Date: May 1st, 2000
When it comes to taking care of our aging bodies, some things are obvious: exercise regularly, reduce fat intake, watch your cholesterol, get plenty of rest, and eat a well-balanced diet. But what exactly is a well-balanced diet? Do some vitamins and minerals really have anti-aging benefits? And if so, which ones should you be taking?
Research has indicated that supplementation of some vitamins and minerals above the RDA (Recommended Dietary Allowances) can reduce the risk of age-related disease. But there is still much controversy, even among the experts, about which ones work for whom, at what levels, and whether we should get them from food or supplements.
Most agree that getting the proper nutrients through diet is better, but the truth is, many of us don't eat a well-balanced diet. So what exactly should we be taking? Hopefully, ongoing research will provide some clearer answers soon. In the meantime, here are some generally agreed-upon tips from the experts about vitamins and minerals.
Remember, though, that guidelines are changing constantly. Even the Supplement Facts labels on the bottles - which began appearing in March 1999 - are often misleading and out-of-date. They also don't tell you about possible drug interactions, maximum safe dosages, and specific recommendations about who should and should not take the supplement.
Take a Cautious Approach
Until we know more about dietary supplements, many groups studying the issue recommend a cautious approach and rigorous self-education. These include the National Institutes of Health, the Food and Drug Administration, the National Academy of Sciences (NAS), the Federal Trade Commission, the Center for Science in the Public Interest, the U.S. Department of Health and Human Services, and even the Council for Responsible Nutrition (a Washington-based trade association representing more than 100 nutritional supplement companies). For example, the NAS emphasizes that there is no valid scientific evidence of any benefit to consuming more than the RDA of any nutrient. And John Hathcock, vice president of the Council for Responsible Nutrition, was quoted in a recent Wall Street Journal article saying, "I think that the consumer has got to read . . . and be inherently skeptical. No one should mistake [the supplement labels] with being up-to-date health advice."
Talk to Your Doctor
The most important safeguard you can follow is to check with your doctor to find out what is best for your particular medical condition. Vitamins and minerals can interact with certain medicines you may be taking, and high doses of nutrients can be particularly dangerous for some individuals. (For example, St. John's wort, an herbal supplement with antidepressive effects, has been linked to interactions with powerful protease inhibitors used to fight HIV infection, and organ rejection in two heart transplant patients taking the drug cyclosporin.)
Multivitamin pills: There is no evidence to suggest that supplementing your diet with a traditional daily multivitamin is harmful. Just don't use it as a substitute for healthy eating. Multivitamins are a simple and inexpensive way to ensure that you get at least a minimum level of nutrients. But beware of multivitamin formulas that pack in a lot of extra "botanical" ingredients such as gingko and ginseng. Not enough is known about the effects of botanicals, and they can increase the risk of drug interactions.
Beta-carotene: Numerous studies conducted during the past decade have demonstrated that a high intake of foods rich in beta-carotene reduces the risk of cancer. Beta-carotene is also thought to protect against cardiovascular disease and memory loss, but more research is needed to confirm that. It is best to get beta-carotene through diet as supplementation in high doses is still controversial - recent Finnish studies have shown that it may actually increase the risk of cancer in smokers. Good dietary sources are: yellow, orange and green leafy vegetables.
Folic acid: Absorption of this important nutrient decreases with age. The recommended daily intake is 400 mcg. High levels of folate and vitamin B6 have been shown to reduce the risk of heart disease in women. Good sources of folic acid (or folate) are: leafy vegetables, liver, yeast and some fruits.
Vitamin A: Older people should not take vitamin A supplements because they are at risk for vitamin A toxicity. Vitamin A is easily absorbed, tends to build up in the liver and produces toxins that are slow to clear out of the body. Symptoms of acute vitamin A toxicity are: headache, drowsiness, dizziness, irritability, nausea, vomiting and diarrhea. Symptoms of chronic toxicity include: skin disorders, disturbed hair growth, fatigue and an enlarged liver or spleen.
Vitamin B6: The recommended daily intake is 4 mg. Many older people are deficient in vitamin B6, which can affect the ability to fight disease and lead to increases in homocysteine, a risk factor for heart disease and stroke. Good dietary sources are: chicken, fish, kidney, liver, pork, eggs and, to a lesser extent, unmilled rice, soybeans, oats, whole wheat products, peanuts and walnuts.
Vitamin B12: The recommended daily intake for vitamin B12 is .01 mg. About one in 20 older adults suffers from vitamin B12 deficiency, a condition that is associated with anemia, neurologic disorders and other major health problems. Good food sources are red and organ meats.
Vitamin C: The recommended daily intake is at least 200 mg. Some researchers recommend daily doses up to 2000 mg, but doses higher than 1000 mg can cause kidney stones and chronic diarrhea in some people. Vitamin C deficiency is associated with poor wound healing, easy bruisability and scurvy. Recent evidence suggests that low blood levels of vitamin C are also associated with memory loss in older people, but this requires further research. Good dietary sources are: citrus fruits, berries, peppers, potatoes and tomatoes.
Vitamin E: Recommended daily dose is 200 to 400 international units. Vitamin E supplements are probably not needed, though. Good dietary sources are: common vegetable oils and the products made from them, margarine, shortening, wheat germ, nuts and green leafy vegetables.
Requirements for most minerals do not change with age, with the exception of iron and possibly calcium. Here are a few guidelines:
Calcium: The recommended daily intake of calcium is 1200 mg for men and 1500 for women. The usual diet of older people includes about half that, so calcium supplements should be taken if necessary to raise daily intake. Calcium helps retard age-related bone loss and prevent fractures. Good dietary sources are: dairy products, broccoli, kale, collards and calcium-fortified foods.
Iron: After menopause, women need less iron, although iron deficiency is common among older people. This is probably due to a poor diet and decreased absorption in the stomach and intestine. Unless an iron supplement is recommended by your doctor, stick to food sources, which are: meat, eggs, vegetables and fortified cereal.
Selenium: A mineral with antioxidant properties. Daily supplementation of 200 mcg per day has been associated with a 50 percent reduction in total mortality and significant reductions in the incidence of lung, colorectal and prostate cancer. Good food sources are: fish, especially tuna, asparagus, brazil nuts, meat, poultry and bread.
Despite all the media hype, experts say the only justifiable hormone intervention at this time is estrogen replacement therapy for some post-menopausal women - and that's only after a careful evaluation by a physician. Although there is substantial interest in the anti-aging effects of other hormones such as DHEA, melatonin, human growth hormone and testosterone, they are not recommended at this time. They may even be harmful.
Sites you can try:
- U.S. Department of Agriculture (USDA) Food and Nutrition Center. This site has information on the vitamins and minerals in your food. You can also download to information about vitamins, minerals and botanicals from USDA and other public and private sources.
- National Library of Medicine. This site has fact sheets on supplements.
- The Office of Dietary Supplements of the National Institutes of Health (NIH). This office recently joined forces with the Clinical Center at NIH to issue fact sheets on supplements.
- Nutrition Navigator. Developed by Tufts University and funded through a grant from Kraft Foods, this site collects nutrition information from throughout the Web and determines its scientific validity.