Have you ever noticed that every month seems to bring a trendy new diet and yet obesity

rates continue to rise and with it a growing number of health problems?

That's why I wrote my new book How Not To Diet.

Check it out at your local public library.

Welcome to the Nutrition Facts Podcast.

I'm your host, Dr. Michael Greger.

Today we continue our series on vitamin supplements with a close look at

multivitamins.

Do we need them and what role do they play in heart disease, cancer and longevity?

About one in three Americans take some multivitamins.

Is that helpful, harmful or just harmless, always the money?

In 2011, the Iowa Women's Health Study reported that multivitamine use was

associated with a higher risk of total mortality, meaning in effect women who

took a multivitamine appeared to be paying to live shorter lives.

But this was an observational study, meaning they didn't split them up into two groups,

put half on a multivitamine and see who lived longer.

They just followed a large population of women over time and found that those who happened

to be taking multivitamins were more likely to die.

But maybe they were taking multivitamins because they were sick.

The researchers didn't find any evidence of that, but ideally what we'd have is a randomized

double blind placebo controlled trial, thousands of people fall for over a decade, half

given a multivitamine, half a placebo and see what happens.

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