Still, “there’s no substitute for preaching a healthy diet and good behaviors” such as exercise, Sesso cautioned.
As scientists debate, here are some questions and answers to consider in the vitamin aisle:
Q: Why the new focus on multivitamins?
A: Multivitamins have grown more popular in recent years as research showed that taking high doses of single supplements could be risky, such as beta-carotene.
Multivitamins typically contain no more than 100 percent of the daily recommended amount of various nutrients. They’re marketed as sort of a safety net for nutrition gaps; the industry’s Council for Responsible Nutrition says they’re taken largely for general wellness.
Q: What are the latest findings?
A: With Alzheimer’s on the rise as the population ages, Harvard researchers wondered if long-term multivitamin use might help keep older brains agile. They examined a subset of nearly 6,000 male doctors, age 65 or older, who were part of a larger study. The men were given either multivitamins or dummy pills, without knowing which they were taking.
After a decade of pill use, the vitamin-takers fared no better on memory or other cognitive tests, Sesso’s team reported Monday in the journal Annals of Internal Medicine.
Q: Did that Harvard study find any other benefit from multivitamins?
A: The results of the Physicians Health Study II have been mixed. Overall it enrolled about 15,000 health male doctors age 50 and older, and the vitamin-takers had a slightly lower risk of cancer — 8 percent. Diet and exercise are more protective. They also had a similarly lower risk of developing cataracts, common to aging eyes. But the vitamins had no effect the risk for heart disease or another eye condition, Sesso said.
Q: Might vitamins have a different effect on people who already have heart disease?
A: As part of a broader treatment study, a separate research team asked that question. They examined 1,700 heart attack survivors, mostly men, who were given either a special multivitamin containing higher-than-usual doses of 28 ingredients or dummy pills. But the vitamins didn’t reduce the chances of another heart attack, other cardiovascular problems, or death.