Do Slimmer, Younger Women Have More Breast Cancer?

Do Slimmer, Younger Women Have More Breast Cancer?

For some time now, the evidence has been pretty clear about obesity and breast cancer in older women. Obesity brings a 20-40% increase in breast cancer risk to women after menopause. But before menopause, the opposite is true. Now, new research provides a much clearer picture for younger women. A new study in JAMA Oncology tells us tells us that adiposity can bring a big reduction in breast cancer risk for women before menopause.

This observation is very consistent across the range of BMI. In the extreme, researchers found a four-fold difference in risk for women with a BMI less than 17 compared to those with a BMI over 35. Of course, a BMI less than 17 is unhealthy for many reasons beyond cancer risk.

Important for Understanding Breast Cancer

You might think these findings a bit confusing. Much has been made lately about obesity increasing the risk of cancer. And those facts remain true. NCI tells us that we have good evidence for 13 different kinds of cancer that are more common if you have obesity. For women after menopause, this includes breast cancer. And most of that cancer does indeed occur after menopause. So obesity is a lousy strategy for preventing cancer, even breast cancer.

But the real value of this research is to gain a better insight into the mechanisms of breast cancer and potential strategies for preventing it. Why does adiposity seem to have such a big effect on the risk? Answers to that question might bring better ways to prevent it, especially in younger women.

Disease – whether it’s cancer or obesity – is the enemy. And if we know the enemy better, we will be better able to defeat it.

Click here for the study, here and here for further perspective.

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July 1, 2018