I Didn’t Know That...

Q: Will some gelatin products really promote healthy joints and bones and strong fingernails?

A: Despite promotional promises, they won’t, according to both the UC Berkeley Wellness Letter and the Johns Hopkins Medical Letter. Some new products are the same old gelatin that has always been sold, with a little bit of calcium added. While it is true that gelatin contains certain amino acids, it does not contain those involved in forming nails and hair. The amino acids it does contain are manufactured plentifully by the body, and extra supplies will not build nails, hair or cartilage.

Clarification: Because of an arithmetic error, last week’s I Didn’t Know That . . . gave the wrong rotational speed for Earth’s surface. At the equator, Earth is moving at 17 miles per minute.