1. Promote heart health and lower the risk of heart disease
Meta-analysis published by Cambridge University in 2015 concludes that participants who consumed soy products show a significant reduction in the concentration of serum low-density lipoprotein (LDL) cholesterol and TAG (triglyceride). Furthermore, a significant increase in serum high-density lipoprotein (HDL) cholesterol concentration was also observed from participants taking soy product.
How does LDL cholesterol increase the risk of heart disease?LDL cholesterol, also known as the bad cholesterol, is a well-known risk factor for heart disease. Although our body does need cholesterol as a nutrient, high level of LDL cholesterol is often associated with a high risk of heart disease. This occurs because LDL cholesterol tends to form plaque and build up in the arteries’ wall (blood vessel that delivers oxygen to tissue). As a consequence, blood vessel is narrowed causing blood cannot flow through smoothly to deliver oxygen and essential nutrients to our organs. This process is known as atherosclerosis, which can result in heart attack or even heart failure when limited oxygen is transported to our heart. Hence, reducing the consumption of LDL cholesterol can aid in reducing the risk of heart disease.
How does HDL cholesterol reduce the risk of heart disease?HDL cholesterol is also known as the “good” cholesterol. It is “good” because it carries cholesterol away from our bloodstreams and toward liver. Then in the liver, cholesterol will then be removed from our bodies, thereby reducing serum cholesterol.
How triglyceride increase risk of heart disease?Triglyceride is the major type of fat stored in adipose tissue (fat tissue). It is normally used as an energy source when our body glucose level is low. Triglyceride together with and cholesterol in bloodstream can contribute to the hardening and narrowing of arteries through plaque formation (as mentioned above under LDL section). Therefore, high level of triglyceride is believed to increase risk of heart disease since it promotes atherosclerosis.
2. Obesity treatment and Weight loss
A study in 2019 indicated soy isoflavones, a natural active ingredient found high in soy, are able to suppress visceral fat synthesis, accelerate fat hydrolysis and promote AMP-activated protein kinase (AMPK) activity, which is a major regulator of lipid metabolism. Therefore, with the ability of regulating lipid homeostasis in visceral adipose tissue by preventing lipid accumulation, soy isoflavones are beneficial in the treatment of obesity and weight loss.
3. Improve bone strength, promote bone health and protect against osteoporosis
Apart from being a good source of calcium which is important for the healthy development of bone, soy is also high in isoflavones that is beneficial in treating osteoporosis. Post-menopausal women often have a higher risk of developing osteoporosis due to the reduction of estrogen hormone production that has a role in regulating bone growth. Consuming soy can help protect against osteoporosis because soy isoflavones from soy have similar structure and function as estrogen, hence being able to act as a “weak” estrogen to regulate bone growth and compensate the low production level of estrogen.
4. Reduce risk of type II Diabetes
Numbers of epidemiological studies have pointed out the correlation between increasing dietary soy isoflavones and lower risk of type II diabetes. It is suggested it is soy isoflavones that play a significant role in this effect, and it achieves this via improving tissue sensitivity to insulin and glucose tolerance, thereby reducing blood glucose level.
A study from the University of Massachusetts in 2009 identified soy isoflavones helps to improve insulin sensitivity and glucose tolerance by targeting key transcription factor that is responsible for glucose uptake and insulin sensitivity.
