Eggs are a common food source and have been eaten by humans across the world for thousands of years.
Eggs are produced by the female animals of many different species, but by far and away the most common choice for consumption is the egg of the chicken.
The US is regarded as the world's largest exporter of eggs1 and it is estimated that in 2014, 256 eggs will be produced for each member of the population - the highest rate of production in the past 8 years.2
This Medical News Today Knowledge Center feature is part of a collection of articles on the health benefits of popular foods. It provides a nutritional breakdown for eggs, an in-depth look at their possible health benefits, tips on how to incorporate more eggs into your diet and any potential health risks of consuming eggs.
Possible health benefits of eggs10
As suggested by their wide nutritional content, shown below, there are several health benefits that can be derived from eggs:
A medium-sized egg typically contains 5.53 g of protein and only 63 Calories.
Strong muscles: the protein within eggs helps keep muscles working well while slowing the rate at which they are lost.
A healthy brain: eggs contain vitamins and minerals that are needed for the regular functioning of cells, including the brain, nervous system, memory and the metabolism.
Good energy production: eggs contain all the daily vitamins and minerals that are needed to produce energy in all the cells of the body.
A healthy immune system: likewise, vitamin A, vitamin B12 and selenium are all key to keeping the immune system healthy.
Lower risk of heart disease: having a healthy immune system helps. Choline plays an important part in breaking down the amino acid called homocysteine, which is associated with the development of heart disease.
Healthy baby development during pregnancy: nutrients within eggs help to prevent birth defects such as spina bifida.
Healthy eyesight: lutein and zeaxanthin help to prevent macular degeneration, an eye condition which is the leading cause of age-related blindness. Other vitamins also promote healthy vision.
Weight loss and maintenance: the high quality of protein within eggs has been found by researchers to keep people energized and feeling fuller for longer. Feeling full prevents unhealthy snacking and reduces overall calorie intake.
A healthy appearance: some vitamins and minerals within eggs help promote healthy skin and work to prevent the breakdown of body tissues. A strong immune system also contributes to a healthy look overall.
Nutritional breakdown of eggs3-6
Eggs contain many vitamins and minerals that are essential parts of a healthy and balanced diet. Below is a list of nutrients that can be found in eggs, along with a brief summary of what they are useful for:
- Vitamin A: maintains the skin, immune system and normal vision.
- Vitamin B2 (riboflavin): aids energy metabolism, red blood cells, vision and the nervous system.
- Vitamin B12: aids energy metabolism, red blood cells, the immune system and the nervous system.
- Vitamin B5 (pantothenic acid): aids energy metabolism and mental functioning.
- Vitamin D: keeps bones and teeth healthy and aids absorption of calcium.
- Vitamin E: keeps the reproductive system, nervous system and muscles healthy.
- Biotin: aids energy metabolism, maintains skin, hair and the immune system.
- Choline: aids fat metabolism and liver function.
- Folic Acid: aids blood formation and tissue growth during pregnancy.
- Iodine: aids thyroid gland function, maintains the skin and nervous system.
- Iron: assists red blood production and the transportation of oxygen throughout the body.
- Lutein and zeaxanthin: maintain normal vision and protect from age-related eye disease.
- Phosphorus: maintains bones and teeth and aids energy metabolism.
- Protein: needed for building and maintaining muscle, organs, skin and tissue, and producing antibodies, enzymes and hormones.
- Selenium: protects cells from oxidative damage, maintains the immune system and aids thyroid gland function.
Eggs are considered to be one of the best sources of protein available. One medium-sized egg weighing 44 g typically contains 5.53 g of protein. Nutritionists often use eggs as a point of comparison when assessing whether another food is a good source of protein or not. Around 12.6% of the edible portion of an egg is protein.
Around 9% of an egg's content is fat, found almost exclusively in the egg's yolk.
The majority of fat in an egg is that which is generally regarded to be the most healthy; approximately 38% is monounsaturated and 16% is polyunsaturated, with only 28% being saturated.
Eggs are also a rich supply of long-chain omega-3 fatty acids. These are predominantly in the form of docosahexaenoic acid (DHA) which helps with the maintenance of brain function and normal vision.
These fatty acids are most commonly found in oily fish and so eggs provide an alternative source for people that are unable to eat fish.
On the next page we look at eggs and cholesterol. We also discuss how to incorporate more eggs into your diet and the possible health risks associated with consuming eggs.