Eggs have a bad reputation because of their high cholesterol content: 185 milligrams in the yolk of a large egg. But, in fact, dietary cholesterol has relatively little effect on blood cholesterol in most people (saturated and trans fats are the bigger culprits)—and more recent research, including two new studies, has largely exonerated eggs and even suggested that they may provide some heart benefits.
Eggs and your heart
You may be surprised to know that dietary cholesterol, found in animal foods, raises blood cholesterol in only about one-third of people. And, as shown in some egg studies, dietary cholesterol causes the body to produce HDL (“good”) cholesterol along with LDL (“bad”) cholesterol in these “hyper-responders,” thus helping offset potential adverse effects. Moreover, the LDL particles that form are larger in size—and larger LDL particles are thought to be less dangerous than small ones.
Several years ago, research from the University of Connecticut found that eating three eggs a day for 30 days increased cholesterol in susceptible people, but their LDL particles were larger, and there was no change in the ratio between LDL and HDL, which suggests no major change in coronary risk. In a more recent study from the same university, published in Metabolism in late 2012, 40 middle-aged people with heart and diabetes risk factors ate either three eggs or cholesterol-free egg substitute daily, while also moderately restricting carbohydrates. After 12 weeks, total and LDL (“bad”) blood cholesterol did not change in either group. Moreover, though both groups showed a range of cholesterol improvements due to the carb restriction, the egg eaters had a greater boost in HDL (“good”) cholesterol as well as increases in sizes of both HDL and LDL particles, which was attributed, at least in part, to types of fat in eggs called phospholipids.
More significantly, eggs do not appear to contribute to heart disease in most people. A pivotal study from Harvard in 1999, of nearly 120,000 men and women, found no association between eggs—up to one a day—and heart disease, except in people with diabetes. Nor did it find a link between eggs and strokes. Studies since then have similarly vindicated eggs, including a Japanese study of more than 90,000 middle-aged people published in the British Journal of Nutrition in 2006, and a study in 2007 from the University of Medicine and Dentistry of New Jersey, which both found no link between frequent egg consumption and heart disease. Most recently, an analysis of eight observational studies found no relationship between eggs (up to one a day) and heart disease or stroke. Published this year in BMJ, it included nearly half a million people who were followed from 8 to 22 years, on average.
In light of these findings, recommendations about eggs have changed over the years, and cholesterol guidelines, in general, are being rethought.
The unsaturated fats and other nutrients, including B vitamins, in eggs may even be beneficial to heart health. It’s the foods that typically accompany eggs (bacon, sausage, cheese and biscuits) and how eggs are often prepared (fried in lots of butter) that can raise blood cholesterol and the risk of heart disease. A large egg has only 1.5 grams of saturated fat and about 70 calories. A Bacon, Egg & Cheese Biscuit from McDonald’s, on the other hand, has 12 grams of saturated fat (59 percent of the daily value for someone eating a 2000-calorie-a-day diet) and 420 calories, along with 1,130 milligrams of sodium.