Known for their protein and excellent nutritional value, eggs are one of the most popular animal products on the market. But, when talking about egg health, cholesterol is almost always associated with such conversations, in respect to their health woes. Besides their negative stigma, eggs are harshly misunderstood in terms of their health benefits. 

Each large egg includes 185 mg of cholesterol. The American Heart Association advises that 300 mg of cholesterol intake should be the limit per day. Thus, eating two eggs per day would significantly exceed the cholesterol intake limit. This recommendation, however, has been proven false by recent findings. Research has suggested that the cholesterol in food has little effect on blood levels of cholesterol in your body, both with regards to total cholesterol and LDL cholesterol. In a study conducted in 2006 at the University of Connecticut, it was proven that modest egg consumption, such as one egg a day, did not cause an increased risk for heart disease in healthy individuals.

Each day, your body makes between 1 and 2 grams of cholesterol. In other words, this equates to about 5-10 times the cholesterol content of one egg. When more cholesterol (in the diet) is consumed each day, the body makes less cholesterol on its own. The same holds true vice versa, as you consume less dietary cholesterol each day, your body will automatically produce more of it. This has been referred to as one of body’s thermostat mechanisms wherein it can regulate and control itself.

Surprisingly, cholesterol is one of the most essential nutrients in the body. It is present in the outer layers of every cell membrane and is essential for the production of various hormones, as well as necessary for growth in both infants and adults. 

For those individuals who have trouble regulating their total cholesterol and LDL cholesterol levels, egg yolks should be taken more sparingly, selecting egg whites instead. For diabetes patients, it has been shown that if one or more eggs are consumed each day, the risk for heart disease increases. According to the Harvard School of Public Health, those suffering from either heart disease or diabetes should limit their intake to at most 3 egg yolks a week. 

In a controlled trial conducted in 2013 at the University of Connecticut, participants were told to eat up to 3 eggs a day, whilst on a diet plan that focused on weight loss. The trial exhibited that participants experienced weight loss and less inflammation. Moreover, these individuals either sustained their current blood cholesterol level or the levels improved.

Cholesterol aside, egg yolks are an extremely nutrient-dense food source. Compared to egg whites, which are primarily composed of water and protein, egg yolks comprise 90% of the essential nutrients of the egg, such as calcium, phosphorus, zinc, iron, thiamine, folate, vitamins B6 and B12, and pantothenic acid. They also contain omega-3 fatty acids and fat-soluble components, like Vitamin A, D, and E. Egg yolks also contain choline, a crucial nutrient for brain and cardiovascular function.

It has been proven that increased intake of choline in the diet decreases inflammation, as well as decreases risk for heart disease, diabetes and Alzheimer’s disease. They also contain special antioxidants lutein and zeaxanthin, known for filtering damaging light wavelengths in the eyes, consequently decreasing the risk for macular degeneration. Despite the high cholesterol content, the egg nutrition appears to outweigh the risks. Nevertheless, it is important to know if you are at risk for these diseases, so that you are able to limit or control your intake of egg yolks, as necessary.

References: 

Eggs and Heart Disease [Internet]. [cited 2014 Oct 30]. Available from: http://www.hsph.harvard.edu/nutritionsource/eggs/

Fernandez ML. Dietary cholesterol provided by eggs and plasma lipoproteins in healthy populations.Curr Opin Clin Nutr Metab Care. 2006; 9:8-12. (http://www.ncbi.nlm.nih.gov/pubmed/16340654) 

Blesso CN, Andersen CJ, Barona J, Volek JS, Fernandez ML. Whole egg consumption improves lipoprotein profiles and insulin sensitivity to a greater extent than yolk-free egg substitute in individuals with metabolic syndrome. Metabolism. 2013. 62(3):400-10. (http://www.ncbi.nlm.nih.gov/pubmed/23021013)

Berardi, J. Eggs: Healthy or Not? [Internet]. 2013 July 16. [updated 2013 Sept 15; cited 2014 Oct 30]. Available From: http://www.huffingtonpost.com/john-berardi-phd/egss-and-health_b_3499583.html

Helpful Peer-Reviewed Medical Articles:

Sparks, N. H. C. (2006). The hen's egg–is its role in human nutrition changing?. World's Poultry Science Journal, 62(02), 308-315.

Weggemans, R. M., Zock, P. L., & Katan, M. B. (2001). Dietary cholesterol from eggs increases the ratio of total cholesterol to high-density lipoprotein cholesterol in humans: a meta-analysis. The American journal of clinical nutrition, 73(5), 885-891.

Applegate, E. (2000). Introduction: nutritional and functional roles of eggs in the diet. Journal of the American College of Nutrition, 19(sup5), 495S-498S.

Gilbert, L. C. (2000). The functional food trend: what’s next and what Americans think about eggs. Journal of the American College of Nutrition,19(sup5), 507S-512S.