Researchers tested whether eggs with lower cholesterol could help prevent heart disease in mice. They found that mice eating low-cholesterol egg yolks had smaller fatty deposits in their arteries, lower cholesterol levels in their blood, and less inflammation compared to mice eating regular eggs. The special eggs also changed the bacteria in the mice’s guts in helpful ways and improved how their bodies processed cholesterol. While these results are promising, this was a study in mice, so scientists need to do more research in humans before we know if these eggs would have the same benefits for people.

The Quick Take

  • What they studied: Whether eggs with reduced cholesterol could slow down or prevent the buildup of fatty deposits in arteries (atherosclerosis) that leads to heart disease
  • Who participated: Laboratory mice that were genetically engineered to develop heart disease easily. The mice were given egg yolk extracts at doses equal to what one or two eggs per day would be for humans
  • Key finding: Mice that ate low-cholesterol egg yolks for 8 weeks had significantly smaller fatty plaques in their arteries, lower blood cholesterol levels, and less inflammation compared to mice eating regular eggs
  • What it means for you: This suggests that low-cholesterol eggs might be a better choice for people worried about heart disease, but this is early-stage research in mice. More human studies are needed before we can say for certain that these eggs would help prevent heart disease in people

The Research Details

Scientists used special mice that are prone to developing heart disease because of their genes. They gave different groups of mice either low-cholesterol egg yolk extracts or regular egg yolk extracts for 8 weeks. The doses were designed to match what humans would eat if they had one or two eggs per day. After 8 weeks, the researchers examined the mice’s arteries, blood samples, liver tissue, and gut bacteria to see what changed.

The researchers measured many different things: the size of fatty plaques in the arteries, cholesterol levels in the blood, markers of inflammation and oxidative stress (cellular damage), the types of fats in the blood, how well the liver was processing cholesterol, and the composition of bacteria living in the gut. This multi-layered approach helped them understand not just whether the eggs helped, but also how they might have helped.

Using mice that naturally develop heart disease allows researchers to test whether a food might prevent disease without waiting years for results in humans. By measuring multiple markers of heart health, the researchers could understand the different ways the eggs might be protective. This approach provides a foundation for deciding whether human studies would be worthwhile

This study used a controlled laboratory setting where all variables could be carefully managed, which is good for understanding cause-and-effect. However, mice don’t always respond the same way humans do to foods and treatments. The study examined multiple biological pathways, which strengthens the findings. The research was published in a peer-reviewed journal, meaning other scientists reviewed it before publication. The main limitation is that this is preliminary research in animals, not humans

What the Results Show

After 8 weeks, mice eating low-cholesterol egg yolks had significantly smaller fatty plaques in their arteries compared to mice eating regular eggs. This is important because plaque buildup is what causes heart attacks and strokes.

The mice eating low-cholesterol eggs also had lower total cholesterol and LDL cholesterol (the ‘bad’ cholesterol) in their blood. They had less inflammation, shown by lower levels of inflammatory molecules called TNF-α and IL-1β. The mice also had improved antioxidant activity in their arteries, meaning their cells were better protected from damage.

Interestingly, the low-cholesterol eggs changed the composition of fats in the blood, increasing a beneficial type of fat called DHA-rich PE. The mice’s livers also showed improved cholesterol processing, with better clearance of LDL cholesterol and conversion to bile acids that help digest fat.

The study revealed that low-cholesterol eggs increased beneficial bacteria in the gut (Lactobacillus and Akkermansia) while decreasing potentially harmful bacteria (Rikenella and Faecalimonas). This is significant because gut bacteria play an important role in overall health and cholesterol metabolism. The eggs also increased specific bile acids (UDCA and TUDCA) that may have protective effects, while decreasing others (LCA and DCA) that might be harmful. The liver showed upregulation of genes involved in cholesterol clearance, suggesting the eggs helped the body process cholesterol more efficiently

Previous studies in humans found no clear link between eating regular eggs and increased heart disease risk, which surprised many people since eggs contain cholesterol. This new research suggests that the type of cholesterol and the specific fats in eggs might matter more than the total cholesterol content. The findings align with growing evidence that gut bacteria and bile acid metabolism play important roles in heart health. This study provides a potential explanation for why eggs haven’t been shown to harm heart health in humans—the beneficial components may outweigh the cholesterol content

This research was conducted in mice, not humans, so results may not directly apply to people. The study used extracted egg yolk lipids rather than whole eggs, which might not capture all the effects of eating actual eggs. The mice were genetically engineered to develop heart disease, so they may respond differently than healthy humans. The study lasted only 8 weeks, which is relatively short. We don’t know if the benefits would continue if mice ate these eggs for longer periods. The study doesn’t tell us about potential effects in people without genetic predisposition to heart disease

The Bottom Line

Based on this research alone, we cannot recommend that people switch to low-cholesterol eggs as a heart disease prevention strategy. However, this study provides promising preliminary evidence that warrants human studies. For people with high cholesterol or heart disease risk, eggs in general appear to be safe based on previous human research, and low-cholesterol eggs might be a reasonable choice if available. People should continue following their doctor’s advice about diet and cholesterol management. Confidence level: Low to Moderate (this is animal research only)

This research is most relevant to people with high cholesterol, family history of heart disease, or existing heart disease who are concerned about egg consumption. It may also interest food scientists and cardiologists looking for new dietary approaches to heart disease prevention. People without cholesterol concerns don’t need to change their egg consumption based on this single study. Anyone with diagnosed heart disease or taking cholesterol medications should discuss egg consumption with their doctor

In the mice, benefits appeared after 8 weeks of consistent consumption. If similar effects occur in humans, it would likely take several weeks to months of regular consumption to see changes in blood cholesterol levels. However, we don’t yet know if humans would see the same benefits or on what timeline. Any changes in diet should be discussed with a healthcare provider

Want to Apply This Research?

  • If someone wants to test whether low-cholesterol eggs affect their health, they could track: (1) weekly egg consumption type and quantity, (2) energy levels and digestion, (3) periodic cholesterol levels from blood tests (with doctor approval), and (4) any changes in heart disease risk factors like blood pressure or weight
  • A practical change would be to gradually replace regular eggs with low-cholesterol eggs if available and affordable, while tracking how you feel and any changes in digestion or energy. Keep a food diary noting egg consumption and any symptoms or changes you notice. This creates a personal baseline for comparison
  • Over 8-12 weeks, track egg consumption consistency, any digestive changes, energy levels, and appetite. If possible, get baseline and follow-up cholesterol blood tests through your doctor. Monitor for any changes in heart disease symptoms like shortness of breath or chest discomfort. Keep notes on overall wellbeing and any dietary changes made simultaneously

This research was conducted in laboratory mice, not humans. The findings are preliminary and should not be used to replace medical advice from your doctor. If you have high cholesterol, heart disease, or are taking cholesterol-lowering medications, consult your healthcare provider before making dietary changes, including switching to low-cholesterol eggs. This study does not provide evidence that low-cholesterol eggs will prevent heart disease in humans. Individual responses to dietary changes vary greatly. Always discuss major dietary changes with a qualified healthcare professional, especially if you have existing health conditions or take medications