(P18-017-25) Egg Fractions Differentially Alter Clinical Immune Profiles in an Age-Dependent Manner

Objectives: We previously found that egg white vs. whole egg intake differentially alters HDL and immune profiles in a young healthy population. However, the isolated effects of egg yolks, and whether the effects of consuming different egg fractions are age-dependent, warrants further study given that HDL and immune function declines with age. Therefore, we investigated the effects of whole egg, egg white, and egg yolk intake on clinical cardiometabolic, HDL, and immune profiles in younger and older healthy adults.

Methods: Younger (18–30y; n = 18) and older (and 50–75y; n = 9) healthy men and women are participating in an ongoing 20-week randomized, crossover intervention trial. Participants consume 3 whole eggs/day, 3 egg whites/day, or 3 egg yolks/day for 4 weeks, with the first dietary phase preceded by a 2-week egg-free run-in period, and the subsequent egg diet phases separated by 3-week egg-free washout periods. Body composition measures and fasted blood samples are collected after the run-in (baseline) and each egg diet period to assess clinical predictors of cardiometabolic and infectious/inflammatory disease outcomes, including immune subset counts and neutrophil:lymphocyte (NLR) and neutrophil:HDL-cholesterol (HDL-C) ratios.

Results: Across egg diets, no changes were observed in body composition, serum lipids, or glucose levels in younger or older adults. Independent of age, % lymphocytes and % monocytes decreased following the egg yolk and whole egg periods, respectively, relative to the egg white period. While NLR was higher on average in the older group, diet-induced changes in NLR were only observed in the younger group, with NLR being higher after the egg yolk vs. the egg white periods. Trends toward decreased neutrophil:HDL-C ratios were observed following the egg white diet relative to baseline and egg yolk periods independent of age, whereas a trend toward decreased neutrophil:HDL-C ratios following the whole egg period was only observed in the younger group. Overall, a greater number of correlations between diet-induced changes in cardiometabolic and immune markers was observed in younger female participants.

Conclusions: These findings suggest that intake of different egg fractions may age-dependently alter clinical immune profiles.

Funding Sources: American Egg Board