Protein, fat, and phospholipids – more reasons to love eggs

By Jen Houchins PhD, RD

For only 70 calories, eggs provide 6 grams of high-quality protein, which is 12% Daily Value (% DV) on the Nutrition Facts label.  The % DV accounts for both the amount of protein and is adjusted for protein quality (eggs have the highest protein quality score).1 Almost 60% of the protein is found in the egg white, and more than 40% in the yolk.2 While people often choose eggs because of the high-quality protein, eggs are a complex nutrient-rich food that provides so much more.  New research is exploring how the different components of eggs may impact health.

Besides protein, large eggs have 4.75 grams of total fat, which is rounded to 5.0 grams on the label.  Eggs  primarily contain mono- and poly-unsaturated fat (2 grams, and 1 gram, respectively) and also contain 1.5 g saturated fat.  The 2015 DGA recommends that “Individuals should aim to shift food choices from those high in saturated fats to those high in polyunsaturated and monounsaturated fats,” and reduce saturated fats intake to less than 10 percent of calories per day.3   The fat composition of eggs is consistent with this recommendation. In fact, eggs “…only contribute about 2.5% of total saturated fatty acid intake among U.S. adults.4,5

Of additional interest to the Egg Nutrition Center are the components in eggs that don’t show up on the label.  For example, eggs are a bioavailable food source of lutein + zeaxanthin (252 mcg per large egg),2 and a source of phospholipids, which are components of all biological membranes (~1.3 g per large egg).4 Emerging research shows these dietary components can have a positive impact on health.6

A recent study in mice added 0.1% egg sphingomyelin (a class of phospholipid) into a high-fat, cholesterol-enriched diet and compared to a control diet.  After eight weeks, there was no difference found in serum lipids between groups, but the mice fed the sphingomyelin-enriched diet had less lipid accumulation in the connection between the heart and the aorta (aortic root).  These preliminary data indicate egg sphingomyelin may have the potential to help prevent atherosclerosis, however, further research in a clinical setting is needed to better understand the impact in humans.7

One of the Dietary Guidelines for Americans key recommendations is to include a variety of protein foods, including seafood, lean meats and poultry, eggs, legumes (beans and peas), nuts, seeds, and soy products.3   As part of the protein food group, eggs are an especially nutrient-dense choice that can help meet not only protein requirements, but also provide a mixture of fats, vitamins, minerals, and dietary components that are associated with health.  For more information on dietary components in eggs and the relationship to health, please see our recent public comments submission.

 Resources

  1. Schaafsma, G., The protein digestibility-corrected amino acid score. J Nutr, 2000. 130(7): p. 1865s-7s.
  2. U.S. Department of Agriculture and Agricultural Research Service. FoodData Central. 2019; Available from: https://fdc.nal.usda.gov/index.html.
  3. U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015-2020 Dietary Guidelines for Americans. 2015; 8:[Available from: http://health.gov/dietaryguidelines/2015/guidelines/].
  4. Blesso, C.N. and M.L. Fernandez, Dietary Cholesterol, Serum Lipids, and Heart Disease: Are Eggs Working for or Against You? Nutrients, 2018. 10(4).
  5. O’Neil, C.E., et al., Food sources of energy and nutrients among adults in the US: NHANES 2003-2006. Nutrients, 2012. 4(12): p. 2097-120.
  6. Blesso, C.N., Egg phospholipids and cardiovascular health. Nutrients, 2015. 7(4): p. 2731-47.
  7. Millar, C.L., et al., Dietary Egg Sphingomyelin Prevents Aortic Root Plaque Accumulation in Apolipoprotein-E Knockout Mice. Nutrients, 2019. 11(5).