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The humble egg has been on a roll lately. First, the US Department of Agriculture recalculated the amount of dietary cholesterol in a typical large egg downward—from 215 to 185 milligrams—and vitamin D upward (to 41 IU, 10% of the Daily Value). Then, earlier this year, the Dietary Guidelines Advisory Committee (DGAC) concluded, given current intakes of dietary cholesterol in the US, it was no longer necessary to recommend that most people limit dietary cholesterol to 300 milligrams daily. (See the May newsletter for details.) That limit had led many people to avoid eggs.
So is it OK—even advisable—to eat eggs again? Tufts professor Alice H. Lichtenstein, DSc, who served as vice-chair of the DGAC, advises, “Having an egg every day or a couple of eggs every other day, without bacon or sausage, should be fine for most people. Going back to the high levels of cholesterol intake we saw in the 1950s is likely not fine for most people.”
HEART HEALTH: The link between egg consumption and cardiovascular disease or unhealthy blood cholesterol levels has always been tenuous. In 2000, a review of epidemiological studies concluded that,when other dietary factors were considered, no association was seen between egg consumption at levels up to about one egg per day and the risk of coronary heart disease in non-diabetic men and women. A 2005 study found that healthy older adults who spent a month eating three eggs a day saw increases in both unhealthy LDL and healthy HDL cholesterol; overall, however, the LDL/HDL and total cholesterol/HDL ratios did not change.
Even at 185 milligrams of dietary cholesterol, one egg represents more than half of the long-standing limit of 300 milligrams a day. But the cholesterol in foods like eggs is different from the LDL cholesterol in your blood that contributes to heart disease. “Cholesterol in food is not the major factor in unhealthy blood cholesterol levels,” says Lichtenstein, noting that the American Heart Association dropped its recommended dietary cholesterol limit in 2013. “The major focus needs to be replacing saturated fat with polyunsaturated fat, as in liquid vegetable oils.”
CAUTIONS: People who have been told they have high LDL cholesterol or other heart disease risk factors, or people already suffering from type 2 diabetes, may still want to limit their cholesterol consumption—and eggs are a concentrated dietary source of cholesterol.
And anyone concerned about health should take care about what accompanies eggs on your plate. If you typically eat a couple of pieces of bacon or other processed meats whenever you eat an egg, you may be increasing your health risks—but don’t blame the eggs. Other typical breakfast foods often served with eggs, such as pancakes, waffles, muffins and toast, can add refined carbohydrates to your diet; make sure to choose whole grains at breakfast as at other meals.
NUTRIENT RICH: On their own, eggs are a nutritional powerhouse with only 70 calories per large egg. Except for fiber and carbohydrates, eggs deliver at least some of almost every important nutrient and are an exceptional source of protein. The seven grams of protein in a large egg contain all the essential amino acids; the World Health Organization uses eggs as the standard for evaluating the biological value of protein in all other foods.
Eggs contain small amounts of all the B vitamins, but are most notable for choline, a nutrient usually grouped with the B-complex vitamins that is important for brain and nerve function. Most Americans get only about 300 milligrams of choline daily, short of the adequate intake (AI) of 425 milligrams for women and 550 for men. One large egg has about 125 milligrams of choline.
Although eggs are not a particularly rich source of minerals, they do contain selenium (15.3 micrograms, 20% of the DV), which people who don’t like seafood may not get enough of. Eggs also contain iodine (24 micrograms, 16% of the DV), which people who don’t consume dairy products or iodized salt may lack.
Egg yolks are a source of the carotenoids lutein and zeaxanthin, which help protect the eyes against conditions such as macular degeneration. Although the amounts in eggs are relatively small, some research has shown these may be more readily used by the body than when obtained from other foods.
Eggs can be a source of omega-3 fats, which benefit both the heart and brain. Producers have boosted levels of omega-3s as high as 250 milligrams per egg by adding krill, algae and flaxseed oil to hens’ diets. But Lichtenstein cautions, “This is not the case for the majority of eggs; consumers pay a high price to get omega-3s from eggs.” Better and cheaper sources include soybean and canola oils and flaxseed.
YOLK VS. WHITE: The nutrients in eggs are split between the yolk and the white, with a little more than half the protein found in the white and almost all the fat and calories in the yolk. The yolk also contains all the carotenoids, vitamins A, D, E and K, and most of the mineral content of the egg. The white has most of the niacin and riboflavin, while the yolk is higher in other B vitamins.
Liquid egg substitutes are made from the white only, so have fewer calories and no fat or cholesterol. Some varieties contain added vitamins and minerals to make up for those otherwise found in the yolk; check the label.