Omega-3 fatty acid rich eggs as an alternative to fish in the diet: effects on human platelet aggregation and plasma lipids

Abstract

Consumption of the omega-3 fatty acids indigenous to fish has been associated with decreased heart disease risk and improved neural tissue development in preterm infants. To increase the availability of these fatty acids, laying hen diets may be manipulated to increase yolk omega-3 fatty acid levels similar to those found in lean .fish. The current study investigated the usefulness of these enriched shell eggs for mediating the health affects associated with the omega-3 fatty acid consumption. Healthy male and female subjects (n=32) were assigned randomly to consume self-selected diets restricted in omega-3 fatty acids plus either regular (CON) or omega-3 enriched shell eggs (4/week), the latter from hens fed flaxseed (LNA, high in linolenic acid) or menhaden oil (DHA, high in docosahexaenoic acid). Subjects consumed all types for 6 weeks with a 4 week washout period between each for a total of 3 test periods. Plasma total cholesterol (TC) and triacylglycerol (TG) were determined enzymatically. Platelet aggregation was studied using collagen stimulated platelet-rich plasma preparations in 7 subjects per treatment. Percentage change for the above parameters was determined from day 0 to week 6 for each subject per period. Dietary intake was monitored using 3-day food records (2/period) by Nutrient Data System (University of Minnesota, 1994). Data were analyzed by analysis of variance using the general linear model procedure of SAS (SAS Institute, 1992). Nutrients did not vary between dietary treatments or test periods. Egg consumption resulted in no significant changes in TC. Subjects consuming DHA eggs exhibited 10% and 25% reductions in TG during periods 1 and 2, respectively; however, this effect was significant (P<.05) only during the second test period. LNA egg consumption resulted in a significant negative change in TG during Period 3 although a similar trend was observed in Period 1. Changes in platelet aggregation were consistent among treatments for all periods. CON eggs tended to increase aggregation while consumption of DHA eggs reduced (P<.04) platelet aggregation. These data indicate that omega-3 fatty acid-rich shell eggs may positively impact variables associated with cardiovascular disease risk, but that this effect varies with egg omega-3 fatty acid profile.