Narrator: This is Science Today. A new study suggests elderly women, who receive most of their dietary protein from animal, rather than vegetable products, are more likely to have bone loss and hip fractures. Dr. Deborah Sellmeyer, lead author of the University of California, San Francisco study, says one explanation for this may be the fact that animal protein is more acidic than vegetable protein.

Sellmeyer: As we get older - even if we're totally healthy - our kidneys just get less and less able to handle that acid. So the body turns to other sources to help handle that acid and one of the big sources is bone. Bone is made up of calcium, hooked up with what is known as base, which helps neutralize acid.

Narrator: And since vegetable proteins are very high in base, eating more may prevent the body from turning to the base-rich bones. But Sellmeyer says their study is by no means against animal protein.

Sellmeyer:The message is more to maintain a balanced diet and to realize that we should all just start working more fruits and vegetables into our diet.

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