Dietary Supplements
Most CAM practitioners and many conventional medical practitioners agree that food sources are the best way to obtain nutrients. They do, however, allow that it is impossible for some people to get all the nutrients they need, or sufficient quantities of specific vitamins or minerals, from their daily diets. For example, many researchers and nutritionists feel that the diets of the majority of Americans do not contain enough chromium and most women do not consume adequate amounts of iron. Further, the CAM principle of treating each patient as an individual with unique physiologic and biochemical needs suggests that some individuals may need more of specific nutrients than others.
Advocates of dietary supplements feel that the recommended dietary allowances (RDAs) are too low for some vitamins and minerals, and they observe that it is difficult to obtain higher than the RDA of certain vitamins without also consuming an excess of fat and calories. An example of this dilemma is vitamin E, an antioxidant found in high-fat vegetable and seed oils. In The Best Alternative Medicine Dr. Pelletier points out that for men to get the RDA (fifteen IU) of vitamin E, they would have to eat "248 slices of whole wheat bread, 16 dozen eggs, or 20 pounds of bacon." Several studies suggest that far higher doses—twenty to thirty times greater than the RDA—may protect against heart disease or some cancers, but to obtain such doses from diet alone is impossible.
Whether to prescribe diets supplemented with vitamin E is one of many questions about this particular issue. Another concern is the form of vitamin E available—supplements contain only alpha tocopherol instead of the variety of tocopherols available in foods. Is it better to take higher doses of one form of vitamin E at the risk of losing other perhaps equally valuable forms of vitamin E? Critics of dietary supplements use this question to support their view that people should attempt to obtain as many needed nutrients from food sources as possible, without relying on dietary supplements. Further, there is no consensus about dosages higher than the RDA, although it is known that some vitamins and minerals, such as vitamins A and E and chromium, are toxic in high doses. For example, more than four hundred IU of vitamin E taken daily may increase the risk of stroke, and high doses of vitamin E are generally not advised for people taking medications to reduce blood clotting, such as Coumadin.
Unlike drugs, dietary supplements do not need to be approved by the Federal Drug Administration (FDA) and therefore go to market with far less testing and scrutiny. This has caused debate and may lead to the ultimate FDA banning of certain supplements, as in the case of the herb ephedra, a dietary supplement used for weight loss that was taken off the market in 2004 after it was linked to 155 deaths and dozens of heart attacks and strokes.
The Hormone Debate
Our bodies would not function without hormones—they keep our bodies working as they should. They help regulate body temperature, blood pressure, and blood sugar levels. In childhood, they help us "grow up," and in the teen years, they stimulate puberty. As we age, some hormones increase (such as parathyroid hormone, which helps regulate the amount of calcium in our blood and bones), and others decrease (such as estrogen in women and testosterone in men). Some diseases cause our bodies to produce fewer hormones, in which case they may need to be supplemented. Conventional medical practice does not recommend taking additional hormones unless an individual has a documented deficiency of a necessary hormone, such as thyroid hormone deficiency.
Although there are many advertisements and products claiming that taking certain hormones can help prevent effects of aging, this has not been proved and may be harmful. It is now understood that unsupervised, off-label (use for purposes other than those approved by the U.S. Food and Drug Administration), or even physician-prescribed use of hormones may be dangerous. In fact, in July 2002, a Women's Health Initiative (WHI) study conducted by the U.S. National Institutes of Health (NIH) concluded that the risks associated with hormone replacement therapy (HRT), which included the hormones estrogen and progestin and was routinely prescribed for postmenopausal women (those who no longer ovulate or have menstrual periods) to prevent osteoporosis and heart disease, were found to be greater than the benefits. Though there were some benefits of estrogen plus progestin, including fewer cases of hip fractures and colon cancer, in healthy menopausal women HRT was no longer recommended due to an increased risk of invasive breast cancer. According to the NIH, the trial also found increases in coronary heart disease, stroke, and pulmonary embolism. The study was scheduled to run until 2005, but was stopped after an average follow-up of 5.2 years. Most physicians and other health care practitioners advised patients to stop taking HRT.
In March 2004 the NIH halted the estrogen-only portion of the WHI study because it found that after seven years of follow-up, estrogen alone does not appear to affect the risk of heart disease, yet it does appear to increase the risk of stroke. The researchers announced that one more year of study, as had been planned, likely would not change the results, and they had enough data to assess the overall risks and benefits of the use of estrogen; thus they stopped the study so as not to increase the risk of stroke in otherwise-healthy women. The increased risk of stroke in the estrogen-alone study is similar to what was found in the WHI study of estrogen plus progestin when that trial was stopped two years earlier. On the positive side, estrogen-only therapy has not increased the risk of breast cancer during the time period of the study, and it has been found to decrease the risk of hip fracture.
DOES DHEA SLOW OR REVERSE AGING?
Dehydroepiandrosterone (DHEA) is the most plentiful steroid hormone in the body. It is produced in the adrenal glands, brain, and skin; in the body it is converted into other hormones such as estrogen and testosterone (the primary female and male sex hormones, respectively) and other steroid hormones. DHEA levels may be measured using a blood test. The amount of DHEA in the body starts to decline gradually at about age thirty years; it is also reduced during periods of illness. Laboratory research (as opposed to research conducted on human subjects) reveals that low DHEA levels are linked to heart disease and certain cancers.
In view of these findings, some CAM practitioners favor supplementing DHEA for people who no longer have peak levels of the hormone. They claim that studies support the findings that DHEA replacement increases physical stamina, muscle mass, immune functions, and emotional well-being while simultaneously promoting weight loss and reducing bone loss from osteoporosis. Skeptics cite other studies showing that taking DHEA may cause excessive, unwanted hair growth; a reduction in high-density lipoprotein (HDL), the lipid that protects against heart disease; and resistance to insulin, the hormone involved in glucose metabolism. They caution that replacing any hormone that normally declines with advancing age is perilous, especially because some cancers, such as breast and prostate cancers, thrive in the presence of hormones.
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