Yolk vs. Egg white — Health Impact and Nutrition Comparison

Macronutrients and Calories

Egg yolk is considerably denser in nutrients, containing only 52% water, whereas egg white consists of 88% water.

One average size of egg white is considered to be 33g, while an egg yolk’s serving size is equal to 17g.

Vitamins

Egg yolk is significantly richer in most vitamins. A 100g of egg yolk covers the recommended daily values of vitamin B2 by 40%, vitamin B5 by 60%, vitamin B9 (folate) by 36.5%, vitamin B12 by 81%, vitamin D by 36.3%, and vitamin A RAE by 42%.

Egg yolk is also richer in vitamin B1, vitamin E, and vitamin K.

Egg white is rich only in vitamin B2, providing 33% of the recommended daily value per 100g serving. Egg white contains insignificant amounts of other B-complex vitamins and is absent in fat-soluble vitamins A, D, E, and K, as they cannot exist in the fat-free environment of egg whites.

Both egg white and yolk entirely lack vitamin C.

Vitamin Comparison

Vitamin comparison score is based on the number of vitamins by which one or the other food is richer. The "coverage" charts below show how much of the daily needs can be covered by 300 grams of the food.

Yolk

11

Egg white

1

Contains more Vitamin AVitamin A	+∞%
Contains more Vitamin EVitamin E	+∞%
Contains more Vitamin DVitamin D	+∞%
Contains more Vitamin B1Vitamin B1	+4300%
Contains more Vitamin B2Vitamin B2	+20.3%
Contains more Vitamin B5Vitamin B5	+1473.7%
Contains more Vitamin B6Vitamin B6	+6900%
Contains more Vitamin B12Vitamin B12	+2066.7%
Contains more Vitamin KVitamin K	+∞%
Contains more FolateFolate	+3550%
Contains more CholineCholine	+74463.6%

Contains more Vitamin B3Vitamin B3

+337.5%

~equal in Vitamin C ~0mg

Minerals

Egg yolk is richer in almost all minerals as well. The yolk is especially rich in selenium, phosphorus, iron, zinc, and choline. The yolk is also richer in calcium, copper, manganese, and choline. The yolk is also much lower in sodium.

Even though the yolk is 2.8 times richer in selenium, egg white can also be considered rich in selenium. Egg white is also comparably higher in magnesium and potassium than egg yolk.

Mineral Comparison

Mineral comparison score is based on the number of minerals by which one or the other food is richer. The "coverage" charts below show how much of the daily needs can be covered by 300 grams of the food.

Yolk

8

Egg white

2

Contains more CalciumCalcium	+1742.9%
Contains more IronIron	+3312.5%
Contains more CopperCopper	+234.8%
Contains more ZincZinc	+7566.7%
Contains more PhosphorusPhosphorus	+2500%
Contains less SodiumSodium	-71.1%
Contains more ManganeseManganese	+400%
Contains more SeleniumSelenium	+180%

Contains more MagnesiumMagnesium	+120%
Contains more PotassiumPotassium	+49.5%

Glycemic Index

Both egg white and yolk contain so few carbohydrates that measuring the glycemic index would be exceedingly difficult. For this reason, their glycemic index values are assumed to fall in the low category.

Eating egg white or yolk alone should not have much effect on your blood glucose levels (4).

Acidity

Egg white has a pH value ranging from 7.6 to 9.2. The egg white's pH increases as the egg ages (5).

On the other hand, egg yolk has a pH value ranging from 6 to 6.9. The pH of egg yolk decreases during egg storage (5).

The acidity of the whole egg tends to be neutral.

Another way to look at the acidity of foods is the potential renal acid load (PRAL). The PRAL shows us how much base or acid the given food produces in our bodies.

The PRAL value for egg white has been calculated to be 2.1, making it acid-producing. Egg yolk has a higher acid-forming PRAL value of 18.1.

Cardiovascular Health

Section reviewed by cardiologist Astghik Grigoryan

Many of us know the risks of high cholesterol levels and how they can impact our heart health. It is worth noting that egg yolks contain a significant amount of cholesterol, with a 63-gram egg yolk containing around 237 mg of cholesterol, nearly the same amount found in a 12-ounce beef burger. In contrast, egg whites do not contain any cholesterol (9).

However, a moderate amount of cholesterol, consumed in a healthy diet, is not only harmless but also necessary for many functions of the organism (10).

Scientists have found that moderate egg or egg yolk consumption is not associated with an increased risk of cardiovascular disease or stroke among healthy individuals (11). But for people with existing cardiovascular health issues who need to control their cholesterol levels, it is better to opt for egg whites only or reduce whole egg consumption (12).

Additionally, egg yolks are rich in phosphatidylcholine, a compound converted into trimethylamine by intestinal bacteria. When absorbed, trimethylamine is oxidized in the liver to form trimethylamine N-oxide (TMAO), which has been shown to cause atherosclerosis in animal studies. In a study conducted on 4007 patients who underwent coronary angiograms, it was found that those with TMAO levels in the top quartile had a 2.5-fold increase in the risk of stroke, myocardial infarction, or vascular death over three years (9).

Diabetes

Even though both egg white and yolk have very low glycemic indices, their consumption is not advised for people at risk of diabetes.

High levels of whole egg consumption have been found to have an association with an increased risk of diabetes mellitus type 2, as well as heart disease risk for people with diabetes (13, 14).

Possible mechanisms for these effects are the oxidative and inflammatory effects of choline found in the yolk and slower carbohydrate absorption from chemicals found in egg whites (15).

In contrast, some studies found either an inverse or no association between high egg consumption and diabetes (16, 17 ).

Ocular Health

According to the American Journal of Clinical Nutrition, egg yolk is a highly bioavailable source of lutein and zeaxanthin, the two main carotenoids in the eyes and vital for healthy vision (18).

Carotenoids have antioxidant properties, prevent the formation of free radicals, and may delay the progression of age-related macular degeneration and cataracts (19).

Egg white, however, is absent in lutein and zeaxanthin.

Immune System

Egg white proteins, such as ovalbumin, ovotransferrin, ovomucin, etc., are studied to have antimicrobial and immunomodulatory properties due to their direct action on inflammatory pathways.

Egg yolk livetin, yolkin, and immunoglobulins have also been studied to have anti-inflammatory and antimicrobial effects. The yolk's micronutrients may also enhance immunity. However, increased egg yolk consumption may induce inflammation due to its high cholesterol content (20, 21, 22).

Cancer

Quite a few studies have suggested a correlation between egg consumption and certain types of cancers.

One research study, in particular, found that high egg consumption increases the risk of several cancers: oral cavity and pharynx, upper respiratory and digestive tracts, colorectal, lung, breast, prostate, and bladder (23).

Another study found that the agents causing lymphosarcomas and lung adenocarcinomas were present in egg white and yolk, whereas mammary carcinogens were only found in egg yolk (24).

Heartburn

Egg yolk, high in fat, is more likely to trigger heartburn in people with GERD (gastroesophageal reflux disease) than egg white (25).

Allergy

Egg allergies are among the most common allergies worldwide, especially in children. People are more often allergic to egg whites than yolks, as most allergenic egg proteins are found in egg whites (26).

Egg allergy symptoms can range from a mild rash, indigestion, and coughing to an anaphylactic reaction (27).

Biotin Deficiency

Consuming raw egg white for a prolonged period can cause biotin deficiency. 

A protein present in egg white, avidin, tightly binds biotin, also known as vitamin B7, making it unavailable for intestinal absorption. This problem does not occur with cooked eggs, as high heat changes the structure of avidin (28).

Salmonella Poisoning

Even though only 1 in every 20000 eggs may be contaminated with Salmonella, eating raw eggs may still be hazardous to health (29). Thoroughly cooking eggs kills bacteria.

Salmonella poisoning symptoms may include nausea, vomiting, diarrhea, fever, and stomach cramps. This is particularly dangerous for children, pregnant women, and elderly people.