QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by César, T. B. Articles by Maranhão, R. C. Search for Related Content PubMed PubMed Citation Articles by César, T. B. Articles by Maranhão, R. C.

---

Nutrition and Disease

High Cholesterol Intake Modifies Chylomicron Metabolism in Normolipidemic Young Men¹

Thais B. César^*, Maria Rita M. Oliveira^*, Carlos H. Mesquita and Raul C. Maranhão^**,,2

^* Faculty of Pharmaceutical Sciences, São Paulo State University, Araraquara, São Paulo, Brazil; Energy and Nuclear Research Institute-CNEN/SP, São Paulo, Brazil; and ^** The Heart Institute of the Medical School Hospital and Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil

² To whom correspondence should be addressed. E-mail: ramarans{at}usp.br.

Whether the consumption of egg yolk, which has a very high cholesterol content without excess saturated fats, has deleterious effects on lipid metabolism is controversial. Absorbed dietary cholesterol enters the bloodstream as chylomicrons, but the effects of regular consumption of large amounts of cholesterol on the metabolism of this lipoprotein have not been explored even though the accumulation of chylomicron remnants is associated with coronary artery disease (CAD). We investigated the effects of high dietary cholesterol on chylomicron metabolism in normolipidemic, healthy young men. The plasma kinetics of a chylomicron-like emulsion, doubly-labeled with ¹⁴C-cholesteryl ester (¹⁴C-CE) and ³H-triolein (³H-TG) were assessed in 25 men (17–22 y old, BMI 24.1 ± 3.4 kg/m²). One group (n = 13) consumed 174 ± 41 mg cholesterol/d and no egg yolk. The other group (n = 12) consumed 3 whole eggs/d for a total cholesterol intake of 804 ± 40 mg/d. The nutritional composition of diets was the same for both groups, including total lipids and saturated fat, which comprised 25 and 7%, respectively, of energy intake. Serum LDL and HDL cholesterol and apoprotein B concentrations were higher in the group consuming the high-cholesterol diet (P < 0.05), but serum triacylglycerol, apo AI, and lipoprotein (a) did not differ between the 2 groups. The fractional clearance rate (FCR) of the ¹⁴C-CE emulsion, obtained by compartmental analysis, was 52% slower in the high-cholesterol than in the low-cholesterol group (P < 0.001); the ³H-TG FCR did not differ between the groups. Finally, we concluded that high cholesterol intakes increase the residence time of chylomicron remnants, as indicated by the ¹⁴C-CE kinetics, which may have undesirable effects related to the development of CAD.

KEY WORDS: • egg yolk • dietary cholesterol • chylomicron metabolism • lipid emulsion • young men