Niha Zubair, Arivale Clinical Research Scientist, PhD
Nutrition science can be a rollercoaster. First a food is bad, then it’s good, then it’s bad all over again. Such is the current fate of one popular breakfast staple.
A recent study found a higher consumption of eggs was significantly associated with an increased risk of cardiovascular disease, as well as death from all causes. Does this mean eggs are once again a “do not eat” food?
Let’s take a step back and understand the debate on eggs.
The Egg Controversy
The controversy surrounding eggs stems from their high dietary cholesterol content. But, scientific studies and public health guidelines are mixed on whether cholesterol in our diets negatively impacts our health.
For example, some studies have shown dietary saturated fat, rather than dietary cholesterol, has the biggest impact on your cholesterol levels. Furthermore, as the New York Times notes, public health dietary recommendations are contradictory. The Dietary Guidelines for Americans 2015-2020 states we “should eat as little cholesterol as possible while consuming a healthy eating pattern.” While the Scientific Report published with these guidelines says, “Cholesterol is not a nutrient of concern for overconsumption.”
This new study published March 19 in JAMA examined cardiovascular disease outcomes over time in nearly 30,000 adults. The main finding was that higher consumption of eggs and other sources of dietary cholesterol, such as meat, were significantly associated with incidence of cardiovascular disease and all-cause mortality.
What this means – in eggxact terms – is that each additional half-egg eaten per day was associated with a 6 percent increased risk of cardiovascular disease and an 8 percent increased risk of death from any cause. Researchers deduced this risk from eggs was due to their dietary cholesterol content. (The risk was more for dietary cholesterol as a whole, with a 17 percent increased risk of cardiovascular disease and 18 percent increased risk of death for every additional 300mg of cholesterol eaten per day.)
While these new findings may call into question our consumption of eggs, you may not need to forego your favorite scramble just yet.
Another study reviewed by Arivale found completely different results: compared to individuals who never ate eggs, daily egg-eaters had an 11 percent lower risk of cardiovascular disease, an 18 percent lower risk of dying from cardiovascular disease, and a 26 percent lower risk of hemorrhagic stroke.
This other study was conducted in a Chinese population – rather than a US one – but both studies were large and well-conducted. And, these aren’t the only large studies to find opposing results about eggs. So, what could explain such mixed results?
First, diet data is messy and prone to error. This month’s JAMA study relied on a single measurement of egg and dietary cholesterol consumption from individuals using a mixture of dietary assessment tools. Unfortunately, a single-day snapshot of a person’s diet does not necessarily reflect their “typical” day.
Second, as noted by the researchers, other unmeasured factors could have been at play. For example, genetics could explain why some individuals are more susceptible to increased LDL cholesterol – aka “bad” cholesterol – from eggs and other sources of dietary cholesterol (and therefore be more susceptible to cardiovascular disease or death).
Here’s where we stand: while removing eggs from your diet shouldn’t be at the top of your list, if you’ve already made significant diet changes (such as reducing saturated fat, losing weight, and eating more fruits and vegetables) and you still aren’t seeing a corresponding change in your blood cholesterol, you might consider reducing or eliminating eggs as an experiment.
- Everything You Need to Know About Cholesterol
- Can Too Much ‘Good’ Cholesterol Be Bad for You?
- At Low Risk for Heart Disease? It Still Pays to Watch Your Cholesterol
[Arivale Hot Topics address health stories currently in the news. The Arivale Clinical Team’s commentary on these news articles is not a review of the scientific evidence, nor an endorsement of a specific study, and is not meant as official medical opinion.]