Search

To determine whether diets differing in fats affect cholesterol synthesis in normal individuals, nine men were randomly assigned to three groups that received three diets in a crossover design for 2 wk. Diets were either monounsaturated (MONO), polyunsaturated (POLY), or saturated (SAT). Subjects then drank a dose of deuterium oxide, and unesterified cholesterol fractional synthesis rates (FSR) were calculated during consecutive fed and unfed periods. Absolute synthesis was calculated as the product of FSR and pool size, the latter obtained from a decay curve following a [4-(14)C]cholesterol injection. Serum cholesterol concentrations varied with each diet consumed (P = 0.001); the SAT diet produced the highest and the POLY diet the lowest. Triglyceride concentrations were highest when subjects consumed the SAT diet and lowest with the POLY diet (P = 0.03); values obtained with the MONO diet did not differ significantly from those seen otherwise. HDL cholesterol concentrations were lowest when the SAT diet was consumed, highest when subjects were fed the MONO diet (P = 0.05), and midway but not significantly different with the POLY diet. Cholesterol FSR were greater when subjects consumed (P = 0.001) rather than not, and FSR during 12-h periods were greater (P = 0.045) when subjects ate the POLY diet rather than the SAT diet. Absolute synthesis was also greater (P = 0.04) when subjects were fed, but did not differ with fat type (P = 0.789). Results suggest that cholesterol synthesis is greater when men are fed than when they are not fed, and reduced synthesis is not responsible for the effect of different fats on cholesterol concentrations. [ABSTRACT FROM AUTHOR]

Purpose: University science students who have taken a nutrition course possess greater knowledge of fats than do those who have not; whether students apply this knowledge to their diet is unknown. We measured and compared science students' total and saturated fat intake in the first and fourth years, and evaluated whether taking a nutrition course influenced fat consumption., Methods: A sample of 269 first- and fourth-year science students at a small undergraduate university completed a survey with both demographic questions and a semi-quantitative food frequency questionnaire about fats in the diet. Data were analyzed using chi-square tests and independent-sample t-tests., Results: Fourth-year science students consumed fewer grams of total and saturated fat than did first-year science students (p<0.001). Science students who had taken a nutrition course consumed fewer grams of total and saturated fat than did those who had not (p<0.001)., Conclusions: Taking a nutrition course may decrease first-year students' fat consumption, which may improve diet quality and decrease the risk of chronic disease related to fat consumption.

Purpose: Students entering university often lack knowledge about fats; whether students gain such information during four years at university is unclear. Students' knowledge of fat in the first and fourth years was measured and compared. The effect of a nutrition course on knowledge was also examined., Methods: A total of 215 science students at a small undergraduate university completed a 15-item, closed-ended questionnaire concerning knowledge of fats in the diet., Results: Fourth-year science students have greater nutrition knowledge of fats than do first-year science students (p<0.005). Given that the majority of first-year students reside on campus and the majority of fourth-year students reside off campus, the purchasing of food and preparation of meals may explain the senior students' greater knowledge of fat. Students who have taken a nutrition course know more about fats than do those who have not (p<0.001)., Conclusions: Taking even one course in nutrition greatly increases nutrition knowledge. Universities could encourage undergraduate students to take a basic nutrition course, which should emphasize the identification and understanding of different types of dietary fats.

To determine whether the rates of cholesterol esterification in normal individuals are affected by diets differing in fats, nine men were randomly assigned to three groups receiving a diet rich in monounsaturated (MONO), polyunsaturated (POLY), or saturated (SAT) fat for 2 weeks using a crossover design. Subjects drank a dose of deuterium oxide, and the fractional esterification rate (FER) was calculated during fed and unfed periods. Total esterified cholesterol was calculated as the product of the FER and pool size, the latter obtained from a decay curve following injection of [4-14C]-cholesterol. The POLY diet produced the lowest serum cholesterol concentration and the SAT diet the highest (P < .001). For cholesterol ester (CE) deuterium enrichment, an interaction was noted between diet and time (P < .01). The FER was greater (P < .003) in subjects fed the POLY diet versus either of the other diets, although the amount of esterified cholesterol produced, expressed as either milligrams per day (P < .103) or milligrams per kilogram of body weight per day (P < .100), did not differ among groups. No effect of the feeding state was found for either the FER (P < .187) or total esterified cholesterol expressed as milligrams per day (P < .146) or milligrams per kilogram of body weight per day (P < .128). The results suggest that the diet fat type, but not the feeding state, may be responsible for serum esterified cholesterol concentrations.

Consumption of saturated fats contributes to elevated circulating cholesterol levels, whilst either polyunsaturated or monounsaturated fats are linked to depressed levels. Since elevated serum cholesterol is a risk factor for coronary heart disease, it is of interest to understand the factors responsible for the responses elicited by dietary fat quality. Changes in faecal sterol excretion, exogenous cholesterol absorption, lipoprotein composition, and lipoprotein catabolism can coincide with changes in fat intake but may not necessary cause them. Whether or not rates of whole-body cholesterol synthesis respond to dietary fat quality is not known. To date, animal studies suggest that shifts in LDL receptor-mediated cholesterol transport are to blame for responses of circulating cholesterol levels to dietary fat.