There are lots of good reasons to try and follow a healthier diet. You lose weight. You feel good, but the main reason to live a longer, happy, productive life.

Sounds good, right? And though it may sound deceptively easy, the devil is in the details.

Welcome to the Nutrition Facts podcast. I'm your host, Dr. Michael Greger.

Today on Nutrition Facts, we continue our series on the efficacy of mammograms. As it turns out, for every life saved by mammography, as many as 2-10 women are over diagnosed and turned into breast cancer patients unnecessarily, along with all the attendant harms of chemo radiation or surgery without the benefits.

What was the impact of the 2009 shift in recommendations to delay routine screening to late 50?

Ironically, mammography rates of women in their 40s may have actually gone up. The thought is that all the media attention may have just reminded women about it, underscoring the need to better translate evidence into practice.

The new recommendations bring the US closer to European standards, mammograms of a few years starting at age 50. In 2015, the American Cancer Society split the difference in recommended starting at 45 annually than switching to every other year at 55, suggesting this would decrease the lifetime risk of dying from breast cancer from 2.7% down to under 2%.

Based in part on a systematic review performed by the Cochrane Collaboration, a highly respected bastion of evidence-based medicine.

The authors of the Cochrane Review, however, wrote in to say they use the wrong number, and that if you look at the studies they considered were adequately randomized, there did not appear to be any significant mortality benefit from mammograms at all.

And that the data certainly do not support the popular idea that breast cancer screening saves lives, accusing the American Cancer Society of being more of a political organization with financial ties to the multi-billion dollar mammogram industry.

The Cochrane Review they're talking about concluded that the studies which provided the most reliable information evidently showed the screening did not reduce breast cancer mortality.

If that's true, that changes everything. They conclude that the time is therefore come to reassess whether routine mammograms should be recommended for women of any age, which is what the Swiss medical board did.

They were struck by how non-obvious it was that the benefits of mammography screening outweighed the harms.

It's easy to promote mammography screening when the majority of women believe that a prevents or reduces the risk of getting breast cancer and saves in many lives through early detection of aggressive tumors.

I mean if those beliefs were valid, they'd be all for it.

Unfortunately, they concluded they are not.

And so believe that women need to be told so.

From an ethical perspective, a public health program that does not clearly produce more benefits in harm's and it's hard to justify.

Their report not surprisingly caused an uproar. Critics argue that the report unsettled women.

But we wonder how to avoid unsettling women given the available evidence.

If you ask women what they perceive to be the benefits of regular mammogram screening, they think it cuts the risk of dying from breast cancer in half.

First of all, the risk of dying from breast cancer regardless is smaller than most women think.

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