In June, the consumer group Center for Science in the Public Interest blew its top -- excoriating egg companies in a news release for adding omega-3 fatty acids to their eggs (via nutrients added to the hens' feed) then trumpeting the eggs' nutritional fabulousness. An egg contains just more than 200 milligrams of dietary cholesterol, above the dietary limit set by the American Heart Assn. for people at increased risk of heart disease.
The center was angered because at least some of the egg companies add a flaxseed-derived omega-3 called AHA to the feed. This, although an omega-3, is only inefficiently converted to the DHA and EPA omega-3s that help the heart. The group was equally outraged at the idea that eggs, with all their cholesterol, would be considered a healthful delivery system.
But, in fact, they may just be.
The main dietary culprit in raising cholesterol is not the cholesterol we eat, says Dr. Joseph Keenan, a professor of medicine and cholesterol researcher at the University of Minnesota. A diet high in saturated fats has a far greater effect on the bad, or LDL, cholesterol in our bloodstream. That's partly because our bodies use only 25% of the cholesterol we eat but 75% of cholesterol in the bloodstream.
Some researchers say that the confusion over blood cholesterol and dietary cholesterol may have resulted in the egg getting a far worse reputation than it deserves. Eggs, they note, are inexpensive, full of protein and contain high levels of lutein and zeaxanthin, which may protect against blindness from macular degeneration.
A recent issue of Nutrition Source, a consumer bulletin published by the Harvard School of Public Health, ticked off a few more egg attributes, including the vitamins B12 and D, riboflavin and folate, which may help lower the risk of heart disease.
Clouding the issue is the fact that many studies have been funded by the American Egg Board, a trade association. But a 1999 study published in the Journal of the American Medical Assn. by Harvard University researchers and funded by university and federal money found that an egg a day does not increase the risk of heart disease in healthy people.
Currently, the American Heart Assn recommends that people with no risk of heart disease consume less than 300 milligrams of dietary cholesterol daily and that people with diabetes, heart disease or elevated LDL levels consume less than 200 milligrams per day.
But these dietary guidelines are reviewed every 10 years, most recently in 2000, and a Heart Assn. spokesperson doesn't rule out the possibility that eggs could come up for review in 2010. For now, though, the association sticks by its current position.
"A single egg contains about 213 milligrams of dietary cholesterol. So an egg a day could fit within an individual's dietary budget only if dietary cholesterol from other sources such as meats, poultry and dairy products were limited," says Alice Lichtenstein, past chair of the American Heart Assn.'s nutrition committee and a nutrition professor at Tufts University in Boston.
-- Francesca Lunzer Kritz