Effects of Soybean-germ Oil on Reducing Serum Cholesterol Levels in a Double-Blind Controlled Trial in Healthy Humans

Soybean-germ oil was extracted from hypocotyle enriched raw soybean and was found to contain 4 times as much plant sterol as soybean oil. Its capacity for cholesterol-lowering effects in humans was evaluated using a double-blind, controlled protocol. Forty-nine healthy male volunteers, average age 45 (SD11), with serum total cholesterol (TC) below 260 mg/dl, consumed test food everyday for 12 weeks. The test food was mayonnaise containing 11 g cooking oil. The test groups were i) 11 g Soybean-germ oil and ii) 11 g safflower oil group (Control group). In the sub-group of subjects with initial TC above 220 mg/day, serum TC in Soybean-germ oil group decreased significantly (4wk: p < 0.01, 8wk: p < 0.05) and it was lower than that in the Control group throughout the test period. This effect may be mainly due to the inhibiting cholesterol absorption of plant sterols contained in Soybean-germ oil. These results suggest that daily intake of Soybean-germ oil can be effective for maintaining normal serum cholesterol level in humans.