One of the most talked about foods in relation to health is the soybean; a little seed nestled inside of a hairy pod. It is packed with nutrients and is one of the few plant foods that contain all the essential amino acids of a complete protein crucial to sustaining human life. It is rich in omega-3 fats, polyunsaturated fat, B-vitamins, iron, zinc, antioxidants, phytochemicals and fiber. The soybean contains 40% protein and is considered an elegant rival to animal protein. It is highly valued source of protein for vegetarians. One cup of cooked soybeans provides half of the daily requirement of protein.
The other reason why soybeans have gained so much attention in the health community is their potential role in the prevention and control of disease, particularly cancer and heart disease. The idea partly came from observing other cultures around the world. For example, Asians who typically eat a diet rich in soy products, fish and fiber are known to have lower rates of breast cancer, high blood pressure and heart disease. Yet when they move and adopt a westernized diet stacked with meat and processed foods, their health profile is negatively impacted. This suggests that the health they enjoyed at home may not be due to genetics alone, but their diet as well.
This notion has set off a flurry of studies, thousands in fact, to see what health effects soy has on the human body. And what we have learned so far is soy can be a little two-faced: it can have conflicting positive and negative properties.
It's not clear why researchers are having trouble getting dependable findings. It could be inherent in the study; diet research is notoriously difficult to conduct and control. Or the fact that soy comes in many forms with varying components. Or the study population muddies the findings because people around the world have different personal and ethnic physiology.