Exploring the sense and nonsense of food and health

The “Crazy” World of Diet Supplements

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Herbal supplements

Herbal supplements (Photo credit: Ano Lobb. @healthyrx)

A popular herbal supplement, Aristolochia, commonly sold as birthwort has recently been linked to kidney failure and kidney and bladder cancer.  This herb is commonly prescribed in Taiwan as part of traditional medicine and it was recently observed that nearly 12% of that country’s population suffers from chronic kidney disease.  Now the herb has been conclusively associated with these diseases through gene analysis.

This herb is not marketed in the U.S. since 1994 following FDA warnings. Since cancer may take years to develop, it still may be a causative substance even since it’s ban. In the case of supplements, manufacturers must ensure safety, efficacy, and proper labeling but this regulation does not appear to be enforced. Due to the passage of a supplement law, Congress may be allowing similar problems to occur in the U.S. by not requiring “natural” substances such as some herbs to be labeled for safety and effectiveness, as they should be.  In 2009, the U.S. Public Health Service added aristolochic acid to the list of human carcinogens. But how many other “birthworts” are out there?

Another supplement toxic alert involved only two young soldiers who died suddenly from heart attacks during workouts, having taken two products called “Jack3d” and “Oxyelite PRO  that contain the unregulated amphetamine- like dimethylamylamine, DMAA as the suspected cause. Since then, these two supplements were banned from military bases.  However, you can still buy these products at GNC and Vitamin Shoppe as well as bodybuilding websites.

Two-thirds of all Americans take some sort of dietary supplement and Americans spent about $11.8 billion on vitamins and minerals in 2010. While medications undergo safety and efficacy testing in order to receive approval by the FDA for release to market, dietary supplements do not. The 1994’s Hatch – Harkin Act, the Dietary Supplement Health and Education Act (DSHEA), was passed by Congress and subsequently released potentially harmful substances into the marketplace under the guise of “dietary supplements” many of which have not been evaluated for safety or effectiveness.

Supplements made from products available on the U.S. market prior to 1994 can be sold with no agency review, including a wide variety currently available. Sellers of products containing substances unavailable prior to 1994 need only advise the FDA and do not require approval to be sold

There have been approximately 51,000 new ingredients brought to market since DSHEA passed, of which about 0.3% or 170 out of 51,000 have documented safety tests.  Any claims made by the manufacturer is accompanied by “This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease”.

Weight Loss Products

Not only may some supplements may be downright dangerous, others such as some OTC weight loss products just plain don’t work.  Most of these products have never been tested for safety or efficacy.  Ephedra was the ingredient in many of these products that is now banned by the U.S. government since it caused serious health problems and in some cases deaths. Many supplements have been revised to include non-ephedra ingredients but are similar to ephedra and still may be dangerous.  From the Tufts Health & Nutrition Letter:

  • 5-hydroxytryptophan (5-HTP).. 5-HTP has not been proven to effectively promote weight loss and is under constant scrutiny for safety. In larger doses, 5-HTP may have a negative effect on the liver.
  • Chitosan (KITE-o-san). This dietary supplement is made from chitin, a starch found in the skeleton of shrimp, crab, and other shellfish making it not absorbed and binding to some fat in the diet. Several studies, however, found no more weight loss from Chitosan than from a placebo (sugar pill).
  • Chromium is thought to enhance the effect of insulin and therefore the breakdown of carbohydrates. It has been touted as a weight loss aid and a fat burner. Much of the evidence is inconclusive on chromium’s effect on weight loss. Several studies have failed to show any benefit in weight loss after taking this mineral.
  • Glucomannan. Made from the root of Amorphophallus Konjac, glucomannan is said to contribute to weight loss by delaying the absorption of glucose from the intestines. Small limited studies have shown glucomannan to be effective in decreasing body weight. This effect is believed to be due to a “feeling of fullness” which may be due to the swelling of the glucomannan in the gut once it has been exposed to liquids. However, esophageal obstruction has been reported in several people taking glucomannan. Glucomannan and glucomannan-containing products have been banned in several countries due to the high incidence of gastrointestinal obstruction.
  • Garcinia (hydroxycitric acid). An ingredient found in at least 14 weight loss supplements comes from a plant native to India and Southeast Asia. To date, the best available data show this product is not effective in weight loss.
  • Yerba Mate. Also known as Paraguay tea, yerba mate is a strong brain stimulant (the doses typically used mimic that of 100 to 200 mg of caffeine). The principle side effects reported are excessive stimulation and high blood pressure. It has not been proven to promote weight loss.
  • Guar Gum. Also known as guar, guar flour, and jaguar gum, guar gum is a dietary fiber obtained from the Indian cluster bean. It has been noted to decrease appetite by providing a “feeling of fullness.” However, like glucomannan, guar gum may cause obstruction of the esophagus. The water-retaining capacity of the gum permits it to swell to 10- to 20-fold and has led to gastrointestinal obstructions. Reviews of multiple studies show it has no effect on weight loss.

It is very possible that sometime in the future, some unregulated substance will kill a number of people or cause a dangerous health problem that could have been prevented by a more careful scrutiny of “dietary” supplements.  At the very least, more people are also affected by wasting their money on often expensive products that have never been shown to live up to their claims.  Buyers beware!

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