The way most people think about eggs has changed over the decades, from a breakfast staple to suspected culprit behind the rising rates in cardiovascular disease. Of course this is due in large part to the fact that eggs are high in dietary cholesterol and that consuming eggs would increase blood serum cholesterol. The reality is dietary cholesterol and serum cholesterol are two different things. The body actually manufactures serum cholesterol because it is integral to many important functions, such as a necessary substrate for the creation of cell membranes, a precursor for hormone production, and vitamin D synthesis—just to name a few. Any excess cholesterol that the body doesn’t need is packaged with bile in the liver and then excreted through the intestines. Studies have shown that dietary cholesterol in foods has little long term affect on serum cholesterol levels for the majority of people.1
This misinformation has led to an explosion of egg white this-or-that foods, where the yolks are completely discarded. What a waste! While the white albumen does contain the bulk of of an egg's protein, most of the nutritional benefit is in the yolk. If you're interested in minimizing risk for chronic diseases and supporting a healthy aging process, you need to know about these nutrients.
The whole egg is one of the best sources of choline, an important nutrient converted into the neurotransmitter acetylcholine. Acetylcholine is responsible for supporting good brain function, including cognitive ability and memory as we age, keeping a good mood balance so we don't experience extreme emotional highs and lows, as well as managing muscle control signaling. A single egg has about 25% of our Daily Value (DV) requirement for choline. Only beef liver has more!
You may have heard of biotin, a member of the B-vitamin family that is most known for its use in preventing aging skin and hair loss. Eggs contain about 1/3 of our DV for biotin—about the same as liver. Biotin is a cofactor needed by the digestive system to break down proteins, carbohydrates and fats that can then be used as the building blocks for hair, skin and nails. A note of caution here about eating raw egg whites, though. The whites contain a protein called avidin that in its raw form binds with biotin, making it unavailable for absorption in the intestines. So only raw egg yolk smoothies! Cooking the white denatures this protein and allows its absorption. B-vitamins work together synergistically so it’s not advisable to supplement with biotin alone, but rather obtain it from whole foods or a food-based B-complex supplement.
Another vitamin that should be on everyone’s radar, particularly those who want to minimize risk of cardiovascular disease and improve bone health is vitamin K2. This tiny-but-mighty vitamin is responsible for transporting calcium to bones for storage, thus removing it from circulating in the bloodstream where it can cause plaque build up in our arteries. Egg yolks are a rich source of vitamin K2, second only to natto (Japanese fermented soybeans) and goose liver. Buying pasture-raised eggs from chickens allowed to graze on small insects and grasses is the best way to get the greatest amount of K2 in your eggs. Look for a yolks with a deep yellow or even orange color.
There are certainly more types of eggs in the market these days, but don’t be lured by words like “natural,” “cage-free” or “high omega-3” on the carton. Instead, look for the “Certified Human Raised and Handled” or “Animal Welfare Approved,” or better yet, find an egg producer at your local farmers’ market. Pastured-raised eggs have been shown to have higher amounts of vitamins A and E, and omega-3 fats.2 Expect to pay more for these eggs so treat them with respect for the nutritional value they bring and waste nothing.
Try to think about eating eggs for other meals, not just for breakfast. This frittata recipe is an all time favorite that you can easily adapt depending on the vegetables you have on hand. This one pictured includes red bliss potatoes and early spring asparagus. The cilantro sauce is the magic ingredient that brings everything together.
1. Fernandez ML, 2012, Rethinking dietary cholesterol. Curr Opin Clin Nutr Metab Care. 2012 Mar;15(2):117-21. doi: 10.1097/MCO.0b013e32834d2259. https://www.ncbi.nlm.nih.gov/pubmed/22037012
2. Pennsylvania State University (Pennstate News). (2010, July 20). Research shows eggs from pastured chickens may be more nutritious. Retrieved from http://news.psu.edu/story/166143/2010/07/20/research-shows-eggs-pastured-chickens-may-be-more-nutritious