The joint's a rockin: keeping arthritis at bay

Nutrition Action Healthletter, June, 2003 by David Schardt

Sore, aching knees, hips, fingers, back. Pain after too much activity. Pain after too little.

Eventually, almost everyone gets osteoarthritis. Sometimes it's the result of decades of wear-and-tear on the shock-absorbing cartilage that prevents bone from rubbing against bone. Sometimes it starts sooner, after an injury to the knees or other joints. (Rheumatoid arthritis has similar symptoms, but it's an autoimmune disease that usually strikes younger people.)

"By the age of 70, nearly everyone has osteoarthritis, though not all suffer the symptoms," says Roland Moskowitz, professor of medicine and director of the Northeast Ohio Multipurpose Arthritis Center at Case Western Reserve University School of Medicine in Cleveland.

Can eating certain foods cause--or aggravate--osteoarthritis? At one time or another, soy, dairy products, potatoes, tomatoes, eggplant, and peppers have all been implicated. But there's no good evidence that they, or any other foods, have anything to do with arthritis. Even so, if you think something you're eating is making your joints ache, cut it out and see if you feel better.

Beyond food, "there are steps that everybody can take to try to prevent, or at least slow down, the onset and progression of osteoarthritis," says Moskowitz.

1. Control your weight. Do the math. "Every ten pounds of extra body weight puts 30 to 50 pounds of extra stress across the knee for every step you walk," Moskowitz points out. Most knees can't sustain that burden without something eventually giving way or wearing out.

It doesn't take much weight loss to have a big impact.

"In the Framingham Knee Osteoarthritis Study, overweight women who lost an average of 11 pounds over a ten-year period cut their risk of symptomatic osteoarthritis of the knees by more than half, compared with women who didn't lose weight," says rheumatologist David Felson, professor of medicine and public health at the Boston University School of Medicine. (1)

"If you already have osteoarthritis, being overweight will probably increase your symptoms," says Moskowitz. "But if you lose weight, we believe that you can keep the disease from progressing as much."

2. Avoid injury or too much stress on the joints. "Injuries to joints can lead to arthritis very early on, or they can increase the risk of developing arthritis later in life," says Lynn Millar, a physical therapy and exercise expert at Andrews University in Berrien Springs, Michigan.

"Even when you just sprain a joint, there's a trauma that occurs around, and sometimes within, the joint that seems to increase the potential for arthritis," she explains. "Breakdown in the cartilage can occur, and it progresses from there."

Warming up can minimize the risk of injury during physical activity. "It prepares the muscles to absorb the force of impact," says Millar. "Your chances of twisting something like an ankle are reduced if your body is warmed up and ready for activity."

You can also damage a joint during a repetitive activity like running if the joint isn't properly aligned, says Millar. If, for example, you favor one side of one foot when you jog, over time you can stress your ankle. "That can lead to arthritis if it's not corrected," she adds.

How can you tell if you're over-stressing a joint? "Many people will experience pain," says Millar. "But they ignore it, or try to treat it themselves with painkillers or little inserts for their shoes."

While you can't always avoid trauma to the joints, "you can make sure your joints are properly rehabilitated after an injury," says Millar. "Otherwise the problem may worsen and arthritis will become more likely.

"Proper rehabbing doesn't mean just waiting until the joint is no longer painful and then going back to your normal activity," she cautions. "It's making sure you strengthen the muscles around the joint and that you do some exercises that improve what we call its 'proprioception." That's the sensation that goes from the muscles back to the brain.

In other words, you've got to repeat the movement until, without thinking, you can do it in a way that minimizes the risk of re-injuring the joint.

Skip these steps, says Millar, and you could permanently damage the joint.

3. Maintain good muscle tone. "You want to make sure that the muscles are strong around any joint you're routinely putting stress on," says Millar. Researchers don't have solid proof that good muscle tone will delay arthritis, but they think it will.

"When the muscles around a joint are weak," she explains, "there's more force being transmitted through the joint."

For example, says Moskowitz, "keeping your quadriceps and hamstrings good and strong can slow down the onset or progression of osteoarthritis of the knee." The stronger the muscles in the front and back of the thighs, the greater the load they can take off the knee. (Moskowitz's advice assumes that your knee is properly aligned and stable. If it isn't, recent studies suggest that strengthening the thigh muscles could worsen your arthritis.)