Exploring the sense and nonsense of food and health

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The Dangers of Herbal Supplements

Folk medicine has used herbs for  centuries to treat and prevent disease. Today, they appear to be more popular than ever. It is estimated that about 1 in 6 Americans use herbs to treat or prevent illnesses. Herbal supplements are relatively inexpensive and easy to obtain – no prescription necessary.  Prescription medicines are tested for safety and efficacy and side effects are clearly available from the manufacturers.

Doses are regulated and standardized and physicians and pharmacists are trained to be aware of drug interactions that may occur that can cause dangerous sometimes fatal results. Herbal preparations have none of these safeguards. Here is what you need to know:

  • Many botanical components are toxic by themselves or in combination with other herbal components.
  • The FDA has issued warnings about ingredients such as comfrey, kava, and aristolochic acid.
    • Ephedra found in many weight loss preparations was found to cause heart attacks and strokes and was removed from the market in 2004. Ephedra extracts not containing ephedrine are not banned (according to Wikipedia) and can be found on the Internet.
  • Herbal supplements are subject to contamination of pesticides, microbes, metals and other toxins.
  • Doses are not thoroughly tested for purity and concentrations.
  • Some supplements should not be taken two to three weeks prior to surgery, e.g. St. John’s wort can prolong and intensity narcotic drug effects.
  • Herbal supplements should not be taken during pregnancy.
  • Do not give herbs to children.
  • Do not use herbs for long periods of time.
  • Do not fall for false health claims made by the manufacturer.

Source:   Smolin, Lori A., Grosvenor, Mary B. Nutrition: Science and Applications, Third Edition.


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Magnesium: The Forgotten Nutrient?


Functions of Magnesium

Magnesium is often a neglected nutrient. Low intakes are common and are associated with cardiovascular disease, type 2 diabetes, and osteoporosis. Along with an adequate intake of potassium and calcium, these minerals favor a lower risk of hypertension.

50 to 60% of magnesium in the body is found in bone. The rest resides inside the body cells with a small percentage in the blood. It functions in over 300 enzyme systems, many of which involve the release of energy, proper functioning of nerves and muscles including those of the heart and in the many steps of DNA, RNA and protein synthesis. It also affects the metabolism of calcium, sodium and potassium.

How Much Do We Need?

The Recommended Dietary Intake (RDI) is 400 mg for adults and children over the age of 4. The Upper Tolerable Level (UL) is 350 mg from non-diet sources.

An intake below the RDA is commonly seen in the population but a blatant deficiency is rare. The use of diuretics can increase urinary loss and the use of proton pump inhibitors to treat gastroesophageal reflux disease GERD) can interfere with magnesium absorption.

Food Sources

The best food sources are:

Seeds and nuts

Garbanzo beans

Leafy greens like spinach

Processed foods are poor choices. For example, a cup of whole wheat flour contains about 166 mg. of magnesium. When that grain is refined and thus more processed, the white flour only contains 28 mg.

Magnesium Supplements

Since magnesium is not found abundantly in many foods, magnesium supplementation is popular and claimed to be beneficial for just about any disorder.

Research on the role of magnesium in other medical conditions is sparse. For example, magnesium levels in the body may alleviate the effects of osteoporosis. Dietary magnesium may have some benefit, but using supplements does not appear to have the same effect. The same may be true for its role in controlling hypertension. Its claims often include treating anxiety, ADHD, depression, and muscle cramps; however, most research does not report much help from supplements. One common side effect of magnesium supplementation is its laxative effect with some forms. Magnesium taurate and magnesium glycinate appear to not have this effect.

Always tell your doctor about any supplements you take. Dietary supplements are not regulated by the FDA, so buyer beware.















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Antioxidants: Cancer Cures?


The following article provides the facts about antioxidants in general.  However, getting your antioxidants from foods like fruits and vegetables is a  habit that contributes to overall positive healthy benefits. Check out my previous post on supplement use  HERE.


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Antioxidant Supplements and Cancer Cells

The structure of the antioxidant vitamin ascor...

The structure of the antioxidant vitamin ascorbic acid (vitamin C). (Photo credit: Wikipedia)

By Sally J. Feltner, PhD, RDN

Antioxidants are supposed to protect our cells from free radicals that are dangerous highly reactive molecules seeking a missing electron. In that process, cell and DNA damage can occur contributing to disease. Antioxidants are claimed to help prevent many chronic diseases thought to be due to this damage like heart disease, cancer, macular degeneration and others. However, there is a growing body of evidence that suggests antioxidant supplements may actually promote cancer and not prevent it as they are claimed to do.

Most dietary supplements that do not exceed the Daily Values are harmless, but it is a good idea to avoid any supplement that boasts vitamin and/or mineral content over 100% of the Daily Value. Keep in mind that the studies that showed potential harm used what is known as megadoses (those greatly exceeding 100% RDA.)

Antioxidant vitamins include: beta carotene (a form of vitamin A), vitamin E and vitamin C. The mineral selenium is also considered an antioxidant.

The notion that megadoses of beta carotene might be harmful comes from studies in 1994 that resulted in smokers given megadoses of beta carotene developed 18% more cases of lung cancer than those individuals in the placebo group. A subsequent study with men smokers or those exposed to asbestos reported 28% more lung cancer cases in the beta-carotene and vitamin A groups. See my previous post HERE.

More recently, a trial in 2011 with 35,500 men found that men older than 50 years of age had a 17% higher risk for prostate cancer when given large doses of vitamin E.

Due to these disturbing studies, conclusions point to the possibility that antioxidants at least at high doses may protect cancer cells from free radicals. A recent study gave the antioxidant N-acetylcysteine (NAC) to mice genetically susceptible to melanoma. In this case, the dose was similar to those found in human consumption of antioxidants. The treated mice developed more tumors in lymph nodes that suggested a higher rate of metastasis (spread of cancer).

In addition, they added NAC or vitamin E to cultured human melanoma cells and found that antioxidants aided the cell’s ability to invade nearby tissues (a sign of increased metastasis)

In a lung cancer study using antioxidant supplements, researchers found that they turned off the activity of a known tumor suppressor gene called p53. The protein encoded by the gene monitors cells for damage to their DNA. It can trigger DNA repair; stop cell division; and even cause cancer cells to commit suicide (apoptosis).

Cancer develops in three stages: initiation, promotion and progression. It is thought that antioxidant supplements do not initiate cancer cells but speed up the progression to malignancy of undiagnosed or already present cancer cells.

To give us an idea of the labels on some selected products at a popular health food store:

Beta Carotene is a form of vitamin A.

1 capsule provides 15 mg – 500% Daily Value.

Vitamin C 1000 mg.

! caplet provides 6667% Daily Value

Health Claim on Label: A protective antioxidant that provides immune support.

Vitamin E 1000 IU

1 capsule provides 3333% of Daily Value

Health Claim on Label: Helps support a healthy cardiovascular system

Some cancer researchers believe that people who are at a higher risk for lung cancer or melanoma or have any form of cancer should avoid antioxidant supplements. However, there is widespread evidence that eating fruits and vegetables can help lower the risk of heart disease and certain cancers. Do not fall for the hype of supplement sellers and manufacturers who ignore the science. The concept of the free radical theory of disease is a complex issue and should not be left to the interpretations of those who only take in the profits of possibly harmful products.


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Magnesium Deficiency and Pancreatic Cancer?

English: Pancreatic Cancer Action logo

English: Pancreatic Cancer Action logo (Photo credit: Wikipedia)


Description and Function 

Magnesium is a mineral that affects the metabolism of calcium, sodium, and potassium. About 50-60% is in bone. Most of the rest is inside cells. It is a cofactor for over 300 enzymes, many of which participate in the generation of energy as ATP from carbohydrate, fat and protein. It is necessary for the proper functioning of the nerves and muscles, including the heart. It is important for DNA and RNA synthesis and for almost every step in protein synthesis.

Food Sources

Magnesium is a component of chlorophyll and therefore found in leafy greens such a spinach and kale. Nuts, seeds, bananas and the germ and bran of whole grains are also good sources. Processed foods are generally poor sources. For example, removing the bran and germ of a whole wheat kernel reduces the magnesium content of a cup of white flour to only 28 mg, compared with the 166 mg in a cup of whole-wheat flour. One cup of whole grain cereal, spinach or legumes contain about 100 mg of magnesium.


According to my textbook, deficiency is rare in the healthy population, but does occur in alcoholism, kidney disease, and gastrointestinal disease. Some medications such as diuretics (commonly taken for hypertension) can contribute by increasing magnesium loss in the urine. Proton pump inhibitors (PPI‘s) taken to prevent GERD, may cause low blood magnesium by interfering with magnesium absorption. Talk to your doctor about any medications you take and their drug-nutrient interactions.

Deficiency symptoms include muscle weakness and cramping, irritability, anxiety and changes in blood pressure and heartbeat. Low blood levels of magnesium affect levels of blood calcium and potassium so some of the symptoms may be due to alterations in these minerals as well.

Nevertheless, the typical intake of magnesium in the U. S. is below the RDA of 400 mg/day for young men and 310 mg/day for young women. After 30 years of age, the recommended intake increases to 420 and 320 mg/day for men and women, respectively.

There has been no large systematic study of the adequacy of magnesium body stores in Americans. In 2009, the World Health Organization published a report that stated that 75% of Americans consumed less magnesium than needed. Some say that we have a nationwide magnesium deficiency, especially those who sell supplements. It would be helpful if the National Institutes of Health or the Centers for Disease Control and Prevention could fund serious research to determine the status of Americans’ magnesium body stores. I fully have supported getting our nutrients from the diet and not from supplements, most of which are unnecessary. However, the current American processed food diet as well as our fast food intake may warrant magnesium supplementation for some consumers.

Low intakes of magnesium have been associated with heart disease; type 2 diabetes, hypertension and osteoporosis.

Magnesium Supplements

There are no adverse effects of magnesium intake from foods, but supplements of all types may have some side effects. Some elderly patients who have impaired kidney function may suffer from toxic effects of magnesium-containing laxatives and antacids such as milk of magnesia. The Tolerable Upper Intake Levels (UL) for adults and adolescents over 9 years of age is 350 mg from nonfood sources of magnesium.

Calcium in the diet decreases absorption in the digestive tract; therefore, the use of calcium supplements can reduce the absorption of magnesium.

Source: Smolin, Grosvenor: Nutrition, Science and Applications, Third Edition, Wiley.

Little is known about the relationship of diet and pancreatic cancer. Mortality rates from pancreatic cancer are increasing and there is a great need for more research in its prevention.   FYI article follows on magnesium deficiency and its proposed association with pancreatic cancer.