Diet, exercise can ease impact of knee arthritis

Osteoarthritis of the knee is an increasingly common pain condition that can have a significant impact on a person's quality of life. Knee OA is a common cause of disability in the elderly and women are at increased risk. Disability from OA of the knee can be as debilitating as heart disease.

OA can develop when the cartilage in the knee begins to deteriorate or is lost. The bones become thicker and develop bone spurs. Over years, when the cartilage is gone, the leg bones rub against each other and wear away resulting in severe deformity and pain. Risk factors include excess weight (heavy women are four to five times more likely to develop knee OA), injury (especially sports-related injury), congenital deformities of the hip and knee, menopause, weaker leg muscles, and low levels of vitamins C and D.

In 2005, the cost of knee replacement surgery exceeded $11 billion. Over the next two decades, with an increase in age and obesity, there is a projected dramatic increase in knee OA and knee replacement surgery.

There are a number of medications that are effective in relieving the pain associated with OA. These medications do not change the underlying reasons for osteoarthritis and so the condition progresses. Also, a number of effective dietary supplements are available for the pain of OA, but it will still progress.

However, according to two medical studies, simple lifestyle changes — exercise and weight loss — can prevent and dramatically slow the progression of osteoarthritis.

The first study, Intensive Diet and Exercise enrolled 454 obese men and women who already had knee OA. They were randomized to three groups, diet only, exercise only and diet plus exercise. They were followed for 18 months. All three groups had pain reduction, but the diet and exercise group had a 50 percent reduction in pain with one-third of this group reporting little or no pain at all. Walking speed increased the most in the diet plus exercise group and this group also had the greatest reductions in blood markers of inflammation.

A Netherlands study suggests even minimal weight reduction can have a significant impact on the prevention of OA of the knee. In this study, 200 women were randomized to a diet plus exercise program or normal activity. Over two years, the diet plus exercise group lost, on average, only about 7 pounds. At the end of the study, 25 percent of the control group developed OA of the knee. In contrast, in the diet plus exercise group, only 19 percent developed OA.

Extrapolating these findings to knee replacement costs, a little exercise and weight loss could save almost $700 million per year. Considering the many medical benefits of weight loss and exercise, it would be much less expensive for the government and insurance companies to subsidize health club memberships for all adults than the eventual medical costs.

Ÿ Patrick B. Massey, M.D., Ph.D is medical director for complementary and alternative medicine for the Alexian Brothers Hospital Network. His website is www.alt-med.org.