Egg Yolks: Are They Good or Bad for Cardiovascular Health?
Eggs have been enjoying a new status of a super food after some studies found it so, in spite of the fact that egg yolks have lot of cholesterol and so may affect blood cholesterol levels. Due to the reason that they have plenty of nutritional value, eggs have now made a comeback albeit their high cholesterol content, which gave them a bad rap earlier.
A newly published research led by Dr. David Spence found that in Canadians attending vascular prevention clinics, who also participated in the study, the regular consumption of egg yolks is about two-thirds as bad as smoking when it comes to increased build-up of carotid plaque, a risk factor for stroke and heart attack. The research is published online in the journal Atherosclerosis.
The researchers have found that with aging, plaque builds up gradually in the arteries and egg yolks make it build up faster, about two-thirds as much as smoking. In the long haul, egg yolks are not okay. Spence added that the effect of egg yolk consumption over time on increasing the amount of plaque in the arteries was independent of sex, blood cholesterol, blood pressure, smoking, body mass index and diabetes.
Formation of Plaque –
Atherosclerosis is hardening and narrowing of the arteries, which begins with the damage to the endothelium of the arteries, caused by high cholesterol in the blood, besides some other causes. This damage leads to formation of plaque. Plaque creates a bump on the artery wall. As atherosclerosis progresses, the bump gets bigger. When it gets big enough, it can create a blockage in the artery.
This is the usual cause of heartattacks, strokes and peripheral vascular disease, together called cardiovascular disease.
Undoubtedly, the findings of the above study will create confusion in the minds of many, especially those who have been enjoying eggs as a super food.
There are some studies, which show that eggs may even have anti-atherogenic properties. In particular, it has been suggested that eggs consumption may increase the size of low density lipoprotein (LDL) particles, making them less atherogenic. Moreover, they are also major dietary sources of lutein and zeaxanthin, two potent antioxidants, which may reduce LDL oxidation.
A study published in Nutrition Journal shows that egg consumption is found to be non-detrimental to endothelial function of the vessels and adults having elevated levels of lipids in the blood.
Before making any conclusion regarding if an individual should consume eggs in plenty, we will have to consider risk factors present in the individual that can boost one’s cholesterol level.
Three important risk factors for the development of high cholesterol that can’t be modified are gender, age and family history, whereas factors like diet, weight and physical activity or exercise are controllable.
An individual having the risk factors that can’t be controlled should avoid eating particularly egg yolks. People having risk factors like unhealthy diet, overweight and obesity, or physical inactivity should first control them before they begin to consume eggs. But, even after they begin to consume, they should keep a watch that their total consumption of saturated fat and cholesterol is not high.
In other words, regular consumption of egg yolk should be avoided by persons at risk of cardiovascular disease. In fact, more studies are needed to validate the above results in order to remove contradictions that exist due to conflicting results of some studies.
Atherosclerosis 224(2):469-73 · August 2012
Nutr J. 2010; 9: 28. Published online 2010 Jul 2. doi: 10.1186/1475-2891-9-28