Chopsticks may be bad to the bones

Chopsticks, with a history that dates 5,000 years, provide a simple and neat way to get small bites of food to your mouth. They also may contribute to arthritis in the fingers.

A study of 2,500 elderly residents of Beijing who had used chopsticks throughout a lifetime of eating and cooking has linked the mechanical stress of manipulating chopsticks with osteoarthritis of the thumb, index and middle fingers.

The condition, also known as degenerative arthritis, is the wearing away of the cartilage that cushions a joint, leaving bone to scrape against bone. In addition to pain and stiffness, it restricts the ability to extend and bend the fingers.

Researchers at the Boston University School of Medicine X-rayed participants’ hands looking for signs of arthritis, such as narrowing inside the joint space, worn-out cartilage and the formation of bony knobs at the ends of the joints. They also compared the hand that wielded chopsticks with the hand at rest during eating.

Men and women alike had an elevated risk of developing osteoarthritis in the thumb and middle finger of the hand they used for eating, the study found. Women had an additional risk of developing it in the index finger. Researchers haven’t quantified the stress that chopstick use places on the fingers, but they have determined its effects. Among women, the stress accounted for 36% of the likelihood of developing osteoarthritis in the small joint of the thumb; the figure was 25% among men, said lead researcher Dr. David J. Hunter.

Researchers asked about other hand activities, “including calligraphy, which is very common among Chinese, and did not find any risk associated with those activities,” Hunter said.

The findings were announced last month at the American College of Rheumatology Scientific Meeting in Orlando, Fla.