, and certain types of cancer.2 Compared to other foods, chia seed contains more dietary fiber than an equivalent volume of flax (Linum usitatissimum, Linaceae) seed. High fiber intake also promotes gastrointestinal and digestive health.

Chia seeds and oil are not only known for their macronutrient and micronutrient contents, but also for their antioxidant properties.7 Phenolic compounds present in chia have been found to protect against certain diseases, such as cardiovascular disease and diabetes.11 The most important polyphenols found in chia seeds and seed oil include chlorogenic and caffeic acids, which play a crucial role in the protection against free radicals and inhibit fat, protein, and DNA peroxidation.2,11,12 The flavonols myricetin, quercetin, and kaempferol are other active compounds present in chia seeds.7 Flavonols are known for their antioxidant, cytotoxic, anti-inflammatory, and anti-thrombotic effects.5,13 Researchers have found that these polyphenols and others found in chia seed and seed oil (e.g., rosmarinic, protocatechuic, and gallic acids) have a high antioxidant capacity.12,14

Historical and Commercial Uses

Chia has been used by Mesoamerican cultures for more than 1,000 years for medicinal, culinary, artistic, and religious purposes.7,15 The Chumash and Cahuilla peoples in the coastal southern regions of California cultivated chia for its seeds, which were collected, hulled, and winnowed by hand.16 After the introduction of wheat, chia was still a preferred crop, and small amounts of chia flour were used to improve the flavor of wheat flour.

The seed of the chia plant is the part most often used for medicinal purposes, but the root and aerial parts were also used occasionally.15 Prior to Spanish colonization in the 16th century, chia seed was used by native tribes to provide energy, treat respiratory infections, and for obstetrics treatment. Prized by Aztec warriors in central Mexico, chia seeds were eaten to promote endurance and consumed with bread prior to battle or with water before running long distances.8

The Diegueño people of Baja California took chia seeds on journeys, kept a few seeds in the mouth and periodically chewed them to maintain their strength.16 One tablespoon of chia seed was believed to be sufficient to feed a person for a day. After the 16th century, a mucilaginous paste made from chia seeds and water was used therapeutically to treat eye obstructions and infections.17 Medical uses of chia seed prior to Spanish colonization included soothing skin conditions, treating gastrointestinal conditions, lowering fevers, and as a poultice for open wounds.15,16

The chia seed has been used for culinary purposes in multiple forms: whole, ground (flour), mucilage, and oil.7,15 Seeds were ground into flour and used to make biscuits, cakes, and a porridge called pinole.16 Traditional foods, such as tortillas and tamales, were made from chianpinolli, or roasted and ground chia seed.15,17 Chia flour was used to make an array of beverages during the height of the Aztec Empire, but modern use of this tradition has declined.15 The most recognized use of chia seeds in the 18th and 19th centuries was infusing chia seeds in water, which was believed to make the alkaline desert water taste more palatable. “Chia fresca,” or “agua de Chia,” was also a popular, thirst-quenching beverage that combined chia seeds with fruit juices.15-17

Chia seed oil was also used for artistic purposes, primarily in paints and lacquers to create a glossy finish on clay or gourd vessels.15 The oil was also used as the basic ingredient for ceremonial face or body paint. Chia-infused beverages were historically consumed during ceremonies, festive occasions, and holy observances. Other religious uses included the use of chia flour to make dough that was formed into the shape of the goddess Chicomecoatl, the “maker and giver of things necessary to live,” as an offering. With the rediscovery of chia as an important food source, modern uses of chia seed and oil focus on its omega-3 fatty acid content for nutritional supplementation, and it is sold commercially as cold-pressed seed oil or whole seeds as ingredients for baked goods, snacks, bread, yogurt, and bars.2

In 1977, the Chia Pet, small hollow-bodied animal figurines made out of terra cotta, became a registered trademark of Joseph Enterprises, Inc.18 Moistened chia seeds are applied to the grooved ridges on the outside of the figurine, and water is added to the hole inside the figurine to help the seeds germinate. Within days, the figure grows a thick coat of chia sprouts. For more than 30 years, Chia Pets have offered customers amusement and an introductory lesson to the practice of cultivating plants.

Modern Research

Cardiovascular Disease Risk Factors

The nutrient profile and bioactive compounds found in chia seed and oil have demonstrated cardioprotective effects by reducing disease risk factors in humans. Hypertension, a known risk factor for developing cardiovascular disease, is generally asymptomatic and can be difficult to control with drug therapies alone. Diet interventions can offer a complementary approach.19 Supplementation with ground chia seed for 12 weeks was shown to reduce blood pressure in individuals with treated and untreated hypertension. Participants in the study were randomly assigned to one of three groups: consumption of chia with previously used medications (CHIA-MD), chia without medications (CHIA-NM), or a placebo group with medications (PLA-MD). Subjects in the two treatment groups consumed 35 grams of chia flour per day. The PLA-MD group received 35 grams of roasted wheat bran as a placebo. Researchers found that the two chia groups had significantly reduced diastolic and systolic blood pressures from baseline. The CHIA-MD group also had significantly reduced total blood pressure from baseline.

A 2015 systematic review investigated current literature on consumption of whole or ground chia seeds and its effect on preventing or managing risk factors associated with heart disease, such as hypertension, diabetes, dyslipidemia, and obesity.20 The review focused on seven clinical trials published between 2007 and 2013. The chia seed preparations used in the studies varied in quantity (4-50 grams per day) and type (e.g., whole or milled). There were also differences in sample size, methodology, and participant characteristics (e.g., diabetic, obese, hypertensive). Therefore, the authors state that the findings on chia consumption and the effects of reducing cardiovascular risk factors are inconclusive. They recommend additional randomized, double-blind, placebo-controlled clinical trials on the consumption of chia to obtain reliable results and to determine an appropriate dose for cardioprotective benefits.

Obesity is a condition that has been associated with a state of chronic oxidative stress. Reactive oxygen species damage cell proteins, lipids, and DNA, and can result in impaired function and potentially cell death. Obesity also impedes the body’s enzymatic antioxidant system, reducing the activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase.24 Additionally, obesity correlates with a reduction in levels of protective thiols, vitamins, minerals, and polyphenols. A study on chia seed’s efficacy for weight loss and decreasing disease risk factors in overweight adults found increases in plasma ALA levels. However, consumption of chia seed in high doses (50 grams per day) had no effect on weight loss or changes in disease risk factors related to cardiovascular disease (e.g., blood pressure, high-density and low-density lipoprotein, total cholesterol, or blood triglyceride levels).21Another randomized, double-blind, placebo-controlled study assessed the effectiveness of chia seed (whole or ground) supplementation for changing disease risk factors for overweight women.22 For 10 weeks, participants consumed 25 grams per day of ground or whole chia seeds or a placebo. Multiple outcome measures were assessed, and researchers observed a 58% and 39% increase in plasma ALA and eicosapentaenoic acid (EPA) levels, respectively, in the ground chia treatment group.

Glucose Levels

The use of chia as a food ingredient holds promise in the area of so-called “functional foods.” A 2013 study observed the effects of bread supplemented with chia seed flour on post-prandial (after-meal) blood sugar levels in healthy adults. Thirteen healthy adults consumed nine test meals that included bread supplemented with different doses (seven, 15, and 24 grams) of whole or ground chia.23 Bread without chia was used as the control. Researchers concluded there was a significant dose-dependent effect on blood glucose levels for both whole and ground seeds compared to the control, but no differences were evident between the same doses of the whole and ground seed groups. This may indicate that the quantity of seeds given in the diet will demonstrate hypoglycemic properties and not the form in which chia is ingested. The seeds used in the study were a specific varietal bred from black chia and proved effective for reducing blood glucose levels, but future research is needed to further investigate the benefits of different chia strains.

Antioxidant Properties

Chia’s antioxidant potential was analyzed in a 2015 rat study.24 Results demonstrated that daily consumption of chia seed and chia seed oil enhanced plasma antioxidant levels through catalase, glutathione peroxidase and thiol level reduction. Chia seed and seed oil intake resulted in a significant reduction in plasma levels of 8-isoprostane, the most specific biological indicator for assessing oxidative stress in vivo. High levels of 8-isoprostane can occur with a diet high in fat and fructose and result in pro-oxidative effects. This may be the mechanism by which chia seed and seed oil produce a hypolipidemic effect. Lipid peroxidation in rat livers was not reversible; however, levels of glutathione reductase were increased as well as thiol levels, resulting in improved antioxidant status.

Other Uses

Carbohydrate-loading refers to the practice of increasing dietary intake of carbohydrates prior to athletic events that last more than 90 minutes. This intake results in a greater capacity of muscle glycogen stores and aids in improved athletic performance.8 A 2011 study compared performance test results of six male marathon runners who were given two different carbohydrate-loading treatments: a commercial sports drink and the same commercial sports drink supplemented with chia. The runners participated in two trials in a crossover, counterbalanced, repeated-measure design with a two-week washout period between testing to allow participants to recover from the intense exercise and to avoid any carry-over effects from the treatments. While the researchers found no statistical difference between the control and the test groups in performance parameters, the athletes in the chia group significantly decreased their dietary intake of sugar while boosting intake of omega-3 fatty acids, which indicates that the chia drink may be a healthier option for athletes who choose to carbohydrate-load.

Chia seed oil is also used topically. Approximately 30% of patients with diabetes or end-stage renal disease (ESRD) suffer from skin disorders including pruritus, which is characterized by itchy, dry skin and inflammatory lesions caused by scratching.13 This study followed five patients with these conditions (three with diabetes; two with ESRD) and five patients without these conditions who all exhibited xerotic pruritus (abnormally dry, itchy skin) for eight weeks. A topical oil and water emulsion containing 4% chia seed oil were applied to the affected skin. Lotion without chia seed oil was used on participants as a placebo. After eight weeks of application, statistically significant improvements in skin hydration, chronic itching, and prurigo nodularis (hard, itchy lumps on the skin) were observed in the treatment group with diabetes and ESRD, while similar significant improvements in skin hydration and epidermal permeability were also observed in the group of patients without these conditions.

Consumer Considerations

Consumption of whole or ground chia seed has shown no evidence of toxicity or allergenic effects.2However, the Dietary Guidelines for Americans, eighth edition, issued by the US Department of Health and Human Services and US Department of Agriculture listed a standard portion size of chia as one tablespoon (or roughly 50 grams) per day.25 This may be due to clinical studies that have not exceeded a dose of 50 grams per day, and thus the potential adverse effects have not been adequately studied above this amount.

The PUFA content, as well as the low concentration of tocopherol and phenolic compounds, account for the low oxidative stability of chia oil. Within 300 days, a 30% drop in the tocopherol content of chia seed oil was observed.9 The antioxidant capacity of chia oil is relatively low due to the hydrophilic nature of the phenolic compounds within the chia seed. Despite chia seed’s rich omega-3 and omega-6 content, there is a technological disadvantage in the production of chia seed oil in regards to its stability and short shelf life, especially when exposed to light or oxygen. Chia seed oil is best kept in the refrigerator after opening and should be used quickly to gain its full range of nutrients.

Nutrient Profile26

Macronutrient Profile: (Per 1-ounce seeds)

138 calories
4.7 g protein
11.9 g carbohydrate
8.7 g fat

Secondary Metabolites: (Per 1-ounce seeds)

Excellent source of:

Manganese: 0.8 mg (40% DV)
Dietary Fiber: 9.8 g (39.2% DV)
Phosphorus: 244 mg (24.4% DV)
Magnesium: 95 mg (23.8% DV)

Very good source of:

Calcium: 179 mg (17.9% DV)
Thiamin: 0.2 mg (13.3% DV)
Niacin: 2.5 mg (12.5% DV)
Iron: 2.2 mg (12.2% DV)

Also provides:

Folate: 14 mcg (3.5% DV)
Potassium: 115 mg (3.3% DV)
Riboflavin: 0.05 mg (3% DV)

Trace amounts of:

Vitamin C: 0.5 mg (0.8% DV)
Vitamin E: 0.14 mg (0.7% DV)
Vitamin A: 15 IU (0.3% DV)

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

Strawberries-and-Cream-Chia-Pudding-4-2

Recipe: Strawberries and Cream Chia Pudding

Adapted from Emily Han27

Ingredients:

  • 8 ounces fresh strawberries
  • 3/4 cup coconut milk
  • 2 tablespoons honey
  • 1/2 teaspoon vanilla extract
  • 1/2 teaspoon grated lime zest
  • 1/4 cup chia seeds

Directions:

  1. Combine the strawberries, coconut milk, honey, vanilla, and lime zest in a blender. Puree until smooth. Taste and add more honey, if desired.

  2. Place the chia seeds in a large bowl and add the strawberry mixture. Whisk thoroughly to combine. Let the mixture stand for 10 minutes, then whisk again.

  3. Cover and refrigerate for at least four hours and up to three days. Stir before serving. The pudding will set up thicker the longer it sits.

References

  1. Salvia hispanica – L. Plants for a Future website. Available at: www.pfaf.org/user/Plant.aspx?LatinName=Salvia+hispanica. Accessed August 24, 2017.
  2. Muñoz LA, Cobos A, Diaz O, Aguilera JM. Chia seed (Salvia hispanica): An ancient grain and a new functional food. Food Reviews International. 2013;29:394-308.
  3. Taxon: Salvia hispanica L. US National Plant Germplasm System website. Available at: https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?32939. Accessed August 24, 2017.
  4. Kaiser C, Ernst M. Center for Crop Diversification Crop Profile: Chia. Lexington, KY: University of Kentucky College of Agriculture, Food and Environment. February 2016.
  5. Ali NM, Yeap SK, Ho WY, Beh BK, Tan SW, Tan SG. The promising future of chia, Salvia hispanica L. Journal of Biomedicine and Biotechnology. 2012;171956.
  6. Porras-Loaiza P, Jiménez-Munguía MT, Sosa-Morales ME, Palou E, López-Malo A. Physical properties, chemical characterization and fatty acid composition of Mexican chia (Salvia hispanica L.) seeds. International Journal of Food Science and Technology. 2014;49:571-577.
  7. Valdivia-López MA, Tecante A. Chia (Salvia hispanica): A review of native Mexican seed and its nutritional and functional properties. Advances in Food and Nutrition Research. 2015;75:54-71.
  8. Illian TG, Casey JC, Bishop PA. Omega 3 chia seed loading as a means of carbohydrate loading. Journal of Strength and Conditioning Research. 2011;25(1):61-65.
  9. Bodoira RM, Penci MC, Ribotta PD, Martínez ML. Chia (Salvia hispanica L.) oil stability: Study of the effect of natural antioxidants. LWT – Food Science and Technology. 2017;75:107-113.
  10. Kačmárová K, Lavová B, Socha P, Urminská D. Characterization of protein fractions and antioxidant activity of chia seeds (Salvia hispanica L.). Potravinarstvo. 2016;10(1):78-82.
  11. Pandey KB, Rizvi SI. Plant polyphenols as dietary antioxidants in human health and disease. Oxidative Medicine and Cellular Longevity. 2009;2(5):270-278.
  12. da Silva Marineli R, Moraes ÉA, Lenquiste SA, Godoy AT, Eberlin MN, Maróstica Jr MR. Chemical characterization and antioxidant potential of Chilean chia seeds and oil (Salvia hispanica L.). LWT – Food Science and Technology. 2014;59:1304-1310.
  13. Jeong SK, Park HJ, Park BD, Kim I. Effectiveness of topical chia seed oil on pruritus of end-stage renal disease (ESRD) patients and healthy volunteers. Ann Dermatol. 2010;22(2):143-148.
  14. Martínez-Cruz O, Paredes-López O. Phytochemical profile and nutraceutical potential of chia seeds(Salvia hispanica L.) by ultra high performance liquid chromatography. Journal of Chromatography A. 2014;1346:43-48.
  15. Cahill J. Ethnobotany of chia, Salvia hispanica L. (Lamiaceae). Economic Botany. 2003;57(4):604-618.
  16. Immel DL. Plant Guide: Chia. Washington DC: United States Department of Agriculture Natural Resources Conservation Service. 2003.
  17. Hershey DR. Don’t just pet your chia. Science Activities. 1995;32(2):8-12.
  18. Edwards O. Chia Pet. Smithsonian Magazine. December 2007. Available at: www.smithsonianmag.com/arts-culture/chia-pet-180308610/. Accessed August 24, 2017.
  19. Toscano LT, Oliveira da Silva CS, Toscano LT, Monteiro de Almeida AE, Santos AdC, Silva AS. Chia flour supplementation reduces blood pressure in hypertensive subjects. Plant Foods Hum Nutr. 2014;69:392-398.
  20. de Souza Ferreira C, de Sousa Fomes LdF, Santo da Silva GE, Rosa G. Effect of chia seed (Salvia hispanica L.) consumption on cardiovascular risk factors in humans: a systematic review. Nutrición Hospitalaria. 2015;32(5):1909-1918.
  21. Nieman DC, Cayea EJ, Austin MD, Henson DA, McAnulty SR, Jin F. Chia seed does not promote weight loss or alter disease risk factors in overweight adults. Nutrition Research. 2009;29:414-418.
  22. Nieman DC, Gillitt N, Jin F, et al. Chia seed supplementation and disease risk factors in overweight women: a metabolomics investigation. J Alt Complement Med. 2012;18(7):700-708.
  23. Ho H, Lee AS, Jovanonvski E, Jenkins AL, DeSouza R, Vuksan V. Effect of whole and ground Salba seeds (Salvia hispanica L.) on postprandial glycemia in healthy volunteers: A randomized controlled, dose-response trial. Eur J Clin Nutr. 2013;67:786-788.
  24. da Silva Marineli R, Lenquiste SA, Moraes ÉA, Maróstica Jr. MR. Antioxidant potential of dietary chia seed and oil (Salvia hispanica L.) in diet-induced obese rats. Food Research International. 2015;76:666-674.
  25. US Department of Health and Human Services and US Department of Agriculture. 2015-2020 Dietary Guidelines for Americans. 8th ed. December 2015. Available at: http://health.gov/dietaryguidelines/2015/guidelines. Accessed September 14, 2017.
  26. Basic Report: 12006, Seeds, chia seeds, dried. United States Department of Agriculture Agricultural Research Service website. Available at: https://ndb.nal.usda.gov/ndb/foods/show/3610. Accessed August 23, 2017.
  27. Han E. Dairy-Free Dessert Recipe: Strawberries & “Cream” Chia Pudding. The Kitchn website. May 8, 2013. Available at: www.thekitchn.com/recipe-strawberry-chia-pudding-recipes-from-the-kitchn-189016. Accessed August 23, 2017.
  28. Bauman H, Bates K. Food as Medicine: Strawberry (Fragaria x ananassa, Rosaceae). HerbalEGram. 2015;12(5). Available at: http://cms.herbalgram.org/heg/volume12/05May/FaM_Strawberry.html. Accessed September 11, 2017.

Clinical Efficacy of Olive Oil in Improving Body Composition and Blood Pressure in Overweight/Obese Women

Consumption of extra virgin olive (Olea europaea, Oleaceae) oil (EVOO), rich in the monounsaturated fatty acid (MUFA) oleic acid, has been shown to reduce the risk of cardiovascular disease (CVD). Risk of CVD has been associated with excess body fat, and both conditions have been linked with metabolic syndrome. Use of EVOO for weight control rests on epidemiological observations that a “Mediterranean diet,” rich in olive oil, is significantly less likely than other diets to promote obesity. However, such diets have many functional low-density foods. Randomized clinical trials (RCTs) have been inconclusive. “Good fats” in energy-restricted low-fat diets have been shown to improve taste and compliance, but there is no clear evidence of EVOO’s effects on body weight/fat loss. In this double-blinded, placebo-controlled RCT, EVOO was compared to soy (Glycine max, Fabaceae) bean oil in women with excess body fat.

Of 753 recruited through advertisements in Viçosa, Minas Gerais, Brazil, site of the Universidade Federal de Viçosa, 77 from 19-41 years of age were randomly assigned to 2 groups. Included subjects had >32% body fat (normal range for women of this age is 25-31%); mostly used soybean oil to cook; and were nonsmokers, not pregnant, and not lactating. Exclusion criteria were drinking alcohol >15 g/d, being elite athletes (>10 hrs exercise/week), habitual use of olive oil (>8 mL/d), recent diet or exercise changes, use of supplements or drugs except contraceptives, allergy/aversion to test ingredients, and gastrointestinal or other acute or chronic disease besides obesity. Of those randomly assigned, 16 dropped out before the intervention—11 from the control and 5 from the EVOO group, leaving 28 in the former and 33 in the latter. Of these, 3 from the control group dropped out during the RCT, as did 7 from the EVOO group, leaving 25 in the control and 26 in the EVOO group to complete the intervention. Data from 5 of those in the control and 5 in the EVOO group were excluded from the analysis, leaving 41 subjects. Retrospective power calculations showed that 21 subjects were sufficient to detect increments of −1.09 kg body fat in the EVOO group. An increment of −1 kg body fat was considered relevant.

The RCT lasted 9 weeks ± 5 days to prevent hormonal interference. For 1 week before the intervention, subjects refrained from olive oil and alcohol but maintained other dietary and activity habits. The night before the intervention began, subjects ate a standard dinner. They were tested for anthropometric, body composition, and blood pressure measured at baseline and on the last day of the RCT, including weight, height, and body mass index (BMI). Waist, hip, neck, and thigh circumference and sagittal abdominal diameter also were measured at those times. Waist/hip ratio and conicity index were calculated. Blood pressure was taken in both arms. Dual-energy X-ray absorptiometry (DXA) scan assessed lean mass, total body fat, and fat distribution. Blood was analyzed for serum glucose, total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), uric acid, urea, creatinine, alkaline phosphatase (AP), aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, serum very-low-density lipoprotein cholesterol, and serum insulin. Insulin resistance and atherogenic index (TG:HDL-c) were calculated. Levels of pro-inflammatory interleukin (IL)-8, IL-1β, IL-10, IL-12p70, and tumor necrosis factor-α (TNF-α) were measured. Participation was delayed for any inflammation or intestinal disorder at baseline.

After assessment and each succeeding day, subjects had a breakfast with 300 mL of a high-fat milk-derived flavored drink containing 25 mL of either soybean oil (Corcovado®; Archer Daniels Midland; Uberlândia, Brazil) or EVOO (Andorinha®; Sovena S.A.; Algés, Portugal), according to the group. The milk-derived drink, served in the laboratory on weekdays and provided for subjects’ weekend use at home, was the same for both groups except for oil content. Two low-fat cookies also were offered. Breakfast meals had a rotating menu of 6 “breakfast flavors” with similar nutritional composition, to avoid monotony and to improve compliance. Each subject was prescribed an individual energy-restricted low-fat diet for other meals. Energy requirements for overweight/obese women were calculated and caloric restriction applied, with coefficients for sedentary and low-active women. There were no differences between groups in diets’ energy or macronutrient content. No high-MUFA food, other than the breakfast EVOO for the EVOO group, was included. Food diaries were used on 3 non-consecutive days before and during the RCT.

Per-protocol analyses were used since many subjects were lost after randomization. Body weight and BMI fell in both groups but the EVOO group lost more total fat than control (−2.4 ± 0.3 kg, 95% confidence interval [CI] −3.1 to −1.73 kg vs. −1.30 ± 0.40 kg, 95% CI −2.21 to −0.44 kg; Pinter=0.037). [Note: In the article text, this result is presented in reverse order.] Fat loss was 80% greater in the EVOO group. This is the first clinical evidence that EVOO increases fat loss from energy restriction even in a non-Mediterranean diet. Both groups had decreases in all anthropometric variables except waist/thigh ratio [referred to as waist/hip index in Suppl. Table 2]. Both had reductions in total fat and at specific fat sites, but not lean mass. Lean mass did not change in control but increased in the EVOO group (Pinter=0.195). Serum glucose fell in both groups. In the control group only, HDL-c was reduced and IL-10 increased. Creatinine rose and AP fell in the EVOO group only, with a trend toward reduced IL-1β (P=0.060). Diastolic blood pressure fell only in the EVOO group and rose slightly in control (−5.05 ± 1.60 mmHg, 95% CI −8.39 to −1.70 mmHg vs. +0.25 ± 1.16 mmHg, 95% CI −2.18 to 2.68 mmHg; Pinter=0.011). [Note: In the article text, this result is presented in reverse order. The report is marred by further text errors, e.g., attributing downregulation of inflammatory pathways to increased consumption of α-linolenic acid—exactly the opposite of this trial’s results.]

While the results of this clinical study are promising, and consideration of EVOO in a healthy diet is warranted, further evidence is needed to support the use of olive oil for the reduction of excess body fat.

Resource:

Galvão Cândido F, Xavier Valente F, da Silva LE, Gonçalves Leão Coelho O, Gouveia Peluzio MdC, Gonçalves Alfenas RdC. Consumption of extra virgin olive oil improves body composition and blood pressure in women with excess body fat: a randomized, double-blinded, placebo-controlled clinical trial. Eur J Nutr. August 14, 2017; [epub ahead of print]. doi: 10.1007/s00394-017-1517-9.