Narrator: This is Science Today. In trying to identify why aging bones become more brittle, researchers at the Lawrence Berkeley National Laboratory discovered it's not necessarily associated with bone density. Robert Ritchie, who also serves as chairman of Material Sciences at the University of California , Berkeley , led the study.
Ritchie: With age, the mineral density diminishes. So, in essence, there's less bone there and that was considered to be the reason why you were more prone to fracture. That theory is known as bone quantity. And it's clearly the case; you do lose bone with age. But there's been studies of late which have tried to look at the risk of fracture in people with the same bone density, but of different age groups and they found that there was not a perfect correlation.
Narrator: Ritchie studied bone of all ages and found that changes in bone quality , or how the bone resists to formation and growth of cracks, are what lead to breaks.
Ritchie: So, it's not to say that bone density is unimportant, but there's something else going on there as well.
Narrator: For Science Today, I'm Larissa Branin.