Exercise in middle age linked to arthritis

Risk highest with high impact sports

Exercising too much in middle age may increase your risk of arthritis, new research suggests.

High impact exercise involving running and jumping may cause damage to a person's knees without them realising, and put them at risk of osteoarthritis later in life. "Our data suggest that people with higher physical activity levels may be at greater risk for developing knee abnormalities and, thus, at higher risk for developing osteoarthritis," said Dr. Christoph Stehling, from the University of California, San Francisco.

Osteoarthritis is a degenerative disease of the joints, leading to pain, stiffness and swelling. It is the most common cause of arthritis in the UK and affects approximately 8 million people. It is more common in women than men, and usually affects people over the age of 40. In the study, 236 men and women between the ages of 45 and 55 answered questionnaires about the amount of physical activity they did, and were then divided into low, medium and high activity groups. All were within a healthy weight range.

A person in the high activity group generally did several hours of walking, sports or other exercise a week as well as gardening and various types of housework. All the participants knees were then scanned using MRI, to look for any damage to the bones, cartilage and ligaments.

The researchers found the severity of knee damage was linked to activity levels and unrelated to the person's age or sex. "The prevalence of the knee abnormalities increased with the level of physical activity," Dr. Stehling said. "In addition, cartilage defects diagnosed in active people were more severe."

The findings also indicated that some activities carry a greater risk of knee damage over time. "This study and previous studies by our group suggest that high-impact, weight-bearing physical activity, such as running and jumping, may be worse for cartilage health," said Dr. Stehling.

"Conversely, low-impact activities, such as swimming and cycling, may protect diseased cartilage and prevent healthy cartilage from developing disease." He also added that more research should be carried out to compare the effect of low and high impact exercise on the risk of developing arthritis.

The Family GP