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Regardless of which type you buy, all eggs deliver plenty of nutrition.aprilfoto88/Getty Images/iStockphoto


What kind of eggs should I buy? What's the difference between free-range, free-run, cage-free and organic eggs? Am I better off, nutritionally, buying omega-3 eggs? I eat two eggs every day – is that too much cholesterol?


I remember when the biggest decision to make when buying eggs was choosing between brown or white shells. Or, medium or extra-large sized eggs. Not so, any more.

With so many different claims stamped on egg cartons – e.g. organic, omega-3 enriched, free-run, free-range and enriched-housing – deciding which variety to buy isn't a simple task. That's particularly true if you don't know what those claims mean. (I certainly learned a few things while researching this column.)

Regardless of which type you buy, all eggs deliver plenty of nutrition. They're an excellent source of protein, vitamin B12 (half a day's worth in one large egg) and selenium, an antioxidant that protects the body from harmful free radicals. All for only 70 to 75 calories. (Brown eggs and white eggs are equally nutritious; eggshell colour depends on the breed of the hen.)

And thanks to their long-vilified cholesterol-rich yolk, eggs top a relatively short list of foods that supply a hefty amount of choline, an essential nutrient that's needed for healthy brain development, nerve function and liver metabolism. More on cholesterol later.

Standard eggs

The eggs you grew up eating, and likely still do, are produced by hens that live in cages without access to nests, perches or scratching areas. (Hens are naturally compelled to scratch at the ground with their toes in search of seeds, greens or bugs to eat.)

In conventional "battery" cages – coined for the rows and columns of identical cages connected together – hens are raised in small social groups and have equal access to food and water. Living space is crowded, providing 432 square centimetres (67 square inches) per bird, which doesn't allow the hens to behave naturally.

The vast majority – 90 per cent – of eggs in Canada come from hens living in conventional cages. Over the next 20 years, however, conventional egg production will be phased out due to animal welfare considerations. By 2036, all eggs produced in Canada will come from hens living in free-run, free-range or enriched-housing conditions.

Free-run eggs

These hens are cage-free; they move freely in a wide open barn and have access to nests, perches and scratching areas but not the outdoors.

Free-run hens have twice as much space (929 square centimetres per bird) than conventionally caged hens. National guidelines set out in the Recommended Code of Practice for the Care and Handling of Poultry outline density regulations for egg-laying hens.

Free-range eggs

Like free-run hens, free-range birds live cage-free in barns with nests, perches and scratching areas. The difference, though: they're given access to the outdoors, weather permitting.

Enriched-cage-housing eggs

You'll find eggs produced by hens living in this type of housing labelled "Nestlaid" (Burnbrae Farms) or "Comfort Coop Eggs" (Farmer's Finest). These hens live in cages that provide three-quarters more space (748 square centimetres ) than conventional battery cages.

The cages are "enriched" with nests, perches and scratching areas. Enriched housing provides a more natural environment for hens and produces eggs with a lower price tag than free run or free range eggs.

Organic eggs

Certified organic eggs are produced by free-range hens (e.g. they have access to the outdoors) that live barns with nests, perches and scratching areas. The hens are fed organic feed, grains that have been pesticide-free for at least three years.

Organically-raised hens are not given antibiotics, nor do they receive growth-promoting hormones. (Conventionally-raised hens do not receive growth hormones; hormones have not been used in egg-laying hens for more than 50 years.)

Omega-3 eggs

Hens that lay omega-3 eggs are fed a diet rich in flax, a seed packed with an anti-inflammatory omega-3 fat called alpha linolenic acid (ALA). An omega-3 egg contains about 300 mg of ALA, a reasonable amount considering women need 1,100 mg of ALA per day and men require 1,600 mg. (One tablespoon of chia seeds or ground flax delivers 1200 to 1600 mg of ALA.)

Omega-3 eggs also contain a little docosahexaenoic acid (DHA), the omega-3 fat in oily fish that's linked to heart and brain health. Flax-fed hens provide about 75 g DHA per egg; those that have their feed enriched with fish oil have more.

But I don't suggest you trade in your salmon for omega-3 eggs. Omega-3 eggs have at most 125 mg of DHA, considerably less than the 1800 mg found in a small three-ounce portion of salmon.

If you eat oily fish each week (e.g. salmon, trout, char, sardines, herring) and regularly include ALA-rich foods in your diet (e.g. ground flax, flax oil, chia seeds, hemp seeds, walnuts, soy beans), you don't need omega-3 enriched eggs.

That said, omega-3 eggs can deliver more than ALA and DHA. Burnbrae Farms' Naturegg Omega-3 Plus, for example, has added vitamin D, lutein for eye health and half a day's worth of vitamin E.

The cholesterol conversation

It's true that egg yolks have a lot of cholesterol, about 190 mg in one large egg. ("Extra large" eggs have 215 mg and "jumbo" eggs have 235 mg.) But cholesterol in foods has little impact on most people's blood cholesterol level.

That's why the most recent U.S. Dietary Guidelines, released in December 2015, dropped its daily cholesterol intake limit of 300 mg. Not all experts, however, agree that there's no link between food cholesterol and blood cholesterol.

Even so, people with heart disease and/or diabetes should limit cholesterol intake to 200 mg a day. Studies suggest that people with diabetes absorb more cholesterol from foods and are more responsive to its blood cholesterol-raising effect.

Leslie Beck, a registered dietitian, is based at the Medisys clinic in Toronto.