Should I avoid eggs because of their cholesterol content?
It’s a question I get asked a lot: “Should I avoid eggs because of their cholesterol content?” or: “How many eggs can I safely have in a week?”. It was once thought that eggs, because they contain some cholesterol, would negatively impact cholesterol levels and that they should be limited or avoided. Unfortunately this is quite an outdated opinion that has managed to stick in people’s minds and pass from generation to generation.
What a lot of people don’t realise is that dietary cholesterol actually has a very small impact on blood cholesterol levels. Because of this, dietary recommendations around the world no longer set a limit on dietary cholesterol consumption. It is saturated fat that is of major concern and influence. In saying that, some people are more sensitive to dietary cholesterol, those with something called an ApoE4 phenotype which significantly affects the metabolism of cholesterol [1,2].
The good news is that eggs are a wonderful little package of nutrition and will not impact cholesterol levels, even in those more sensitive. This has been thought for some time now and has recently been reconfirmed by a study conducted by the University of Eastern Finland and published in the American Journal of Clinical Nutrition. The Finnish population have a high prevalence of carriers of the apolipoprotein E type 4 allele- estimated at around one third of the population [1,2]. So this study was of particular interest to this group.
About the study
The study was conducted on 1,032 men that were aged between 42 and 60. Out of this number, 32.5% had the ApoE4 phenotype (those highly susceptible to dietary cholesterol). The participants were followed up after 21 years; at this time there had been 230 occurrences of Coronary Artery Disease (CAD) [2].
The findings were positive and showed two important outcomes:
1. There was no link between high intakes of dietary cholesterol OR having one egg a day (which provides a significant amount of cholesterol) and an increased risk of CAD. This was the same even for the participants with the ApoE4 phenotype [1,2].
2. There was no association between egg and dietary cholesterol intake with the thickening of carotid artery walls [1, 2].
This therefore suggests that a diet high in dietary cholesterol / frequent consumption of eggs will not impact blood cholesterol levels, even in those who carry the gene that makes them more vulnerable to the effects of dietary cholesterol on serum cholesterol levels [2].
As with any study, there will be limitations. For example, the study was only conducted on men and not women, and the highest intake of cholesterol was 520mg per day with an intake of one egg per day so the results cannot be generalised beyond this quantity. However, these results should be adequate to put people’s minds at ease when it comes to eggs and cholesterol levels.
Quick to blame cholesterol but what about fat?
Somehow dietary cholesterol always gets pinpointed and people tend to ignore saturated fats. We seem to be happy to avoid foods like eggs because of their cholesterol content yet they are highly nutritious. Then it comes to high fat foods, which we know increase cholesterol levels and can also be very nutrient poor, but we let them slide.
References
1. Virtanen J, Mursu J, Virtanen H, Folgelholm M, Salonen J, Koskinen T, Woutilainen S, Tuomainen T. Associations of egg and cholesterol intakes with carotid intima-media thickness and risk of incident coronary artery disease according to apolipoprotein E phenotype in men: the Kuopio Ischaemic Heart Disease Risk Factor Study. Am J Clin Nutr [Internet]. 2016 [Cited 2016 April 20]. Available from: http://ajcn.nutrition.org/
2. University of Eastern Finland. High-cholesterol diet, eating eggs do not increase risk of heart attack, not even in persons genetically predisposed [Internet]. Finland: University of Eastern Finland; 2016 Feb [Cited 2016 April 20]. Available from: https://www.uef.fi/en
