RENEE MONTAGNE, HOST:
When it comes to promoting good health, a lot of us turn to multivitamins. More than 1 in 3 American adults, to be precise, are in the habit of taking a daily vitamin, even though we hear mixed messages on whether those little capsules really do any good. A new study sheds light on the potential benefits. NPR's food and health correspondent Allison Aubrey joined us to talk about it. Good morning.
ALLISON AUBREY, BYLINE: Hi there, Renee.
MONTAGNE: This study evaluated, I gather, the effect of taking multivitamins over a very long period of time. What did the researchers find?
AUBREY: So the new study's published in the "Journal Of Nutrition." It's really trying to get at whether taking a multivitamin might help cut the risk of death from heart disease. Now, as you might imagine, many factors influence the risk of disease - right? - everything from your diet, your exercise habits, whether you smoke. So to try to figure out the effect of any one factor is tough. But to try and disentangle this, researchers back in the early 1990s began studying a group of about 9,000 adults, all of whom were in their 40s or older. And the researchers went into the people's homes, interviewed them about a whole range of health habits, asked about diets, smoking. They also asked about multivitamin use and what they have found, 20 years later, is that women who'd been in the habit of taking a daily multivitamin with minerals for three years or longer had a lower risk of dying from heart disease. Interestingly, they did not see this benefit in men.
MONTAGNE: And what might explain the difference between men and women?
AUBREY: Well, it's unclear. And in fact, this is not the first study to show multivitamins don't lower the risk of death from heart disease in men. A large study of physicians came to the same conclusion. And so it's possible that for unknown reasons, women may benefit where men don't. But it's also possible that women who take multivitamins are more proactive in their health. So maybe what's being captured here is the result of healthy living, not just the result of taking a multivitamin. It's hard to suss out.
MONTAGNE: If researchers are not certain that multivitamins help cut the risk of heart disease, are there other reasons to take one?
AUBREY: Well, the answer to that question really depends on who you ask. On one hand, the U.S. Preventive Services Task Force - that's a panel of health experts that make evidence-based recommendations - says that there's insufficient evidence on vitamins. And some doctors say, hey, you know, it's a waste of money. There's evidence that taking more than the recommended amounts can be harmful. But what's clear is that this is still a very active area of research. The physicians' health study I mentioned, though it found no heart disease benefit, did find that multivitamin use was associated with reduced cancers and cataracts. So researchers are planning a follow-up study. And I'd say, in a way, the jury's still out.
MONTAGNE: What about overall health? Is there a case to be made that a multivitamin, say, might give us nutrients we miss out on if we don't eat enough fruits and vegetables?
AUBREY: Yes, I think there is a case to be made. In fact, I spoke to Jeffrey Blumberg at Tufts University. He's a senior scientist at the nutrition school there. And he says the argument in favor of taking a multivitamin is that it's a way to sort of plug the nutritional gaps in our diets. I mean, to put this in context, at a time when the government's official dietary advice is that we should all be filling half of our plates with fruits and vegetables, CDC data shows that on average, Americans only eat about one fruit and one vegetable a day. As a result, Blumberg points out, many Americans don't meet target intakes for vitamins. So his view is this.
JEFFREY BLUMBERG: Everybody should eat better. But if you're not, it's a very prudent thing for most people to choose to take a multivitamin.
AUBREY: And I'd say the bottom line is even if you are taking a multivitamin, you should still be trying to eat better as well.
MONTAGNE: All right. Allison, thanks.
AUBREY: Thank you, Renee.
MONTAGNE: NPR's food and health correspondent Allison Aubrey.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.