Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1500 BCE. The most widely consumed eggs are those of fowl, especially chickens. Eggs of other birds, including ostriches and other ratites, are eaten regularly but much less commonly than those of chickens. People may also eat the eggs of reptiles, amphibians, and fish. Fish eggs consumed as food are known as roe or caviar.
Bird and reptile eggs consist of a protective eggshell, albumen (egg white), and vitellus (egg yolk), contained within various thin membranes. Egg yolks and whole eggs store significant amounts of protein and choline, and are widely used in cookery. Due to their protein content, the United States Department of Agriculture formerly categorized eggs as Meat within the Food Guide Pyramid (now MyPlate). Despite the nutritional value of eggs, there are some potential health issues arising from cholesterol content, salmonella contamination, and allergy to egg proteins.
Chickens and other egg-laying creatures are kept widely 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 worldwide from a total laying flock of approximately 6.4 billion hens. There are issues of regional variation in demand and expectation, as well as current debates concerning methods of mass production. In 2012, the European Union banned battery husbandry of chickens.
While it’s true that just one large egg yolk has 200 mg of cholesterol—making it one of the richest sources of dietary cholesterol—eggs also contain additional nutrients that may help lower the risk for heart disease. In addition, the moderate amount of fat in an egg, about 5 grams, is mostly monounsaturated and polyunsaturated fat. It’s also crucial to distinguish between dietary cholesterol and cholesterol in the blood, which are only weakly related. The focus on dietary cholesterol alone was de-emphasized as more attention was placed on the influence of saturated and trans fat on blood cholesterol. Accordingly, the Dietary Guidelines for Americans 2015 removed the prior recommendation to limit consumption of dietary cholesterol to 300 mg per day.
Given their history, “are eggs healthy?” has become a frequently asked nutrition question. To answer this, it’s important to look at eggs not only on their own, but in context of the entire diet, especially when compared to foods they may replace (and vice-versa).
Source Of
- Cholesterol
- Protein
- Choline
- Biotin – Vitamin B7
- Vitamin A
- Antioxidants lutein and zeaxanthin
Eggs and Health
- Research on moderate egg consumption in two large prospective cohort studies (nearly 40,000 men and over 80,000 women) found that up to one egg per day is not associated with increased heart disease risk in healthy individuals.
- Eggs were previously associated with heart disease risk as a result of their high cholesterol content. However, a solid body of research shows that for most people, cholesterol in food has a smaller effect on blood levels of total cholesterol and harmful LDL cholesterol than does the mix of fats in the diet.
Of course, this research doesn’t give a green light to daily three-egg omelets. While a 2008 report from the Physicians’ Health Study supports the idea that eating an egg a day is generally safe for the heart, it also suggests that going much beyond that could increase the risk for heart failure later in life. You also need to pay attention to the “trimmings” that come with your eggs. To your cardiovascular system, scrambled eggs, salsa, and a 100% whole-wheat English muffin is a far different meal than scrambled eggs with cheese, sausages, home fries, and white toast.- People who have difficulty controlling their total and LDL cholesterol may also want to be cautious about eating egg yolks and instead choose foods made with egg whites. The same is true for people with diabetes. In studies including the Nurses’ Health Study and Health Professionals Follow-up Study, heart disease risk was increased among men and women with diabetes who ate one or more eggs a day. For people who have diabetes and heart disease, it may be best to limit egg consumption to no more than three yolks per week.
- Furthermore, to truly assess eggs and heart health, we need to examine how they stack-up to foods we might choose in their place—the classic nutrition substitution analysis. Using some common breakfast options as an example:
- While eggs may be a much better choice than sugary, refined grain-based options like sweetened breakfast cereals, pancakes with syrup, muffins, or bagels, they may fall short of other options. A bowl of steel-cut oats with nuts and berries, for example, will be a much better choice for heart health than an egg-centric breakfast. Consumption of whole grains and fruit predict lower risk of heart disease, and when it comes to protein, plant sources like nuts and seeds are related to lower cardiovascular and overall mortality, especially when compared to red meat or eggs.
