Eggs and brain health

Eggs are a nutrient-dense food and great for overall health. They are rich in choline, a critical, but often overlooked nutrient, essential for liver function, muscle health and cell structure, but also really important for brain health. Now, new research suggests that higher levels of choline may even reduce your risk of Alzheimer’s disease.

Eggs are one of the best sources of choline available to us, and people who don’t eat eggs may struggle to get enough choline in their diets. Here we look at how eating eggs helps to keep our brains healthy and may reduce our risk of Alzheimer’s Disease.

1.   What is choline?

Choline is a B-vitamin like substance and considered an essential nutrient for health and because the human body can only make a little of it, we have to consume it in our food. In this way it is similar to omega 3 fatty acids – as they are both vital for health and have to be included in the diet.

Eggs are a particularly good source of choline, with a large egg containing nearly 200mg of choline. Whilst other animal foods, and some plant foods also contain some choline, regularly eating eggs is the most reliable way of ensuring you have an adequate supply in your diet.

2.  Eggs and brain health - what we already know

Choline found in eggs is well recognised as critical for brain health and for helping to protect us against neurodegenerative diseases:

• It is used to make the neurotransmitter acetylcholine, which is essential for neural communication and cognitive processes in the brain. 

• Acetylcholine is involved in many important functions including memory, mood, muscle control, and other brain and nervous system activities.

• Choline is also needed to maintain the health and integrity of the neuronal membranes, which help protect us against age-related cognitive decline.

Adequate choline intake is linked to improved cognitive function and may help in the prevention of neurodegenerative conditions.

This Photo by Unknown Author is licensed under CC BY-NC-ND

Previous studies have shown improvements in cognitive function with higher levels of choline:

• The Framingham Heart Offspring cohort study of 1391 volunteers, found that dietary choline was positively associated with specific cognitive functions  -  verbal and visual memory. 

• A study, involving 2,393 adults aged over 60 found choline intakes of 187 and 400 mg/day improved cognitive performance in three separate measures (assessing learning, processing speed, sustained attention, and working memory) compared to intakes of less than 187 mg/day.

• In a study of 2195 older adults (aged 70-74), high versus low blood levels of choline were significantly associated with greater performance at cognitive tests assessing sensory motor speed, perceptual speed, executive function and global cognition.

• Traumatic brain injury – Citicoline (choline combined with cytidine) appears to limit memory deficits and the duration and severity of other post-traumatic symptoms (e.g., headache, dizziness, attention disorder) in patients with mild-to-moderate injuries

Brain development in babies

Choline is also essential for women during pregnancy as it supports the healthy development of the baby’s brain and spinal cord.

‘New and emerging evidence suggests that maternal choline intake during pregnancy, and possibly lactation, has lasting beneficial neurocognitive effects on the offspring’

Taylor C. Wallace, 2018

From: Taylor. C. Wallace et al, 2018 Choline ‘The Under consumed and Underappreciated Essential Nutrient’, Nutrition Today

3.   New research on eggs and Alzheimer’s Disease

Given what is known about the protective effects of choline on the brain, a new study has investigated the association between egg consumption and the incidence of Alzheimer’s disease.

What the researchers did

• Researchers examined the health records of 39,498 participants in the Adventist Health Study 2 Cohort

• Diet and lifestyle factors were assessed using a validated food frequency questionnaire.

• Egg consumption was categorized by frequency, ranging from never/rarely to  more than 5 times per week.

• Participants were followed up for an average of 15.3 years, and during this time 2858  developed Alzheimer’s disease.

Key findings

Key findings included the following:

• Higher egg consumption was associated with a lower risk of Alzheimer’s disease 

• The protective effect appeared to be largely explained by higher choline intake

• Choline intake was associated with better cognitive performance and brain health markers

This was an observational study, and this type of study can only show an association between higher egg consumption and lower risk of Alzheimer’s Disease and cannot prove a causal link. However, the study aligns with previous studies showing:

• Higher dietary choline is linked with better memory performance

• Increased choline intake is associated with reduced markers of brain ageing, such as white matter damage

• Lower levels of choline have been found in people with Alzheimer’s Disease.

These findings suggest a potential neuroprotective benefit of nutrients found in eggs when consumed as part of a balanced diet.

This Photo by Unknown Author is licensed under CC BY

4.   Why links eggs and brain health?

There are several plausible biological mechanisms:

a.    Neurotransmitter Support

Choline is required to produce acetylcholine, a neurotransmitter essential for memory and learning. Low acetylcholine levels are a hallmark of Alzheimer’s disease.

b.    Brain Cell Structure

Choline is a key component of phospholipids, which form brain cell membranes. Adequate intake helps maintain cell integrity and function.

c.    Anti-inflammatory and protective effects

Eggs also contain nutrients such as lutein and zeaxanthin, which may help reduce oxidative stress and inflammation in the brain.

d.    Improving executive function

Egg-derived tryptophan, an amino acid found in eggs has been shown to enhance attention, reduce stress  and improving executive function in older adults.  Tryptophan, is also important for cognition and mood

5.   How much choline do we need?

The US and European countries all recommend a minimum daily intake of choline, however unfortunately the UK does not specify this requirement.  A minimum of 400mg daily is recommended for all adults in the US, with European countries recommending 425mg for women and 500 mg for men. Pregnant and breastfeeding women are recommended a higher daily intake.

One large egg contains nearly 200mg of choline, so if you eat eggs regularly you are likely to be meeting your daily requirements for choline

5. How to get choline if you don’t eat eggs

Choline is found in other foods, notably liver, cod roe, and other animal foods as shown in the chart below. However, most plant foods contain much smaller quantities of choline, and it is therefore difficult to meet your choline requirements through diet alone if you don’t eat eggs, or are on a vegan diet. Vegans in particular, and vegetarians who don’t eat eggs,  are therefore advised to use supplementary choline to meet their daily requirements.

7. Conclusion

Emerging evidence suggests that eggs—largely due to their choline content—may support brain health and could be linked to a lower risk of Alzheimer’s disease.

While more research is needed, eggs represent a simple, affordable, and nutrient-rich food that may contribute to long-term cognitive wellbeing.