Narrator:       This is Science Today. Osteoporosis is often viewed as an ‘old ladies' disease, since the majority of women today develop fragile bones after menopause. But Sabrina Agarwal, a biological anthropologist at the University of California, Berkeley has studied the skeletons of ancient populations and found that was not always the case. Part of the reason for their stronger bones she says, is the fact that in the past, women had more babies and breastfed them for longer periods of times. This seems to have strengthened their bones over time.

Agarwal:        None of us are going to suddenly have 10 babies again and have the ability to, in our cultural environment, to breastfeed them for three to four years. But the fact that the skeleton is more evolved in these conditions is something that I don't think we should ignore.

Narrator:       As a bioarcheologist, Agarwal says she is trying to understand how the skeleton forms through human evolution.

Agarwal:        Not saying that we should go back, but try to figure out what are these types of influences, not ignore them, but what are these influences and then if we really try to package them or make them into a pill, try to identify what they are.

Narrator:       For Science Today, I'm Larissa Branin.