Is the unique combination of vitamins, carotenoids and phospholipids in egg yolks inflammatory protective?
Eggs are an example of a food that is naturally health promoting, despite containing a moderate amount of saturated fat, due to a combination of balancing bioactive components in the yolk.
Researchers at Ohio State University were interested in understanding various components of egg yolk with respect to an important inflammatory signal called NF-kappa B (NF-kB]. They presented research findings at the annual scientific sessions of the American Society for Nutrition [Shen, 2015].
In order to determine potential anti-inflammatory components, egg yolk was specially separated into two fractions 1) the polar-rich fractions of yolk and 2) the non-polar fractions. Although lower in fat, the polar-rich egg yolk still contained about 80% of the cholesterol and half of the triglyceride fat found in whole egg yolk.
The polar-rich yolk differed substantially from the non-polar egg yolk in that it retained much more cholesterol and triglyceride fat than the non-polar egg yolk, but it also retained the potentially bioactive vitamins and the carotenoids lutein/zeaxanthin.
In other words, although the non-polar egg yolk component was substantially reduced in cholesterol and triglyceride, it did so at the expense of losing fat-soluble vitamins and carotenoids with anti-inflammatory potential.
When the researchers measured the potential to reduce inflammation in pre-adipocyte (fat) cells, they found whole egg yolk to be neutral, but the lower-fat, carotenoid-rich polar yolk version to be anti-inflammatory. Although the non-polar fraction was much lower in fat, it showed no statistical effect on inflammation, likely due to the loss of lipid soluble vitamins and lutein/zeaxanthin.
They concluded that:
“partially delipidated EY-P [egg yolk-polar] fraction leads to the inhibition of NF-kB activation and its downstream inflammatory targets.”
NF-kB is a particularly important regulator of chronic inflammation, having been shown to impact inflammatory mediated central adiposity and type-2 diabetes [Harte, 2013].
Studies such as this by Shen et al. demonstrate that the final impact of specific foods on human health depends on the combination of nutrients and other bioactive components found naturally in food acting holistically.
Shen, Q, K Riedl, RM Cole, C Lehman, L Xu, H Alder, M Belury, SJ Schwartz, and O Ziouzenkova. “Egg yolks attain anti-inflammatory properties after partial delipidation.” Poster presented at: Experimental Biology, American Society for Nutrition Annual Scientific Session: 2015 April 29; Boston MA. This study was funded by grants from the American Egg Board.
Harte, AL, G Tripathi, MK Piya, TM Barber, JC Clapham, N Al-Daghri, D Al-Disi, W Kumsaiyai, P Saravanan, AE Fowler, JP O’Hare, S Kumar, and PG McTernan. “NF kappa B as a Potent Regulator of Inflammation in Human Adipose Tissue, Influenced by Depot, Adiposity, T2DM Status, and TNFa” Obesity 2013;21(11); 2322–2330.
Barbara Lyle, PhD, is President of B Lyle, Inc. a nutrition and innovation firm and blogger for the Egg Nutrition Center.
Views expressed by the author may not be those of the Egg Nutrition Center.
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