The foods you eat can affect the health of your joints, though not the way you might think.

Being overweight significantly increases your risk of developing osteoarthritis. “Other than that, the role that food plays in preventing arthritis is a ‘data-free zone,’” says Chad Deal, MD, a rheumatologist and head of the Center for Osteoporosis and Metabolic Bone Disease at the Cleveland Clinic.

Scale Back:
Being just 10 pounds overweight increases the force on your knees by 30 to 60 pounds with each step, Dr. Deal says. It may also speed up the rate at which cartilage breaks down in the knees. Being obese increases the risk of developing osteoarthritis in the knees by a whopping four times.

Maintaining a healthy weight, which means a body mass index (BMI) of less than 25, is one of the best things you can do to lower your risk of developing osteoarthritis or to slow its progression if you have it.

Diet Do’s and Don’ts:
Although no particular food is known to ward off osteoarthritis, certain foods may relieve the discomfort once you’re diagnosed. Foods rich in omega-3 fatty acid, especially salmon and tuna, can reduce inflammation. But avoid another omega fatty acid, omega-6, found in the corn, sunflower, safflower, soybean and cottonseed oils that are prevalent in snack foods. It can cause inflammation in joints, and these foods can also lead to weight gain.

MORE: How to Get Your Omega-3s (Not All From Fish!)

Try This:
If you need to lose weight and don’t have a regular exercise program, choose a time of day you know you can commit to (perhaps first thing in the morning or after dinner) and start walking for 30 minutes a day. If 30 straight minutes of walking is too much for you, break it into chunks throughout the day: 10 minutes in the morning, 10 at lunch, 10 after dinner.

If you have osteoarthritis, eat more fresh fruits and vegetables, especially brightly colored ones such as blueberries, red peppers and cantaloupe. They are rich in antioxidants, which protect your cells against damage and may decrease the activity of the hormone-like compounds COX1 and COX 2, which cause joint swelling and pain, according to the Arthritis Foundation.

Also, try eating nuts, sipping tea and — yes — indulging in a bit of chocolate. They all contain phytochemicals and antioxidants that may reduce inflammation.

Wonder Pills?
Chances are you know someone with osteoarthritis who swears by glucosamine and chondroitin. She probably says that ever since she started using the stuff she has been pain-free. Glucosamine and chondroitin are molecules in joint cartilage, so in theory replacing them should aid in repair. But the research is inconclusive at best. Dr. Hardin says that many studies, most of them controversial, have looked at the effects of glucosamine, chondroitin and other supplements on joint health. “The more rigorous the study, the fewer benefits we observe,” he says. “I don’t encourage my patients to use them because I just don’t know if they are cost effective.” 

On the other hand, the journal American Family Physician has concluded that glucosamine “significantly reduces pain.” The bottom line: Glucosamine doesn’t seem to be harmful, but, as Dr. Hardin says, “the jury is still out” on whether it really helps. Less research has been done on chondroitin, and the results are mixed.

What About Other Supplements?
Hundreds of studies of supplements thought to help the discomfort of osteoarthritis have been conducted. The most-studied supplements are methylsulfonylmethane, Harpagophytum procumbens (devil’s claw), Curcuma longa (turmeric) and Zingiber officinale (ginger). Still, there is not enough data proving their safety or their effectiveness for physicians to recommend them.

The supplement S-adenosylmethionine (SAMe) seems to help with pain, but according to American Family Physician, it may cause anxiety, headache and insomnia. If you’re interested in taking it or any other supplement, check with your health care provider. Supplements can interact with your other medications, prescription or over-the counter, to lessen their effectiveness or cause side effects.

by Dana Sullivan