Author: Suzanne C. Ho et al
Publication: Journal of Nutrition. 2000;130:2590-2593
Recently a lot of literature showed the health benefits of soy. Consumption of soy and soy protein seems to improve the blood lipid profiles, reduce the severity of menopausal symptoms and could reduce the risk for breast and prostate cancer. Asians have lower mortality rates for breast cancer and heart disease and fewer menopause symptoms than Western people. Many studies suggest that this beneficial effect of soy is caused by the isoflavones. Studies have shown that Asian populations consume between 15 and 200 mg isoflavones daily. This study examined the relation of soy consumption with blood lipid concentrations in the Hong Kong Chinese population. A total of 1010 persons participated in this study. The average age of the participants was 46 years. The study population underwent a physical examination and a blood test and were interviewed about their diet. The following blood tests were done: LDL cholesterol, HDL cholesterol and total triglycerides. The questionnaire included following products: soybeans, canned soybeans, silk tofu, firm tofu, deep fried tofu, dried tofu, soymilk, bean curd skin and been curd sheet. About 88 percent of the participants had consumed soy products during the previous week. About 80 percent of the soy isoflavones were coming from the consumption of tofu and only 9 percent was obtained from soy milk. Soy products provided about 6 percent of the total protein intake.
The researchers found that in men the soy consumption and LDL cholesterol (= bad cholesterol) were negatively correlated. Men who eat more soy had a healthier plasma lipid profile. Soy isoflavones may have an estrogenic effect that lowers LDL cholesterol and increases HDL cholesterol.
The study showed that soy intake by the Hong Kong population has a moderate effect on the blood lipid profile. However compared to Japanese the Hong Kong people only eat about half the quantity of soy protein. The Hong Kong population should increase their soy intake by at least twofold in order to meet the recommendations of the China Nutrition Assacociation.