Fri Feb 7

Are eggs good or bad for our health?

Written by: Lauren Ball, Professor of Community Health and Wellbeing, The University of Queensland

You might have heard that eating too many eggs will cause high cholesterol levels, leading to poor health.

Researchers have examined the science behind this myth again ^[1], and again ^[2], and again ^[3] – largely debunking the claim.

A new study ^[4] suggests that, among older adults, eating eggs supports heart health and even reduces the risk of premature death.

Let’s unpack the details.

What was the study?

Researchers examined data from a large, ongoing study that is following older adults and tracking their health (the ASPREE study ^[5]).

In their analysis of more than 8,000 people, they examined the foods people usually eat and then looked at how many participants died over a six-year period and from what causes, using medical records and official reports.

Researchers collected information on their diet through a food questionnaire, which included a question about how frequently participants ate eggs in the past year:

never/infrequently (rarely or never, 1–2 times per month)
weekly (1–6 times per week)
daily (daily or several times per day).

Overall, people who consumed eggs 1–6 times per week had the lowest risk of death during the study period (29% lower for heart disease deaths and 17% lower for overall deaths) compared to those who rarely or never ate eggs.

Eating eggs daily did not increase the risk of death either.

How reputable is the study?

The research was published in a peer-reviewed journal, meaning this work has been examined by other researchers and is considered reputable and defensible.

Study participants reported their egg intake on an questionnaire. Sincerely Media/unsplash ^[6]

In the analysis, factors such as socioeconomic, demographic, health-related and clinical factors, and overall dietary quality were “adjusted” for, as these factors can play a role in disease and the risk of early death.

Researchers received funding from a variety of national funding grants in the United States and Australia, with no links to commercial sources.

What are the limitations of this study?

Due to the type of study, it only explored egg consumption patterns, which participants self-reported. The researchers didn’t collect data about the type of egg (for example, chicken or quail), how it was prepared, or how many eggs are consumed when eaten.

This analysis specifically looked for an association or link between egg consumption and death. Additional analyses are needed to understand how egg consumption may affect other aspects of health and wellbeing.

Lastly, the population sample of older adults were relatively healthy, limiting how much findings can be applied to older adults with special needs or medical conditions.

The study didn’t look at the type of eggs or serving sizes. Jakub Kapusnak/Unsplash ^[7]

What is ASPREE?

ASPREE ^[8] (ASPirin in Reducing Events in the Elderly) is an ongoing, large, randomised, placebo-controlled clinical trial involving more 19,000 participants in Australia and the US. This means some people in the trial were given an intervention and others weren’t but neither the participants nor the researchers knew who received the “placebo”, or dummy treatment.

ASPREE started in 2010 to investigate whether low-dose aspirin (100 micrograms daily) could help prolong older adults’ health and lifespan, specifically by preventing heart disease and stroke. The first findings ^[9] were published in 2018.

One of the fundamental conclusions of the ASPREE trial was there was no benefit from taking aspirin to prevent cardiovascular disease (heart disease or stroke).

ASPREE is still ongoing as a longitudinal study, which means it provides information on other aspects of healthy living and long-term outcomes in older adults – in this case, the link between egg intake and the chance of death.

Why the focus on eggs?

Eggs are a good source of protein, and contain B vitamins, folate, unsaturated fatty acids, fat-soluble vitamins (A, D, E and K), choline, and minerals.

The fuss over eggs comes down to their cholesterol content and how it relates to heart disease risk. A large egg yolk contains approximately 275 mg of cholesterol ^[10] — near the recommended daily limit of cholesterol intake.

In the past, medical professionals warned ^[11] that eating cholesterol-rich foods such as eggs could raise blood cholesterol and increase heart disease risk.

But newer research shows the body doesn’t absorb dietary cholesterol well ^[12], so dietary cholesterol doesn’t have a major effect ^[13] on blood cholesterol levels.

Rather, foods such as saturated and trans fats play a major role ^[14] in cholesterol levels.

The body doesn’t absorb the cholesterol from eggs very well. Nichiiro/Unsplash ^[15]

Given these changing recommendations over time, and the nuances of nutrition science ^[16], it’s understandable that research on eggs continues.

What does this mean for me?

Whether you prefer boiled, scrambled, poached, baked or fried, eggs provide a satisfying source of protein and other key nutrients.

While the science is still out, there’s no reason to limit egg intake unless specifically advised by a recognised health professional such as an accredited practising dietitian. As always, moderation is key.