It was previously thought that eggs raises blood or serum cholesterol levels -- one of the main causes of heart disease. One large egg has about 213 mg of cholesterol — all of which is found in the yolk. Egg whites contain no cholesterol. The yolk in a single large egg also contains about five grams of fat, so it was only natural for nutritionists to assume that eggs clogged up people's arteries, especially since they also contain dietary cholesterol.
It is important to understand the difference between dietary cholesterol and blood cholesterol. Dietary cholesterol is found in certain foods, such as meat, poultry, seafood, eggs, and diary products. Blood cholesterol (also called serum cholesterol) is produced in the liver and floats around in our bloodstream. Blood cholesterol contain High-Density Lipoprotein (HDL), and Low-Density Lipoprotein (LDL). LDL cholesterol is considered bad because it sticks to artery walls. Too much of it can increase the risk of coronary heart disease or stroke in men or women. Many studies now show that consuming food high in dietary cholesterol e.g. egg does not increase blood cholesterol.
A long term study conducted over 25 years by Dr. Wanda Howell and colleagues at the university of Arizona shows that eating a lot of dietary cholesterol doesn't increase blood cholesterol. The study revealed that people who consume two eggs each day with low-fat diets do not show signs of increased blood cholesterol levels.
A recent study published in the American Journal of Clinical Nutrition showed that siginificantly reducing your dietary cholesterol consumption will only lower blood cholesterol levels by an average of 1%!
Another study conducted in 2007 of 9,500 people reported in Medical Science Monitor shows that eating one or more eggs a day did not increase the risk of heart disease or stroke among healthy adults, and that eating eggs may be associated with a decrease in blood pressure. Also in 2007, researchers showed that egg consumption contributed less than 1 percent of the risk for heart disease when other risk factors were taken into account. The researchers concluded that broad recommendations to limit egg consumption may be misguided, particularly when eggs' nutritional contributions are considered.
So what does raise blood cholesterol? One of the main theories is that saturated fat does. Of the three types of fat (saturated, monounsaturated and polyunsaturated), saturated fat raises blood cholesterol and LDL levels. Eggs contain mostly polyunsaturated fat, which can actually lower blood cholesterol if one replaces food containing saturated fat with eggs.
All-natural eggs are rich in nutrients. Each egg has 13 essential vitamins and minerals, high-quality protein, healthy unsaturated fats and antioxidants. The high quality protein in eggs helps you to feel full longer and stay energies which contributes to weight management. The high-quality protein also help active adults to build muscle strength and help prevent muscle loss in middle-aged and aging adults. Eggs are also helpful in pregnancy. Egg yolks are an excellent source of choline, an essential nutrient that contributes to fetal brain development and helps prevent birth defects. Two eggs provide about 250 milligrams of choline, or roughly half of the recommended daily intake for pregnant and breastfeeding women. Choline also aids the brain function of adults by maintaining the structure of brain cell membranes, and is a key component of the neuro-transmitter that helps relay messages from the brain through nerves to the muscles. Eggs are also beneficial to the eyes. Two antioxidants found in egg yolks, lutein and zeaxanthin, help prevent mascular degeneration which is a leading cause of age-related blindness.
A survey of healthy adults conducted by the Egg Nutrition Center shows that nearly one out of four Americans still avoid eggs for fear of dietary cholesterol. This is despite the fact that 30 years of research has never linked egg consumption to heart disease. As a result of this myth, many Americans are missing out on the beneficial nutrients of the egg.