A staple food for many, eggs are a versatile cooking ingredient, and can be the main feature of a dish or part of a mix when making desserts. They’re also a great source of vitamins and other important nutrients.
The most common eggs come from chickens, but you can also buy duck, goose and quail eggs.
There are many misconceptions about the health benefits of eggs, so in this guide we’ll separate fact from fiction so you can enjoy eating them without worrying.
The health benefits of eggs
They’re a complete source of protein
Protein is one of the three macronutrients — the essential nutrients we need in relatively large amounts — alongside carbohydrates and fat. We need to get macronutrients through our diets because our bodies either cannot make them, or cannot make enough of them.
Protein is in every cell, from muscles and bones to skin and hair. It’s made up of amino acids, which are known as the body’s building blocks because they help with so many processes, including:
- The production of enzymes
- The production of some hormones and neurotransmitters
- The growth, repair and maintenance of tissue and muscle
- Breaking down food
- Maintaining the body’s pH balance
- Providing energy
- Providing structure to cell membranes, organs, hair, skin and nails
There are 20 amino acids which are important for bodily functions, and nine of these are considered essential. Eggs are described as a complete source of protein because they contain all nine essential amino acids. These are the amino acids which we can only get through food. They are:
- Histidine, which is used to make blood cells, protect nerve cells, and grow and repair tissue
- Isoleucine, which controls blood sugar and improves energy levels
- Leucine, which helps improve energy during exercise
- Lysine, which transports fats across cells so they can be burned for energy
- Methionine, which helps break down fats
- L-Phenylalanine, which helps to produce important molecules in the body
- Threonine, which helps liver function and helps to form collagen, elastin and tooth enamel
- Tryptophan, which aids the sleep-wake cycle
- Valine, which helps to grow and repair muscle and tissue
The protein in an egg is mostly found in the white, but don’t discount the yolks — they’re nutritious in their own right. Eggs tend to contain around 6-7 grams of protein, although it will vary depending on their size. The Recommended Dietary Allowance (RDA) for protein is 0.8 grams of protein per kilogram of body weight.
They’re a source of vitamins and minerals
Egg yolks contain plenty of vitamins and minerals, including:
- Vitamin A, which is needed for:
- Encouraging the production of white blood cells
- Regulating cells
- Supporting bone health
- Supporting eye health
- Vitamin B12, which is needed for:
- Developing brain cells
- Developing nerve cells
- Forming DNA
- Forming red blood cells
- Vitamin B2, also known as riboflavin, which is needed for:
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- Breaking down substances like fat and medication
- Cell growth
- Energy
- Vitamin D, which is needed for:
- Absorbing key nutrients like calcium and phosphorus
- Controlling infections
- Reducing inflammation
- Vitamin E, which is needed for:
- Boosting the immune system
- Preventing clots forming in arteries
- Protecting cells from damage by free radicals
- Iodine, which is needed for:
- Keeping the metabolism at normal levels
- Making thyroid hormones
- Phosphorus, which is needed for:
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- Activating enzymes
- Keeping blood pH levels at normal levels
- Regulating nerves and muscles
- Selenium, which is needed for:
- Making DNA
- Protecting cells
They’re a source of nutrients
As well as vitamins and minerals, eggs also contain plenty of nutrients. The yolk, for example, has polyunsaturated and monounsaturated fats, which are healthy fats the body needs for brain function and cell growth, and are said to reduce the risk of heart disease. The yolk also contains:
- Carotenes, especially lutein and zeaxanthin, which play a role in preventing cataracts (cloudy patches in the lens of the eye) and macular degeneration (when part of the retina is damaged and you begin to lose your central vision).
- Essential omega-3 fatty acids, which maintain the function of your heart and brain. Some eggs are enriched with extra omega-3 fatty acids.
Eggs are a source of the nutrient choline, which aids with brain function and development, as well as cell formation.
Eggs and cholesterol
It’s true that eggs are high in cholesterol. However, eggs don’t seem to raise our cholesterol levels. Most of the cholesterol in our bodies is made by the liver, which responds to saturated fat and trans fat we consume. Reducing saturated and trans fat intake will help to reduce cholesterol levels.
How many eggs should you eat?
Research doesn’t give us one set answer, but health professionals seem to agree that most adults are able to eat up to seven eggs per week safely. However, people at risk of heart disease or with high cholesterol levels may be advised to eat less than this.
The way eggs are prepared also affects how healthy they are. Boiled or poached eggs are considered to be better for you than fried eggs, for example, because they don’t require any cooking fat and are relatively quick to make. The less time an egg cooks, the more nutrients it retains — just make sure the white is cooked through.
What’s the difference between caged, cage-free, free-range and organic eggs?
- Caged eggs come from hens which are kept in cages.
- Cage-free eggs come from hens which have an area where they can roam freely, but can’t necessarily go outdoors.
- Free-range eggs come from hens which can roam freely in an indoor area and are able to go in an enclosed area outdoors.
- Organic eggs come from hens which are cage free or free range, and are given organic feed.
How to store eggs
In the US, eggs must be kept in the fridge. This is because they’re cleaned to prevent Salmonella, but the cleaning process can damage the cuticle and make it easier for bacteria to reach the white and yolk inside. Storing eggs in the fridge reduces the chance of bacteria growing.
Keep your eggs in their original carton, at the back of a fridge which is set to 40℉ or less. This stops them being affected by changes in temperature as the door opens and closes.
How long do eggs last?
Eggs which have been stored properly can last for 3-5 weeks if they’ve spent less than two hours at room temperature before being put away.