Once demonised as bad for the heart, eggs have been repositioned as a health food in recent years as researchers have found that not only are they good for hearts, but can even help you to lose weight.
More importantly, a report by Ying Rong of Huazhong University of Science and Technology and her colleagues published in the British Journal of Medicine in January, reviewed 17 different egg studies.
The study concluded, "Higher consumption of eggs (up to one egg per day) is not associated with increased risk of coronary heart disease or stroke. The increased risk of coronary heart disease among diabetic patients and reduced risk of hemorrhagic stroke associated with higher egg consumption in subgroup analyses warrant further studies."
So how did eggs get so controversial in the first place?
A lot of it has to do with cholesterol. A large egg contains about 186 mg of cholesterol. And since the American Heart Association (AHA) recommends a limit of 300 mg per day, eat two eggs and you've exceeded that limit.
So, eggs are bad then?
Not so fast. There happens to be a problem with the AHA's recommendation. It assumes that when you eat more cholesterol (from eggs and other animal foods), your blood cholesterol increases.
Assume that and, of course, it makes sense to eat fewer eggs. Your blood cholesterol would be lower. Your heart and arteries would stay healthier for longer. But here's the AHA's dirty little secret: your body doesn't work that way. Indeed, the research consistently and reliably shows that the cholesterol you eat has very little impact on how much cholesterol is in your blood. If that sounds weird, maybe this will help... Your body makes cholesterol. Lots of it, in fact. Every single day you produce between 1 and 2 grams of it on your own. (That's 5-10 times the cholesterol in a large egg.)
The interesting twist? When you eat more cholesterol from foods like eggs, your body produces less of it. And when you eat less cholesterol from foods like eggs, your body produces more.
That's because you have a cholesterol "set point." Think of it like a thermostat that's largely determined by your genetics, exercise habits, and stress. Funny enough, diet plays a surprisingly small role.
Furthermore cholesterol isn't so bad for you anyway...
Cholesterol is a very important part of the body. It is a structural molecule that is an essential part of every single cell membrane. It is also used to make steroid hormones like testosterone, estrogen and cortisol. Without cholesterol, we wouldn’t even exist.
More evidence eggs are really a healthy food.
Since your body naturally has all it needs from producing its own cholesterol, there is no dietary requirement for more cholesterol. But the American diet contains plenty, since we eat a lot of animal products. All animal products contain some cholesterol, but they also contain saturated fat, an even more significant culprit in heart-disease risk. Actually the major determinant of plasma LDL level is saturated fat. And while eggs are high in cholesterol, they're relatively low in saturated fat (1.6 grams in the yolk). Interestingly, people in Japan — consumers of some of the largest quantities of eggs in the world (averaging 328 eggs consumed per person per year — have low levels of cholesterol and heart disease compared with other developed countries, especially the United States. Why? In part, it's because the Japanese eat a diet low in saturated fat.
Americans do just the opposite. Research has shown that we usually have our eggs alongside foods high in saturated fat, such as bacon, sausage and buttered toast. This meal pattern raises LDL levels and makes the effect of eating eggs worse than it actually is.
And what about eggs and weight loss?
Interestingly, in controlled trials -- the best kind of research -- where people were instructed to eat up to three eggs per day while on a weight loss diet, good things happened.
These folks lost weight, decreased inflammation and either maintained or improved their blood cholesterol levels. (They were consuming 555 mg of cholesterol every day from eggs alone!)
Some more reasons to introduce eggs into your diet
Egg yolks are one of the most nutrient-dense, antioxidant-rich and vitamin-laden foods on the planet! (Compared to the yolks, the whites are pretty much protein and water.) Egg yolks contain 90% of the calcium, iron, phosphorus, zinc, thiamin, B6, folate, pantothenic acid and B12 of the egg. In addition the yolk contains all of the fat-soluble components, such as vitamins A, D and E, not to mention the heart-healthy omega-3 fatty acids.
Egg yolks are also a rich source of some other very interesting nutrients such as choline, lutein and zeaxanthin.
Choline is essential for cardiovascular and brain function. Eating more of it may mean mean less inflammation, heart disease, diabetes, Alzheimers, and more.
Lutein and zeaxanthin are the major antioxidants in eggs. They protect the eyes by filtering harmful light wavelengths and lowering risk of macular degeneration.
Indeed, those people eating only egg whites -- or avoiding eggs entirely -- are missing out on many of these key nutrients.
How much is too much
Many experts say an egg a day is fine. "The amount that one egg a day raises cholesterol in the blood is extremely small, so small in fact that the increase in risk in heart disease related to this change in serum cholesterol could never be detected in any kind of study," says Walter Willett, professor of epidemiology and nutrition at Harvard's School of Public Health."Elevations in LDL of this small magnitude could easily be countered by other healthy aspects of eggs."
Bottom line: if you eat a healthful diet, go ahead and eat an egg a day. On the other hand, if your cholesterol is high and if you eat the typical American diet — high in saturated fat, devoid of fruits, vegetables and fiber — maybe you shouldn't be eating an egg a day.
But will taking eggs out of an unhealthy diet make a positive difference? Probably not. Certainly you too happened to hear people complaining "I've cut out eggs, but my cholesterol is still high!". The impact of a healthy, balanced diet cannot be denied here.
Sources: http://www.dailymail.co.uk/, http://authoritynutrition.com/, http://www.livescience.com/