Results of a study of people living in southern Greece suggest that eating hearty amounts of olive oil and cooked vegetables may reduce the risk of developing rheumatoid arthritis. Rheumatoid arthritis is a chronic inflammatory disease of the joints.

Its cause is unknown, but genes, infectious agents, hormones, and diet have been suggested as possible causes. Consumption of both cooked vegetables and olive oil was inversely... associated with risk of rheumatoid arthritis, meaning that individuals who had higher levels of these oils in their diets had a lower risk of developing rheumatoid arthritis.

The team did not find evidence that fish consumption reduced the risk. The investigators found that people who consumed the least olive oil were 2.5 times more likely to develop rheumatoid arthritis than those who consumed the most olive oil. Further, those who consumed the most cooked vegetables had a 75% lower risk of developing rheumatoid arthritis.

Although the mechanism by which these foods might lower the risk remains unclear, the authors suggest that antioxidant substances could play a role. Olive oil is rich in vitamin E, which has a beneficial biological role as (a free) radical quencher. Free radicals are molecules involved in several chronic diseases as well as aging. It is possible that heat destroys the cell walls of cooked vegetables, helping the body to absorb more of a potentially beneficial substance.

The typical American diet is rich certain types of fat that are broken down to hormones that promote inflammation. The fatty acid in olive oil, on the other hand, is broken down to hormones that inhibit inflammation.

American Journal of Clinical Nutrition December 1999;70:1077-1082

Dr. Mercola's Comments:

It is interesting to note that olive oil and vegetables appear to be associated with a decreased risk of a devastating chronic illness, rheumatoid arthritis. I suspect that they are also associated with a decreased risk of other chronic illnesses. I would disagree with the author's conclusions as to the mechanism of action. It is important to note that this is an observational study. They did not give some people raw vegetables and others cooked vegetables. I believe the observation of a decreased risk of RA in those who ate cooked vegetables is an artifact. Eating any vegetables--even cooked--is better than eating no vegetables. I do not believe it is directly related to antioxidant intake and would not recommend extra antioxidants. The benefit is from the food, not the supplements. I also suspect that those who ate extra olive oil consumed less of the damaging preprocessed foods that are high in trans fat. Olive oil is excellent oil, but I do not believe it has any particularly outstanding qualities that limit chronic illness. I suspect most of the improvement was a result of eating less of the other dangerous oils, and similar benefits could be obtained by using freshly ground seeds such as sesame, sunflower, pumpkin and flax as a source of oil. I believe they would even provide better benefits than olive oil, as they are less refined and fresher. You can use a $10 coffee grinder to grind the seeds. They should be freshly ground immediately prior to use to obtain the maximum benefit. Otherwise, the oxygen in the air will tend to quickly damage the highly perishable fatty acids in the seeds.