Digesting the latest research on eggs

Eggs are back in the news — again. A study from the March 2019 JAMA found that higher intakes of cholesterol and eggs were associated with a greater risk of cardiovascular disease (CVD) and death.

The researchers reported that ingesting an additional 300 milligrams of cholesterol per day raised this risk, as did eating an average of three to four eggs per week.

Should we finally resign ourselves to taking our toast without a sunny-side-up yolk? Not so fast.

What did the study find?

Human diets are complex and notoriously hard to study. This is one reason why health headlines are often maddeningly contradictory.

For the JAMA analysis, participants provided diet information at the beginning of the study that was used to interpret their health up to 30 years later. The JAMA study, like many nutrition studies, was observational. As a result, it could not prove that a particular action (eating more cholesterol or eggs) caused an effect (raising the risk of CVD and death). Still, the results might seem worrisome for egg lovers.

The authors themselves note that the effect seen from their study was modest. Higher risks of CVD or death were observed from total dietary cholesterol than from eggs in particular. And the majority of dietary cholesterol reported in this study came from meat sources.

Associations were also stronger for people consuming more saturated fat (about 14% of total calories). Saturated fat typically comes from four-legged animals, like cows and pigs, and also from processed foods. The average American still consumes more of this type of fat than the USDA Dietary Guidelines’ recommended daily limit of less than 10% of daily calories.

Translating the paper to your plate

Keep in mind that while an egg contains 180 milligrams of cholesterol, a 6-ounce rib eye steak contains 140 milligrams of cholesterol — with six times as much saturated fat. So someone with an increased risk of stroke and a love of steak and eggs might want to cut back on both.

Based on this study, limiting eggs to fewer than three per week would be a cautious approach, since no association was seen at this amount. For those who include more plant-based proteins in their diet, like beans, nuts, and seeds — which help keep both cholesterol and saturated fat intake low — there is less cause for concern.

The reality is that many people benefit from eggs. They are a cheap, quick protein source. They also contain nutrients that certain populations do not get enough of. Lacto-ovo vegetarians, who include eggs and dairy in their diets, can rely on them as a source of B₁₂, a vitamin that supports neurological functions like memory, decision-making, and balance.

Aside from fatty fish, eggs are one of the only natural sources of vitamin D in the diet. (The form of vitamin D present in yolks might be more potent than previously thought.) People who live in northern climates, and especially those who work indoors, may lack the ability to produce sufficient vitamin D, due to limited sun exposure. Eggs are also one of the best sources of choline, an important nutrient for fetal brain development that most pregnant women do not adequately consume.

Overall this study does not change what we have been saying all along: eat more plants. Plant-based proteins such as beans, and unsaturated fats like those found in nuts, are associated with heart health. For people with an increased risk of CVD and a diet high in animal protein, it might be worth cutting back on eggs as well as meat.

But eggs also serve as an important source of nutrients — and making drastic diet changes based on one study would be like putting all of them in one basket.