Most Americans limit their use of chopsticks to the occasional Chinese dinner. But used for all meals, the chosen eating utensils of 1.5 billion people worldwide can cause osteoarthritis, say researchers who X-rayed the hands of some 2,000 elderly Chinese living in Beijing. We spoke and exchanged e-mails with lead researcher David J. Hunter of the Boston University Arthritis Center about the study, published in the journal Arthritis and Rheumatism.

What is it about chopsticks that causes osteoarthritis?

We think the grip produces excessive pressure on the thumb joint and the pointer and middle fingers.

How likely is chopstick use to cause osteoarthritis?

Chopstick use accounted for 19 percent of the risk of developing osteoarthritis in the small joint in the thumb in men, and 36 percent in women. Among people over 65, about half will show signs of osteoarthritis in the hand they use to eat. About half of those will show symptoms, including stiffness and pain.

Your study found a clear link between chopstick use and hand osteoarthritis in women but not in men. Any thoughts about why?

Older women appear predisposed to the condition -- perhaps as a result of estrogen depletion at menopause. The fact that Chinese women, and not men, typically use chopsticks for food preparation as well as eating amplifies the risk.

-- Rita Zeidner