Cracking the code on egg-carton labeling

Eggs have long been a symbol of new beginnings. Now they are celebrating a new chapter of their own, with the Scientific Report of the 2015 Dietary Guidelines Advisory Committee's recommendation to lift the long-held limit on dietary cholesterol. It turns out that for the vast majority of people, the cholesterol we eat doesn't significantly raise our blood cholesterol; rather, saturated fat does. So foods that are relatively low in saturated fat but high in cholesterol, primarily shellfish and eggs, have been freed from the yoke of restriction (pardon the pun, I couldn't help myself).

Eggs have a lot going for them. For just 70 calories, a large egg provides 6 grams of satisfying protein, vitamin D, a variety of B vitamins, essential minerals such as iron and zinc, choline, which is important for brain health, and lutein and zeaxanthin, which promote eye health. Plus they are fast, easy to cook and very economical, running between 25 and 45 cents each, depending on which kind you buy.

Actually, deciding which carton of eggs to grab at the market can be the most difficult thing about them. The confusing claims on the shelf are nothing short of mind-boggling. Now that there's a green light to eat eggs more freely, here's some information to make the retail egg hunt a bit easier.

Farm-fresh or all-natural: These are marketing terms; they have no official meaning whatsoever. They are used to conjure a wholesome impression of the product for the consumer, like the picture of a farm might. Disregard these words - and any images of bucolic fields, for that matter.

Cage-free, free-range or pasture-raised: These labels pertain to the way the egg-laying hens are treated. Cage-free means the birds are housed in barns where they can walk freely, rather than being confined to cages. Free-range means they are not only uncaged, they also have at least some access to the outdoors. And pasture-raised hens are kept outdoors for most of the year and brought indoors at night for protection.

The issue of confusion here is that there is no mandatory regulation of these terms for egg production. To ensure that these claims are verifiable - that someone is literally watching the hen house - look for products with third-party certifications, such as "certified humane" or "animal welfare approved."

Organic: Eggs with the USDA Organic seal come from hens that are raised on organic feed (grown without synthetic pesticides, fungicides or fertilizers) and are free-range (uncaged with outdoor access). Facilities are checked by accredited inspectors.

Hormone-free or antibiotic-free: Hormones or antibiotics are not used in egg production, so these claims are irrelevant, akin to seeing a "fat-free" sticker on a banana.

Vegetarian-fed: This means the chicken's feed contained no animal byproducts. But because the bird's natural behavior is to forage for insects, it also implies they did not spend time feeding outdoors.

Pasteurized: These eggs are heated until just below the temperature at which they coagulate so they can be used in recipes that call for raw eggs, such as many Caesar dressings.

Omega-3: Eggs enhanced with this good-for-you fat come from hens whose feed is spiked with omega-3-rich ingredients such as flaxseed, marine algae or canola. The eggs contain anywhere from 100 mg to 600 mg omega-3 each, whereas a regular egg has about 30 mg. Although this may offer some benefit, it's worth noting that the predominant type of omega-3 in eggs is a form that is the considerably less potent (ALA) than that found in fish (DHA and EPA).

Grade: There are three grades bestowed upon eggs by the U.S. Agriculture Department as part of a voluntary quality program: AA, A and B. Grade AA is best, with thick, firm whites, high, round yolks and clean, unbroken shells. Grade A eggs, most commonly found in stores, have the same qualities as AA but with slightly less firm whites. Grade B, rarely sold retail, are primarily used in prepared egg products.

Color: Different breeds of hens lay different colors of eggs, so although brown eggs have a certain healthful visual appeal, and blue eggs (which have been popping up more markets) are fun to bring home to wow the kids, they are no different from white in quality, flavor or nutrition.

• Ellie Krieger is a registered dietitian, nutritionist and author. She blogs and offers a biweekly newsletter at www.elliekrieger.com. She also writes weekly Nourish recipes in The Washington Post's Food section.