Arrow-right Camera
The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Ask Doctor K: Eggs aren’t the culprit once thought

Anthony L. Komaroff M.D.

DEAR DOCTOR K: I hope you can answer this question once and for all: Are eggs bad for your health or not?

DEAR READER: I don’t think any medical issue is ever settled “once and for all.” New knowledge sometimes modifies or even replaces old knowledge.

Regarding eggs, I was taught, first by my parents and then in medical school, that you should eat them infrequently. The reason? A single egg yolk contains a whopping 213 milligrams of cholesterol. The thinking, then, went that eggs would raise your blood cholesterol levels. That, in turn, would increase your chance of developing atherosclerosis – cholesterol-filled plaques on the walls of arteries. And that in turn would increase the risk of heart attacks and strokes.

Eggs also contain some heart-healthy substances: protein, vitamins B12 and D, riboflavin, folate, antioxidants and unsaturated fats. But the negative effects of cholesterol were thought to trump the positive effects of these substances.

Then research discovered that saturated fats in your diet raise your blood levels of total cholesterol and “bad” LDL cholesterol a lot more than does cholesterol in your diet. Why? Because most of the cholesterol in your body does not come from your diet. Rather, it is made by your liver. And saturated fats in your diet cause your liver to make lots of cholesterol. (A large egg contains only about 1.5 grams of saturated fat.)

The next discovery came from large observational studies. Hundreds of thousands of people in these studies have been followed for decades.

These studies show that the average healthy person suffers no negative health effects from eating an egg a day. Plus, some studies have shown that eating eggs regularly increases “good” HDL cholesterol and decreases triglycerides.

However, the studies did find some evidence that people with diabetes or people who already have heart disease probably should eat no more than three egg yolks per week. (Eating just the whites is fine.)