Cholesterol metabolism homeostasis is the result of a balance between synthesis, degradation and intestinal absorption. It is well established that intestinal cholesterol absorption efficiency can be modified by the intake of phytosterol-enriched food and, therefore, have a serum cholesterol-lowering effect. Recent epidemiological and clinical studies have shown that presence of phytosterols at normal diet levels could also be effective on lowering total and LDL serum cholesterol since they affect whole-body cholesterol metabolism even at those moderate doses. The aim of this study was to analyze the effect of the levels of the naturally-occurring phytosterols in the diet on cholesterol metabolism parameters. In order to do that a group of 99 healthy volunteers was studied for their dietary habits and surrogate markers of cholesterol synthesis and absorption. The mean daily dietary intake of phytosterols, measured by a food semiquantitative frequency questionnaire, was found to be 494 mg being β-sitosterol the major contributor to it. Subjects were classified into tertiles according to their total phytosterol intake and comparisons were done between subgroups. No statistical differences were observed for surrogate markers of intestinal cholesterol absorption, but a significant increase in the cholesterol synthesis surrogate marker lathosterol-to-cholesterol ratio associated to highest dietary phytosterol intake was observed. Regardless of this, only a non significant trend toward a less atherogenic lipid profile was observed in the upper tertile. In conclusion, the intake of moderate amounts of phytosterols naturally present in habitual diet may affect cholesterol metabolism and specially the rate of cholesterol synthesis as estimated by the surrogate marker lathosterol-to-cholesterol ratio in serum.

中文翻译：

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从习惯性饮食中适量摄入植物甾醇会影响胆固醇代谢。

胆固醇代谢稳态是合成、降解和肠道吸收之间平衡的结果。众所周知，肠道胆固醇吸收效率可以通过摄入富含植物甾醇的食物来改变，因此具有降低血清胆固醇的作用。最近的流行病学和临床研究表明，正常饮食水平的植物甾醇也可以有效降低血清总胆固醇和低密度脂蛋白胆固醇，因为即使在中等剂量下，它们也会影响全身胆固醇代谢。本研究的目的是分析饮食中天然存在的植物甾醇水平对胆固醇代谢参数的影响。为了做到这一点，研究了一组 99 名健康志愿者的饮食习惯和胆固醇合成和吸收的替代标志物。通过食物半定量频率问卷测量，植物甾醇的平均每日膳食摄入量为 494 毫克，其中 β-谷甾醇是其主要贡献者。根据他们的植物甾醇总摄入量将受试者分为三等分，并在亚组之间进行比较。没有观察到肠道胆固醇吸收的替代标志物的统计学差异，但观察到与最高膳食植物甾醇摄入量相关的胆固醇合成替代标志物 lathosterol-to-cholesterol 比率的显着增加。无论如何，在上三分位数中仅观察到致动脉粥样硬化脂质分布不显着的趋势。