Mark Messina: Hello! I am Mark Messina. I am an Adjunct Associate Professor at Loma Linda University. And on behalf of The Soyfoods Council I will be outlining a few of the reasons why you should incorporate soy into your diet. First and foremost, soy foods are excellent sources of protein. There is a misunderstanding that because the soybean contains protease inhibitors, that soy protein is poorly digested. However, many studies clearly show that's not the case. Typically the digestibility of soy protein exceeds 90%. For this reason and because soy protein has an excellent amino acid profile, the quality of soy protein is comparable to the quality of animal protein. The first clinical studies demonstrating the high quality of soy protein were conducted in the 1980s at the Massachusetts Institute of Technology. Also, soy foods are very heart healthy. They have an excellent fatty acid profile. They are low in saturated fat and high in polyunsaturated fat, and they are one of the few good plant sources of both omega-6 and omega-3 fatty acids. Consequently, when soy foods replace more conventional sources of protein in Western diets, saturated fat intake is reduced. As a result blood cholesterol levels and risk of coronary heart disease are reduced. Also, soy protein directly lowers blood cholesterol levels. Furthermore, soy foods may reduce risk of heart disease independent of their effects on blood cholesterol. For example, there is evidence indicating that soy foods lower blood pressure and may directly improve the health of the coronary arteries. So even if your cholesterol levels are normal, soy foods can help to reduce the risk of coronary heart disease.
In addition, there is very intriguing evidence indicating that soy foods may reduce risk of cancer. For example, studies suggest consuming as little as one serving of a soy food per day when young may reduce breast cancer risk later in life by as much as 50%. In regard to prostate cancer, epidemiologic studies show that Asian men who consume about two servings of soy foods per day are about 50% less likely to have prostate cancer as are Asian men who consume very little soy. There is also very solid evidence based on 19 studies indicating that the plant estrogens in soy alleviate hot flashes. Most women can expect about a 50% reduction in hot flash severity and frequency. But men don't have to worry about the feminizing effects of soy because the plant estrogen in soybeans are very different form the hormone estrogen and the clinical research clearly shows that soy doesn't increase estrogen levels or decrease testosterone levels. So there are plenty of reasons why everyone should add soy to their diet. Try to find a few soy foods you enjoy and try to eat about two servings per day.