The B’s have it – bursting the belly and bones myth

Posted by Liz on Dec 3, 2010 in bone health | 2 comments

When it comes to aging and women, bone health is a big deal. As I’ve written time and again on Flashfree, women are at a particularly high risk for bone loss as they age because of declining estrogen levels, and in turn, a reduced ability to prevent an increase in net bone resorption (i.e. bone loss due to the activity of bone cells). And while we’ve been told that excess body fat actually protects against bone loss, novel research is putting that myth to rest. This news may affect the millions of women who are considered obese based on their body mass index (BMI > 30), who, although at greater risk for heart disease, diabetes and joint disease, were at least believed to have a weapon against osteoporosis.

In a small study that was presented at this week’s Radiological Society of North America meeting, an assessment of the abdominal and total fat and bone mineral density of 50 premenopausal women of varying BMI showed surprising results. According to the lead researcher, Dr. Miriam Bredella, “the general consensus has been that increased body fat protects against bone loss and obese women are at decreased risk for developing osteoporosis. However, we found that visceral fat — the deep belly fat — makes bone weaker.” In fact, the researchers found that women with more belly fat had significant declines in their bone mineral density and increases in the degree of fat within their bone marrow, but that total body fat or fat existing right below the skin had little impact on bones.

An important challenge for women is not only that metabolism slows and the risk for obesity increases as we age, but also, a natural increased risk for redistribution of fat to the abdominal area. And unfortunately, it’s one of the most challenging areas to address, requiring significant increases in physical activity and decreases in caloric intake. Some data suggest that isoflavones might help reduce waist circumference as well, although they are hardly definitive at this point. Still, a word to the wise: that belly fat is not going to protect your bones. Time to start moving and eating correctly; your bones will thank you.