July 2019 Question of the Month: Eggs and Cholesterol
Should we think of eggs as a heart attack on a plate, or is this study not all it's cracked up to be?
Here we go again. Just when we thought we could eat our omelets guilt-free, out comes another headline-grabbing study published in the Journal of the American Medical Association that rekindles the debate on whether we should fret about cholesterol intake. After scrutinizing data on nearly 30,000 adults from six studies spanning three decades, researchers concluded that eating an additional 300 milligrams of dietary cholesterol per day—one egg yolk, in comparison, has about 185 mg—raises incident cardiovascular disease by 17% and early death from any cause by 18%. For each additional half egg consumed daily (3–4 eggs weekly), there was a 6% higher risk of CVD and an 8% increased risk of early death. Higher egg consumption had these associations regardless of race, age, activity levels, smoking status, blood pressure or cholesterol levels. Should we think of eggs as a heart attack on a plate, or is this study not all it’s cracked up to be?
Before we collectively demonize dietary cholesterol, there are study limitations worth bringing to light. For starters, diet data was based on recall, which is notoriously unreliable. Even worse, participants were not given multiple questionnaires as the study progressed; instead, they filled out one diet questionnaire during follow-up (median period was 17.5 years); this does nothing to address long-term changes in eating habits.
Moreover, the study findings couldn’t prove that eating more cholesterol or more eggs causes heart disease; they merely suggested a relationship. And the association between egg consumption and heart disease disappeared when the researchers adjusted for overall cholesterol consumption, meaning cholesterol from everything, including eggs, meat and dairy.
Also, the egg-heart disease link doesn’t jibe with findings from other notable cohort studies concluding that moderate egg consumption, typically defined as 1 egg a day, plays no significant role in early death from disease. (Daily cholesterol limits were removed from the 2015 Dietary Guidelines for Americans because science did not support the idea that dietary sources of cholesterol have a significant impact on blood cholesterol levels.) If people frequently eat fried eggs with a side of bacon instead of a hard-boiled egg alongside oatmeal, what role does an overall dietary pattern play in disease risk versus cholesterol being the sole culprit?
Still, it would be a mistake to dismiss these findings outright, and they warrant further investigation. Does this study make you rethink putting eggs and other cholesterol-containing foods on your plate? Is cholesterol a concern for you? Do you agree with the Dietary Guidelines that dietary cholesterol is not a health hazard for most people? How do you communicate this type of conflicting nutrition research to your clients?
Send your answers to Sandy Todd Webster at [email protected]