Eggs are an affordable, highly nutritious food that many people include as part of a healthy diet.
However, egg yolks have a very high cholesterol content. Some people avoid eggs because they have heard that eating too many egg yolks can cause heart disease.
Is it ok to include egg yolks as part of a healthy diet or are they something we should avoid?
This article will review the latest research on egg yolks and help you make the best decision for your long term health.
Is Egg Yolk Good for Health?
Yes. Current research shows that when consumed in moderation whole eggs provide many health benefits and may actually help prevent heart disease (1).
The idea that too much dietary cholesterol could raise blood cholesterol levels and lead to an increased risk of heart disease was first proposed in 1968. At that time health organizations including the American Heart Association (AHA) suggested limiting cholesterol intake to 300 mg per day (1).
One egg yolk contains about 184 mg of cholesterol, more than half of the suggested daily limit. As a result, eggs were targeted as high cholesterol food to avoid. Egg consumption dropped significantly after the AHA’s recommendation.
Since that time researchers have not been able to find a link between dietary cholesterol and heart disease. In fact, in 2015 the Dietary Guidelines for Americans (DGA) removed the recommendation to limit dietary cholesterol to 300 mg per day (2).
The DGA continue to emphasize that we should limit our daily intake of cholesterol-containing foods. This is because many foods that are high in cholesterol such as ice cream and baked goods are also high in added sugar and saturated fat, nutrients which are known to contribute to weight gain and other chronic conditions.
Here are some of the health benefits of eating whole eggs that have been identified by research.
1. Eye Health
Several nutrients of an egg yolk have been shown to play a role in eye health. These include vitamin A, zinc, and the carotenoids lutein and zeaxanthin. Carotenoids are compounds that naturally provide color to foods. Common carotenoids in our diet include beta carotene in carrots and lycopene in tomatoes.
A diet rich in lutein and zeaxanthin containing foods has been shown to protect our eyes against cataracts and help reduce the risk of developing age-related macular degeneration, one of the leading causes of blindness in older individuals (3).
One study found that when older adults ate one whole egg per day for five weeks their blood levels of lutein increased significantly compared to another group that did not eat eggs. More importantly, this study found no changes in blood cholesterol or triglyceride levels during this same time period (4).
Eating whole eggs is a great way to increase your intake of this valuable nutrient.
2. Brain Health
Eggs are an excellent source of choline, an under-consumed nutrient that is essential for brain health, metabolism, muscle control, and other nervous system functions (5). One whole egg contains 35% of the recommended daily intake (RDI) of choline.
Recent research has found that people who regularly eat foods rich in choline are at a lower risk of developing dementia and long term cognitive decline (6).
3. Reduced Inflammation
Low-grade chronic inflammation is thought to contribute to the development of many health conditions. Eggs contain high levels of antioxidants, molecules that help the body fight off inflammation.
One study found that when people with type 2 diabetes ate one egg a day with breakfast for a period of five weeks, markers of inflammation in their blood decreased significantly when compared to another group who ate a daily serving of oatmeal for breakfast (7).
4. Gut Health
A protein called ovomucin found in egg whites has been studied for its potential role in maintaining gut health. Laboratory studies have shown that ovomucin can bind to harmful bacteria such as E. coli and possibly prevent them from making us sick.
Ovomucin may also help help keep the lining of our gut healthy. More research is needed in this area to confirm these findings (8).
5. A Boosted Immune System
Diet can have a significant impact on how well our immune system functions. Many vitamins and minerals that are found in eggs play a significant role in our immune response including vitamin A, vitamin B12, vitamin E, selenium, and zinc.
6. Lower Blood Pressure
Egg yolks contain compounds called peptides including one known as phosvitin that have been studied for their potential ability to lower blood pressure and improve heart health. Early research suggests these compounds may help lower pressure. More robust studies involving human subjects are needed to verify these findings (9).
7. Weight Loss
With their high protein content, eating eggs can help regulate body weight and reduce belly fat (10). Replacing carbohydrates with high-quality protein foods, for example replacing toast with scrambled eggs at breakfast boosts the production of appetite-suppressing hormones.
This can help you eat less and feel full longer, raising your chances of weight loss success (11).
Egg Yolk Nutrition Facts
Egg yolks are the most nutritious part of an egg. Here is the nutrition information for one large egg yolk.
- Calories: 55
- Protein: 2.7 grams
- Fat: 4.5 grams of which 1.6 gram grams saturated)
- Cholesterol: 184 mg
- Carbohydrate: 0.61 grams
- Selenium 9.5 mcg or 17% of the DV
- Vitamin B12: 0.55 mcg or 23% of the DV
- Vitamin D: 44 IU or 7% of the DV
- Vitamin A: 260 IU or 8% of the DV
The protein in the egg is considered high quality because it supplies all nine essential amino acids. Essential nutrients are something our bodies cannot produce and we must obtain from our foods. Amino acids are building blocks used by our bodies to create proteins and perform other important functions.
Egg yolk nutrition can vary depending on the diet of the hen that laid the eggs. Omega 3 eggs and pasture raised eggs have much higher levels of Omega 3 essential fatty acids including DHA. Pastured raised eggs also have been shown to have higher levels of vitamin A and vitamin E compared to conventionally raised eggs (12).
Egg White vs Egg Yolk
Although the majority of the nutrients in an egg are concentrated in the egg yolk, egg whites do provide some nutritional value.
One large egg white provides 3.6 grams of protein compared with 2.7 grams in the yolk. The egg white also contains selenium and a small amount of potassium, magnesium, folate, and riboflavin.
If you are trying to increase your protein intake to build more muscles, there is evidence that you should be eating whole eggs. In a recent study a group of men were given egg whites or whole eggs immediately after a workout. The group that ate whole eggs saw higher rates of muscle protein synthesis compared to the group that consumed the same amount of protein from egg whites (13).
How Many Egg Yolks Are Safe to Eat a Day?
The research is now clear that an egg intake of around one whole egg each day is perfectly save and may provide many health benefits for most people (14).
It is important to note that no studies have looked at the long term effect of eating several eggs every day. Like other healthy foods, eat eggs in moderation.
The Bottom Line
Egg yolks can be part of a healthy diet. Early research had suggested that a diet high in cholesterol may lead to the development of heart disease and a higher risk of heart attack and stroke.
Follow up studies have shown that despite being high in cholesterol eating egg yolks in moderation does not contribute to heart disease risk and may even be beneficial for heart health by lowering blood pressure.
Be sure to include whole eggs as part of a healthy diet that features plenty of fresh fruits and vegetables, lean protein, and other nutrient-rich foods. Many of the nutrients from egg yolks including choline, omega 3 fatty acids, and vitamin D are hard to obtain from other food sources and can provide numerous other health benefits.
- Soliman, Ghada. “Dietary Cholesterol and the Lack of Evidence in Cardiovascular Disease.”Nutrients, vol. 10, no. 6, 2018, p. 780. Crossref, doi:10.3390/nu10060780.
- “A Closer Look Inside Healthy Eating Patterns – 2015-2020 Dietary Guidelines | Health.Gov.” Dietary Guidelines for Americans, health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/chapter-1/a-closer-look-inside-healthy-eating-patterns/#dietary-cholesterol. Accessed 20 July 2020.
- Buscemi, Silvio, et al. “The Effect of Lutein on Eye and Extra-Eye Health.” Nutrients, vol. 10, no. 9, 2018, p. 1321. Crossref, doi:10.3390/nu10091321.
- Goodrow, Elizabeth F., et al. “Consumption of One Egg Per Day Increases Serum Lutein and Zeaxanthin Concentrations in Older Adults without Altering Serum Lipid and Lipoprotein Cholesterol Concentrations.” The Journal of Nutrition, vol. 136, no. 10, 2006, pp. 2519–24. Crossref, doi:10.1093/jn/136.10.2519.
- Wallace, Taylor C., and Victor L. Fulgoni. “Assessment of Total Choline Intakes in the United States.” Journal of the American College of Nutrition, vol. 35, no. 2, 2016, pp. 108–12. Crossref, doi:10.1080/07315724.2015.1080127.
- Ylilauri, Maija P. T., et al. “Associations of Dietary Choline Intake with Risk of Incident Dementia and with Cognitive Performance: The Kuopio Ischaemic Heart Disease Risk Factor Study.” The American Journal of Clinical Nutrition, vol. 110, no. 6, 2019, pp. 1416–23. Crossref, doi:10.1093/ajcn/nqz148.
- Ballesteros, Martha, et al. “One Egg per Day Improves Inflammation When Compared to an Oatmeal-Based Breakfast without Increasing Other Cardiometabolic Risk Factors in Diabetic Patients.” Nutrients, vol. 7, no. 5, 2015, pp. 3449–63. Crossref, doi:10.3390/nu7053449.
- Tu, Aobai, et al. “Potential Role of Ovomucin and Its Peptides in Modulation of Intestinal Health: A Review.” International Journal of Biological Macromolecules, vol. 162, 2020, pp. 385–93. Crossref, doi:10.1016/j.ijbiomac.2020.06.148.
- Yousr, Marwa, and Nazlin Howell. “Antioxidant and ACE Inhibitory Bioactive Peptides Purified from Egg Yolk Proteins.” International Journal of Molecular Sciences, vol. 16, no. 12, 2015, pp. 29161–78. Crossref, doi:10.3390/ijms161226155.
- Loenneke, Jeremy P., et al. “Quality Protein Intake Is Inversely Related with Abdominal Fat.” Nutrition & metabolism, vol. 9, no. 1, 2012, p. 5. Crossref, doi:10.1186/1743-7075-9-5.
- Leidy, Heather, et al. “Role of Protein in Weight Loss and Maintenance.” OUP Academic, Oxford Academic, 29 Apr. 2015, academic.oup.com/ajcn/article/101/6/1320S/4564492.
- Anderson, K. E. “Comparison of Fatty Acid, Cholesterol, and Vitamin A and E Composition in Eggs from Hens Housed in Conventional Cage and Range Production Facilities.” Poultry Science, vol. 90, no. 7, 2011, pp. 1600–08. Crossref, doi:10.3382/ps.2010-01289.
- Vliet, Stephan van, et al. “Consumption of Whole Eggs Promotes Greater Stimulation of Postexercise Muscle Protein Synthesis than Consumption of Isonitrogenous Amounts of Egg Whites in Young Men.” The American Journal of Clinical Nutrition, vol. 106, no. 6, 2017, pp. 1401–12. Crossref, doi:10.3945/ajcn.117.159855.
- Drouin-Chartier, Jean-Philippe, et al. “Egg Consumption and Risk of Cardiovascular Disease: Three Large Prospective US Cohort Studies, Systematic Review, and Updated Meta-Analysis.” BMJ, 2020, p. m513. Crossref, doi:10.1136/bmj.m513.