Research Shows Eating 12 or More Eggs Weekly Does Not Affect Cholesterol

New research indicates that a diet high in eggs may not significantly affect cholesterol levels as it was previously believed.

Early findings from a recent study reveal that individuals who consumed 12 or more fortified eggs weekly did not have noticeably different cholesterol levels compared to those who abstained from eggs entirely. The study will be presented during the Annual Scientific Session of the American College of Cardiology in Atlanta, Georgia on April 6th.

Eggs have been controversial in nutritional diets due to fears that they could potentially raise cholesterol levels and negatively impact heart health. This latest research, however, could help to alleviate such fears, even for individuals at greater risk.

'The impact of eggs, a food high in cholesterol but also protein, on heart health has long been contentious,' said Fatima Rodriguez, MD, MPH, an associate professor of cardiovascular medicine at Stanford University. 'This small study gives some insight into the health effects of consuming large amounts of eggs, which can be further investigated in larger, controlled studies.'

This article will look at the latest research on eggs and examine how they can affect cholesterol levels. We will also discuss how eggs can be included in a balanced diet, even for people who are closely monitoring their heart health.

Eggland's Best sponsored the study. This company is one of the largest egg farmers in the United States. The researchers investigated the impact of a diet high in fortified eggs compared to a diet without eggs on various cardiovascular health markers. This included cholesterol levels, inflammatory markers, micronutrient levels, and other endpoints.

Fortified eggs are eggs that have increased nutritional value by adding nutrients such as vitamin D, selenium, vitamins B2, 5, and 12, and omega-3 fatty acids.

Out of the 140 individuals who participated in the study, they were divided into two groups—the fortified eggs group who ate 12 or more fortified eggs per week and the non-egg diet group who consumed two or fewer eggs per week. Participants were permitted to cook the eggs in any way they liked.

All study participants were over 50 years old and had either suffered one previous cardiovascular event or had at least two cardiovascular risk factors. About 27% of the participants were Black and 24% suffered from diabetes.

Participants had in-person meetings after one month and again after four months to check their vital signs and blood cholesterol levels. To monitor egg consumption, researchers also conducted phone check-ins throughout the study.

Researchers compared levels of HDL-cholesterol (good cholesterol) and LDL-cholesterol (bad cholesterol) in participants from both groups at the commencement of the study and again after four months.

After four months, both study groups showed comparable HDL- and LDL-cholesterol levels. Results indicated a slight decrease in HDL- and LDL-cholesterol in the fortified egg group versus the non-egg diet group. However, these changes were not considerable enough to be statistically relevant.

Such findings suggest that consuming 12 or more fortified eggs each week did not have adverse effects on blood cholesterol levels.

The study carried out is termed as a neutral study, a study that discloses no significant differences between the study groups. This implies that while there's no evidence of harm, there is also no proof of any benefit, specifically considering changes in HDL- and LDL-cholesterol levels.

Study results also showed slight reductions in the blood levels of high-sensitivity troponin, a marker for heart damage, and slight increases in vitamin B levels in the fortified egg group.

'In this small, single-center study, consuming more than 12 fortified eggs weekly did not change blood cholesterol levels significantly after four months,' said Rodriguez. 'This study offers some evidence that this level of egg consumption may be acceptable.'

Despite evidence suggesting that consuming 12 or more eggs weekly did not negatively affect blood cholesterol levels, experts urge caution interpreting the results.

The small, single-center study was conducted following a single protocol at one site, relied on self-reported egg consumption and other dietary habits of patients. Moreover, patients were aware of their group (egg-eating or non-egg-eating), which could have influenced their health behaviors.

All these factors 'make it challenging to draw robust conclusions from this study,' according to Matthew Tomey, MD, a cardiologist and assistant professor of medicine at the Icahn School of Medicine at Mount Sinai.

'While I agree that the data shared do not provide evidence of harm with eating more eggs, I might stop short of citing the present study as sufficient 'reassurance' of the absence of harm,' Tomey told Health.

Information provided on the study also does not go into details regarding the participant's diet outside of their egg consumption, including whether they ate fewer overall calories or consumed less saturated fat, or if these results apply to non-fortified eggs, according to Martha Gulati, MD, professor of cardiology and director of preventive cardiology at Cedars-Sinai.

Experts are also interested in knowing more about the long term cardiovascular effects of fortified egg consumption. 'Four months is a good follow up period but I would want a longer study. Hopefully, they have food diaries on participants that will be analyzed and perhaps this study will have a long follow up to assess for CV [cardiovascular] outcomes', said Gulati.

Though the study's results suggest that egg consumption does not impact cholesterol as much as we once thought, when it comes to diet and cholesterol, it is the entirety of one's diet that ultimately determines heart health.

'Nutrition is complicated and we need to be careful about looking at any one food in isolation,' said Tomey. 'The impact of our diet on our health is a product of the totality of our food choices. When we avoid one food, the question comes, how are we replacing it in our diet?'

'I think dietary guidance is always a bit difficult,' added Gulati. 'It is never one food that causes heart disease, it is the entire diet and the total saturated fat.'

As for whether eggs are a safe addition to a daily diet, experts agree that the answer is yes—in moderation and as long as the diet is balanced overall.

'Eggs are so commonly part of the American diet, and people want to know if they can eat eggs. It is a common clinical question posed to me,' said Gulati. 'My answer is always this: You can consume eggs in moderation, but I need to know more about your diet and if you consume other sources of saturated fats. Because ultimately it is the total saturated fat consumption that will affect your LDL and increase the risk for atherosclerosis.'

For people who are looking to make a change to their diet, Tomey said it's more important to zoom out and look at the big picture, rather than focusing on one ingredient. 'I would encourage anyone considering a dietary change for health promotion,' he said, 'to evaluate the diet holistically.'