10/12/2011 04:12 pm ET | Updated Oct 12, 2011

Exercise, Healthy Diet Tied To Early-Onset Menopause

Exercise is supposed to be a key to extended youthfulness, right? According to a recent Japanese study, that might not be the case. Women who spend a lot of time exercising and eating a heart-healthy diet may actually reach menopause earlier.

This counter-intuitive conclusion was reached after studying 3,115 premenopausal women over the course of 10 years. All of the women were between the ages of 35 and 56. During the decade that the study was going on, 1,790 of the women went through menopause. While the numbers aren’t surprising, the correlation between early menopause and what most would consider healthy lifestyle choices, was.

Women who exercised between eight and 10 hours each week were 17 percent more likely to enter menopause during the study period than women who consistently skipped the gym. The same held true (15 percent) for women who consumed foods high in polyunsaturated fats -- the type of fat found in many fish and vegetable oils. Other dietary choices -- including total fat consumed -- were found to be irrelevant when it looking at early onset menopause.

So what are the implications of this information? Although researchers have been quick to caution that these results do not prove direct causation, they may have something to say about cancer prevention. As JoAnn E. Manson, M.D., president of the North American Menopause Society explained to Fox News, both exercise and a diet high in polyunsaturated fats are lifestyle choices that minimize women’s exposure to high levels of estrogen. Higher levels of estrogen also mean a higher risk of developing breast cancer, which could explain why women who go through menopause later in life are also more likely to get these types of tumors.

However, don’t stop exercising and start binging on red meat just yet. As Manson told Fox News:

I wouldn't want women to be concerned that they would be at higher risk of cardiovascular disease or osteoporosis if they make lifestyle modifications. The benefits far outweigh any risks.

Living in a country where nearly one-third of all adults are considered obese and obesity rates have consistently increased over the last decade, too much exercise and too much healthy dieting are probably the least of our worries. Being severely overweight comes with its own set of health issues, exposing individuals to a higher risk of cardiovascular disease, Type 2 diabetes and certain types of cancer.

Exercise alone has been linked to numerous health benefits: reduced risk of depression, Type 2 diabetes and arthritis, as well as higher energy levels -- just to name a few. And interestingly, there has been a push within the cancer community to promote exercise for patients as a complementary treatment.

So while it’s great to take note of this study, there’s no need to respond with any drastic, lifestyle changes. Your evening yoga class is likely doing way more good than harm.