Are Eggs Good for You or Not?

The reputation of the common chicken egg has taken quite a wild ride over the last fifty years. While it was once the staple of a wholesome breakfast, the egg’s reputation spiraled downward to the point where its name became almost a dirty word, rarely uttered by anyone seeking a healthy lifestyle. Blaming cholesterol and fat for the epidemic of heart disease in the western world, nutrition experts condemned the egg as a weapon of mass health destruction. But the tide seems to be turning for the once reviled egg, and some health experts are now exalting its benefits. So what is the truth of the matter? Does eating a couple of eggs for breakfast every morning guarantee an early death, or can we find a way to clear the egg’s name?

The first health benefit many people will point to when considering the merits of the egg is the protein content. Indeed, they have been a favorite of bodybuilders and strength athletes for decades. The protein in eggs is of such high biological value to humans that researchers use eggs as the basis for the measurement of other protein sources.

One large egg contains about 70 calories, 6 grams of protein, no carbohydrates and 5 grams of fat. The white of the egg is composed entirely of lean protein, about 4 grams worth. The yolk contains the bulk of the fat, plus a couple of grams of protein. For this reason, nutrition professionals often advocate consuming only the white and ditching the yolk.

Many health advocates are reconsidering that recommendation, citing important nutrients within the yolk. Calcium, magnesium, and phosphorus are minerals contained within the egg's yolk in high percentages compared to the white. Eggs are packed with potassium, 25% of which is found in the yolk. Eggs yolks are a good source of carotenoids, which may help protect against macular degeneration and cataracts. Yolks contain essential fatty acids and nutrients such as choline which are important for brain and nervous system health, among other things. Eggs are also a great source of vitamin D.

The fat content of eggs has often come under fire, but saturated fat is the thing experts recommend avoiding. Of the 5 grams of fat in a large egg, only 1.5 is saturated fat. Experts suggest keeping saturated fat for the average adult under 20 grams per day, so one could eat quite a few eggs and remain under that number.

But eggs do contain a lot of cholesterol, a fact that may have contributed to their downfall more than anything else. The American Heart Association suggests keeping cholesterol levels below 300 mg per day, and an egg contains about 200 mg. Seems like to avoid a heart attack you can’t eat more than one egg per day, and who eats only one egg? But where did we get this idea that dietary cholesterol is so bad for you anyway, and why are some experts backpedalling on their original recommendations to reduce the amount of cholesterol we eat to maintain a healthy heart?

The smear on dietary cholesterol starts back half a century with Ancel Keys and the Lipid Hypothesis. Working off the idea that dietary fat was somehow linked to heart disease, Keys conducted a study based on the nutrition information from twenty-two different countries in hope of finding a correlation. Sure enough, Keys found that populations who consumed less animal fat had lower incidence of heart disease, and he therefore concluded that consumption of animal fat leads to heart disease. Furthermore, serum cholesterol was a strong indicator of heart disease. Key’s conclusions became known as the Lipid Hypothesis, and were adopted by the U.S. Government as official policy. Ever since then, fat and cholesterol in the diet have been scorned, based on the work of Ansel Keys.

But there are few problems with Dr. Keys’s research. For one thing, even though he had data on twenty-two countries, for some reason he tossed out fifteen of them and based his findings on only seven countries. He threw out countries where citizens ate a lot of fat and cholesterol but had little heart disease, and he threw out countries where people ate very little animal fat but still had high incidence of heart disease. Indeed, Keys has been highly criticized for bending the data to fit his original hypothesis.

More recent research has poked holes in Key’s work. Many cite the fact that in the years since Key’s recommendations have become official U.S. policy our citizens have become fatter and sicker. Other studies more directly point out that cholesterol and even animal fat are in no way related to heart disease.

The Framingham Study is one such project. Since 1948, residents of Framingham, Massachusetts, have been participating in a health study which monitors their food intake, among other measurable points. In various reports, again and again researchers have been unable to correlate cholesterol levels and heart disease.

So, does this mean that the cholesterol in eggs won’t make you have a heart attack? Apparently, like everything else in nutrition, it depends on who you believe. The American Heart Association continues to trumpet a reduced-cholesterol and low-saturated-fat diet to ward off heart problems, but research is gradually beginning to point to inflammation caused by high blood sugar as the culprit in cardiovascular disease. Some claim the Lipid Hypothesis will be out the window in the decade or so to come, but until then official recommendations still say to watch your dietary cholesterol.

Should you eat whole eggs, eat only the yolk, or avoid them altogether? The best advice is probably to examine the data yourself and decide. Eggs have many health benefits, from serving as a great protein source, to preventing eye problems, to maintaining brain health. The downside is the cholesterol.

Research is ongoing, and hopefully science will eventually be able to tell us once and for all if the egg is really the evil destroyer of health many experts have claimed for decades. But most people aren’t waiting for this verdict: About 75 billion eggs are produced in the United States each year, and consumed or used in one form or another. That’s a lot of eggs! If that number can be any indication, it seems that most people do believe eggs are good for your health!