Health Risks
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The main health risks from eggs are from allergic reactions to the proteins in the egg white rather than the yolk and intolerances to eggs are widespread.
Allergic reactions are more common in infants than adults, whereas most
children will outgrow it by the age of five.
Eggs are susceptible to Salmonella contamination, though thorough cooking eliminates the direct threat (i.e. cooked egg whites that are solid and not runny), but the threat of cross-contamination remains.
Eggs and Cholesterol Myth
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Cholesterol is an essential health-promoting component in the body that is
required by every living cell and is manufactured by the liver from stored
triglycerides.
A medium egg contains about 186mg of cholesterol, 62% of the 300mg RDA. However…
... only 20% of the cholesterol in your blood comes directly from your diet, as our bodies can’t actually absorb a lot of cholesterol that’s found in food - the rest (80%) is produced in response to bodily requirements.
It is the saturated fat content of the diet, not dietary cholesterol that influences blood cholesterol levels the most.
The body tightly regulates the amount of serum cholesterol by controlling
internal production; when cholesterol intake in the diet goes down, the body makes more and vice versa.
EGGS
How many eggs can you eat a week?
● The NHS state that there is no limit to the amount of eggs people should eat.
The Bottom Line:
Eggs are one of the healthiest foods around. Its complete protein, beneficial fats,
fat-soluble vitamins, minerals and choline give it some seriously great nutritional
credentials and health benefits. If you are still worried about the cholesterol or fat
levels then you can remove an egg yolk or two say from an omelette. Poaching
is still the healthiest way to cook an egg, followed by scrambled then fried in the
littlest amount of oil possible. Free range and organic only!
Welcome to Vacherin’s food in focus.
Each month our nutritionist Gary Baverstock will
provide some basic science and will help
to demystify certain foods in our diet.
Eggs
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Eggs are laid by female animals of many different species, including birds,
reptiles, amphibians, and fish, and have been eaten by humans for thousands of years.
Bird and reptile eggs consist of a protective eggshell, albumen (egg white), and vitellus (egg yolk), contained within various thin membranes.
The chicken eggshell is 95-97% calcium carbonate crystals, which are
stabilized by a protein matrix.
The most popular eggs consumed are chicken, followed by duck, quail, roe
and caviar.
Egg yolks and whole eggs store significant amounts of protein and choline
and are widely used in cookery.
Despite the nutritional value of eggs, there are some potential health issues arising from egg quality, storage, and individual allergies.
Chickens and other egg-laying creatures are widely kept throughout the world, and mass production of chicken eggs is a global industry.
In 2009, an estimated 62.1 million metric tons of eggs were produced world
wide from a total laying flock of approximately 6.4 billion hens.
Nutritional Composition of Egg White
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The primary natural purpose of egg white is to protect the yolk and provide additional nutrition for the growth of the embryo (when fertilized).
Chicken egg white is about two-thirds of the total egg’s weight out of its shell, with nearly 92% of that weight coming from water.
The remaining weight of the egg white comes from protein, fats, glucose,
selenium, vitamin D, B6, B12 and minerals such as zinc, iron and copper
An average raw large egg white weighs 33g with 3.6g of protein, 0.24g of
carbohydrate, 55 milligrams of sodium contains 17 calories and no cholesterol.
Egg white is an alkaline solution and contains approximately 40 different
proteins.
Eggs contain all nine Essential Amino Acids making it a complete protein
crucial to health.
Nutritional Composition of Egg Yolk
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The yolk is the part of an egg intended to feeding the developing embryo.
The yolk makes up about 33% of the liquid weight of the egg; it contains
approximately 60 calories, three times the caloric content of the egg white.
The yolk of one large egg (17 g) contains approximately: 2.7g protein, 210mg cholesterol, 0.61g carbohydrates, and 4.51g total fat.
All of the fat-soluble vitamins (A, D, E and K) are found in the egg yolk.
Egg yolk is one of the few foods naturally containing vitamin D.
The composition of the most prevalent fatty acids in egg yolk is typically
as follows:
Unsaturated Fatty Acids: Oleic acid 47% Palmitic acid 23%
Linoleic acid 16% Palmitoleic acid 5%
Saturated Fatty Acids:
Linolenic acid 2%
Myristic acid 1%
Stearic acid 4%
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Egg yolk is a source of lecithin (9% of yolk) – the compound that enables emulsification in recipes such as hollandaise or mayonnaise, as well as egg oil for cosmetic and pharmaceutical applications.
The yellow colour is due to lutein and zeaxanthin, which are yellow or orange carotenoids known as xanthophylls.
At a glance: One large egg contains:
78 calories
6.3g protein
5.3g fat
1.6g saturated fat
212mg cholesterol
Cooking
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Eggs contain multiple proteins, which gel at different temperatures within the yolk and the white, and the temperature determines the gelling time.
Egg yolk begins to gellify/solidify, when it reaches temperatures between about 63 and 70 °C (145 and 158 °F).
Egg white gels at slightly higher temperatures, about 60 to 80 °C (140 to 176 °F) - the white contains ovalbumin that sets at the highest temperature.
However, in many cooking processes the white gels first because it is exposed to higher temperatures for longer and due to its proximity to the heat.
If a boiled egg is overcooked, a greenish ring sometimes appears around egg yolk due to the iron and sulphur compounds in the egg that are released –
sulphur providing the smell.
Health Benefits
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As a complete protein this means it helps to provide the neurotransmitters that are essential for the correct function of all of the body’s systems.
Eggs contain vitamins and minerals that are needed for the regular functioning of cells, including the brain, nervous system, memory and the metabolism.
Eggs contain all the daily vitamins and minerals that are needed to produce energy in all the cells of the body.
Vitamin A, vitamin B12 and selenium are all key to keeping the immune
system healthy.
Choline plays an important part in breaking down the amino acid called
homocystiene, which is associated with the development of heart disease.
B12 and B9 help to prevent birth defects such as spina bifida, neural tube
defects and choline is important for brain development.
Lutein and zeaxanthin help to prevent macular degeneration, an eye condition, which is the leading cause of age-related blindness.
The protein helps to keep muscles working well while slowing the rate at which they are lost.
In traditional Chinese medicine, eggs are recommended to strengthen the blood and increase energy by enhancing digestive and kidney function.