This article was written by our regular contributor; registered dietitian – Maeve Hanan.
Eggs, and egg yolks in particular, are often seen as an unhealthy food that should be limited. But eggs are extremely nutritious, which is why they are often called “nature’s multivitamin”.
So let’s take a look at the nutritional content of eggs.
Protein
Eggs are high in protein, with a medium egg providing roughly 7g of protein. This is mainly found in the white of the egg.
The type of protein found in eggs also provides good amounts of all of the essential amino acids that our body needs.
Protein plays a number of important roles in our body, such as:
- Keeping our body issues healthy, like our muscle, bones and skin
- Functions within our immune system
- Transporting nutrients around the body
- Creating enzymes and certain hormones
Fats
We need fats for creating certain hormones, absorbing certain vitamins (vitamin A, D, E and K) and creating cell membranes. Omega-3 fats also have anti-inflammatory properties and are involved in the brain development of a foetus. For good heart health we are advised to consume more unsaturated fat than saturated fat.
Eggs contain a medium amount of fat and saturated fat, but more unsaturated than saturated fat overall. This is found in the egg yolk.
Some types of eggs are produced to contain higher amounts of omega-3 fats as the hens laying the eggs are fed flaxseeds (1).
Eggs have a bad rep when it comes to heart health and cholesterol levels. This is because eggs contain dietary cholesterol which was previously thought to be linked with increasing cholesterol levels in our body. However, the latest research shows that this isn’t the case and saturated fat in the diet is the main dietary culprit when it comes to high cholesterol in the body. As mentioned above, eggs are not high in saturated fat.
Therefore, there is no recommended egg limit for the general population or for those with heart disease. The only exception to this is for those who have a genetic condition called familial hypercholesterolemia, those with this condition are usually advised to limit their egg intake to 4 per week.
For example, a recent large study found that moderate egg consumption (up to 1 egg per day) was not associated with a higher risk of heart disease, but interestingly, this was linked with a possible lower heart disease risk in Asian populations (2).
Vitamins
Egg yolks contain a number of of vitamins, including:
- Vitamin A: needed for our immune system, fertility, supporting vision in low light, cell communication and healthy membranes.
- Vitamin D: this nutrient is vital for muscle, bone and tooth health, as well as playing an important role in our immune system.
- Riboflavin (vitamin B2): involved in cell growth and functioning, releasing energy from food and eye, skin and nervous system health.
- Niacin (vitamin B3): needed for skin and nervous system health, releasing energy from food and cell communication.
- Pantothenic acid (vitamin B5): important for creating fatty acids and obtaining energy from food.
- Biotin (vitamin B7): involved in releasing energy from food, creating fatty acids, cell signalling, genetic function and supporting skin, hair and nail health.
- Vitamin B12: vital for keeping our nervous system and blood cells healthy (including avoiding a type of anaemia), and is also involved in DNA formation and releasing energy from food.
Minerals
Egg yolks are also a good source of:
- Selenium: this antioxidant helps to balance free radical levels in the body as well as being involved in fertility, thyroid health, our immune system and DNA production.
- Phosphorus: combines with calcium to form bone and tooth structure, also needed for our pH balance, enzyme function and obtaining energy from food.
- Chloride: this mineral is involved in balancing pH and fluid levels, nerve and red blood cell function, muscle contraction, maintaining blood pressure and producing stomach acid.
- Manganese: involved in enzyme function, blood clotting and nervous system health.
- Iodine: vital for creating thyroid hormones and fertility, as well as supporting brain and bone development of a foetus and baby.
Other Nutrients Found In Eggs
Eggs are a good source of choline. This nutrient is similar to a B-vitamin and it plays an important role in brain health and brain development, due to its involvement in the creation of a chemical messenger called acetylcholine. Choline is also involved in cell structure, cell signalling and transporting lipids in the body.
Eggs also contain the carotenoids lutein and zeaxanthin. These are compounds that act as antioxidants in our body and are particularly important for eye health and reducing the risk of conditions such as cataracts and macular degeneration in older age (3).
Other Considerations:
The affordability and convenience of eggs shouldn’t be overlooked, particularly as they pack such a nutritional punch as well. Many people also find eggs to be filling and satisfying, which may be related to their protein and fat content.
Due to the risk of salmonella poisoning, pregnant women are advised to avoid raw or partially cooked eggs. However, eggs that have a British Lion stamp can be consumed by pregnant women when raw or partially cooked as these have a lower risk of containing salmonella.
Conclusion
As you can see, eggs contain a variety of important nutrients that support our health.
Concerns about eggs significantly increasing cholesterol are out of date, so unless you have familial hypercholesterolemia you don’t need to stick to a specific weekly egg limit. Pregnant women also need to avoid raw or partially cooked eggs, unless they have a British Lion stamp.
Eggs are also affordable, convenient and filling. All the more reason to get egg-cited about eggs!
The nutritional values in this article were obtained from Nutritics Software September 2021.
References:
- Shakoor et al. (2020) “Development of omega-3 rich eggs through dietary flaxseed and bio-evaluation in metabolic syndrome”. Food Sci Nutr. [accessed September 2021 via: https://pubmed.ncbi.nlm.nih.gov/32566179/]
- Drouin-Chartier et al. (2020) “Egg consumption and risk of cardiovascular disease: three large prospective US cohort studies, systematic review, and updated meta-analysis”. BMJ. [accessed September 2021 via: https://www.bmj.com/content/368/bmj.m513]
- Mares (2016) “Lutein and Zeaxanthin Isomers in Eye Health and Disease”. Annu Rev Nutr. [accessed September 2021 via: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5611842/]
- Great Britain nutrition and health claims (NHC) register [accessed September 2021 via: https://www.gov.uk/government/publications/great-britain-nutrition-and-health-claims-nhc-register]
- National Institute of Health (NIH) “Dietary Supplement Fact Sheets” [accessed September 2021 via: https://ods.od.nih.gov/]
