Docosahexaenoic acid(DHA) Highlighted as a cause of "becoming intelligent" from 5 years ago. Various functions such as improvement in visual acuity or anti-cancer activity have been demonstrated.

"Japanese children are intelligent because they diet on fish." ? A British nutritionist, Michael Crawford gave the opinion that the high I. Q. of Japanese children was due to a physiological function of Docosahexaenoic acid (DHA) contained in fish oil, which led to the immediate highlighting of DHA 5 years ago.

The processes of learning and memory are achieved by information communication between brain cells (neurones), which contain DHA at their tips. Therefore, a diet rich in fish will increase learning and memory abilities.

DHA, which is categorized as a highly unsaturated ω -3 fatty acid, is highly enriched in the eye sockets of fish such as the bonito and the bluefin tuna. It is also called an essential fatty acid because it cannot be produced by the body itself.

Besides improvement of learning ability, it has been found that DHA has the property of lowering cholesterol suppression and prevention of thrombosis. Recently, various functions such as activity against allergic tendencies, improved visual acuity and anti-cancer activity have been successively demonstrated.

Concerning the ability to improve visual sensation, Mr. Hiramitsu Suzuki, Chief of the Physiological Function Laboratory of the National Food Research Institute, has been investigating an experiment in which 27 males and females between the ages of 4 years and 22 years, were given bread containing 300mg of DHA daily. As a result, over one month, 11 participants showed an improvement in visual acuity of more than 0.2 degree.

DHA has been highly investigated not only in Japan but also in Europe, where fish are not a daily diet, and many studies have been reported one after the other. An epidemiological survey of physiological function by DHA and EPA reported that the Inuit in Greenland live on fish and they seldom suffer from circulatory diseases such as thrombosis. This role of DHA is supported by the latest study from researchers at Harvard University. This experiment was investigated on 2 millions and 551 male physicians between the ages of 40 and 84 years, and a 52% decrease was observed in sudden death among those who ate fish at least once a week. Researchers consider that these results are due to the effects of ω-3 highly unsaturated fatty acids in improving the blood circulation and prevent ischaemia in the heart. In addition, the effect of DHA against cancer has been gradually revealed. A research group at UCLA investigated a dietetic therapy in which 4,000 mg of fish oil was administered daily to breast cancer patients, leading to an apparent decrease in the risk of breast cancer.

Although many effects of fish oil with DHA have been demonstrated, recently, there is concern of a move "away from fish", especially among the younger generation in Japan. The role of DHA as a functional nutirent has been recognized by support from the Ministry of Agriculture, Forestry and Fisheries, and its application to food, such as an additive in powdered milk and sausages, is progressing nowadays. More extensive uses can be expected in future.