Let’s Clear the Yolk’s Good Name

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Eggs have long been a source of debate among the nutrition community. Unfortunately, this debate has led to the egg yolk receiving a bad reputation for being too high in cholesterol to be a regular part of anyone’s diet – let alone those with existing high cholesterol. The egg white, on the other hand, has been praised for its high-protein contribution to a healthy diet.

A large egg has about 6 grams of protein, 40% of which is in the yolk. The protein in an egg is considered to be complete: it contains all of the essential amino acids. Because of this, eggs are used as the standard for measuring the protein quality of other foods and ingredients. The protein in eggs is easily digested and readily available so our bodies can utilize it very efficiently.

Although eggs are high in protein, the egg yolks are high in cholesterol. However, research shows little evidence of adverse effects of daily egg intake on cardiac risk factors for adults with coronary artery disease.1-2 As it turns out, dietary cholesterol does not impact our blood cholesterol the way physicians and dietitians once believed. It’s saturated fat—not dietary cholesterol—that has the greatest dietary impact on raising blood cholesterol.3 Other factors that influence high cholesterol are family history, age, gender, weight, physical activity, and stress.4

Egg yolks actually provide a host of nutritional benefits. Yolks contain vitamins B6 and B12, folic acid, pantothenic acid, thiamin and choline, as well as vitamins A, D, E and K. Egg yolks are one of the few foods that naturally contains vitamin D. Additionally, yolks provide the antioxidants lutein and zeaxanthin, and several trace minerals.5

Eat your yolks, folks!


References:

  1. Djoussé L, Gaziano JM. Egg consumption and risk of heart failure in the Physicians’ Health Study Circulation. 2008;117:512–516.
  2. McNamara DJ. The impact of egg limitations on coronary heart disease risk: do the numbers add up? J Am Coll Nutr. 2000;19:540S–548S.
  3. Hu FB, Stampfer MJ, Manson JE, et al. Dietary fat intake and the risk of coronary heart disease in women. N Engl J Med. 1997;20:1491–1499.
  4. National Institutes of Health, National Heart, Lung, and Blood Institute. Coronary heart disease risk factors. Version current 9 June 2015. Internet http://www.nhlbi.nih.gov/health/health-topics/topics/hd/atrisk (accessed 28 July 2015).
  5. Goodrow EF, Wilson TA, Houde SC, et al. Consumption of one egg per day increases serum lutein and zeaxanthin concentrations in older adults without altering serum lipid and lipoprotein cholesterol concentrations. J Nutr. 2006; 136:2519–2524.

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