Can diet reduce dementia risk? Sarah Di Lorenzo on brain foods that research suggests may help protect memory

In my clinical experience I would have to say dementia would be one of the most feared diagnoses.

Most people believe that cognitive decline is a consequence of ageing. Science tells very different information and as a clinical nutritionist, I feel it is so important to share this because the evidence for diet and lifestyle as genuine protective factors against dementia is now so robust, compelling and an important health message.

First to look at numbers. The 2024 Lancet Commission on Dementia Prevention identified 14 modifiable risk factors that together could potentially prevent or delay about 45 per cent of future dementia cases globally. To modify means to change which means to reduce risk. Diet is central to almost all of them including blood pressure, cholesterol, obesity, physical inactivity, diabetes, social isolation, depression and systemic inflammation.

These are all directly influenced by what we put on our plate every single day.

The food that is getting the most attention in brain health research is eggs.

A large prospective study from Loma Linda University, using data from the Adventist Health Study-2 and published in 2026, followed tens of thousands of adults and found that eating eggs as infrequently as one to three times per month was associated with a 17 per cent lower risk of Alzheimer’s disease compared to rarely or never eating them. Eating eggs two to four times per week pushed that reduction to 20 per cent, and five or more times per week to about 27 per cent.

A key proposed mechanism involves choline which is a nutrient found almost entirely in the yolk. Choline is the direct precursor to acetylcholine, the neurotransmitter essential for memory and learning. As we age, acetylcholine levels naturally decline and this decline is one of the neurological features defining Alzheimer’s disease.

Dietary choline from eggs provides the raw material the brain needs to keep producing it. The yolk also delivers DHA, the long-chain omega-3 fatty acid that the brain is literally built from, and lutein, which accumulates in brain tissue and helps neutralise the oxidative stress that drives neuronal damage. Always eat the yolk!!!

Looking at other brain healthy foods, extra virgin olive oil, even only half a tablespoon per day, has been associated with a 28 per cent lower risk of dying from dementia in a Harvard-led study of more than 90,000 adults. This is because of the oleocanthal, a polyphenol that may help activate the brain’s own waste-clearance systems, supporting the removal of amyloid beta proteins that accumulate to form the plaques characteristic of Alzheimer’s disease as well as being anti-inflammatory. Half a tablespoon is achievable for anyone to consume daily.

Berries, especially blueberries and strawberries, deliver flavonoids that cross the blood–brain barrier, reduce neuro-inflammation, and support memory formation.

Strawberry consumption specifically has been associated with a 20–25 per cent reduction in Alzheimer’s risk in at least one large observational study. I recommend to all my patients they have half a cup daily.

Leafy green vegetables such as spinach, kale, silverbeet and rocket are the food prioritised above all others in the MIND diet, the dietary pattern specifically developed from the dementia-prevention literature.

People who eat six or more servings of leafy greens per week show measurably slower cognitive decline. This is equivalent to being about 11 years younger neurologically than those eating the least. The folate, vitamin K, lutein, and nitrates in leafy greens each contribute neuroprotective mechanisms, from supporting methylation to improving cerebral blood flow.

Mushrooms are also on this list. There is emerging research that suggests the beta-glucans and ergothioneine in mushrooms, which is a unique antioxidant found almost exclusively in this food, have genuine neuroprotective properties and are associated with better cognitive performance and slower cognitive decline in regular consumers.

In long-term observational studies, people eating mushrooms at least once per week have shown measurably better cognitive scores that include word recall and executive function more than those who don’t consume them. Plus mushrooms are affordable, delicious and versatile to cook with.

On the other hand, the foods associated with increased dementia risk are those that are ultra-processed. Diets higher in ultra-processed foods are associated with substantially higher dementia risk.

Replacing just 10 per cent of ultra-processed food with minimally processed or whole-food alternatives has been estimated to reduce dementia risk by about 19 per cent. It is not just because they’re nutritionally poor, it is the active disruption of the gut microbiome, the systemic inflammation, and the metabolic dysregulation that ultra-processed foods produce, all of which compound the neurological damage that drives cognitive decline.

The most important message is dementia prevention is not a single intervention or something you do for a short period of time.

It is a daily way of life, a diet full of diverse, colourful, whole foods that together reduce neuroinflammation, support the gut–brain axis, protect cerebrovascular health, and provide the raw materials the brain needs to maintain its structure and function across decades.

The earlier you start, the more protective it becomes. It is never too late. Meaningful improvements in biomarkers and risk factors for brain health are achievable at any age when dietary patterns shift in the right direction.