Unscrambling Eggs' Nutritional Benefits

Eggs are a versatile food, used in both sweet and savory dishes. They provide a source of highly bioavailable protein, as well as choline and xanthophyll carotenoids. However, their cholesterol content has long cast a shadow over their potential nutritional benefits. Research on this topic has yielded convoluted if not outright contradictory results, and to the general public, the recommendations may seem rather scrambled. Are eggs part of a healthy diet or not?

One large egg weighs around 50 grams and contains approximately 72 calories, 6.2 grams of protein, 1.6 grams of saturated fat, and 207 mg of cholesterol (USDA 2019). By comparison, an equivalent amount of cooked 85% lean ground beef contains approximately 125 calories, 13 grams of protein, 2.9 grams of saturated fat, and 44 mg cholesterol (USDA 2019). Other meat products follow a similar pattern, and typically foods that are high in cholesterol are also relatively high in saturated fat. There are a few exceptions to this rule, namely eggs and shellfish, which are low in saturated fat despite their high cholesterol content. Why does this matter?

Studies have consistently shown that increased saturated fat intake is correlated with increased blood lipid levels, including total and LDL cholesterol, and with an increased risk of cardiovascular disease. But establishing the impact of cholesterol intake on these factors has been more challenging, largely due to its frequent co-occurrence with saturated fat in foods. Both the 2015–2020 and 2020–2025 Dietary Guidelines for Americans included recommendations to minimize cholesterol intake but did not quantify a daily upper limit. In its report, the Dietary Guidelines Advisory Committee cited insufficient evidence to support a relationship between dietary cholesterol and blood lipids or cardiovascular disease as the reason for this omission (Dietary Guidelines Advisory Committee 2020).

If it is difficult to establish a relationship between cholesterol and cardiovascular risk, one can imagine that establishing a relationship between eggs specifically and cardiovascular risk is even more difficult. The authors of one observational cohort study from 2019 concluded that whole egg consumption was associated with increased risk of all-cause mortality and mortality from cardiovascular disease, cancer, and diabetes (Zhuang et al. 2019). An earlier review, though, concluded that egg consumption did not increase risk of cardiovascular disease, and even suggested a potential cardioprotective effect from the anti-inflammatory xanthophyll carotenoids lutein and zeaxanthin found in egg yolks (Clayton et al. 2017). Another observational cohort study from Italy published in 2022 found no association between egg intake and hypertension, diabetes, or high cholesterol. This study also suggested that moderate egg consumption of one to three eggs per week may have cardioprotective effects, at least in individuals of Mediterranean origin (Kouvari et al. 2022).

Additional studies have produced similar results, with most concluding that whole egg consumption does not increase risk of cardiovascular disease or mortality. Some limitations should be noted, however. As with many studies involving dietary intake, there is a question as to the accuracy of participants’ reported versus actual intake. In the studies by Zhuang et al. and Kouvari et al., only baseline dietary intake was measured, even though the studies followed participants for an average of 16 and 10 years, respectively. Thus, any dietary changes participants made over the years of follow-up were not taken into account. Lastly, many other factors, such as alcohol, red meat, and fruit and vegetable intake, can impact one’s risk of disease, and studies have differed in which factors they have considered.

The consensus among researchers seems to be that whole eggs can be included as part of a healthy diet and that the focus should be on overall dietary patterns, rather than on egg consumption. Per the American Heart Association, healthy individuals can include up to one egg per day in their diets (Carson et al. 2020). Eating a diet rich in whole grains, fruits, vegetables, unsaturated vegetable oils, and lean proteins, including eggs, will have a greater beneficial impact on one’s risk of cardiovascular disease than a diet focused on reducing cholesterol intake alone.