Eggs and Cholesterol

The egg has gotten a negative reputation due to its elevated cholesterol content.

Is the egg as harmful to cardiovascular patients as had been thought?

The egg is the richest of animal products in cholesterol (425 mg/100 g). Only brain tissue is higher (2,200 mg/100 g).

The egg contains so much cholesterol because this lipid is indispensable for the development of the nervous system andendocrine glands of the embryo. However, humans do not need to take in cholesterol through their food, since the liver is capable of producing even more than the body needs.

One egg contains about 250 mg of cholesterol, an amount close to the 300 mg daily upper limit. This means that eating one egg a day and any other animal product (milk, meat, fish, etc.) substantially surpasses the 300 mg of cholesterol considered the maximum daily allowance.

In addition to an increase in cholesterol level, other factors such as smoking, lack of physical exercise, or obesity, contribute, as well, to lipoprotein oxidation and to arteriosclerosis. To the contrary, vegetables and fruit rich in antioxidants inhibit this degenerative process.



Eggs Raise Cholesterol Only Slightly......


A study at the Copenhagen Clinic for the Study of Preventive Health (Denmark) demonstrates that eating two hardboiled eggs a day for six weeks produces:

• an increase in HDL cholesterol (beneficial) of 10%.


• a slight increase in total cholesterol of 4%.

If this is the case with two eggs a day, it is reasonable to say that moderate consumption of two or three eggs a week does not raise blood cholesterol level.

This and other discoveries confirm that the moderate use of eggs does not increase blood cholesterol level. In fact, cholesterol from food has a relatively limited impact on the blood levels of this lipid. Saturated fat increases cholesterol levels more than food cholesterol itself.

......But Promote Arteriosclerosis

Even though eggs do not raise blood cholesterol levels as much as was once thought, they do promote arteriosclerosis to a greater degree than was thought.

Cholesterol is only dangerous when it is deposited on the walls of arteries, which become hardened and narrower. Recent investigations have shown that this process, known as arteriosclerosis, is initiated by the oxidation of low-density lipoproteins (LDL), the substances transporting cholesterol in the blood plasma.

Studies conducted at the Rambam Medical Center in Haifa (Israel), have shown that the consumption of two eggs a day for three weeks increases oxidation of plasma lipoproteins by 42%. This means that eggs promote the process of arterial deterioration and arteriosclerosis.

Prevention of Arteriosclerosis and Cardiovascular Disease

Those at high risk for arteriosclerosis and cardiovascular disease in general because of high cholesterol levels or other causes, should:

• Avoid eating eggs, and use substitutes in their place.


• Discard the yolk of the egg. The egg white contains no fats, and as has been shown, its use reduces cholesterol levels.


• Use eggs enriched with omega-3 fatty acids, which do not increase cholesterol and reduce triglyceride levels.


• Never eat more than two eggs a week.


• Avoid fried eggs, which supply more fat since they retain frying oil, thus promoting an increase in cholesterol.

The Egg and Hygiene

The egg is the ideal medium for the development of microorganisms. Although eggs contain protective membranes and antibacterial proteins such as lysozyme, many commercially available eggs are contaminated, even in developed countries.

A study conducted at the Institute of Social Medicine and Epidemiology in Berlin (Germany) shows that Salmonella bacteria in eggs are responsible for 67% of all food-related poisonings.

Avoiding Egg-Transmitted Infections

• Avoid eating raw eggs: Sauces, particularly mayonnaise, are excellent media for the development of microorganisms from: 1). the egg itself. 2). external contamination from hands, hair, and saliva of those handling the material during preparation. Pasteurized egg products should be used in place of raw eggs.


• Discard eggs with cracked shells. Intact eggs may be contaminated with salmonella because bacteria penetrate the shell through its numerous pores. Those with damaged shells present an even greater risk of contamination.


• Discard eggs contaminated with feces on the shell. Washing does not eliminate the possibility of contamination, since the microbes have usually already entered the egg.


• Store eggs in the refrigerator and never longer than three weeks.


• Use the freshest (most recently laid) eggs possible. The longer an egg is stored, the greater the possibility that bacteria have developed in its interior.

How To Tell if an Egg Is Fresh

Recently laid eggs sink in water. As time passes, part of the water within the egg evaporates through the pores in the shell. This enlarges the air space in the egg and causes it to float.

The yolk in recently laid eggs is found in the center. As the egg ages, the yolk moves to the side.

By observing a back-lit egg, one can see the size of the air space and the position of the yolk. As the egg ages, the separation between the yolk and the egg white becomes less distinct.