Soy and heart health
Heart disease is a leading cause of death worldwide, accounting for one-third of all deaths. Studies have shown that a healthy diet, including a higher intake of plant protein, and a healthy lifestyle can reduce the incidence of heart disease. Many observational studies and meta-analyses have examined the relationship between increased soy consumption and heart disease. Asians have a much lower incidence of heart disease than North Americans, a difference that has been attributed to their high consumption of soy. Processed soy products, such as soy burgers and soy nuggets, can be high in sodium and added sugars, which can counteract any potential heart health benefits. It is best to choose whole soy foods, such as tempeh, natto, tofu, edamame, and soy milk, which are minimally processed and low in added sugars and sodium.A Chinese study examined the associations between soy intake and type 2 diabetes and cardiovascular disease. Using a meta-analysis of 1963 studies, they found that coronary heart disease and stroke were 17% and 13% lower, respectively, in participants with the highest soy consumption. This study concluded that soy consumption was negatively associated with the risk of coronary heart disease and stroke [1].
Lowers cholesterol
Studies have shown that consumption of soy protein can lower levels of bad cholesterol and increase levels of good cholesterol. This is likely due to the fact that soy protein is rich in compounds called isoflavones, which have been shown to inhibit the absorption of cholesterol in the intestines.Lowers blood pressure
Several studies have suggested that consumption of soy products may have a beneficial effect on blood pressure. This is likely due to the fact that soy is rich in peptides, which are small proteins that have been shown to have a relaxing effect on blood vessels. A meta-analysis concluded that soy consumption significantly improved systolic and diastolic blood pressure compared to controls [2].Improves endothelial function
Endothelial cells line blood vessels and play an important role in regulating blood flow and preventing blood clots from forming. Studies have suggested that consumption of soy products may help improve endothelial function, which in turn may help reduce the risk of heart disease. Isoflavones have antioxidant and anti-inflammatory effects and induce the production of nitric oxide to maintain a healthy endothelium [3]. Daily consumption of soy protein with isoflavones may result in beneficial vascular effects independent of lipid and antioxidant effects in healthy postmenopausal women [4].Reduces inflammation
Inflammation is a key factor in many chronic diseases, including heart disease. Studies have suggested that consumption of soy products may help reduce inflammation and protect against heart disease. A Chinese study examined the association between soy food intake and markers of inflammation in humans. They found that the inflammatory markers IL-6 and TNFα were inversely associated with soy food intake, with a difference between the highest and lowest quintiles of 25.5% for IL-6 and 14% for TNFα [5].References
[1] X Zuo et al. Soy Consumption and the Risk of Type 2 Diabetes and Cardiovascular Diseases: A Systematic Review and Meta-Analysis [2] Z Mosallanezhad et al. Complement Ther Med. 2021;59:102692. Soy intake is associated with lowering blood pressure in adults: A systematic review and meta-analysis of randomized double-blind placebo-controlled trials.[3] K Yamagata. Soy Isoflavones Inhibit Endothelial Cell Dysfunction and Prevent Cardiovascular Disease. J Cardiovasc Pharmacol 2019 Sep;74(3):201-209.
[4] F M Steinberg et al. Soy protein with isoflavones has favorable effects on endothelial function that are independent of lipid and antioxidant effects in healthy postmenopausal women. The American Journal of Clinical Nutrition, Volume 78, Issue 1, July 2003
[5] S H Wu et al. Soy Food Intake and Circulating Levels of Inflammatory Markers in Chinese Women. J Acad Nutr Diet. 2012 Jul; 112(7): 996–1004.