DIET AND ARTHRITIS

By Shona Wallace

Until recently, the diet of people living with arthritis was not thought to affect their illness. However, in reality, what we eat plays a major role in the general health of all of us, and there is convincing scientific evidence that the food we eat could help diseases of the joints. Joints, which are at the spaces separating the ends of bones, are capsules filled with fluid. The ends of the bones are a rubbery tissue called cartilage. Arthritis happens when the normal processes going on in the joint go wrong. Here, I write about two different types of arthritis: osteoarthritis and rheumatoid arthritis.

In osteoarthritis, the breaking down and rebuilding of the joint cartilage leads to aching joints which become sorer with use. Researchers have not come to definite conclusions yet about the diet that is best for an osteoarthritis patient, but what follows are some of the possibilities raised by research in the last few years.

OBESITY

There is strong evidence that being very overweight (obesity) increases the chances of getting osteoarthritis, and that if you are overweight, losing weight improves the symptoms of osteoarthritis. Scientists believed this was because the large weight load strained the joints, but as obese people also develop more osteoarthritis of the hand than non-obese people, there may be a metabolic cause. The best way for a very overweight person to lose weight is to ask their GP for a consultation with a dietician. The important things are to cut down on fats and oils (they have the highest number of calories per gram of any food), avoid oily or sugary snack foods, and eat more vegetables, bread and cereals.

ANTIOXIDANT NUTRIENTS: VITAMIN C AND VITAMIN E

Osteoarthritis is more common in older people, and antioxidant nutrients are thought to protect against diseases of aging, so some scientists believe that eating plenty of vitamin C and vitamin E could lower our chances of getting osteoarthritis. This has not been scientifically proven, but some experiments on people who already have the disease have shown that vitamins C and E can reduce joint pain and reduce the risk of progression to a worse stage. Scientists do not yet know exactly why these vitamins can help osteoarthritis. They may mop up potentially damaging molecules called reactive oxygen species, which are produced in the joint. Also vitamin C seems to be needed for the building of new healthy cartilage, and vitamin E might act by reducing inflammation. To eat vitamin C, try fresh fruit, especially blackcurrants, strawberries and oranges. Also there is a lot of vitamin C in fruit juice, green leafy vegetables, and green peppers. Vitamin E is found in extra virgin olive oil, wheat germ oil and other vegetable oils.

VITAMIN D

Vitamin D is very important for bones, and recent research suggested that people with not enough vitamin D had worse progression of their osteoarthritis. This is probably because vitamin D is necessary for the health of the bones on either side of the diseased joint, but it is also possible that the vitamin may be used by the joint cartilage itself. We get most of our vitamin D from sunlight, but you can eat it in the form of cod liver oil, herring, kippers, sardines or tuna. Some margarine and milk is fortified with vitamin D. It tells you on the packet.

In rheumatoid arthritis joints become inflamed. It usually affects more than one joint, causing pain, swelling and stiffness in the mornings. There are other changes that affect the rest of the body also. The cause of rheumatoid arthritis is one of the big areas of research in medical science, but the effect of diet on the disease receives only a little attention from researchers.

FISH OILS AND PLANT OILS

Fish oils contain substances known as n-3 fatty acids. Most oils and fats in the modern Western diet contain a different kind of fatty acid called n-6 fatty acids. So a diet rich in oily fish like mackerel or tuna, or with a supplement of fish oil tablets, has a higher proportion of n-3 fatty acids compared to n-6 fatty acids. Experiments show that this reduces joint tenderness and swelling in rheumatoid arthritis. Oil from the evening primrose flower contains an n-6 fatty acid which also is thought to improve rheumatoid arthritis. You can buy this in the chemist. Flax seed oil is an alternative. It’s a good idea to talk to your doctor before starting to take oils as supplements.

GLUCOSAMINE/CHONDROITIN

These are commonly used because people believe that they can improve joint pain. The scientific evidence has never been conclusive, but since there are very few reports of adverse events people thought that it was reasonable to try them. However recent large-scale scientific studies of glucosamine and chondroitin failed to find evidence that they are of real benefit.

OVERALL DIET

Studies carried out in America on the health of people with rheumatoid arthritis, and comparisons with the rest of the population, showed that on average, rheumatoid arthritis patients eat too little vitamin B6, folic acid, zinc, copper and magnesium, and they generally eat too much fat and too little fibre. Also researchers found that the illness had made a quarter of the patients malnourished. So we can see that it’s very important for people with rheumatoid arthritis to pay attention to their whole diet, eating plenty of fruit and vegetables, bread and cereal, and possibly taking a vitamin and mineral supplement to give the right daily amounts of nutrients.

Although much of the research described here is quite new, and work is still going on to find ways that osteoarthritis and rheumatoid arthritis can be improved by changing diet, it has been known for some time that what we eat can make a big difference to our health. You can get more advice on eating a healthy diet from your doctor.


Diet and Arthritis © Shona Wallace. All Rights Reserved.