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Open Access Research

Effects of supplementing n-3 fatty acid enriched eggs and walnuts on cardiovascular disease risk markers in healthy free-living lacto-ovo-vegetarians: a randomized, crossover, free-living intervention study

Bonny Burns-Whitmore12, Ella Haddad1, Joan Sabaté1 and Sujatha Rajaram1*

Author Affiliations

1 Department of Nutrition, School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA

2 Department of Human Nutrition and Food Science, California State Polytechnic University, Pomona, 3801 West Temple Ave, Pomona, CA 91768, USA

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Nutrition Journal 2014, 13:29  doi:10.1186/1475-2891-13-29

Published: 27 March 2014

Abstract

Background

Plant and marine n-3 fatty acids (FA) may favorably modify select markers of cardiovascular disease risk. Whether supplementing the habitual diet of lacto-ovo-vegetarians (LOV) with walnuts (containing α-linolenic acid, ALA) and n-3 FA enriched eggs (containing primarily docosahexaenoic acid, DHA and ALA) would have equivalent effects on CVD risk factors is explored in this study.

Methods

In this study, 20 healthy free-living LOVs following their habitual diet were randomly assigned in a crossover design to receive one of three supplements: n-3 FA enriched egg (6/week), walnuts (28.4 g, 6/week) or a standard egg, 6/week (control) for 8 weeks each with 4-wk washout between treatments. Erythrocyte membrane fatty acids, serum lipids and inflammatory markers were measured at the end of each treatment.

Results

Dietary compliance was observed by an expected increase in erythrocyte membrane ALA following the walnut treatment and in DHA following the n-3 FA enriched egg treatment. Walnut treatment lowered serum triacylglycerol, total cholesterol and Apo B (p < 0.05) compared to the standard egg but not the n-3 FA enriched egg treatment. However, walnut treatment significantly reduced total: HDL cholesterol ratio compared to both egg treatments. There were no differences between treatments for any of the inflammatory markers.

Conclusions

For LOV, a direct source of DHA such as n-3 FA enriched eggs seems necessary to increase membrane levels of DHA. However for producing an overall favorable blood lipid profile, daily consumption of a handful of walnuts rich in ALA may be a preferred option for lacto-ovo vegetarian.

Keywords:
Walnuts; n-3 fatty acid enriched eggs; Lacto-ovo vegetarians; Cardiovascular risk factors; Eggs; Inflammation markers; Blood lipids