1. The isoflavone (total) content of 1/2 cup of cooked dry soybeans is approximately 35 milligrams.

2. There is a huge body of literature focused on the cardiovascular benefits of omega-3 fatty acids. Several sources of information suggest that humans evolved on a diet with a ratio of omega-6 to omega-3 fatty acids of approximately 1:1, whereas today, this ratio is 10:1 to 20-25:1, suggesting that Western diets are "deficient" in omega-3 fatty acids. Omega-3 fatty acids have been shown to elicit numerous biological effects on the cardiovascular system, including modulation of prostaglandins, thromboxanes and leukotrienes (collectively known as "eicosanoids"), ability to lower cholesterol, antithrombotic effects, antiarrhythmic effects, and others. For review see A. P. Simopoulos, Omega-3 fatty acids in health and disease and in growth and development.
American Journal of Clinical Nutrition 1991: vol 54, pages 438-463.

The amount of omega-3 fatty acids for optimal cardiovascular benefits have not been firmly established. However, in 1990, the minister of National Health and Welfare in Canada released dietary guidelines for both omega-3 and omega-6 fatty acids based on energy levels in those ranging from birth to over 75 years. [See Scientific Review Committee. Nutrition Recommendations. Ottawa: Minister of National Health and Welfare, Canada, 1990 (H-49-42, 1990E).] These recommendations range from 0.5 grams/day (for infants up to four months) to 1.8 grams/day for men aged 16-18. If you are interested in a more detailed description of these recommendations, I'd be happy to send a fax to you, but they are also included in the Simopoulus paper.

In most studies examining the role of omega-3 fatty acids on cardiovascular health, fish oil has been used, NOT omega-3 fatty acids from soy. The amount of fish oil in these studies ranges from 0.5 grams to 25 grams per day. 100 grams of raw soybeans (or a little more than 1/2 cup, which is 93 grams) contains about 20 grams of fat, 8% of which (or about 1.5 grams) is omega-3 fatty acids.* Thus, according the Canadian guidelines, 1/2 cup of raw soybeans or 1 cup cooked should provide adequate omega-3 fatty acids.

*For cooked soybeans, 100 grams provides 9 grams of fat or 0.72 grams of omega-3 fatty acids.