A new study from Japan provides additional evidence for the health benefits of a diet rich in fish oil and soy products. According to the report, men and women who consumed the highest levels of soy were least likely to die of any cause during the study. Omega-3 fatty acids found in fish oil and fatty fish such as salmon and mackerel were also associated with a lower risk of death among women, but not men. Fish and soy are staples of the diet in Japan, which has the highest reported life expectancy in the world, note researchers in a recent issue of the American Journal of Epidemiology. Numerous studies have demonstrated that dietary soy, which contains plant estrogens known as phytoestrogens, may inhibit some forms of cancer and lower the risk of heart disease. Fish oil is associated with reduced levels of inflammation in the body, reduced clotting and improved blood cholesterol levels. But the relationship between these compounds and longevity is not clear. To investigate, researchers from Gifu University in Japan reviewed food records of nearly 30,000 Japanese adults. About 2,000 died over the 7-year course of the study. An analysis of diet records revealed that adults who were in the top 25% based on their consumption of soy foods were less likely to die during the study than their peers who consumed the least soy. Omega-3 fatty acids were associated with a lower risk of dying from all causes among women but not among men. More research is needed on the relationship between these compounds and specific diseases such as cancer, stroke and heart disease, Dr. Chisato Nagata and colleagues conclude. SOURCE: American Journal of Epidemiology 2002;156:824-831.