Mango - a sweet treat with anti-cancer potential

Mango is the world’s most widely eaten fresh fruit. Mango originated from India and southeast Asia, but is now grown in the Americas, the Caribbean, Africa, and Australia as well – today, Mexico is the world’s largest mango exporter. Mangoes were introduced in the U.S. in the late 1800s, and some are still grown in California and Florida. Mango is part of a nutrient dense family – its relatives include cashews and pistachios, but unlike its family members, the seed of a mango is inedible.

There are over 50 different varieties of mango, and we see about five of these in the U.S. Color varies – green, yellow, orange, red, or a combination. Although unripe mangoes are usually green, the best test of ripeness is how hard or soft the fruit is. A mango that indents in response to gentle pressure is ripe. Tart, unripe green mangoes are used in several ethnic cuisines, and are sometimes sliced and dipped in salt (but not by nutritarians!). Ripe mangoes, however, are extremely sweet and tasty.1-2 

A great deal of research has been done on the health benefits of high antioxidant fruits – blueberries, goji berries, pomegranates, acai – but the mango has been somewhat ignored by scientists because its antioxidant capacity is not quite as high as these other fruits.  Atulfo mangoes – the smaller, yellow mangoes often sold in Asian supermarkets – have the greatest antioxidant content of the five common varieties found in the U.S. Also, the orange flesh of mangoes is full of beta-carotene and vitamin C.3-4

Mangoes

A new study has revealed that mango, despite its low level of antioxidant activity, may have potent anti-cancer properties. Researchers treated cells derived from several common cancers – colon, breast, leukemia, and prostate – with mango polyphenol extract. Breast and colon cancer cells were most significantly affected – the cell cycle was disrupted and they underwent programmed cell death in response to the mango extract. Normal colon cells, however, remained alive and undamaged. The researchers suggest that gallotannins, the most abundant antioxidant polyphenols contained in mango, were responsible for the anti-cancer effects.5

Fresh mango is delicious all on its own. If you haven’t quite yet figured out how to cut a mango, here’s one way. Another is to slice lengthwise on each side of the pit, score the flesh, and then turn each side inside out, as illustrated here

Frozen and dried mango can make a great treat too:

Dr Fuhrman’s Fantastic Mango Ice Cream

Serves: 4

Ingredients:

1/2 cup unsweetened shredded coconut, reserving 1 tablespoon for garnish

1/2 cup hemp, almond or soy milk

1/2 teaspoon lemon juice

1 10-ounce bag frozen mango

4 slices dried mango, unsweetened and unsulfured

Instructions:

Soak dried mango in the plant-milk until soft (overnight or one hour in advance). Then blend all ingredients, including the soaking milk, in a Vita-Mix or other high-powered blender until smooth and creamy. Garnish with reserved coconut.

 

References:

  1. http://en.wikipedia.org/wiki/Mango
  2. http://homecooking.about.com/od/foodhistory/a/mangohistory.htm
  3. Manthey JA et al. Influences of harvest date and location on the levels of beta-carotene, ascorbic acid, total phenols, the in vitro antioxidant capacity, and phenolic profiles of five commercial varieties of mango (Mangifera indica L.). J Agric Food Chem. 2009 Nov 25;57(22):10825-30.
  4. http://www.nutritiondata.com/facts/fruits-and-fruit-juices/1952/2
  5. http://www.sciencedaily.com/releases/2010/01/100111154926.htm

Eggs and poultry with skin double prostate cancer recurrence risk

Eggs

Approximately 1300 men who had been diagnosed with prostate cancer were followed for two years to document their dietary patterns and recurrence or progression of their disease. In this study, two specific animal foods were found to be risky - the men that ate the most eggs or poultry with skin were twice as likely to have their disease recur or progress.1

This study makes three important points.

  1. Diet does matter, even after a prostate cancer diagnosis.
  2. There is something in chicken, specifically in the crispy outer portion and skin that is powerfully cancer-inducing. Heterocyclic amines, carcinogenic compounds that are formed when meat is cooked at high temperatures, are a probable culprit. A November 2009 study of 175,000 men showed an increase in prostate cancer risk with consumption of barbequed and grilled meat.2
  3. Consumption of eggs and egg whites is not without risk. Eggs are high in animal protein, which has been linked to cancers. Our populations’ idea that more protein is favorable and that egg (whites) are the perfect food does not hold up to scrutiny. Eggs also could affect prostate cancer due to their high choline content – egg consumption increases the amount of choline in the plasma, and high plasma choline increases prostate cancer risk.3 

Four previous studies implementing a plant-based diet and exercise following prostate cancer diagnosis found a decrease in prostate cancer progression rates.4 

Dietary strategy for prostate health 

 

References:

1. Richman EL et al. Intakes of meat, fish, poultry, and eggs and risk of prostate cancer progression. Am J Clin Nutr. 2009 Dec 30. [Epub ahead of print]

2. Sinha R et al. Meat and meat-related compounds and risk of prostate cancer in a large prospective cohort study in the United States. Am J Epidemiol. 2009 Nov 1;170(9):1165-77. Epub 2009 Oct 6.

3. http://www.foodnavigator.com/Science-Nutrition/Meat-not-linked-to-prostate-cancer-recurrence-risk

4. R. W.-L. Ma, K. Chapman. A systematic review of the effect of diet in prostate cancer prevention and treatment. J Hum Nutr Diet, 22, pp. 187–199 

Diet high in omega-6 fats increases risk for ulcerative colitis

Ulcerative colitis falls under the category of inflammatory bowel diseases (IBD). It is an autoimmune disease in which excessive inflammation kills cells in the lining of the colon, leaving ulcers behind. Ulcerative colitis is a chronic condition that commonly causes abdominal pain and bloody diarrhea, and it carries with it an increased risk of colorectal cancer. In some severe cases, the colon must be surgically removed. Clearly, this condition also causes a great deal of emotional trauma.1

Recent studies have identified dietary patterns that may predispose individuals to ulcerative colitis. High intake of fats, refined sugars, and fried potato products were positively associated with ulcerative colitis, and fruit consumption was found to be protective.2

Fruit

Most recently, omega-6 fatty acids have been investigated. Omega-6 fatty acids are essential fatty acids, meaning that we must obtain them from our diet for good health, but the typical American diet contains an excessive amount of omega-6, which can produce a pro-inflammatory environment in the body.

Linoleic acid is an omega-6 fat that is highly concentrated in red meat, cooking oils, and margarines. In the digestive system, linoleic acid is metabolized into arachidonic acid, which incorporates into cell membranes of the colon. When arachidonic acid is broken down further, its products are pro-inflammatory – these products are found in excess in the intestinal cells of patients with ulcerative colitis. For these reasons, scientists believed that excess linoleic acid might be linked to ulcerative colitis risk.

Fries

A prospective study of over 200,000 men and women in Europe found that the subjects who consumed the highest levels of omega-6 linoleic acid were 2.5 times more likely to be diagnosed with ulcerative colitis. The researchers also found a negative association between the omega-3 fatty acid DHA and ulcerative colitis – subjects in the highest level of DHA intake decreased their risk by 77%.3

Avoiding excess levels of linoleic acid is simply accomplished by eating a diet that is based on whole plant foods and limits animal products and added fats. A diet of natural whole foods provides us with omega-6 fatty acids in appropriate amounts - not in excess – producing an anti-inflammatory environment.

For those who already have ulcerative colitis, it is important to know that the condition can be improved and sometimes completely resolved with dietary changes – conventional treatment of IBD often includes immunosuppressive drugs with dangerous side effects.  Dr. Fuhrman outlines specific dietary recommendations for sufferers of IBD in his Inflammatory Bowel Disease newsletter

References:

1. http://www.nlm.nih.gov/medlineplus/ulcerativecolitis.html#cat59

2. Shah S. Dietary Factors in the Modulation of Inflammatory Bowel Disease Activity. MedGenMed 2007; 9(1):60

3. Tjonneland A et al. Linoleic acid, a dietary n-6 polyunsaturated fatty acid, and the aetiology of ulcerative colitis: a nested case-control study within a European prospective cohort study. IBD in EPIC Study Investigators. Gut. 2009 Dec;58(12):1606-11. Epub 2009 Jul 23.

http://www.reuters.com/article/idUSTRE5B15S720091202