Abstract P423: Effects of Green Tea and Soy Isoflavones on Plasma Lipids In Healthy Subjects

Abstract

Introduction: Green tea and soy products are widely consumed in daily life and are considered to have beneficial effects on reducing cardiovascular risks. The flavonoids present in soya bean and tea leaves are believed to be responsible for the proposed benefits. Hypothesis: We assessed the hypothesis that epigallocatechin gallate (EGCG), the most abundant active component of green tea and soy isoflavonoids may reduce the plasma lipid levels in healthy volunteers. Methods: Healthy Chinese male subjects were given green tea extract containing EGCG 800 mg once daily for 14 days and soy isoflavones extract 80 mg once daily for 14 days with a wash-out of at least 4-weeks between the two treatments. Sitting blood pressure and fasting plasma lipids were measured at baseline, after green tea and after soy isoflavones, respectively. Results: In 18 healthy male subjects (mean age 26.6 ± 6.0 years, weight 61.7 ± 6.3 kg), consumption of green tea extract, but not soy isoflavones, was associated with significant reductions in plasma low-density lipoprotein cholesterol (LDL-C) (8.1% [95% confidence interval: -2.0, -14.3%], P<0.01) and total cholesterol (4.8 % [0.4,-10.1%], P<0.05) compared to baseline (Table 1). Reduction in LDL-C with green tea was observed in 15 out of 18 subjects and the change in LDL-C was not affected by the baseline levels. Neither product influenced the plasma high-density lipoprotein cholesterol (HDL-C) or triglyceride levels or blood pressure in this normotensive group of subjects (Table 1). Conclusion: This study showed that short term treatment with a high dose of green tea extract, which is equivalent to about 7-10 cups of green tea, reduced plasma LDL-C which may be beneficial for reducing cardiovascular risk.