One gram of fish oil a day could help reduce the pain of patients with osteoarthritis, a new study in Rheumatology reports.

In the largest, most up to date study of its kind, researchers from the University of Surrey examined the link between diet and the effective self-management of osteoarthritis. Analysing 68 previous studies in the field, researchers found that a low-dose supplement of fish oil (one and a half standard capsules) could result in pain reduction for patients with osteoarthritis and help improve their cardiovascular health. Essential fatty acids in fish oil reduce inflammation in joints, helping to alleviate pain.

Researchers also found that a reduction of weight for overweight and obese patients and the introduction of exercise tailored to mobility could also help ease the symptoms of osteoarthritis. Not only does obesity increase strain on joints, it can cause low-grade, systemic inflammation in the body aggravating the condition further.

A calorie restricted diet, combined with strengthening, flexibility and aerobic exercises, was identified as an effective approach in reducing pain in overweight patients.

There is no evidence that a calorie restricted diet does anything beneficial for lean patients with the condition.

Adopting a healthier lifestyle will also help reduce cholesterol levels in the blood -- high blood cholesterol is known to be associated with osteoarthritis.

An increase in foods rich in vitamin K such as kale, spinach and parsley was also found to deliver benefits to patients with osteoarthritis. Vitamin K is needed for vitamin-K-dependent (VKD) proteins, which are found in bone and cartilage. An inadequate intake of the vitamin adversely affects the working of the protein, affecting bone growth and repair and increasing the risk of osteoarthritis.

Margaret Rayman, Professor of Nutritional Medicine at the University of Surrey, said: "The importance of a good diet and regular exercise should never be underestimated. Not only does it keep us fit and healthy, but as we have learned from this study, it can also lessen painful symptoms of osteoarthritis.

"We are what we eat and it is important that we have the right amount of nutrients from our food to ensure that our body systems work as they should."

Ali Mobasheri, Professor of Musculoskeletal Physiology at the University of Surrey, said: "A combination of good diet and regular exercise are necessary to keep joints healthy; you can't have healthy joints with just one, you need both.

"Lifestyle should also be considered when attempting to reduce the pain of osteoarthritis. Patients can't expect miracles with dietary interventions if they are overweight and drink or smoke heavily. Evidence shows that smoking and heavy drinking negatively affects body energy metabolism and inflammatory markers in the liver which may promote inflammation and disease in the body."

Osteoarthritis is the most prevalent form of arthritis in the world with 18 per cent of women and 9.6 per cent of men aged 60 years and over being diagnosed with this painful condition. True numbers are likely to be higher than that as the global burden of osteoarthritis has been much under-estimated. By 2050 an estimated 130 million people will suffer with osteoarthritis placing a substantial burden on health services. Currently there is no effective treatment for this painful ailment, with only painkillers available to treat symptoms and no known cure.