Study says 12 eggs a week may not have an impact

Eggs have been a common component of the human diet for many years. They contain many helpful nutrients, such as protein, vitamin B12, iodine, and vitamin D. There are many options for egg types. Fortified eggs have a high level of nutrients because specific components are added to hens’ feed.

In past years, one of the major concerns about eating eggs has been their cholesterol content and how this could impact the risk for cardiovascular disease and other health outcomes.

The evidence appears to be somewhat conflicting. One recent review suggests that greater levels of egg consumption could increase total cholesterol and raise the low-density lipoprotein (LDL) to high-density lipoprotein(HDL) ratio. However, the review notes that there is also evidence that eating up to one egg a day may not majorly impact the risk for cardiovascular disease.

Another umbrella review published in 2020 found that eating eggs was not associated with cardiovascular disease risk in the general population. However, the authors of this review noted that more research was needed to examine how eating eggs related to heart failure and whether it increased cardiovascular disease risk among people with diabetes. Another review suggested that eggs might actually play a role in decreasing cardiovascular disease risk.

Non-study author Kelsey Costa, MS, RDN, registered dietitian nutritionist and founder of Dietitian Insights, noted the following:

“Eggs are a good source of lean protein and many essential micronutrients, including folate, vitamin A, B2 (riboflavin), B5, B12, phosphorus, and selenium. However, research findings to date have been mixed in regard to the effects of eggs on health markers, including serum cholesterol levels, insulin resistance, oxidative stress, inflammation, and potential cardiometabolic risk. This may be due to the fact that egg composition can vary depending on how they are produced, and cooking methods can also affect the potential benefits or harm related to eating them.”

This study examined the consumption of fortified eggs among people at a certain level of risk for poor cardiovascular outcomes. All participants were at least fifty, and 24% had diabetes mellitus. The average age of participants was sixty-six.

Researchers divided 140 participants into two groups. One group was instructed to eat twelve or more fortified eggs each week, while the other was supposed to eat less than two eggs each week.

The main outcome was examining cholesterol levels, specifically high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol. Researchers also examined levels of certain micronutrients, lipid levels, and cardiometabolic and inflammatory biomarkers.

When researchers compared the two groups, they found similar HDL and LDL changes. This indicates that consuming fortified eggs did not negatively impact cholesterol among participants.

Study author Nina Nouhravesh, MD noted the following to Medical News Today:

“The key finding from this study is the consumption of 12 or more fortified eggs per week, over a period of 4 months, did not negatively impact cholesterol — specifically LDL cholesterol (commonly known as “bad cholesterol”) or HDL (commonly known as “the good cholesterol”) –when compared to patients who had a non-egg supplemented diet.”

The findings from secondary outcomes likely require further investigation. However, researchers found that participants in the fortified egg group had decreased total cholesterol, high-sensitivity troponin, and insulin resistance. This could indicate that more research needs to be done on the potential health benefits of eating fortified eggs. Among participants aged sixty-five and older, researchers found a decrease in bad cholesterol and an increase in good cholesterol, but it was not at a statistically significant level.

At this time, the entire paper is not available and has not been published in a peer-reviewed journal, which limits the ability to analyze the research. The study only lasted a few months, so future research could include longer studies to look at long-term outcomes. Future research could also include more participants. The study also cannot prove that egg consumption causes any particular health outcomes. Some data may rely on participant reporting, contributing to the risk of incorrect data.

In addition, the study received funding from one of the world’s largest egg producers, Eggland’s Best, according to a press release.

Costa noted the following limitations of the research as well:

“While the full study hasn’t been peer-reviewed or published yet, the findings do not really tell us much, as it was a small sample size and not blind. Those eating fortified eggs or the control group may have improved their eating or lifestyle habits due to the ‘Hawthorne effect.’ This phenomenon occurs when people change their behavior in response to being observed. Consequently, the study’s results may reflect changes in participants’ overall dietary patterns or health behaviors rather than the direct impact of consuming fortified eggs on cholesterol levels.”

Results point to the need for further research in this area, possibly with funding from sources where there is less risk for bias. However, additional research could uncover the potential benefits of fortified eggs for particular groups, such as older adults or people with diabetes.

Nouhravesh noted the following:

“Nutritionally optimized foods continue to enter the market, and I hope trials like this will spike interest on performing randomized, rigorous trials so we can settle discussions surrounding good and bad foods. We would definitely like to investigate some of the secondary findings from this study further. In the current trial we saw a signal of potential benefit on cholesterol levels in patients who were older and in patients with diabetes, which we think is data that should be further investigated in larger trials.”