Making Sense of Diet Pills
With so many over-the-counter diet remedies promoting weight loss, it's no wonder that desperate folks continue to throw away their hard-earned money. This section presents ammunition for making a more rational decision the next time you find yourself searching the shelves at your local pharmacy or health food store. Remember to always read every ingredient listed on a brand name label; chances are you'll find one or more of the following substances. If it sounds too good to be true …
- Ephedra (Ma Huang, Ephedrine): Ephedra is the botanical form from the plant ma huang. The synthetic alkaloids, ephedrine and pseudoephedrine, are found in many over-the-counter cold and asthma medications and dietary supplements. Ephedra alkaloids are powerful central nervous system stimulants and cause vasoconstriction and cardiac stimulation. According to a review study in 1995, several studies suggested that ephedrine plus caffeine act by centrally suppressing appetite and peripherally stimulating fat oxidation. Ephedra alone did not show any significant effect on weight loss. That's why you'll generally find caffeine (or guarana) coupled with ephedra in the over-the-counter diet remedies.
Unfortunately, the side effects are extremely dangerous and outweigh any weight-loss advantage: rapid heartbeat, hypertension, arteriole constriction, heart attack, stroke, tremors, insomnia, and death in individuals in otherwise good health.
- Guarana: Guarana, not recommended, is a caffeine alkaloid. What's more, it is a natural diuretic and laxative, and that's what causes the weight loss. Unfortunately, it also speeds up your pulse rate, increases blood pressure, and increases the heart rate. Not worth the risk!
- Chitosan: Found in a few popular diet supplements, chitosan (KITE-oh-san) is a dietary fiberlike substance made from chitin, which forms the hard shells of crabs, lobsters, and other shellfish. Chitosan works by binding to fat and other fat-soluble substances. According to the manufacturers, this undigested fat is then excreted in our bowel movements. By reducing the amount of fat we absorb, these pills hope to make it easier to lose weight. However, there is no clear evidence to suggest that these weight-loss pills have any sort of lasting effect on weight loss. Moreover, some pill manufacturers themselves have stated that there are no guarantees as to their effectiveness.
Chitosan can block the absorption of certain medications and fat-soluble vitamins. For example, drugs such as estrogen and contraceptives are fat-soluble and therefore subject to interference from chitosan. Also, shellfish-allergic folks should stay clear of it.
- Carnitine (L-Carnitine): Carnitine is synthesized in the body from lysine and methionine, two essential amino acids. It plays a central role in transporting long-chain fatty acids into the mitochondria for oxidation. It also affects the metabolism of acetyl-coenzyme-A. However, supplemental carnitine only “provides extra energy” if a true clinical carnitine deficiency exists. There is no evidence that carnitine supplementation in healthy individuals improves energy, or enhances weight loss.
- Chromium: Chromium is an essential trace mineral. In its biologically active form, chromium influences insulin and therefore plays a role in carbohydrate, lipid, and protein metabolism. Because of its potential effect on metabolism, chromium has been used as a weight-loss aid and muscle builder for years. Chromium supplements come in the form of picolinate, chloride, and nicotinate. As expected, many studies have shown that chromium in supplemental form does not enhance weight loss. Furthermore, some of the lousy side effects may include headaches, sleep disturbances, and mood swings. Forget it.
- DHEA (dehydroepiandosterone): DHEA is the most abundant hormone secreted by the adrenal glands and it naturally declines with age. In the tissues, DHEA is converted into active androgens and estrogens and these hormone levels may be connected with body fat, body composition, and waist-to-hip ratio. A 2004 study showed that 52 elderly, DHEA-deficient individuals who were given DHEA supplements had significant decreases in abdominal fat. That doesn't mean everyone should run out and buy DHEA supplements, however, because DHEA may increase the risk for hormone-related cancers such as prostate, breast, and endometrial. If you really want to try DHEA, have your physician measure your blood levels first.
- CLA (Conjugated Linoleic Acid): CLA is a fatty acid processed from sunflower or safflower oil. The fatty acid is also naturally found in beef and dairy products. Preliminary evidence suggests it may have an anti-carcinogenic effect, but only in animal studies—human studies have yet to come. What's more, preliminary animal studies show that CLA may decrease body fat and increase lean body mass, while reducing appetite. This may be an interesting future supplement, but for now, human research is lacking and the long-term safety has not yet been established.
- Yohimbine: Yohimbine is the major alkaloid present in the bark of the yohimbe tree found in West Africa. Yohimbine stimulates norepinephrine release and has been used for weight loss and as an aphrodisiac. Studies have shown some success with weight loss in obese patients who are also on low-calorie diets; however, sample sizes were small and food was restricted. Side effects include nervousness, insomnia, anxiety, frequent urination, dizziness, tremors, headache, joint soreness, and blood pressure swings. To date, there is insufficient evidence regarding the safety and efficacy of yohimbine with weight loss.
- Citrus Aurantium: This herb is better known as bitter orange and—like ephedra—high doses can cause hypertension. It also has the potential to affect the metabolism of other drugs you may be taking. Oh—and did I mention that it probably has no effect on weight?
More on: Children's Nutritional Needs
Excerpted from The Complete Idiot's Guide to Total Nutrition © 2005 by Joy Bauer. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.
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