Avocados Can Help to Treat Metabolic Syndrome, says review

A new review of studies looking at the health effects of avocados finds that there is “satisfactory clinical evidence” that the fruit can help to treat metabolic syndrome.
[A selection of avocados]
Researchers suggest that avocado may help to tackle metabolic syndrome.

Metabolic syndrome is defined as a cluster of risk factors that can raise the risk of other health conditions, such as type 2 diabetes, heart disease, and stroke.

Risk factors include abdominal obesity, low levels of high-density lipoprotein (HDL) cholesterol – or “good” cholesterol – high triglyceride levels, high blood pressure, and high fasting blood sugar.

The presence of at least three of these risk factors warrants a diagnosis of metabolic syndrome.

According to the American Heart Association, metabolic syndrome affects around 23 percent of adults in the United States.

Adopting a healthful diet is considered one of the best ways to prevent or treat metabolic syndrome. The new review – recently published in the journal Phytotherapy Research – suggests that avocados should form a part of this diet.

Avocados are a fruit from the avocado tree, or Persea Americana, which is native to Mexico and Central and South America.

A number of studies have documented the possible health benefits of avocado. A study reported by Medical News Today in 2014, for example, found that eating half an avocado with lunch may aid weight loss, while more recent research linked the fruit to reduced levels of low-density lipoprotein (LDL) cholesterol, known as “bad” cholesterol.

These benefits have been attributed to the bioactive components of avocados, which include carotenoids, fatty acids, minerals such as calcium, iron, and zinc, and vitamins A, B, C, and E.

For their review, co-author Hossein Hosseinzadeh, of Mashhad University of Medical Sciences in Iran, and colleagues set out to determine how these components might help to combat the risk factors of metabolic syndrome.

Avocado has the strongest effect on cholesterol levels

To reach their findings, the researchers analyzed the results of various in vivo, in vitro, and clinical studies that investigated the effects of avocado on metabolic health.

Hosseinzadeh and colleagues found that the fruit has the strongest impact on lipid levels – that is, levels of HDL cholesterol, LDL cholesterol, total cholesterol, and triglycerides.

As an example, the team points to one study of 67 adults, of whom 30 had a healthy lipid profile and 37 had mild hypercholesterolemia. After adhering to an avocado-enriched diet for 1 week, both groups showed significant reductions in total and LDL-cholesterol and triglyceride levels.

“The reported mechanism of this effect was regulating of the hydrolysis of certain lipoproteins and their selective uptake and metabolism by different tissues such as liver and pancreas,” explain the authors.

“Another possible mechanism could be related to the marked proliferation of the liver smooth endoplasmic reticulum which is known to be associated with induction of enzymes involved in lipid biosynthesis.”

An ‘herbal dietary supplement’ to help treat metabolic syndrome

The review also uncovered evidence that avocado is beneficial for weight loss. The researchers cite one study that found overweight or obese adults who ate one avocado every day for 6 weeks experienced significant decreases in body weight, body mass index (BMI), and the percentage of body fat.

Additionally, the team identified a number of studies associating avocado intake with reductions in blood pressure among patients with hypertension, and evidence suggests that the fruit might also help to reduce atherosclerosis – the narrowing or hardening of arteries caused by a buildup of plaque.

Notably, Hosseinzadeh and colleagues found that it is not just the flesh of the avocado that can benefit metabolic health – the peel, seed, and leaves of the fruit may also help.

One study published in 2014, for example, found that a daily dose of oil extracted from avocado leaves led to reductions in total and LDL cholesterol and blood pressure.

Overall, the researchers conclude that avocado may be effective for the treatment of risk factors associated with metabolic syndrome, though further research is warranted. They write:

“In this review article, satisfactory clinical evidence suggested that avocado can be used as herbal dietary supplements for treatment of different components of [metabolic syndrome].

Although, avocado like other herbal products is safe and generally better tolerated than synthetic medications, there is limited scientific evidence to evaluate different side effects because of contaminants, or interactions with drugs. Besides, further studies need to be accomplished on the metabolic effects of different parts of avocado for other possible mechanisms.”

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Medicinal mushrooms are the new turmeric | MNN – Mother Nature Network

Mushrooms are the latest functional food shown to have science-backed health benefits beyond nutrients. Here are 5 to add to your must-eat list.

Source: Medicinal mushrooms are the new turmeric | MNN – Mother Nature Network

Almond Supplementation Lowers Uric Acid Levels in Patients with Coronary Artery Disease

  • Almonds (Prunus dulcis, Rosaceae)
  • Coronary Artery Disease
  • Serum Uric Acid

Higher serum levels of uric acid (UA) are increasing in prevalence globally and are associated with coronary artery disease (CAD) and a higher risk of heart attack or stroke in patients with no history of heart disease and stroke. An increase of 1 mg/dL in serum UA has been found to cause a 12% increase in the risk of CAD mortality. Almonds (Prunus dulcis, Rosaceae) are recognized for their lipid-neutralizing effects and may reduce the risk of cardiovascular disease (CVD). A previous study found almond supplementation to prevent hyperuricemia in a CVD rat model. The goal of this randomized controlled trial (RCT) was to evaluate the UA-reducing potential of almond supplementation in patients with CAD.

The study recruited 150 patients with CAD from the Cardiology Clinic, Aga Khan University Hospital; Karachi, Pakistan. Patients who regularly consumed nuts or had nut allergies were excluded. Patients were randomly assigned into 1 of the following 3 groups of 50: no intervention (NI), supplementation with almonds grown in Pakistan (PA), and supplementation with imported American almonds (AA). Patients in the NI group were asked to abstain from consuming any nuts, specifically almonds, while enrolled in the RCT. Those in the PA and AA groups were given 10 g/day almonds and told to prepare them traditionally—soak overnight, peel, and eat before breakfast daily. Patients kept consumption diaries and compliance was monitored in twice-weekly phone calls. At baseline, blood was drawn and body weight, blood pressure (BP), and other measures were taken. Follow-up visits were scheduled at 6 and 12 weeks with the same measurements taken. Patients in the NI group received almonds at the end of the RCT.

Baseline demographics and serum UA were similar in all the groups (P>0.05). Patient weight and BP remained fairly constant in all groups throughout the 12-week study. At week 6, men in the PA group had a 15% reduction in UA, and women had a 12% reduction in UA, compared to the NI group (P<0.05). Men in the AA group had 17% less serum UA, and women 19% less, compared to NI (P<0.05). At week 12, men in the PA group had 17% less serum UA, and women 16% less, than those in the NI group (P<0.05). In the AA group at the end of the study, men had 20% less serum UA, and women 21% less, compared to NI (P<0.05). Compared to baseline, patients in the NI group showed negligible decreases in serum UA, whereas both the PA and AA groups had significant improvement (P<0.05) at both follow-up visits. Men in both active groups had 13% less serum UA at 6 weeks; women in the PA group, 11% less; and women in the AA group, 16% less. At 12 weeks, men in the PA group had improved 16% over baseline and women in the PA group had improved by 14%; and men and women in the AA group had 18% less serum UA than at baseline. This is the first almond intervention study in patients with CAD reporting on UA reduction.

Serum UA may be considered as a marker for vascular function, with anticipated pathways of damage including pro-oxidative and proinflammatory factors among others. Almond supplementation is known to positively affect some of these factors, including a possible reduction in C-reactive protein reported in some studies. Almonds contain L-arginine, a precursor of nitric oxide that has been reported to reduce BP in vivo. In this RCT, almost all patients were taking antihypertensive medications and no effect on BP was seen.

It should be noted that while this study differentiated between Pakistani and American almonds, and those in the AA group showed slightly more improvement than those in the PA group, there is no botanical difference between these almonds. Differences in constituents caused by time of harvest, a method of storage, and different cultivars might be considered in future studies. It should also be noted that the almond skin, discarded by patients in this study, is a rich source of vitamins and minerals, and possibly of other nutrients of interest. Future studies might compare effects of almonds with skins and those that have been peeled.

Resource:

Jamshed H, Gilani AUH, Sultan FAT, et al. Almond supplementation reduces serum uric acid in coronary artery disease patients: a randomized controlled trial. Nutr J. August 19, 2016;15:77. doi: 10.1186/s12937-016-0195-4.

Food as Medicine: Carrot (Daucus carota, Apiaceae)

History and Traditional Use

Range and Habitat

Ubiquitous at any supermarket, the common root vegetable carrot (Daucus carota, subsp. sativus) is a biennial plant that is an excellent source of vitamin A (one cup contains approximately 600% of the recommended daily value) and fiber.1 Indigenous to Europe as well as parts of Asia and northern Africa, carrots now are cultivated commonly in a wide range of environments as they can withstand frosts.2 The colorful varieties of carrots, as well as their hardiness, make them popular with home gardeners.

Phytochemicals and Constituents

Favored for their sweet flavor and versatility, carrots not only supply an impressive array of vitamins and minerals, but also contain carotenoids such as alpha- and beta-carotene, lycopene, and the flavonoid quercetin. Though the orange carrot is the most well known in modern times, carrots appear in a number of colors including white, yellow, red, and purple.3 In fact, purple was the prevailing color for carrots until about four hundred years ago, when popular theory claims that the unusual orange variety was cultivated in Holland as a sign of Dutch nationalism to honor William of Orange. The exact reason why the orange cultivar became the dominant variety is unknown, though genetic evidence suggests that orange carrots developed from yellow ones.4

The different colors of carrots reveal their various concentrations of phytochemicals.5 Carotenoids give yellow, orange, and red carrots their colors, while anthocyanins produce the deep purple variety. Orange carrots contain high quantities of beta-carotene. Yellow carrots contain low quantities of beta-carotene, but higher levels of lutein, which may protect from age-related macular degeneration and be beneficial for eyesight. Red carrots contain lycopene — a potent antioxidant with potential anti-cancer activity — in concentrations similar to that of tomatoes. Red carrots also contain moderate levels of alpha- and beta-carotene and lutein. Purple carrots contain high levels of anthocyanins, antioxidants that have anti-inflammatory and cardio-protective properties. The white variety has low levels of these phytochemicals but contains high levels of potassium.

Historical Uses

The record of the use of carrots in herbalism dates back to the 10th century, with mentions in the Old English Herbarium and the Leech Book of Bald indicating the use of the root as an emmenagogue as well as a treatment for smallpox and cough.6 Around the world, both root and seed have documented historical uses, typically to promote menstruation or as a diuretic. A different species, the wild American carrot (D. pulsillus), has an ethnobotanical history among many American native tribes as a remedy for colds, fevers, itching, and snake bites.7

Modern Research

Current research suggests that carrots may possess anti-cancer properties,8-10 as well as benefits for people with high blood pressure11 and cardiovascular disease.12 Beta-carotene is converted by the body into vitamin A and is a powerful antioxidant, protecting the body from free radicals and maintaining healthy skin and eyes.13

Consuming large amounts of beta-carotene, especially from carrots, can result in a harmless side effect called carotenemia, which temporarily yellows the skin.13 Infants, whose commercial foods often contain carrot puree as an added ingredient, are most likely to get carotenemia. The yellowing effect subsides as the body processes the excess beta-carotene.

Carrots can be enjoyed cooked or raw, as they retain their nutrients during the cooking process.14 Their sweetness adds to their versatility and supports their use in both sweet and savory dishes. A sweet-and-spicy pickle, for example, enhances the carrot’s natural flavor and a pleasing crunch.


Nutrient Profile

Macronutrient Profile: (Per 1 cup raw carrots)

52 calories
1.26 g protein
12 g carbohydrates
0.23 g fat

Secondary Metabolites: (Per 1 cup raw carrots)

Excellent source of:

Vitamin A: 34,317 IU (~686% DV)
Vitamin K: 16.1 mcg (20% DV)

Very good source of:

Vitamin C: 11.4 mg (18% DV)
Dietary Fiber: 3.7 g (14.6% DV)
Potassium: 394 mg (11.3% DV)

Good source of:

Vitamin B6: 0.2 mg (9% DV)
Manganese: 0.2 mg (8.5% DV)
Molybdenum: 6.1 mcg (8.1% DV)
Thiamin: 0.1 mg (8.0% DV)
Niacin: 1.1 mg (5.6% DV)
Phosphorus: 53.7 mg (5.4% DV)
Magnesium: 18.3 mg (4.6% DV)
Folate: 17.1 mcg (4.3% DV)

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


Recipe: Spicy Pickled Carrots

Adapted from Alton Brown15

Ingredients:

  • 1 lb. baby carrots
  • 2 cloves of garlic, peeled and crushed
  • 1 cup of water
  • 1/2 cup of sugar
  • 1 1/2 cups apple cider vinegar
  • 1/2 teaspoon yellow mustard seeds
  • 1 1/2 teaspoons kosher salt
  • 1 teaspoon dried chili flakes
  • 2 dried red chilies

Directions:

  1. Place carrots and garlic in a 1-quart, spring-top glass jar.

  2. In a non-reactive

    sauce pan

    , bring the water, sugar, cider vinegar, mustard seeds, salt, and dried chili flakes to a boil, stirring to dissolve the sugar and salt. Boil for 4 minutes.

  3. Slowly pour the pickling liquid into the jar, covering the carrots and garlic completely. Submerge the

    chilies

    in the jar and cool before sealing.

  4. Refrigerate for two days (for a milder pickle) or a week (for a spicier pickle). These will get hotter the longer they are kept.

References

  1. Basic Report: 11124, Carrots, raw. US Department of Agriculture National Agricultural Library. Available here. Accessed November 19, 2014.
  2. Taxon: Daucus carota L. Germplasm Resources Information Network – (GRIN) [Online Database]. National Germplasm Resources Laboratory. Available here. Accessed November 19, 2014.
  3. History of the Carrot Part Three: From Medicine to Food – A.D. 200 to 1500. World Carrot Museum website. Available here. Accessed November 19, 2014.
  4. History of the Carrot Part Five: The Road to Domestication and the Colour Orange. World Carrot Museum website. Available here. Accessed November 19, 2014.
  5. Arscott SA, Tarnumihardjo SA. Carrots of many colors provide basic nutrition and bioavailable phytochemicals acting as a functional food. Comprehensive Reviews in Food Science and Food Safety. March 2010;9(2):223-239. Available here. Accessed December 3, 2014.
  6. What the Ancient Herbalists Said about Carrots. World Carrot Museum website. Available here. Accessed November 19, 2014.
  7. Moerman DE. Native American Ethnobotany. Portland, OR: Timber Press; 1998.
  8. Bhanot A, Sharma R, Noolvi M. Natural sources as potential anti-cancer agents: A review. International Journal of Phytomedicine [serial online]. April 2011;3(1):9-26.
  9. Aggarwal B, Shishodia S. Molecular targets of dietary agents for prevention and therapy of cancer. Biochemical Pharmacology [serial online]. May 14, 2006:1397, 1421.
  10. Rana Z, Malcolm R. C, Christine L. Le M. Bioactive Chemicals from Carrot (Daucus carota) Juice Extracts for the Treatment of Leukemia. Journal of Medicinal Food [serial online]. November 2011;14(11):1303-1312.
  11. Potter AS, Foroudi S, Stamatikos A, Patil BS, Deyhim F. Drinking carrot juice increases total antioxidant status and decreases lipid peroxidation in adults. Nutr J. September 24, 2011;10:96.
  12. Buijsse B, Feskens E, Kwape L, Kok F, Kromhout D. Both α- and β-Carotene, but Not Tocopherols and Vitamin C, Are Inversely Related to 15-Year Cardiovascular Mortality in Dutch Elderly Men. Journal of Nutrition [serial online]. February 2008;138(2):344-350.
  13. Vitamin Library: Beta-Carotene. Andrew Weil, MD website. Available here. Accessed November 19, 2014.
  14. Rock CL, Lovalvo JL, Emenhiser C, Ruffin MT, Flatt SW, Schwartz SJ. Bioavailability of beta-carotene is lower in raw than in processed carrots and spinach in women. J Nutr. 1998;128:913-916.
  15. Firecrackers. Food Network website. Available here. Accessed December 3, 2014.