I recently heard a scientific researcher say, “There is so much fighting in the research!”
Her comment struck me as funny. I’d always imagined white-coated, stone-faced researchers doing their tedious work by rote, burned out from the constant quest for scientific truth.
Yet when I delved into the question, “Are eggs bad for cholesterol?” the ongoing tension between the debate’s two sides was plain to see.
Averaging 187 mg each, cholesterol-rich eggs are perennial candidates for research into the artery-clogging consequences of our cholesterol intake. Are they bad for us, good for us, or both?
In September of 2020, Cardiology in Review published a paper authored by medical doctors Steven and George Chrysant. They’re staff cardiologists at the University of Oklahoma Health Sciences Center and the Oklahoma City INTEGRIS Baptist Medical Center, respectively.
In The Debate over Egg Consumption and Incident Cardiovascular Disease, they concluded from reviewing “… 19 pertinent papers, together with collateral literature…” on both sides of the issue:
“Therefore, at present, there is no unanimous agreement on this subject, and the controversy will continue until new confirmatory evidence becomes available.”
Dueling Data: Similar Studies, DifferentAnswers
In March of 2019, the reputable Journal of the American Medical Association (JAMA) published another study headed by Victor W. Zhong, Ph.D., of the Northwestern University Feinberg School of Medicine’s Department of Preventive Medicine.
The researchers analyzed data collected from 29,615 participants between 1985 and 2016. They concluded:
“Among US adults, higher consumption of dietary cholesterol or eggs was significantly associated with higher risk of incident CVD and all-cause mortality in a dose-response manner.”
In other words, the data showed that risks of both cardiovascular disease and mortality from all causes of death increase as egg consumption rises. Eating any eggs increases the rate of mortality.
In that scenario, just eating one whole egg has a considerably more negative impact than eating half an egg. Hence, the more eggs we consume, the more we raise our odds of an earlier death. Surely that settles it?
In May of 2019, Chinese researchers from the Huazhong University of Science and Technology published a meta-analysis of data from 37,121 Americans gathered from 1999 to 2015.
Their effort, found here in Journal of the American Heart Association, came to the exact opposite conclusion of the Northwestern University study published just two months earlier:
“No significant association was found between dietary cholesterol intake and heart disease mortality…”
The study’s Clinical Perspective is more specific:
In this cohort of representative adults in the United States, we did not find a significant association between dietary intake of eggs and all‐cause or heart disease mortality.
Are Eggs Bad for Cholesterol? Even the USDA Seems Confused!
In the raging egg-cholesterol debate that goes back decades, the Northwestern and Huazhong studies are merely the tip of the iceberg. But the discussion has more than theoretical implications.
Conclusions leap from the pages of academic research to influence dietary policy – and official nutritional policies impact not only public health but also food sales and the economy.
For example, in 2015, the USDA-distributed Dietary Guidelines for America quietly reversed four decades of nutrition policy. It stopped listing dietary cholesterol as a “nutrient of concern” and removed the 300 mg daily limit.
The guidelines removed the 300 mg per day limit on dietary cholesterol. However, they immediately walked back their decision by adding:
“… but this change does not suggest that dietary cholesterol is no longer important to consider when building healthy eating patterns… individuals should eat as little dietary cholesterol as possible while consuming a healthy eating pattern.”
Despite the flip-flopping in governmental recommendations, the advice to keep dietary cholesterol as low as possible remains consistent.
In 2020, the USDA’s updated Dietary Guidelines lumped dietary cholesterol in with trans fats:
“The National Academies recommends that trans fat and dietary cholesterol consumption to be as low as possible without compromising the nutritional adequacy of the diet.”
They continued, “The prevalence of coronary heart disease increases with age, and high LDL cholesterol peaks between the ages of 50 to 59 in men and 60 to 69 in women.”
The Eggs-and-Cholesterol Dispute Knows No Boundaries
The Introduction to the 2019 Guidelines from the European Society of Cardiology unequivocally states:
“Thus, there is no longer an ‘LDL-C hypothesis,’ but established facts that increased LDL-C values are causally related to ASCVD [atherosclerotic cardiovascular disease], and that lowering LDL particles and other ApoB-containing lipoproteins as much as possible reduces CV [cardiovascular] events.”
In reality, most of us don’t read academic research or governmental guidelines. We rely on Google. Here’s the first thing Google had to say this morning when queried “egg cholesterol good or bad”:
“The science is clear that up to 3 whole eggs per day are perfectly safe for healthy people.”
The Healthline article’s explanation of its “up to 3 whole eggs” estimate? “Unfortunately, no studies have fed people more than three eggs per day.”
Yet the very next study it cites included an 88-year-old who ate 25 eggs a day and “… had normal cholesterol levels and was in very good health.”
What the article’s author neglected to say was that for some reason, this individual absorbed less than 20 percent of his dietary cholesterol. And his body converted much of that into harmless bile acids:
“His almost complete freedom from clinically important atherosclerosis and its complications may be explained in part by a great reduction in the efficiency of cholesterol absorption from the intestine and by a marked increase in the conversion of cholesterol to bile acids.”
“Evidence-based” Healthline seems to have given this fascinating case too much weight. Their final position in the “are eggs bad for cholesterol” dispute implies as much:
“Overall, eating eggs is perfectly safe, even if you’re eating up to 3 whole eggs per day. Given their range of nutrients and powerful health benefits, quality eggs may be among the healthiest foods on the planet.”
So, despite what Google search tells us, is the science clear? Are eggs bad for cholesterol or not?
More on this controversial subject tomorrow.