Not long ago a study published in the journal Athersclerosis reported that the more egg yolks a people ate the thicker their artery walls became. That indicates a higher risk of heart disease. Also, the effect was nearly as bad as from smoking cigarettes. The Egg Nutrition Center and American Egg Board voiced other ideas.
Researchers measured the buildup of carotid plaque in the arteries of 1,231 subjects. The men and women in the study were all patients at cardiovascular health clinics. For comparison’s sake, the team also measured the carotid plaque buildup of smokers in the study.
Plaque buildup increased according to age – after age 40 in a fairly steady fashion. But among the 20 percent of participants who reported eating the most egg yolks – three or more per week – carotid plaque increased “exponentially,” according to the study. The buildup equaled about two-thirds of that seen among the heaviest smokers in the group.
Arterial plaque buildup is a major risk factor for heart attack and stroke; as plaque accumulates on artery walls, it narrows the space through which blood can pass, making the heart’s job of pumping more difficult. Moreover, plaque buildups can break away from the arterial wall, forming clots that can do terrible, even fatal, damage if they reach the heart or brain.
For the record, here is the nutritional breakdown of a large (56 gram) egg from SELFNutritionData:
Total Fat 6 grams
Saturated Fat 2 grams
Cholesterol 237 mg
Sodium 78 mg
Protein 7 grams
Time Magazine said, ABC News reported reservations about the study. “This is very poor quality research that should not influence patient’s dietary choices,” said Dr. Steven Nissen, who chairs the department of Cardiovascular Medicine at the Cleveland Clinic Foundation, in an email. “It is extremely important to understand the differences between ‘association’ and ‘causation’.”
Nissen said the researchers relied on patients to recall how many eggs they consumed, but asked them once and assumed it remained constant, which isn’t reliable. He said the way researchers measured patients’ plaque has come under “considerable criticism,” and that researchers failed to adjust for other dietary factors.
The researchers concluded, “Our findings suggest that regular consumption of egg yolk should be avoided by persons at risk of cardiovascular disease. This hypothesis should be tested in a prospective study with more detailed information about diet, and other possible confounders such as exercise and waist circumference.
Important accompanying facts that didn’t get included were how much or little the subjects exercised. Also, people who eat eggs a lot tend to eat other high-fat and high-salt high-cholesterol foods, as opposed to hard-boiled eggs. (My emphasis)
The Egg Nutrition Center and the American Egg Board responded, “Eggs have been shown to have a wide range of health benefits, providing 13 essential vitamins and minerals, high-quality protein and antioxidants, all for just 70 calories. Years of credible research has demonstrated the positive effects of the high-quality protein and nutrients in eggs on satiety, weight management, eye health and in supporting a healthy pregnancy….”
They cited, “A Harvard study with more than one hundred thousand subjects found no significant difference in cardiovascular disease risk between those consuming less than one egg per week and those consuming one egg per day. The researchers concluded that consumption of up to one egg per day is unlikely to have substantial overall impact on the risk of heart disease or stroke among healthy men and women. Another study published in Risk Analysis estimates that eating one egg per day is responsible for less than one percent of the risk of coronary heart disease in healthy adults. Alternatively, lifestyle factors including poor diet, smoking, obesity and physical inactivity contribute to 30 to 40 percent of heart disease risk, depending on gender. Additionally, research has shown that saturated fat may be more likely to raise a person’s serum cholesterol than dietary cholesterol.”
On the subject of exercise, they said, “Research indicates that high-quality protein may help active adults build muscle strength and middle-aged and aging adults prevent muscle loss. Consuming eggs following exercise is a great way to get the most benefits from exercise by encouraging muscle tissue repair and growth.” (My emphasis)
I have to confess that I have a horse in this race. My first job as a reporter was on the floor of the Chicago Mercantile. I wrote daily about the commodities futures traded there which included live cattle, shell eggs and pork bellies (bacon). Writing about eggs and talking with folks in the industry, I started eating hard-boiled eggs regularly. I am over 70 years old and ride my bike an average of 20 miles a day. I have no evidence of the problems mentioned by detractors. For the record, I am checking with my doctor on this.