How to stop osteoarthritis; Ask Sam FOOD STANDARDS AGENCY.

Byline: Sam

Q Will cod liver oil protect me from getting osteoarthritis?

A For osteoarthritis, prevention is key. The best thing you can do is maintain a healthy weight by eating a varied and balanced diet and keeping physically active. The aim should be to eat a diet that is rich in starchy foods, such as wholegrain rice and bread, and moderate amounts of meat and dairy products, with at least five portions of a variety of fruit and vegetables every day.

It is also important to eat two portions of fish a week. One of these should be oily fish, such as salmon, mackerel or sardines. This may help people who suffer from rheumatoid arthritis because the fats found in oily fish may have an anti-inflammatory effect.

When someone has osteoarthritis, the smooth cartilage that takes the strain in a normal joint becomes rough, brittle and weak. To make up for this, the bone beneath thickens and spreads out, forming knobbly outgrowths. This causes stiffness and pain.

This form of arthritis is most common in older people and is very rare in people under the age of 40. Women are more likely to suffer from it than men, and people who are overweight or obese are more at risk from the disease, especially in their knees. Joints that have suffered injury are also more susceptible to osteoarthritis.

There has been research into the use of fish oil supplements in treating various forms of arthritis, although the focus is generally on rheumatoid arthritis as opposed to osteoarthritis.

Rheumatoid arthritis is caused by the body's immune system attacking the joints and causing inflammation.

Fats are involved in this inflammation and it is thought that those found in fish can affect the process and help reduce inflammation.

Some studies testing this theory on people with rheumatoid arthritis have shown benefits, while other studies have shown no benefit at all.

Research is continuing.

Some research suggests that having more than an average of 1.5mg per day of vitamin A over many years may affect our bones and make them more likely to fracture when we're older.

This is in addition to the risk of osteoporosis that older people, particularly women, face.

Fish liver oil supplements (as well as many multivitamins) are high in vitamin A. So if you take supplements containing vitamin A, make sure you don't have more than a total of 1.5mg per day from your food and supplements. If you eat liver or liver products such as pate every week, you should avoid taking any supplements that contain vitamin A, because liver is very rich in vitamin A.

Sam Montel is the Food Standards Agency's online nutrition expert and a registered public health nutritionist. She will be answering a different question about healthy eating every week. To find out more about food, visit the Food Standards Agency's website at www.eatwell.gov.uk