3-4 Egg Yolks per Day May Normalize Your Lipids, Reduce Liver & Abdominal Fat as Well as Your CVD & NAFLD Risk
Because of their cholesterol content, eggs have long been touted as a driver of heart disease. As a SuppVersity reader, you know that there are multiple reasons why the notion that the consumption of eggs, or rather egg yolks, would increase your cardiovascular disease risk: (a) there's no mechanistic "if your cholesterol is high, your CVD risk is also high"-link; (b) a causative link between the consumption of dietary cholesterol and serum cholesterol does not exist - at least not in the majority of people; (c) substances in egg yolks, in particular, have been shown to modulate the physical characteristics of your lipoproteins (learn more) and will thus lower, not increase your CVD risk.
Since you know all that, it may seem less important
Three whole eggs deliver the most effective "dose" of egg yolk to improve your blood lipid levels - more specifically: triglycerides ↓ and LDL ↓ but HDL ↑
Whole eggs are also an excellent source of dietary protein
Are You Protein Wheysting?
5x More Than the FDA Allows!
More Protein ≠
= Health Threat
More Protein =
More Liver Fat?
Ok, eventually, this preliminary study confirms the ability of egg yolks to reduce the blood lipid levels in rats, not men. Its results are yet in line with human studies (Fernandez. 2006) and case reports such as Fred Kern Jr's paper with the telling title "Normal plasma cholesterol in an 88-year-old man who eats 25 eggs a day", a paper that was published in the New England Journal of Medicine in 1991, a decade during which the number of people, let alone well-known scientists who questioned the detrimental health effects of cholesterol was low, if not zero.
Table 1: Fatty acid profile and cholesterol content of pork belly oil and egg yolk (% of total fatty acid | Park. 2016)
Today, people (including a handful of doctors and scientists 😉 acknowledge that the ingestion of eggs has been reported to lower, not increase blood cholesterol levels. In the absence of a mechanistic explanation for this phenomenon, however, large parts of the medical establishment still doubt that the anti-CVD and anti-cancer effects of eggs are driven by anything but their relatively high content of anti-oxidants. To identify the actual biochemical metabolic mechanisms by which the oral administration of egg yolk affects blood lipid reduction scientists from the Kangwon National University conducted a preliminary rodent study in which they observed similar reductions in 'bad' blood triglycerides and total cholesterol, as well as increases in 'good' high-density lipoprotein cholesterol as they were observed in the egg eating minority of human subjects in epidemiological studies.
Question: Do the eggs have to be raw? No, probably not. As you've learned in my often-cited article on oxysterols (~oxidized cholesterol), it may yet be a bad idea to eat hard-boiled eggs. Why's that? Learn more in this SuppVersity Classic: "True or False? Butter, Ghee, Lard & Tallow - Are Saturated Animals Fats the Kings and Queens of the Frying Pan?" | read it!
This alone may not sound exciting enough for yet another rodent study to make it into the SuppVersity news. What is exciting enough, though, is the fact that the study is the first study to include
The rats' food intake was examined every 3 days. Their body weight was measured once per week. Based on this data the so-called "diet efficiency" was calculated as the ratio of the diet intake to the daily average body weight gain (diet intake/body weight gain).
As you can see in Figure 1, the latter, i.e.
Beyond cholesterol: weight and body composition improve as well
Against that background, it is not really surprising that the animals "pork belly group" had also accumulated more abdominal and liver fat than those who were fed with egg yolk and ended up being a non-significant 10% leaner (as in having 10% lower abdominal fat masses) than their peers who received nothing but slightly salted water (saline placebo) on top of their std. rodent diet.
The actual news, however, are the health-relevant improvements in triglycerides, HDL-C and LDL-C as well as the reductions in the predictors of selected heart and liver disease, namely the atherogenic index (AI) and the levels of the transaminase enzymes ALT and AST you can see in Figure 3 - changes of which scientists have concluded in other studies that they are indicative of significant metabolic improvements with downstream beneficial effects on your heart and metabolic health; effects for which the study at hand is the first to provide a mechanistic explanation.
What's the latest on egg yolks: While egg yolk is more and more appreciated "as a source of valuable biologically active substances" (Zdrojewicz. 2016 | learn more in FFT), I am pretty sure that future studies will add to the increasing evidence of the health benefits of egg yolk consumption, such as the recently confirmed anti-NAFLD effects
The explanation revolves around the significant reduction in (compared to pork belly oil) or rather normalization (compared to control and pork belly oil) of HMG-CoA, the enzyme that's responsible for the endogenous production of cholesterol and the promotion of cholesterol excretion - two potential mechanism, of which Park and Park point out that they are "supported by previous reports that investigated blood lipid reduction in rats that ingested boiled egg and found an increase in LDL-C in the group given pork belly oil (Houston et al., 2011 )" and in line with the fact that "many studies have emphasised that there is no correlation between the amount of egg ingestion and blood cholesterol in humans (Herron et al., 2004; Greene et al., 2005)" as well as studies showing that "lecithin in the egg yolk lowers the level of blood cholesterol, as it is used for the formation of micelles in the small intestine or increases excretion through the reabsorption of cholesterol as bile acids (Yang et al., 2007; Alqasoumi, 2014)".
Figure 3: Atherogenic index (top, left), liver enzymes (transaminases ALT and AST | top, right) and lipid levels (triglycerides - TG; total cholesterol - TC; HDL; LDL | bottom | Park. 2016).
Eggs, cholesterol, CVD and the metabolic syndrome: With statin-like effects on HMG-CoA and their ability to reduce the uptake of dietary cholesterol from the diet, the small egg-shaped cholesterols bombs (eggs also contain sign. more cholesterol than pork-belly oil) come with everything it takes to keep their effect on your cholesterol levels neutral / beneficial.
In fact, the data from the study at hand indicates that the consumption of 3-4 eggs / day is heart healthy and can help you prevent the accumulation of fat in both, the midsection, as well as the subjacent liver. Two good reasons to eat more eggs, especially in view of the fact that the deposition of fat in the liver is supposedly the starting point for the development of diabetes, heart disease and a plethora of other pathological reasons to die prematurely. When you think about it, it would thus not even be hilarious if egg producers put the (non-FDA approved) claim that eggs "may reduce the risk of heart disease" on the boxes of their produce | Leave a comment on Facebook!
You as a SuppVersity reader know that eggs, or more specifically their yolks are nutrient dense superfoods that will improve the structure of your choles-terol molecules, leave your cholesterol levels unchanged and, as I have pointed out only recently in my article "Whole Eggs Can Boost Your Beta-Carotene and Vitamin E Uptake from Veggie Salad W/ Oil Dressing by 400%-700%", improve the absorption of fat-soluble vitamins sign. more than one would expect if the effect was a result of their fat content, alone | more!