An Indian herb may ease knee pain and suffering.

THE QUESTION Might taking the herb Boswellia serrata, or frankincense, which is thought to have anti-inflammatory properties, relieve the pain of osteoarthritis?

THIS STUDY randomly assigned 75 people (average age 52) diagnosed with knee osteoarthritis to take one of two doses (100 or 250 milligrams) of an enriched frankincense extract (5-Loxin) or a placebo daily. After three months, based on standardized scales, people who'd taken frankincense reported less pain and joint stiffness and more mobility than at the start of the study, compared with those who'd taken the placebo. Among those taking the herb, improvement was noted as soon as a week after treatment started. The number of people experiencing such side effects as nausea and diarrhea was similar in all groups.

WHO MAY BE AFFECTED? People with knee osteoarthritis, a degenerative joint disease that occurs when cartilage that cushions a joint wears down, allowing bones to rub together. It most often affects the hip and knee. An estimated 27 million people in the United States have osteoarthritis, most of them middle-age or older.

CAVEATS The extract used in the study is enriched with an extra 30 percent of the most active ingredient in Indian frankincense; other preparations of the herb might not yield the same results.

LEARN MORE ABOUT osteoarthritis at http:orthoinfo.aaos.org (click "arthritis") and www.arthritis.org.

— The Washington Post