Eggs, Cholesterol and Heart Disease -- Why Whole Eggs Are Healthy
Eggs have been shunned by many health-conscious people in recent years on account of their high cholesterol content. Cholesterol is a soft, waxy substance which, in excess, is believed to cause the development of fatty plaques, leading to clogged arteries and ultimately a heart attack. Found only in the yolk, the cholesterol in a single large egg amounts to around 200mg. Some health organizations, particularly in the United States, recommend that adults should eat fewer than 300 mg of cholesterol per day from all sources. It is not surprising therefore that over the last few years recipes have increasingly called for egg whites rather than the whole egg. But are whole eggs really so bad for you?
Firstly, there are plenty of researchers who believe that high cholesterol is not the prime cause of heart disease.
Secondly, recent research indicates that frequent egg intake does not significantly increase the level of cholesterol in the blood for most people anyway. And for the third of any given population that does respond in this way, it seems that this may not be cause for concern. Studies have shown that this group of people handles cholesterol differently to other people. Cholesterol is transported around the bloodstream in carrier particles called lipoproteins, and people in this group deposit cholesterol in the largest ones. This is important because other studies have already suggested that larger low-density lipoproteins (LDLs) are less likely to enter artery walls and contribute to artery-clogging plaque than small ones. Similarly, larger high-density lipoproteins (HDLs) are better than smaller ones at clearing cholesterol out of the body. In other words, a high level of LDL-cholesterol may not be unhealthy -- it is the size of the lipoproteins which matters.
The cholesterol issue aside, eggs are a good source of high quality protein (about 6 grams each). Egg yolk is also one of the best sources of the highly beneficial nutrients lutein and xenazanthin. Recent research has shown that lutein from eggs is more readily absorbed into the blood than lutein from other sources because of components in the yolk such as lecithin. A good supply of lutein and xenazanthin is thought to help prevent age-related macular degeneration, which is a leading cause of vision loss amongst people over 65. Moreover, lutein appears to inhibit processes that trigger the development of atherosclerosis.
Almost half the fat in eggs is heart-healthy monounsaturated, the same kind found in olive oil. Eggs from chickens which have been fed flax seeds can also be a valuable source of the omega-3 essential fatty acids which many of us are deficient in.
Another important nutrient contained in eggs is choline, the precursor of acetylcholine, which is necessary for proper brain function and memory.
So perhaps we should not be so afraid of the humble egg after all.