For years now, eggs have made new headlines every few months, with one study declaring their nutritional benefits and another implicating yolks as a potential cause of cardiovascular disease. Now, researchers say eating one whole egg a day (hold the ham) is just fine, and isn’t associated with an increased risk of coronary heart disease (CHD) or stroke. Egg-cellent.
What’s the Deal?
In the latest research, researchers reviewed a set of studies conducted between January 1966 and June 2012 Egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies. Rong, Y., Chen, L., Zhu, T., et al. Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China. BMJ 2013 Jan 7;346:e8539.. All the studies examined the link between egg consumption and the risk of CHD and stroke. Additionally, all studies were prospective, meaning they followed people throughout their lives and didn’t just look back at their egg-eating habits. It turns out, for non-diabetic people, there was no association between eating up to one egg a day and CHD or stroke. For diabetics, on the other hand, high egg consumption (up to one egg per day) was linked to an increased risk of heart disease, though the researchers say they didn’t look at enough studies of diabetic patients to draw any definite conclusions.
Is It Legit?
Possibly. The researchers really did their homework, and backed up their claims with a slew of reasons why eggs might not be linked to an increased risk for CHD or stroke. For one thing, some research suggests lowering the amounts of cholesterol in our diet by eating fewer eggs doesn’t actually decrease the risk of cardiovascular disease (CVD) Exploring the factors that affect blood cholesterol and heart disease risk: is dietary cholesterol as bad for you as history leads us to believe? Kanter, M.M., Kris-Etherton, P.M., Fernandez, M.L. Egg Nutrition Center, Park Ridge, IL, USA. Advances in Nutrition 2012 Sep 1;3(5):711-7.. Instead, eating a diet that’s overall low in saturated fat and cholesterol might be a better bet to help reduce the risk of CVD Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies. Clarke, R., Frost, C., Collins, R. Clinical Trial Service Unit, Radcliffe Infirmary, Oxford. BMJ 1997 Jan 11;314(7074):112-7.. The study authors also point out that eating eggs promotes the formation of larger LDL and HDL particles, which might actually protect against artherosclerosis Plasma LDL and HDL characteristics and caretenoid content are positively influenced by egg consumption in an elderly population. Greene, C.M., Waters, D., Clark, R.M., et al. Department of Nutritional Sciences, University of Connecticut, Storrs, CT. Nutrition and Metabolism 2006 Jan 6;3:6.. And there’s some evidence that eating protein-rich foods (such as eggs) instead of carbohydrates could lower the risk of CHD Effects of protein, monounsaturated fat, and carbohydrate intake on blood pressure and serum lipids: results of the OmniHeart randomized trial. Appel, L.J., Sacks, F.M., Carey, V.J., et al. Welch Center for Prevention, Epidemiology and Clinical Research, Division of General Internal Medicine, Johns Hopkins University School of Medicine, Baltimore, Md. JAMA 2005 Nov 16;294(19):2455-64.. Even the dose of vitamin D in eggs might help keep CVD at bay The role of vitamin D in cardiovascular disease: from present evidence to future perspectives. Brandenburg, V.M., Vervloet, M.G., Marx, N. Department of Cardiology, University Hospital RWTH Aachen, Aachen, Germany. Atherosclerosis 2012 Dec;225(2):253-63..
These findings support a range of other research suggesting that, in non-diabetic men and women, an egg a day isn’t associated with an increased risk of heart disease A prospective study of egg consumption and risk of cardiovascular disease in men and women. Hu, F.B., Stampfer, M.J., Rimm, E.B., et al. Department of Nutrition, Harvard School of Public Health, Boston, Mass. JAMA 1999 Apr 21;281(15):1387-94. Egg consumption and risk of cardiovascular disease in the SUN Project. Zazpe, I., Beunza, J.J., Bes-Rastrollo, M., et al. Department of Nutrition and Food Sciences, Physiology and Toxicology, University of Navarra, Spain. European Journal of Clinical Nutrition 2011 Jun;65(6):676-82.. It’s also worth noting that some of the recent research demonizing eggs suggests that egg consumption is only a problem for people already at risk for heart disease Egg yolk consumption and carotid plaque. Spence, J.D., Jenkins, D.J., Davignon, J. Stroke Prevention & Atherosclerosis Research Centre, Robarts Research Institute, London, Canada. Atherosclerosis 2012 Oct;224(2):469-73..
Of course, the study authors acknowledge that there could have been errors in the measurement of egg consumption and other eating habits. And there definitely needs to be more research on the effects of high egg consumption in diabetics and people at risk for heart disease.
Those who are concerned about their cholesterol intake might consider eating just the egg whites. For everyone else, the only question is: fried, poached, or sunny-side up?
Are you concerned that eating too many eggs is unhealthy? Does this research change your mind? Let us know in the comments below or tweet the author at @ShanaDLebowitz.