Eggs have been prized as food for much of our history. Our first ancestors harvested wild eggs and Europeans reared domesticated hens to lay eggs as early as 600 BC. Today, thousands of recipes incorporate eggs.
Previous studies linked cholesterol with heart disease. Since eggs contain significant amounts of cholesterol, this led many authorities such as Health Canada to recommend restrictions on dietary cholesterol, which included limiting or eliminating eggs. However, this view has now reversed and eggs are again in vogue.
Cholesterol and Fat
Science has refined the relationship between cholesterol and heart disease over the last four decades; early researchers could only define fairly crude associations. Today, we know that the components of serum cholesterol (from a blood test) include HDL (good cholesterol) and LDL (bad cholesterol) and that elevated values of LDL relative to HDL are a more accurate determinant of risk for heart disease than total cholesterol values.
People who consume one or two eggs a day show no effects on serum levels. (This relationship might not hold for those with elevated LDL/HDL ratios.) Researchers have discovered that saturated and hydrogenated fat intake, particularly the latter, are the real culprits in LDL/HDL elevation and remain sources of worry regarding heart disease.
Eggs are relatively low in saturated fats. On average, they contain five grams of fat; 1.2 to 1.5 g of this is saturated, 0.74 to 1.1 g polyunsaturated and 1.6 to 2.0 g monounsaturated. Eggs also contain 14 vitamins and minerals, are a rich source of protein and a valuable source of lecithin and essential fatty acids. Most health agencies, including Health Canada, now recommend eggs as part of a healthy diet.
Eggs are one of the most densely nutritious natural foods available. They contain a significant amount of vitamins, A, D, E, B1, B2, B6, B12, folate and pantothenic acid (B5) as well as calcium, phosphorus, magnesium, iron and zinc. All of this with only 71 calories, no carbohydrates and five grams of fat! They are also one of the best sources of protein. Egg protein is easily assimilated and contains all nine essential amino acids necessary for proper metabolism.
The lecithin found in eggs emulsifies fats and improves digestion. It supports liver function, reduces the chance of cholesterol-clogged arteries and prevents the formation of kidney and gallstones. It also serves as a source of choline and inositol, which support proper nerve transmission and brain function. Eggs are one of the few sources of these nutrients in our diets.
Essential Fatty Acids
Polyunsaturated fats occur naturally in eggs as omega-3 and omega-6 essential fatty acids (EFAs) including the omega-3 derivative DHA. They are critical to a variety of functions from circulation and production of hemoglobin to immune function and anti-inflammatory responses. Many of us probably get ample omega-6 from unrefined oils and nuts and seeds but substantially less omega-3. Omega-3 consumption, including DHA, is associated with reduced risk of heart disease and appears to facilitate circulation.
In addition, DHA is important for proper brain-cell development and function. Some egg producers add flax meal, a source of dietary omega-3, to their hens feed to boost omega-3 content. Youll find these marketed as EFA- or omega-3-enriched eggs, although free-range and organic-egg producers often use similar feed enrichments.
How to Buy Eggs
The best places to buy fresh and flavourful eggs are farmers markets and natural food stores. The best eggs are usually free-range or certified organic, meaning theyre from hens that get daily exercise and are fed an antibiotic-free, grain-based feed, preferably enriched with flax seed.
The quality of hens feed and its freshness largely determines the flavour of eggs.
Its also responsible for the colour of yolks; more coloured (for example, corn-based) feeds produce brighter yellow yolks than barley- or wheat-based feeds. Free-range chickens feed on grass and produce darker orange yolks. Some makers of commercial feeds even incorporate marigold blossoms into their product for this reason. In general, yolk colour does not impact directly on flavour. Neither does the colour of the eggshell, whether brown or white. Free-range eggs taste much betterno contest.
Be aware that salmonella bacteria, usually transferred on the eggshell surface, are common in poultry in North America. Its best to use cooked eggs. Wash your hands when handling eggshells, and refrigerate eggs or egg preparations as soon as possible.
Flavour wise, a fresh egg tastes far better than a stale one. How to tell the difference? Place the egg in a bowl filled with cold water. If it sinks to the bottom, its fresh. If it stands up but still remains on bottom, its significantly less fresh, and if it floats, its old. Fresh eggs also tend to have cloudy whites while old eggs often have watery, runny whites.
Enjoy your hunt for eggs! The rewards are worth it.