Are Eggs Good or Bad For You?
Studies in nutrition are like that one person you know who says one thing one moment and then turns around and says the complete opposite. Coffee can disrupt your sleep and give you some unpleasant gut problems, but on the other hand, drinking a few cups a day will extend your life. Wine has the perplexing capability of both extending and shortening one's life. But nothing appears to have created the stir and volleying between “good" and "bad” than eggs. Hopefully after reading this article you will have a good idea what the current science tells us about eggs.
The egg’s tarnished reputation comes from the cholesterol the yolk contains. In 1973, the American Heart Association began urging us to cut down on our egg consumption as a means of protecting against cardiovascular (Heart) disease, which is associated with increased cholesterol levels.
Heart disease includes heart failure, arrhythmias and heart valve problems in addition to strokes and attacks. Raised blood pressure, carrying too much weight or obesity, and elevated blood sugar all contribute to the risk of cardiovascular disease, which is triggered by unhealthy diet, physical inactivity, smoking and excessive use of alcohol.
We now know however that the cholesterol in egg yolks doesn’t have much influence on serum cholesterol levels and by extension the risk of heart disease. As far back as 1999, a study from the Harvard School of Public Health published in the Journal of the American Medical Association found no increased risk of coronary heart disease or stroke among healthy men and women who ate as many as seven eggs per week compared to those who ate fewer than one per week. The researchers tracked over 117,000 American adults for up to 14 years to reach their conclusion.
More recent research suggests that saturated and trans fats - not cholesterol from foods - are the primary dietary factors responsible for increased cholesterol levels, although even the association with saturated fat is now in question.
In a more recent study published this year of over 460,000 adults in China, those that ate chicken eggs daily had an 18% lower risk of dying from cardiovascular disease, which manifests as heart attacks and strokes, compared with adults who did not eat eggs.
In that study, the research team tracked people over nearly nine years. They focused on major coronary events, such as heart attacks and strokes, including hemorrhagic strokes -- when a blood vessel bursts in the brain due, usually, to uncontrolled high blood pressure -- and ischemic strokes -- when a blood vessel feeding the brain becomes blocked, usually by a blood clot.
During follow-up, 9,985 people died of cardiovascular disease, and an additional 5,103 major coronary events occurred. Nearly 84,000 other participants were diagnosed with heart disease in this time period. Analyzing the data, the researchers found that eating about an egg a day related to a lower risk of heart disease compared with not eating eggs.
In fact, participants who ate up to one egg daily had a 26% lower risk of hemorrhagic stroke. Additionally, the egg eaters had a 28% lower risk of dying from this type of stroke. Finally, egg eaters also enjoyed a 12% reduced risk of ischemic heart disease, which is diagnosed in those who show the early signs of gridlocked blood flow to the brain.
It should be kept in mind that this new study is an observational and so cannot show a direct cause and effect between eating eggs and risk of heart disease. This being said, this is a very large study with the researchers doing the best possible job to control for other factor, and that in itself is a major strength.
Other systematic reviews of studies showed that when participants are provided with between 6 and 12 eggs a week, no change occurs in major cardiovascular risk factors, including higher rates of blood sugar, inflammation and cholesterol.
Eggs as Part of a healthy diet
Egg yolks contain a rich array of essential vitamins and minerals, particularly vitamins A, D, E, B12 and K, riboflavin, folate and iron, while the whites are a great source of low-calorie protein.
Based on what we now know, if you enjoy eggs, there is no reason why you should not eat them – including the yolks – several times a week. I do suggest choosing omega-3 enriched eggs from organically raised chickens. To get the omega-3s into the eggs, manufacturers of chicken food add algae, ground flaxseeds or fish oil. Essential fatty acids such as omega-3s cannot be made by our bodies and must be obtained from the diet. We need these healthy fats for optimal brain growth and development. They also have anti-inflammatory effects that may reduce the risk of cardiovascular disease, arthritis, high blood pressure, tumor growth and diabetes. Organic eggs come from chickens that eat food containing no pesticides herbicides, fungicides and commercial fertilizers. The hens are never given antibiotics, and are cage-free with access to the outdoors. Organic chicken feed also contains no animal byproducts.
Overall, eggs from free-range organically raised chickens have a better nutritional profile overall compared to eggs from cage-raised chickens:
⅓ less dietary cholesterol
¼ less saturated fat
⅔ more vitamin A
200 percent more omega-3s
300 percent more vitamin E
7 times more beta-carotene
98 percent smaller risk of salmonella contamination
As mentioned previously, studies have shown that cholesterol in our diet does not appear to cause heart disease, on the other hand however, "oxidized" cholesterol does appear to be highly atherogenic – causing plaques in the coronary arteries that may lead to a heart disease and heart attacks. The effect of cholesterol-containing foods on heart disease risk therefor may depend as much or more on how the foods are prepared as on the amount of cholesterol they contain. For example, breaking the yolk of an egg (the yolk contains all of the cholesterol) during cooking exposes the cholesterol to high temperatures and oxygen (room air), which presumably accelerates the formation of cholesterol oxides. Thus, boiled or poached eggs would be preferable to scrambled eggs, with sunny side up fried eggs probably somewhere in between.