A recent study, published in The Journal of Nutrition, looked at nutrient and herbal supplement use in U.S. adults. The study surveyed over 3,400 people ages 60 and older between 2011 and 2014. “About 70 percent of respondents reported using at least one dietary supplement over the previous 30 days,” says study co-author Johanna Dwyer, DSc, RD, senior nutrition scientist with the Office of Dietary Supplements at the National Institutes of Health and director of the Frances Stern Nutrition Center at Tufts University. Older Americans may want to rethink this practice, however, since a growing number of studies have found that supplements may not have the intended health benefits. Additionally, more information is needed on potential interactions between supplements and prescription drugs.
Disappointing Outcomes: Vitamins, minerals, and other supplements have been touted over the years as a way to make up for nutritional deficiencies, prevent disease, and boost overall health. “Seventy-nine percent or more of survey respondents reported daily use of the most common products like multivitamin/mineral preparations, vitamin D, and omega-3 supplements,” says Dwyer. Unfortunately, these popular products and other supplements may not provide significant health benefits. “Early observational studies suggested we would see benefits from nutrient supplementation, but, unfortunately, many of those benefits have not been realized,” says Alice H. Lichtenstein, DSc, senior scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging and executive editor of Tufts Health & Nutrition Letter. Recently, a review published in the Journal of the American College of Cardiology reported that supplements generally showed no effect on either cardiovascular outcomes or death from any cause. Folic acid, which showed a modest statistically significant reduction in stroke and total cardiovascular disease, was the only exception reported in this study.
Sometimes widespread use of supplements is even associated with negative health effects. “Studies have found a small but significant increase in all-cause mortality in people taking high doses of vitamin E supplements,” says Lichtenstein. “And beta-carotene supplementation has been found to be associated with increased risk of cancer in smokers. These negative effects are not found when these nutrients are consumed in foods.”
That doesn’t mean that all supplement use is bad. “There are some cases where supplements are definitely valuable,” says Lichtenstein. “For example, as we get older, some of us have decreased capacity to absorb vitamin B12, so B12 supplements are important for avoiding pernicious anemia. And women of childbearing age may need extra iron or additional folate. A healthcare provider should decide if any supplements are appropriate on a patient-by-patient basis.”
Twenty-nine percent of the older adults surveyed reported taking more than four supplements a day. “We don’t see the issue as supplement use by itself,” says Jaime Gahche, MPH, a nutritional epidemiologist with the National Institutes of Health’s Office of Dietary Supplements and lead author of the study on supplement use in older adults. “The problem is the potential for overuse of dietary supplements, particularly when multiple products are being consumed, and in conjunction with prescription medications. This can increase the risk of consuming nutrients beyond what is recommended, and could increase the risk of drug-nutrient interactions.”
Supplements and Prescription Drugs: About 90% of older adults take prescription medications, and 39 percent take five or more, putting older Americans at special risk for any potential interactions between dietary supplements and prescription drugs. “We found that there was a high concurrent use of supplements with prescription and other medications,” says Gahche. “Those who reported three or more prescription medications were much more likely to be taking supplements than those who were not taking any prescription medications.” It is essential that patients tell their healthcare providers about any dietary supplements, including herbal and botanical preparations, they are using.
While it may seem like supplements are an insurance policy against poor nutrition, there is no substitute for a healthy dietary pattern. “It’s preferable to get one’s nutrients from food, rather than supplements,” says Lichtenstein. “Supplements won’t compensate for over-consuming sodium or under-consuming fruits and vegetables. You can’t pop a supplement on top of an unhealthy diet and expect better health.”