What you need to know about soybeans

Soybeans are used in a lot of food products lately. When you walk into a regular super market you will find soy milk and yoghurt, tofu, soy nuts, soy oil and lots of other products that contain soy. Much research has been done and thousands of articles have been written about the positives of soy. In this blogpost we try to summarize everything you need to know about soy.

What is soy?Soy beans

Soy is made out of soybeans. The US and Brazil are the two biggest producers of soybeans. The plant is classed as an oilseed rather than a pulse by the UN Food and Agriculture Organization. Soybeans occur in various sizes, and in many hull or seed coat colors, including black, brown, blue, yellow, green and mottled. The height of the plant varies from 1 to 6 ft.

What nutrients does soy contain?

Soybeans are considered to be a source of complete protein. A complete protein is one that contains significant amounts of all the essential amino acids that must be provided to the human body because of the body’s inability to synthesize them.
Soy also contains a lot of iron, manganese, phosphorus and several B vitamins.

What are the health benefits of soy?

Research has shown numerous of positive health benefits. Soy Proteins lower the LDL-cholesterol with 3 to 5 percent. Too high LDL-cholesterol can lead to an increased risk of cardiovascular disease.
A meta-analysis showed that breast cancer occurs less frequently when people have eaten more soy in their lives. Other research has shown that eating soy in your youth can reduce the risk of breast and prostate cancer at a later age.

How much soy do I have to eat?

It’s always good to have a certain amount of soy in your diet, but if you want to enjoy the health benefits as described above you need to eat or drink soy at least daily. All studies above are based on a high soy intake. It is advices to take around 25 grams of soy each day. So you might wonder what kinds of soy product you can eat on a daily basis.
Well beware that many soy products are processed; examples are meat substitutes and bars. This processed soy is usually fermented and contains probiotics. One of these probiotics is phytic acid, which makes for a reduction in the absorption of essential nutrients. The processed form of soy does not always have beneficial effects on health. Therefore, try to avoid processed soy products and choose products like tempeh, natto and miso. These authentic soy foods are not fermented, stimulate your digestive system and ensure better absorption of nutrients.

 

Sources:

[1] Sacks, F.M., Lichtenstein, A., Van Horn, L., Harris, W., Kris-Etherton, P., Winston, M. (2006). Soy protein, isoflavones, and cardiovascular health: an American Heart Association Science Advisory for professionals from the Nutrition Committee. Circulation. 113, 1034–44.
[2] Zhan, S., Ho, S.C.(2005). Meta-analysis of the effects of soy protein containing isoflavones on the lipid profile. Am J Clin Nutr., 81, 397–408.
[3] Wu, A.H., Yu, M.C., Tseng, C.C., Pike, M.C. (2008) . Epidemiology of soy exposures and breast cancer risk. Br J Cancer, 98, 9–14.
[4] Lee, S.A., Shu X.O., Li,H., Yang, G., Cai, H.,Wen, W., Ji,B.T., Gao, J.,Gao, Y.T., et al. (2009). Adolescent and adult soy food intake and breast cancer risk: results from the Shanghai Women’s Health Study. Am J Clin Nutr., 89, 1920–6
[5] Messina, M. (2010). Insights gained from 20 years of soy research. J. Nutr., 140 (12), 2289S-2295S