Arthritis and diet: A new look

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Scientists reassess whether what you put on your plate can affect what happens in your joints

Can food defeat arthritis? Could a simple change in your diet ease the hurt? The answer used to be "No way!" Now, experts are thinking again.

It's long been known that nutrition played a big part in one type of arthritis, a painful disease called gout. Food prohibitions---no wine, beer, organ meats or anchovies--- are standard operating procedure for gout sufferers.

Firm evidence, though, just did not exist for food's role in the two major types of arthritis: rheumatoid arthritis (RA) and osteoarthritis. But now scientists have uncovered the first glimmer of evidence that in some cases, dietary changes might indeed make an impact on the pain and disability of these forms of arthritis. One way that researchers think food might affect arthritis is by tinkering with the inflammation process.

Inflammation flare-ups are common in RA and are bad news because flare-ups can destroy a little more of your joints, according to Arthur I. Grayzel, M.D., senior vice president for medical affairs for the Arthritis Foundation. So avoiding bad flare-ups may actually slow the progress of the disease.

In the latest of a series of small but well-controlled studies, researcher Joel Kremer, M.D., compared two different doses of fish oil to olive oil (a "neutral" agent) in 49 people with RA. (The fish oil contained eicosapentaenoic acid, or EPA, an omega-3 fatty acid prevalent in certain fatty fish.) After six months, signs of inflammation---pain, morning stiffness and fatigue---improved much more in people taking the fish-oil capsules than in those taking olive oil.

And the higher dose of fish oil gave the greater improvement, says Dr. Kremer, professor of medicine at Albany Medical College, New York (Arthritis and Rheumatism, June 1990).

Dr. Kremer's study is his fourth on fish oil. The beneficial effects of omega-3s in people with RA have also been seen by other researchers at Harvard Medical School and Royal Adelaide Hospital in Australia (Arthritis and Rheumatism, September 1987, and Journal of Rheumatology, October 1988).

Fish oil, a polyunsaturated fat, might help lessen inflammation, says Dr. Kremer, because it contains omega-3 fatty acids, instead of omega-6, which is abundant in other polyunsaturated fats. Your body turns omega-6 fatty acids (which are essential to health) into inflammatory chemicals called leukotrienes. Omega-3 fatty acids, on the other hand, serve as alternative building blocks for biochemical products that have far less inflammatory potential.

Research like Dr. Kremer's is complicated by the "here today, gone tomorrow" nature of arthritis flare-ups. They often go away spontaneously---and stay away for long periods. (When this happens right after arthritis sufferers try some new possible remedy, they may mistakenly conclude that the remedy was responsible for the improvement.) "So some of the research subjects naturally will get better on their own, and some will get worse on their own," says Dr. Kremer. "But because we put equal numbers of all types of patients into all three groups, spontaneous improvements should happen about equally in all three and shouldn't bias one group more than the others."

So far, fish-oil researchers have focused on RA. That's because osteoarthritis is not caused by inflammation, but by wearing away of cartilage---tough padding between the hard points of your bones. On the other hand, most doctors agree that osteoarthritic joints can get inflamed. The inflammation occurs when pieces of fractured cartilage break off and wedge themselves like splinters into joint linings. One small study from London did show that 26 people with osteoarthritis had less pain and freer movement after six months on fish oil (Lancet, August 26, 1989). But researchers feel that fish oil's real promise is in RA.

Experts caution, though, that fish oil will never cure arthritis. For one thing, it seems to block only one of several inflammation igniters. Dr. Grayzel says fish oil may be worth a try as a supplement to medication and range-of-motion exercises, but not as a substitute.

Eating more oily fish---as much as three to five times a week---is safer than taking capsules. (Best fish for omega-3s are salmon, tuna, halibut and sardines.) "We don't think there's any long-term danger with fish-oil capsules, but sometimes nature can fool you," says Dr. Grayzel. (Taking several spoonfuls of pure fish oil---like cod-liver oil---can be risky, too. Unlike fish-oil capsules, pure fish oil contains lots of vitamins A and D, which can be toxic in high doses.)

THE ALLERGY ANGLE
Is there such a thing as "allergic arthritis"---that is, inflammation that's triggered by certain foods?

One of the few researchers doing careful, systematic investigations into allergic arthritis started out as a skeptic. He's Richard Panush, M.D., professor and chairman of the department of medicine, St. Barnabas Medical Center, University of Medicine and Dentistry of New Jersey. He had a patient who insisted that her arthritis acted up whenever she had milk, meat or beans. This woman suffered from a number of sore, swollen joints and woke up each morning to a half hour of stiffness. Dr. Panush set out to determine whether she was right or wrong. First, he had her eat only a mixture containing the bare essentials of nutrition, without the alleged offending foods. After several days, her morning stiffness and joint pain disappeared.

Further evidence came when Dr. Panush gave her specially made, unmarked capsules of freeze-dried food to eat. Nothing happened after most food capsules. But after a couple capsules of freeze-dried milk powder (equivalent to an eight- ounce glass), her joints swelled and started to throb, and her morning stiffness returned full force. Her discomfort peaked 24 to 48 hours after popping the capsules. This sequence of taking milk capsules and then experiencing joint pain was repeated four times. When she was given blank capsules between these episodes, again nothing happened. Blood tests showed that her body carried milk antibodies, molecules that signal that an allergic reaction is going on (Arthritis and Rheumatism, February 1986). After these tests, she found that as long as she refrained from milk, she had no intense flare-ups.

Since then, 16 other patients who claimed a food-arthritis connection have undergone similar rigorous testing under Dr. Panush and colleagues. Neither the subjects nor the researchers knew who was trying which capsules at any given time. So far, Dr. Panush has uncovered three people who seem to show arthritic reactions to foods. The three include the milk case, plus a young man who reacted to shrimp, and an intensive-care nurse who reacted to nitrates, a food preservative (Journal of Rheumatology, no. 3, 1990). Subjects in Dr. Panush's experiments seem to be very special cases. Their arthritis is palindromic, which means it acts up now and then---sometimes quite severely--- and then does a vanishing act. Since their joints are perfectly normal most of the time, inflammation comes on like a four-alarm fire, making it easy to record. Panush says that if allergic arthritis is real, it may affect only those with palindromic arthritis, though he doesn't rule out the possibility that some nonpalindromic arthritis may be allergic. Regardless, Dr. Panush speculates that allergic arthritis could only affect a small minority---perhaps less than 5 percent of those with rheumatoidlike arthritis.

A string of clues---some definite, some suspected---make allergic arthritis feasible, says Frederic McDuffie, M.D., arthritis-center director, Piedmont Hospital, Atlanta, and former medical director of the Arthritis Foundation. First, some experts think rheumatoid arthritis allows your bowels to pass larger- than-normal food molecules through to your bloodstream. If king-size food molecules, like undigested milk protein, got into your blood, your body would take them for invaders and create antibodies to fight them. Antibodies might aggravate inflammation if they got into your joints---and we know arthritic joints let in troublemakers like inflammatory blood cells.

Experts caution that trying to identify a food allergy without a doctor's help can be risky. Even Dr. Panush said his patients were missing certain nutrients, like calcium, while he tested them.

Compared to fish-oil research, food-allergy--arthritis studies are more preliminary. And even if the evidence is borne out by larger, longer studies, only a small number of people are likely to be helped. But the potential benefit to those people is tremendous. "Here, you're looking at a cause that may be constantly aggravating arthritis," says Dr. Grayzel. "Maybe if you stopped that aggravation, you would slow down the arthritis. But so far, it's still too early to say."

DIET CHANGES TO MAKE TODAY
While research continues on fish oil and food allergies, there's some nutritional advice that's been proven to help people with arthritis. First: avoid obesity. David T. Felson, M.D., at the Boston University Medical School, has shown that being overweight can cause and aggravate osteoarthritis (Annals of Internal Medicine, July 1988, and American Journal of Epidemiology, July 1988). Dr. Felson is currently testing his theory that obesity causes fluctuating hormone levels that can lead to arthritis.

Keeping weight down can be especially helpful for those who feel at risk because of a family history of arthritis and those who are in the early stages of arthritis, says Dr. Felson. But beware: Moderate weight is best. Being "pencil thin" is a major risk factor for another "osteo." That's osteoporosis---the bodywide skeletal thinning that can be as disabling as arthritis.

Second, get more calcium (from dairy products, sardines and leafy green vegetables) and avoid alcohol---two steps proven to fight osteoporosis. Just having arthritis puts you at greater risk for osteoporosis for three reasons. Joint inflammation breaks down nearby bones; arthritis makes it hard to do bone-strengthening exercise; and corticosteroids often prescribed for arthritis can weaken your skeleton.

Third, keep your overall nutrition at its peak. This will help your body cope with the ups and downs of arthritis.

For more information on diet and arthritis, write to the Arthritis Foundation, P.O. Box 19000, Atlanta, GA 30326.

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By Gloria McVeigh

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