A Handful of Possibility- Peanuts and the Ageing Brain
Article by Dr. Donald Greig
Walking into a room and forgetting why. Searching for a familiar name. Wondering whether a misplaced pair of glasses means something more.
For many of us, the prospect of losing our memory is deeply unsettling. It is not simply about remembering facts. It is about maintaining our independence, recognising the people we love and remaining ourselves.
So, research suggesting that an ordinary food might support the ageing brain deserves our attention.
The food in question is not an expensive supplement or an exotic “superfood”. It is the humble peanut.
The emerging evidence is encouraging, but there is an important distinction between improving performance on a memory test and proving protection against dementia.
What did the Maastricht research find?
A small randomised trial from Maastricht University offers an encouraging starting point. Researchers investigated whether eating unsalted, skin-roasted peanuts every day could improve brain circulation and memory in healthy older adults.
Published in Clinical Nutrition in 2025, the study involved 31 participants, whose average age was 67.
Each participant completed two periods: 16 weeks eating 60 grams of peanuts daily, and 16 weeks without peanuts. An eight-week break separated the periods, allowing researchers to compare each person’s results under both conditions.
Compared with the no-peanut period, researchers found:
3.6% higher blood flow across the brain.
4.5% higher blood flow in grey matter.
5.8% better performance on a delayed verbal-memory test, equivalent to approximately 1.4 additional words recalled correctly.
Approximately 5 mmHg lower systolic blood pressure, the upper number in a blood pressure reading.
However, there was no demonstrated improvement in executive function or psychomotor speed, measures involving thinking skills and the speed of responding.
These were specific, modest improvements, not evidence of better performance in every aspect of brain function.
Peanuts provide unsaturated fats, plant protein and fibre. They also contain plant compounds called polyphenols, which researchers are investigating for possible effects on inflammation and brain health.
One possible explanation involves circulation. The Maastricht findings suggest that improved blood supply might contribute to the observed memory benefit, although the trial does not establish that one caused the other.
A further analysis from the same trial, published in Food & Function in October 2026, examined how the brain responded to insulin. It found a change in responsiveness within a region involving memory-related structures, which the researchers interpreted as potentially beneficial.
This was an additional finding from the same participants, not independent confirmation in a new group. It offers a possible biological explanation, rather than proof of protection against cognitive decline.
Does this mean peanuts prevent dementia?
No. That has not been demonstrated.
Better performance on a particular memory test is not the same as preventing Alzheimer’s disease or another form of dementia. Establishing long-term protection requires larger studies with much longer follow-up.
The wider evidence is also not uniformly positive.
A separate trial published in August 2026 enrolled 30 older adults with memory complaints and cardiovascular risk factors. After 12 weeks, researchers found no significant improvement in cognitive performance or task-related brain activation compared with the control group.
The studies involved different participants and methods, so their results are not directly interchangeable. Nevertheless, the less positive finding matters.
The fair conclusion is that peanuts may support certain aspects of brain function, but their ability to protect the ageing brain over the long term remains uncertain.
Should we all start eating 60 grams a day?
Not necessarily.
The Maastricht study used approximately two small handfuls daily. That is a research dose, not an established prescription for preventing memory loss.
For everyday healthy eating, a small handful of around 30 grams can be a practical portion. Peanuts are energy-dense, so portion size matters, particularly if you are watching your weight.
We do not know whether that smaller portion produces the same brain effects.
My practical suggestion is to consider peanuts as a replacement for a less nutritious snack, rather than automatically adding a large extra portion to your usual diet.
A small, sustainable change is more useful than treating one food as a daily medicine.
Making them part of everyday eating
If you enjoy peanuts and can eat them safely:
Choose unsalted, unsweetened varieties.
Measure out a portion, rather than eating directly from a large packet.
Try them sprinkled over porridge, yoghurt, salads or vegetable dishes.
Consider replacing biscuits, crisps or confectionery with a modest portion.
Remember that chocolate-covered or sugar-coated peanuts bring additional ingredients that may not fit your nutritional goals.
Peanut butter can also fit into a balanced diet, preferably without added salt or sugar. However, we should not assume that it reproduces the findings from a trial using whole, skin-on peanuts.
An important word about allergy
Do not introduce peanuts if you have a known peanut allergy. Reactions can be severe and potentially life-threatening.
If you have previously experienced symptoms after eating peanuts, seek medical advice before trying them again.
A possible memory benefit is never a reason to take an allergy risk.
An appealing food story should not distract us from the broader picture.
Looking after the ageing brain also involves:
Regular physical activity, appropriate to your health and abilities.
Managing blood pressure, diabetes and other cardiovascular risks.
Getting adequate sleep.
Avoiding smoking and limiting alcohol.
Staying socially connected and mentally engaged.
Eating a varied, balanced diet.
No single food replaces these foundations.
Persistent or worsening memory difficulties also deserve medical assessment, particularly when they begin to interfere with everyday activities. They should not be managed simply by changing a snack.
What appeals to me about this research is its practicality. It invites us to consider whether an ordinary dietary choice could make a useful contribution to health.
But patients deserve more than an attractive headline.
I would not describe peanuts as a treatment for memory loss or promise that eating them every day will prevent dementia. The evidence is not there.
For someone who enjoys them, has no allergy and can accommodate them within a balanced diet, a modest portion of unsalted peanuts is a reasonable food choice. Any additional benefit to memory would be welcome, but should not be presented as guaranteed.
The wider lesson is worth remembering: looking after ourselves does not always require dramatic changes. Sometimes it begins with small, manageable choices, repeated consistently, alongside attention to the rest of our health.
My advice is to embrace the possibility without exaggerating the promise.
A handful of peanuts may have a place at the table. Looking after the ageing brain still requires us to consider the whole person.
Disclaimer: This newsletter provides general information, not individual medical advice. Please consult your doctor about memory concerns or dietary changes relevant to your health.
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