Although women with obesity have higher bone mineral density compared to normal weight or overweight, they have more fragility fractures,” said Patricia Canto Cetina, researcher at the Obesity Research Unit of the School of Medicine of the National Autonomous University of Mexico (UNAM), based in National Institute of Medical Sciences and Nutrition Salvador Zubirán (INCMNSZ).

Obesity is associated with higher bone mineral density, according to the research. Canto Cetina explained that (according to a hypothesis) as the skeleton supports more weight, a mechanism is created to form more bone. Thus, it is postulated that adipocytes and osteoblasts (bone-forming cells) could interact to increase bone mineral density.

In a study carried out in Mexico City (doctoral thesis by David Rojano, under the direction of Canto Cetina) bone densitometry was performed on 750 postmenopausal women (no longer producing estrogen, so they stopped menstruating), selected in different first level clinics to identify normal, intermediate bone mineral density (called osteopenia, 57 percent of those over 50 suffer from it in the country) and severe (osteoporosis).

The study also included weight, height, number of children, lactation time, consumption of carbonated beverages, coffee and tobacco, and exercise-sedentary lifestyle.

Of the total, 179 women had normal bone mineral density, 338 had osteopenia and 233 osteoporosis. The latter were recommended follow medical treatment and change their lifestyle and exercise. “I order to prevent fragility fractures at any time in their lives,” said the researcher.

In another investigation with 813 women, when making the obesity-osteoporosis association the amount of bone in the spine, hip and femurs was measured, correlating the data with the normal body mass index, overweight and obesity (grade 1, 2 and 3). The results indicated that 15.13 percent were normal; 39.11 percent were overweight; 25.96 percent obesity grade 1; 11.81 percent, obesity grade 2; and 7.99 percent obesity grade 3.

Paradoxically, “in all cases, the higher the body mass index, the more bone mineral density they had,” Canto Cetina remarked.

Through a genetic screen to women with obesity to detect genetic markers associated with bone formation or faster bone loss, the researchers did not find a mechanism in that regard related to osteoporosis. “One assumption is that women with obesity have a loading mechanism. To the extent that they have more weight, that mechanism comes into operation so that more bone is formed.”