Not sure whether it’s OK to eat eggs? Media coverage of a study released last month in the Journal of the American Medical Association (JAMA) may have added to the confusion. Following up on last week’s column, let’s look at what this study adds to the conversation, and determine whether or not its findings are a compelling reason to change your eating habits.
A history of egg science
Egg confusion started in the 1950s, when researchers found associations between blood cholesterol and heart disease and assumed that dietary cholesterol — egg yolks are one source of it — raised blood cholesterol. While observational studies in the 1980s did find associations between dietary cholesterol and heart disease, it eventually became clear that high-cholesterol diets also tend to be high in saturated fat and refined carbohydrates and low in fiber — and those were the dietary factors that mattered most.
Gradually, more and more studies found no significant links between dietary cholesterol and blood cholesterol, or dietary cholesterol and heart disease. As a result, the 2015-2020 Dietary Guidelines for Americans stopped setting a specific upper limit for dietary cholesterol, with the caveat that people should still minimize cholesterol intake because most foods that are higher in cholesterol are also high in saturated fat. But while that’s certainly true of fatty cuts of meat, eggs are relatively low in saturated fat.
A new, but not necessarily notable, study
The JAMA study combined data from six studies that followed a total of nearly 30,000 people for about 17 years — one followed participants for more than 30 years — to see if they developed cardiovascular disease (heart disease, heart attack, stroke, heart failure) or died from a chronic disease. That looks like a solid study based on numbers, but it actually has some major limitations.
The biggest limitation is that this is an observational study, which can only find associations between things. It can’t establish that one thing, like eating eggs, causes another thing, like cardiovascular disease or death. Only randomized control trials can do that. What’s more, participants were asked only once about their eating habits. Has your diet changed in the past 17 years? What about in the past 30 years? I know mine has.
Finally, even though eggs are specifically called out, the researchers said Americans on average get about 290 milligrams of cholesterol from food each day, but only 93 milligrams comes from eggs — or half an egg, to be precise, as average American egg intake is three to four per week. Further, when the authors did the calculations needed to tease out whether it was cholesterol or eggs themselves that might be causing problems, eggs weren’t the culprit.
Putting risk into perspective
The study found that each additional 300 milligrams of cholesterol consumed above the average 290 milligrams was associated with a 3.24 percent higher risk of developing cardiovascular disease. Now, your personal risk for cardiovascular disease depends on genetics as well as your individual risk factors — high blood pressure, high blood cholesterol, diabetes, smoking. Let’s say you’re a 55-year-old woman with one major risk factor. Your average risk of developing cardiovascular disease by age 80 is 16.7 percent. If you get 600 milligrams of cholesterol per day, that average might be 19.94 percent. But you’re a human, not a statistic or a math problem — and this particular study can’t prove that anyone’s risk would actually increase.
The nutritional benefits of eggs
Nutritionally, there are many reasons to keep eggs in your rotation. One large egg contains 70 calories, 6 grams of protein and 5 grams of fat (including 3 grams of heart-healthy unsaturated fat). It’s an excellent source of choline — a nutrient most people don’t get enough of — and the antioxidant mineral selenium. It’s also a good source of many B vitamins, including vitamin B12, and contains the antioxidants lutein and zeaxanthin, which are important for eye and skin health. That’s in an average egg. If you have room in your food budget to buy pastured eggs, you can get additional nutrition benefits.
According to PCC Community Markets, pastured eggs typically offer six times more vitamin D, four times more vitamin E, eight times more beta-carotene, and three times more omega-3 fatty acids than conventional eggs from confined hens. Why the difference? Both caged and cage-free hens typically eat only chicken feed, but pastured hens are free roaming, so they are exposed to sunshine and get about 20 percent of their diet from foraging on pasture grasses. In addition to PCC Organic Pastured Eggs, pastured eggs may be available locally at farmers markets or specialty retailers. Try them in this springtime-fresh recipe from PCC — perhaps for Easter.
Baked Eggs with Asparagus and Mushrooms
2 tablespoons butter, plus additional for dishes
1/2 cup sliced mushrooms
6 spears asparagus, trimmed and cut into 1-inch pieces
1 clove garlic, minced
1 tablespoon heavy cream
1 1/2 ounces soft-ripened cheese (such as Camembert), cubed
1 teaspoon chopped fresh chives
Salt and pepper to taste
4 large eggs
Crusty bread such as PCC’s Organic Macrina Baguette, for serving (optional)
1. Preheat oven to 450 F. Butter two oven-safe ramekins or gratin dishes.
2. Melt butter in skillet over medium-high heat. Add mushrooms and cook until softened, 6 to 8 minutes. Add asparagus and garlic; cook until asparagus is bright green, about 2 minutes. Remove from the heat and stir in cream, cheese and chives. Season with salt and pepper.
3. Divide mushroom-asparagus mixture between prepared ramekins. Make 2 wells and crack eggs into them.
4. Bake until cheese is melted and eggs are cooked to your liking, 10 to 15 minutes (keep in mind, eggs will continue to cook a little after being removed from the oven). Serve immediately with bread.
Recipe courtesy of PCC Community Markets.