Eggs are one of those foods that provoke controversy, simple though they may seem.

Perhaps the oldest controversy is the classic: Which came first, the chicken or the egg?

The final solution to that is yet unanswered, but over the years, nutritionists and scientists have debated the virtue of the simple egg.

When different people tout diets high in fat, low in fat, high in carbohydrates, low in carbohydrates, high in protein, low in protein, people are left in a quandary. Whatever they eat, someone is out there to say it's bad for them -- except, perhaps, for a few simple greens.

The egg is thrust into the midst of this dilemma.

"Eggs are often thought of as a bad food in regards to heart health, but that is not the case if eaten in moderation," said Michelle Goss, clinical dietitian for the Cherokee Nation.

She performs dietary counseling and answers questions at the new Three Rivers Health Center.

"Yes, egg yolks do contain a high amount of cholesterol, but studies have shown saturated transfat in our diet affects the level of cholesterol in our blood the most," she said. "The cholesterol is in the yolk instead of the white, so that is why you can use egg whites abundantly in place of yolks in recipes. When a recipe calls for one egg, you can replace it with two egg whites and cut down on the cholesterol and the fat that way."

But what do you do with all the egg yolks, if you replace them with egg whites? Goss has heard no good answer for that, although she said some people suggest putting them in pet food to give your dog or cat a glossy coat. Eggs contain protein, iron and vitamin A, and can be a healthy substitute for meat protein. There are approximately 75 calories and 6 grams of protein in one egg.

Goss said the healthiest ways to cook eggs are boiled, scrambled (including substituting two egg whites for one egg in scrambling), or using egg whites in chicken or tuna salad.

Many vegetarians include eggs as one source of protein in their diets, but this is not an option for vegans.

The American Egg Board promotes eggs as "nature's miracle food," saying they contain 13 essential nutrients as well as high-quality protein. They also contain choline, folate and zinc.

According to the Egg Board, choline contributes to fetal brain development and helps prevent birth defects. The National Academy of sciences recommends pregnant women consume 450 milligrams of choline per day, nursing women 550 milligrams of choline. Two eggs contain 250 milligrams of choline.

The board recommends keeping eggs chilled, and advises against using eggs that are cracked, broken or leaking.

It's not uncommon to see shoppers opening and checking several cartons of eggs before selecting one. No one wants to buy a carton of eggs with one missing, or a cracked egg or one that otherwise looks suspect.