"Should We Take a Multivitamin?"
About 1 in 3 Americans takes a multivitamin.
Is that helpful, harmful, or just harmless... a waste of money?
in 2011, the Iowa Women's Health Study,
reported that multivitamin use was associated with
a higher risk of total moratality–
meaning, in effect, women who took a multivitamin
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 multivitamin 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?
Eh... the researchers didn't find any evidence of that,
but ideally what we'd have is a randomized, double-blind
super controlled trial with thousands of people
followed for over a decade
half given a multivitamin and half given a placebo
and see what happens.
And that's what we got the following year,
in 2012, the Harvard Physician Study II.
And after a decade...no effect
on heart attack, stroke, or mortality.
The accompanying editorial concluded
that multivitamins are a distraction
from effective cardiovascular disease prevention.
The message needs to remain simple and focused:
heart disease can be largely prevented
by healthy lifestyle changes.
They did, however, find that for men with a history of cancer
the multivitamin appeared to be protective against
getting cancer again, though there was no
significant difference in cancer mortality or cancer protection
in those who have never had cancer before.
Still, though, that's pretty exciting.
It is just one study though...
ideally we'd have, like, 20 of these
placebo-controlled trials, and then compile all the results together.
And that's what we got in 2013.
A meta-analysis of randomized controlled trials,
21 of them covering more than 90,000 individuals and....
no influence on mortality either way.
Some found more cancer mortality,
some found less cancer mortality,
but all in all, it was a wash.
And that was heralded as good news.
I mean, after the Iowa Women's Health Study
came out we were worried multivitamins could
be harming millions of people.
But instead they don't appear to have much effect either way.
The accompanying editorial asked, "Should meta-analyses
trump observational studies?"
I mean, Iowa Women's Health Study followed
tens of thousands of women for nearly 20 years.
Well, what if we put all the studies together,
The big observational studies along with
the experimental trials?
And that's what we got in December, 2013,
concluding that multivitamins appear to offer...
no consistent evidence of benefit
for heart disease, cancer, or living longer.
Why, though?
Aren't vitamins and minerals good for us?
One explanation for this result could be that
our bodies are so complex that the effects of supplementing
a few components is generally ineffective
or actually does harm.
Maybe we should get our nutrients
in the way nature intended.
The accompanying editorial concluded,
"Enough is Enough," we should stop wasting our money
on vitamin and mineral supplements.
Americans spend billions on such supplements.
A better investment in health would be...
eating more fruits and vegetables.
Imagine if we instead spent those billions
on healthy food!
This is not the aisle we should be getting our nutrients from.
With the money we save on pills
we can buy more of the best multivitamins on Earth.