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
|
|
Protein
|
3.6 g
|
2.7g
|
57%
|
43%
|
|
Fat
|
0.05g
|
4.5g
|
1%
|
99%
|
|
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%
|
|
Tryptophan
|
0.04 g
|
0.03g
|
57%
|
43%
|
|
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%
|
Data
taken from the USDA Nutrient Database for Standard
Reference, Release 15.
Since the
article was written, the USDA has published revisions. The latest, Release 17,
can be found here.
(*The USDA data for
essential fatty acids was not used here, because it shows a negligible amount,
while eggs from chickens raised on pasture are very high in these essential
nutrients.)
|