Assessment of plant sterols in diet: elaboration of a table and tools for diet analysis

Abstract

SummaryAmong chronic diseases, roughly half are attributed to cardiovascular diseases. Obesity and diabetes also present alarming tendencies, for both affecting great part of the population and for its early initiation. Lifestyle changes are recommended by the National Cholesterol Education Program (NCEP) and Adult Treatment Panel (ATP) III reinforce the consumption of vegetal foods, low consume of cholesterol and saturated fat. The universal recommendation for a greater intake of fibers and vegetables in the diet is of capital importance, as a way to reduce LDL-cholesterol (LDL-C). Clinical and experimental studies have demonstrated that phytosterol supplementation to the diet reduces plasma cholesterol, LDL-C and cardiovascular disease risk. Foods of vegetal source (fruits, legumes and lettuces) are good sources of minerals and bioactive components, such as phytosterols. In a comparative study analysing tables of foods source of phytosterols from different countries in Europe, the authors found that the amount of phytosterols (b-sitosterol, campesterol, stigmasterol) varied within the same vegetable depending on the region where it was produced. In spite of the recommendation for greater intake of phytosterols, the composition and quantity of phytosterols in food in natura, in processed foods and consumed foods in Brazil are not known. Therefore, the food tables are inaccurate to perform a proper nutritional evaluation. Objective: This study is aimed to analyse and measure common sources of phytosterols in vegetal foods, and design a table of composition of foods including phytosterol content. We also aim to use this tool to estimating the phytosterol intake in the usual diet of outpatients. Methods: We will evaluate the foods commonly consumed by Brazilian population according to the Research of Family Resources (RFR) 2002-2003. After sample preparation the amount of phytosterols will be analysed by gás chromatography (GC) and mass spectrometry (MS). Based on these results we will create a table of food composition and apply the food frequency questionnaire to 500 outpatients attended at the nutrition clinics. Expected results: This study is unique for the possible contribution to nutrition counseling in stablishing a link between phytosterols and the recommendation for a healthy diet. (AU)