Eggs are a versatile and highly nutritious food, though their precise nutritional content can vary greatly depending on how the chickens that produced them lived and what they were fed. For example, chickens that have been able to feed on open pastures often have higher levels of important Omega-3 fatty acids and vitamin D.
Once considered a nutritional no-no due to dietary cholesterol, eggs have now been exonerated and have found their way to superfood status.
Why it’s a superfood?
- A complete protein source;
- High in vitamin B12, riboflavin, choline, phosphorus and selenium;
- Good source of vitamin B6, folate, pantothenic acid and iron;
- Good source of Omega-3 fatty acids EPA and DHA (in pastured eggs);
- One only a few foods that naturally contain vitamin D.
Healthy evidence
This review article published in 2009 discussed the health benefits of choline, a compound that was only added to the list of recommended nutrients in 1998. The authors noted that eggs are one of the best sources of choline, which is vital in numerous metabolic functions.
For example, choline may help prevent atherosclerosis, neurological disorders and liver disease.
It has also been shown to help reduce the effects of short-term alcohol misuse, also known as a hangover. Choline is so important for alcohol metabolism that it can even protect fetuses against maternal alcohol ingestion (not that you should be consuming alcohol whilst pregnant).
Composition of an Egg
The composition of an egg is usually defined in two parts. The egg white and the yolk. The white is approximately 87% and 13% protein, and contains both vitamins and minerals.
The yolk is approximately 50% water, 33% fat and 17% protein. Similar to the egg white, it also contains both vitamins and minerals.
The nutrients available in an egg are distributed fairly evenly between the egg white and the yolk. This distribution of nutrients is a common characteristic of whole, natural foods and it is one of the main reasons why you should consume the entire egg.
How to choose your eggs
As stated above, the nutrient quality of an egg will depend largely on what living conditions and food available to the chickens that produced the eggs.
Just like all other animals, chickens that are able to express normal behavioural patterns, both socially and physically and are able to eat an optimal diet natural to the species will produce a higher quality egg.
Pastured eggs
Chickens roam freely outdoors, usually alongside cattle or llamas for protection and paddock sustainability. Constant access to sunlight, grass, seeds and bugs, which in turn leads to an excellent nutrient profile. The Gold Standard.
Free range eggs
Are produced by chickens that “may” be permitted outdoors, and have reasonable access to sunlight, grass and bugs resulting in a good nutrient profile.
The term “free range” may be used differently depending on the country and independent laws. In Australia, this means 10,000 hens per hectare in outdoor grazing areas where suitable.
Cage free eggs
Chickens that live indoors in large areas with some sun exposure and are often grain fed. However, the high stocking densities greatly restricts the chickens ability to move freely and conduct normal behavioural patterns, resulting in a lower nutrient profile.
Cage eggs
Chickens live en mass in what is known as battery cages with little to zero room to move about and conduct normal behavioural patterns causing massive amounts of stress. Nil outdoor access and commonly fed a grain based diet, resulting in the poorest nutrient profile.
The bottom line
Eggs are a nutrient dense, highly bio-available whole food. They’re relatively cheap, easy to prepare and can be combined with almost any other food.
Eat them often. Several studies have shown that eating three eggs per day is perfectly healthy. Is there an upper limit? There is no evidence to suggest that eating more is harmful to your health. It just hasn’t been studied enough.
In general, eggs are one of the healthiest and most nutritious foods you can eat. They are one of nature’s most complete foods.
David Marcato 