Jones P J, Ntanios F Y, Raeini-Sarjaz M, Vanstone C A
School of Dietetics and Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Montreal.
Am J Clin Nutr. 1999 Jun;69(6):1144-50. doi: 10.1093/ajcn/69.6.1144.
Dietary plant sterols (phytosterols) have been shown to lower plasma lipid concentrations in animals and humans. However, the effect of phytosterol intake from tall oil on cholesterol and phytosterol metabolism has not been assessed in subjects fed precisely controlled diets.
Our objective was to examine the effects of sitostanol-containing phytosterols on plasma lipid and phytosterol concentrations and de novo cholesterol synthesis rate in the context of a controlled diet.
Thirty-two hypercholesterolemic men were fed either a diet of prepared foods alone or a diet containing 1.7 g phytosterols/d for 30 d in a parallel study design.
No overall effects of diet on total cholesterol concentrations were observed, although concentrations were lower with the phytosterol-enriched than with the control diet on day 30 (P < 0.05). LDL-cholesterol concentrations on day 30 had decreased by 8.9% (P < 0.01) and 24.4% (P < 0.001) with the control and phytosterol-enriched diets, respectively. HDL-cholesterol and triacylglycerol concentrations did not change significantly. Moreover, changes in circulating campesterol and beta-sitosterol concentrations were not significantly different between phytosterol-fed and control subjects. In addition, there were no significant differences in fractional (0.091 +/- 0.028 and 0.091 +/- 0.026 pool/d, respectively) or absolute (0.61 +/- 0.24 and 0.65 +/- 0.23 g/d, respectively) synthesis rates of cholesterol observed between control and phytosterol-fed subjects.
Addition of blended phytosterols to a prudent North American diet improved plasma LDL-cholesterol concentrations by mechanisms that did not result in significant changes in endogenous cholesterol synthesis in hypercholesterolemic men.
膳食植物甾醇已被证明可降低动物和人类的血浆脂质浓度。然而，在食用精确控制饮食的受试者中，妥尔油来源的植物甾醇摄入对胆固醇和植物甾醇代谢的影响尚未得到评估。
我们的目的是在控制饮食的情况下，研究含谷甾烷醇的植物甾醇对血浆脂质和植物甾醇浓度以及胆固醇从头合成速率的影响。
在一项平行研究设计中，32名高胆固醇血症男性被给予单独的预制食品饮食或含1.7 g植物甾醇/天的饮食，持续30天。
未观察到饮食对总胆固醇浓度的总体影响，尽管在第30天时，富含植物甾醇的饮食组的总胆固醇浓度低于对照组（P < 0.05）。对照组和富含植物甾醇的饮食组在第30天时，低密度脂蛋白胆固醇浓度分别下降了8.9%（P < 0.01）和24.4%（P < 0.001）。高密度脂蛋白胆固醇和三酰甘油浓度无显著变化。此外，食用植物甾醇的受试者和对照组受试者循环中的菜油甾醇和β-谷甾醇浓度变化无显著差异。另外，对照组和食用植物甾醇的受试者之间观察到的胆固醇分数合成率（分别为0.091±0.028和0.091±0.026池/天）或绝对合成率（分别为0.61±0.24和0.65±0.23 g/天）均无显著差异。
在北美谨慎饮食中添加混合植物甾醇可通过一些机制改善血浆低密度脂蛋白胆固醇浓度，这些机制不会导致高胆固醇血症男性内源性胆固醇合成发生显著变化。
