The Incredible, Edible Egg Yolk
Excerpts from: The Incredible, Edible Egg Yolk
Egg yolks? But they’re full of cholesterol! I’m sure you’ve heard it before.
Egg Nutrition: Yolk versus White
Egg yolks are indeed full of cholesterol. Like most cholesterol-rich foods, they are jam-packed full of important nutrients.
In fact, the slew of nutrients in an egg yolk is so comprehensive that a few a day would offer better insurance than a multi-vitamin. Most importantly, the yolk contains most of the nutrients in an egg. Egg whites, on the other hand, contain far fewer nutrients.
Don’t believe it? See Table 1 after this article that compares the nutritional value of egg whites and yolks, with data provided by the USDA. I’ve included additional analysis in the last two columns that provides the percentage of the total nutrition found in the yolk and the percentage of total nutrition found in the white.
As you can see from the table, the yolk contains 100% of the carotenes, essential fatty acids, vitamins A, E, D, and K (6 items). The white does not contain 100% of any nutrient.
The yolk contains more than 90% of the calcium, iron, phosphorus, zinc, thiamin, B6, folate, and B12, and 89% of the panthothenic acid (9 items). The white does not contain more than 90% of any nutrient, but contains over 80% of the magnesium, sodium, and niacin (3 items).
The yolk contains between 50% and 80% of the copper, manganese, and selenium, while the white contains between 50% and 80% of the potassium, riboflavin, and essential amino acids.
It should also be kept in mind that the yolk of an egg is smaller than the white. Where the white contains a slim majority of nutrients, such as the essential amino acids, this is not due to a greater concentration in the white, but simply the fact that there is more white in the egg than yolk.
According to the Executive Summary of the Third Report on Nutrition Monitoring in the United States by the Interagency Board for Nutrition Monitoring and Related Research of the Federation of American Societies for Experimental Biology’s Life Sciences Research Office:
- Most groups have a deficient median intake of magnesium.
- Several groups have a deficient median intake of calcium.
- Children aged 1-2 and most females have a deficient intake of iron.
- Blacks over the age of 16 and Mexican-Americans over the age of 60 have a deficient median intake of folate.
All age groups and races have a deficient median intake of vitamins A, E, B6, and copper.
Considering this information, the importance of the egg yolk and relative unimportance of the egg white becomes even more clear. The yolk contains the majority of the copper, nearly all of the calcium, iron, folate, and B6, and 100% of the vitamins A and E.
The white, on the other hand, is only useful as an added source of magnesium, or if the diet is on the whole deficient in protein. The simple addition of an adequate amount of meat in the diet would provide for both.
One important set of nutrients that should not be overlooked is the long-chain omega-3 fatty acids, DHA and EPA. EPA is an important precursor to hormones that inhibit inflammation, and DHA is necessary for the brain and proper retinal function in the eye.
Both these fatty acids are deficient in the Standard American Diet. They are found in fatty fish such as salmon, and many animal products from animals raised on pasture. Pastured egg yolks are an excellent source of DHA, which is itself a precursor to EPA. All essential fatty acids in the egg are contained in the yolk.
To Cook, or Not to Cook?
Many people believe that the health benefits of egg yolks are greater when the yolks are consumed raw. Heat destroys enzymes and reduces the amount of certain nutrients. Those who eat raw egg yolks report easier digestion, increased stamina, and resistance to illness – not to mention a quicker snack if you’re on-the-go. Believe it or not, raw egg yolks taste somewhat like vanilla!
Finding the Right Kind of Eggs
Pastured eggs, meaning eggs from chickens that are free to forage for grass and insects, are of much higher nutritional quality than eggs from confinement chickens. The marginal increase in value, of course, is found mostly in the yolk.
Insects provide a higher DHA content, found exclusive in the yolk, and grass provides a higher vitamin E and carotene content, also found exclusively in the yolk. Egg yolks from pastured chickens are thus a powerful supplement to a healthy diet – a super-food – providing necessary nutrients in which the Standard American Diet is deficient.
To find a source of eggs from chickens raised on pasture, you can visit Local Harvest and do a search for "eggs pastured" or "eggs grass fed" with your zip code. You can also visi Eat Wild and click on your state for a list of farms that pasture their animals.
Additionally, you may be able to find roadside stands in your area that sell eggs from pastured chickens. Be sure to inquire about the farming practices, to make sure that the chickens are able to forage for both grass and insects.
Back to the Basics: Taste!
The truth is that most satisfying meals one could make with eggs just don’t taste right without both the yolk and the white. Most baked goods come out with a richer taste and a better texture when the yolks are included. Food should provide good nutrition– for which inclusion of the yolks is necessary! — but it should also taste good. Food should be fun. It should be rewarding to cook, delicious to eat, and relaxing to indulge in.
The anti-cholesterol establishment upholds its poor theory and unjustified conclusions only to condemn us to a bland and unsatisfying diet, the cornerstone of which is "light cooking" with bland and taste-challenged "foods" like the notorious, emasculated, yolkless egg white. Fear not. You are now armed with the raw facts from the USDA’s nutrition database that shows that missing out on the egg yolks means missing out on the nutrition in your breakfast. Take heart in this the next time you enjoy the incredible, edible egg yolk.
Table 1: Egg Yolks Versus Egg Whites
|Nutrient||White||Yolk||% Total in White||% Total in Yolk|
|Calcium||2.3 mg||21.9 mg||9.5%||90.5%|
|Magnesium||3.6 mg||0.85 mg||80.8%||19.2%|
|Iron||0.03 mg||0.4 mg||6.2%||93.8%|
|Phosphorus||5 mg||66.3 mg||7%||93%|
|Potassium||53.8 mg||18.5 mg||74.4%||25.6%|
|Sodium||54.8 mg||8.2 mg||87%||13%|
|Zinc||0.01 mg||0.4 mg||0.2%||99.8%|
|Copper||0.008 mg||0.013 mg||38%||62%|
|Manganese||0.004 mg||0.009 mg||30.8%||69.2%|
|Selenium||6.6 mcg||9.5 mcg||41%||59%|
|Thiamin||0.01 mg||0.03 mg||3.2%||96.8%|
|Riboflavin||0.145 mg||0.09 mg||61.7%||48.3%|
|Niacin||0.035 mg||0.004 mg||89.7%||9.3%|
|Pantothenic acid||0.63 mg||0.51 mg||11%||89%|
|B6||0.002 mg||0.059 mg||3.3%||96.7%|
|Folate||1.3 mcg||24.8 mcg||5%||95%|
|B12||0.03 mcg||0.331 mcg||8.3%||91.7%|
|Vitamin A||0 IU||245 IU||0%||100%|
|Vitamin E||0 mg||0.684 mg||0%||100%|
|Vitamin D||0 IU||18.3 IU||0%||100%|
|Vitamin K||0 IU||0.119 IU||0%||100%|
|Omega-3 and Omega-6 EFAs||* see note below||0%||100%|
|Carotenes||0 mcg||21 mcg||0%||100%|
|Threonine||0.15 g||0.12 g||55.5%||44.5%|
|Isoleucine||0.22 g||0.15 g||59.5%||40.5%|
|Leucine||0.34 g||0.24 g||58.6%||41.4%|
|Lysine||0.27 g||0.2 g||57.4%||42.6%|
|Methionine||0.13 g||0.064 g||67%||33%|
|Phenylalanine||0.23 g||0.12 g||66%||34%|
|Valine||0.27 g||0.16 g||62.4%||43.6%|