For years, eggs have been one of the most debated foods in nutrition.

Some people avoid them because of cholesterol concerns.

Others see them as a nutritious, affordable source of protein and vitamins that can form part of a healthy diet.

Now, a new 2026 study published in The Journal of Nutrition has added fresh evidence to the debate.

Researchers found that older adults who ate eggs more frequently were less likely to develop Alzheimer's disease¹

The findings do not prove that eggs prevent dementia.

But they do raise important questions about how everyday dietary habits may influence long-term brain health as we age.

What Did the Study Find?

Researchers looked at health and diet data from nearly 40,000 adults taking part in a long-running US health study.¹

Participants were tracked for more than 15 years, with researchers comparing egg intake against rates of Alzheimer’s disease later in life.

They found that people who ate eggs more regularly were less likely to develop Alzheimer’s disease compared with those who rarely ate them.

Interestingly, the link was seen even among people eating eggs just 1–3 times per month. Stronger associations were generally seen at higher levels of intake.¹

The link remained even after researchers accounted for factors including:

• age

• smoking

• education

• physical activity

• alcohol intake

• overall diet quality

  
  

Importantly, this was an observational study. That means researchers observed people’s eating habits and health outcomes over time rather than testing eggs in a controlled clinical trial.

So while the study found a link between egg intake and Alzheimer’s risk, it cannot prove that eggs directly prevent dementia.

Still, because the study was large, long-term and published in a respected peer-reviewed journal, researchers say the findings deserve further study.

Why Are Researchers Interested in Eggs?

Eggs contain several nutrients that researchers believe may help support healthy brain function as we age including:

• choline

• vitamin B12

• lutein

• zeaxanthin

• selenium

  
  

Choline

Choline has attracted growing attention in brain health research. The body uses choline to help produce chemical messengers involved in memory and learning.²

Eggs are one of the richest dietary sources of choline in the UK diet, and some studies have linked low choline intake with poorer memory and increased risk of cognitive decline later in life.³

Vitamin B12

Eggs also provide vitamin B12, which helps support normal nervous system function.⁴ Low vitamin B12 levels become more common with age and can contribute to fatigue, neurological symptoms and memory problems.

Lutein and Zeaxanthin

Egg yolks naturally contain lutein and zeaxanthin — antioxidant compounds often associated with eye health.

Researchers are also exploring whether these compounds may help protect the ageing brain from inflammation and oxidative stress.⁵

Protein and Healthy Ageing

Eggs are also a high-quality source of protein.

Getting enough protein becomes increasingly important as we get older, helping support muscle strength, mobility and overall physical function — all of which are associated with healthier ageing more broadly.⁶

What About Cholesterol?

This is where many readers understandably become cautious.

Eggs do contain cholesterol. But scientists now understand cholesterol in foods rather differently than they once did.

For most people, saturated fat appears to affect blood cholesterol levels more than the cholesterol naturally found in eggs.⁷

The NHS says eggs can be eaten as part of a healthy, balanced diet.⁸

However, individual circumstances still matter.

People with familial hypercholesterolaemia, existing cardiovascular disease, or specific medical advice from their GP or specialist should continue following personalised guidance.

Overall dietary pattern also matters far more than any single food alone.

Long-term brain and heart health are influenced by a wide range of factors, including physical activity, sleep, smoking, social connection and overall lifestyle habits.

Important Limitations of the Study

While the findings are interesting, they should be interpreted carefully.

The study does not prove that eggs prevent Alzheimer’s disease.

A Very Specific Study Population

One important limitation is that the study involved a group of predominantly Seventh-day Adventists in the United States.¹

This is a particularly health-conscious population, with many participants following vegetarian diets and avoiding smoking and alcohol.

That means the findings may not fully apply to the wider UK population, whose diets and lifestyles are often quite different.

Other Healthy Habits May Also Play a Role

People who regularly eat eggs may also:

• exercise more

• smoke less

• eat more nutritious diets overall

• engage in other healthy habits

  
  

Researchers try to account for these differences, but observational studies can never remove them completely.

Dementia Is Complex

Alzheimer’s disease develops over many years and is influenced by:

• genetics

• heart and blood vessel health

• physical activity

• sleep

• social connection

• diet and nutrition

• smoking and alcohol habits

No single food determines whether someone develops dementia.

So, Should You Eat More Eggs?

For many people, eggs can be a nutritious and affordable part of a balanced diet. They provide protein alongside nutrients linked with healthy ageing, including choline, vitamin B12 and lutein.

But the bigger picture still matters most.

The strongest evidence for supporting long-term brain health continues to centre around everyday habits such as:

• staying physically active

• managing blood pressure

• not smoking

• getting enough sleep

• maintaining social connection

• eating a varied, balanced diet

  
  

Rather than relying on any one “superfood”, researchers increasingly believe it is the combination of these habits over many years that has the greatest influence on healthy brain ageing.

This new study adds to growing evidence that the small habits repeated day after day — including the foods we eat regularly — may play a bigger role in healthy brain ageing than we once realised.