Eggsaggerations: cracking open egg myths.
"If you have normal cholesterol, follow a low-fat diet and love eggs, go ahead and enjoy them. Your cholesterol probably won't go up enough to notice."
The egg industry's message isn't falling on deaf ears. From the New York Times to popular magazines like American Health and Forbes, the media has been eagerly printing these "man bites dog" reports. A headline like "Go ahead and eat an egg--it won't kill you isn't just good news for sunny-side-up fans. It's a good story.
Unfortunately, the egg industry's myths--and the reporters who swallow them whole--tend to exaggerate. The result: Millions of Americans are now convinced that not just one, but two or three, eggs a day is okay.
Maybe for egg producers, but not for your arteries.
Myth # 1: Eggs don't raise blood cholesterol.
"Two recent studies published in a leading scientific journal showed that 20 healthy young men and 13 healthy young women with normal blood cholesterol levels could eat up to two eggs a day while on a low-fat diet without significantly boosting their blood cholesterol levels," declares the Egg Board's advertising. "Up to two eggs a day!"
For years, the egg industry has been hammerind a single message into the public's consciousness: Eggs
Yet the National Heart, Lung and Blood Institute, the American Heart Association (AHA), the National Academy of Sciences, and other health authorities have concluded that high-cholesterol foods like eggs do raise cholesterol levels in your blood. The AMA's advice: Eat no more than four egg yolks a week (egg whites are cholesterol-free).
Why the discrepancy? The egg industry relies on studies--many of which it has paid for--that have two major flaws:
* they minimize eggs' impact on blood cholesterol by feeding them to young people with low cholesterol levels, and
* they're poorly controlled because people are not fed all their meals by researchers.
"In the best studies--in which scientists fed healthy people ordinary foods in a research institution to control their diets--the evidence is incontrovertible that cholesterol added to the diet raises both total and LDL ['bad'] cholesterol," says Jeremiah Stamler, a world renowned expert on heart disease who is now professor emeritus at the Northwestern University School of Medicine in Chicago. How much?
Researchers at Oxford University recently published a meta-analysis that pooled results from only well-designed studies. 1 Their estimate: The cholesterol in a single egg yolk raises blood cholesterol by 5.4 points. For a typical serving of two eggs, that's close to 11 points.
For someone with a blood cholesterol of 205--now the average for American adults--11 points means a 5.4-percent increase. That's not peanuts.
"Every one-percent rise in blood cholesterol translates to a two-percent rise in the risk of heart disease," says Stamler. "So adding two egg yolks a day to your diet means a 10.8-percent rise in heart disease risk. That's an important increase."
Myth #2: Eggs cause harm only by raising cholesterol.
What's the evidence that high-cholesterol foods like eggs cause heart disease? To hear the egg industry tell it, the only question is whether eggs raise blood cholesterol.
"Yet that's only a small part of the picture,H says Stamler. Among the evidence that the industry ignores:
* Animal studies. "Thousands of experiments on numerous species--including rabbits, chickens, and monkeys--have shown that you cannot produce lesions in coronary arteries and heart attacks without feeding cholesterol," says Stamler. "Stop feeding them cholesterol and their arteries clear up."
Even when the animals are fed amounts of cholesterol that are too small to cause high blood cholesterol, the animals get lesions in their arteries, he adds."
* Population studies. In a number of studies, people who report eating more cholesterol are more likely to die of heart attacks--regardless of their blood cholesterol levels.
"Dietary cholesterol has an independent effect on heart disease risk over and above its effect on blood cholesterol," says Stamler.
Myth #3: Most people have genes that protect them from cholesterol.
"Today we know that some two-thirds of the population can eat dietary cholesterol without a significant rise in blood cholesterol,H said C. Wayne Callaway in American Health magazine in November 1995. Callaway is an oft-quoted Washington endocrinologist who is not oft-identified as a consultant to the egg industry.
Eggs may raise blood cholesterol more in some people than in others. But some of those apparent differences are due to the fact that a person's cholesterol level varies from day to day.
That's one reason why many scientists won't say how many people do or don't "respond" to cholesterol in foods.
"I wouldn't want to estimate what percent of people are nonresponders," says Richard Weinberg, a gene expert at Bowman Gray Medical School in Winston-Salem, North Carolina. "It depends on your definition of a nonresponder." And that's from someone who serves on the Egg Board's Scientific Council.
Weinberg has found that eggs raise blood cholesterol less in people who have a gene called apo-IV-2 than in other people. "One out of seven people of northwestern European descent have the gene," he says.
"But some people with the gene respond to cholesterol as much as those without the gene." That's because not just one, but many, genes are probably involved, he explains. "We're years away from using information about genes to treat individuals."
Myth #4: It's easy to tell if eggs will raise your cholesterol.
"Ideally, a decision about one's diet would be based on individual tests of susceptibility to dietary cholesterol," explained an article in the New York Times in January 1995. "This would mean, for example, taking blood cholesterol measurements before and about 10 weeks after an increase in egg consumption...."
Sound impractical? That's not the half of it.
"You'd have to know not just how many eggs you eat, but the saturated fat and cholesterol content of your entire diet," says Weinberg.
That's because you might substitute eggs for something else that raises your cholesterol, like a danish that's high in saturated fat. Your cholesterol might not budge, but that wouldn't mean you're a nonresponder.
"And you'd have to test not just total cholesterol but HDL [`good'] and LDL [`bad'] cholesterol on three successive days to compensate for laboratory and individual variation," adds Weinberg.
So much for the self-test.
Myth #5: Eggs raise HDL ("good") cholesterol.
When the University of Washington's Barbara Retzlaff presented the results of her egg study at a conference in 1995, the media homed in on the good news that eggs could raise HDL cholesterol.
That's not what Retzlaff had in mind. The worst result of the media blitz, she says, was that "someone with heart disease called to tell me that he was going to start eating eggs to raise his HDL."
In fact, Retzlaff's goal was to find out if eggs raise cholesterol more in people with high blood triglycerides than in people with normal triglycerides. They did. And HDL also went up when both groups ate eggs.
But the recent British meta-analysis of 227 good studies found that eggs don't raise (or lower) HDL. What's more, even if eggs did raise HDL, that wouldn't give them a clean bill of health. "We can't presume that HDL goes up enough to offset any rise in LDL cholesterol," says Retzlaff. "We think that the American Heart Association's recommendation--to eat no more than four egg yolks a week--is reasonable."
Myth #6: Eggs are an exceptionally nutritious food.
"The egg is actually a powerhouse of good nutrition," wrote dietitian Kristine Napier in American Health magazine in November 1995.
Eggs do contain nutrients, but they're nothing special. Calorie for calorie, they have roughly the same vitamins, minerals, and protein as green peas...except that "incredible, edible" peas are a good source of fiber and have no fat or cholesterol.
The egg industry proudly hails the "complete" or "perfect" protein in eggs. But complete protein only matters if you get all your protein from a single food and if you're just barely getting enough protein. Neither applies to most Americans.
And eggs aren't even all that rich in protein. Two eggs have 12 grams--about as much as a cup of beans or yogurt or half a cup of cottage cheese. Even a small, three-ounce serving of tuna, chicken, or turkey has twice that much.
Myth #7: Only saturated fat raises blood cholesterol.
Saturated fat--in foods like meat, whole or 2% milk, cheese, butter, and pastries--boosts the average American's blood cholesterol more than the cholesterol in foods like eggs.
But the cholesterol in food also raises blood cholesterol. And eggs add more cholesterol to the average person's diet than any other food.
Two eggs also have three grams of saturated fat--that's 15 percent of your daily limit.
Worse yet, in a typical restaurant, a ham-and-cheese omelet has 17 grams of sat fat...awfully close to the 20-grams-a-day quota.
Says Barbara Retzlaff: "Maybe the biggest problem with eggs is how good they taste with butter and cheese."
Boiling it All Down
To some, it's a success story...and a rare one, at that. Since the mid1960s, egg consumption has fallen roughly in half--though some of that decline can be chalked up to a shift from sit-down family meals to breakfast on the run.
"The decline in egg yolk consumption is among the factors responsible for the sizeable decline in heart disease deaths over the last three decades," says Stamler. "Every effort to obscure the link is scientifically unsound and detrimental to the public health."
 Brit. Med. J. 314: 112, 1997.
 Circulation Research 34: 447, 1974
 Arch. Path. Lab. Med. 1 12:1032, 1988.
 N. Eng. J. Med. 331: 706, 1994.
 Circulation (Suppl. I) 92: I-350, 1995.
RELATED ARTICLE: FOR EGG-LOVERS ONLY
* When you scramble, keep the whites but use just one yolk. Also, try substituting a tablespoon of low-fat cottage cheese for every yolk you leave out of your scrambled eggs or omelet.
* When you make egg salad, use only whites, or no more than one yolk. Add low-fat mayo, dried or (better) fresh dill, and mustard and scallions to taste.
* Try using an egg substitute when making baked goods. They're pasteurized, so you can lick the batter without worrying about Salmonella food poisoning.
RELATED ARTICLE: THE BOTTOM LINE
* Eat no more than four egg yolks a week --fewer (or none) if you have high cholesterol.
* Cut back on saturated fat by eating less red meat, butter, cheese, 2% or whole milk, and pastries (see "The Cholesterol Countdown".
* Cook eggs thoroughly to reduce the risk of food poisoning with Salmonella.
RELATED ARTICLE: The Cholesterol Countdown
Use this chart to help you estimate how much cholesterol you typically eat. Within each category, foods are ranked from most cholesterol to least. We've added numbers for total and saturated fat. Sat fat also raises blood cholesterol.
Watch out for any food with more than a gram or two of sat fat per serving. Keep your daily intake to less than 20 grams of sat fat and 300 mg of cholesterol.
[TABULAR DATA NOT REPRODUCIBLE IN ASCII]
|Printer friendly Cite/link Email Feedback|
|Publication:||Nutrition Action Healthletter|
|Date:||Jul 1, 1997|
|Previous Article:||Lettuce be your guide.|
|Next Article:||Eggs: no yolking matter.|