The Role of Diet in Alzheimer’s Disease
Link to Study: Ketogenic diet in Alzheimer’s Disease – BiomedCentral
When I studied neuroscience and human nutrition at university, I never imagined the two fields could truly intersect. Back then, the idea that what we eat could directly affect our brain health felt almost foreign. But how much things have changed in just over a decade!
I remember dreaming about becoming a nutritional neuroscientist. While that’s not exactly my title today, much of the work I do helps clients improve their mood, mental clarity, cognition, and energy—clear signs that how we eat and live has a profound impact on our brain.
A Research Opportunity
In 2021, I was fortunate to be part of an exciting study that looked at the effect of a ketogenic diet on patients with Alzheimer’s Disease (AD). I teamed up with the incredible Dr. Matthew Phillips, a metabolic neurologist at Waikato Hospital, who is pioneering research into how metabolism affects neurodegenerative diseases and even cancer.
There was a need for an additional nutritionist on the study—so I eagerly jumped on board.
Why a Ketogenic Diet?
Alzheimer’s is often referred to as “type 3 diabetes” because of the brain’s impaired ability to use glucose—its usual energy source. This state of insulin resistance means neurons are essentially starved of fuel, leading to their degeneration.
A ketogenic diet shifts the body’s fuel source from glucose to ketones (produced from fats), which the brain can still use efficiently. The idea was simple yet powerful: by providing an alternative energy source, we might be able to protect brain cells and preserve function.
The Study Design
We conducted the first-ever randomised controlled trial comparing a ketogenic diet to the standard New Zealand healthy eating guidelines in people with Alzheimer’s.
26 participants completed both dietary phases (12 weeks each), with a 2-week washout period in between.
My role was to support patients through each phase, helping them stick to the diet, manage side effects, and achieve nutritional ketosis (on the keto arm).
This was no small feat—many participants had to make drastic dietary changes despite living with dementia. But they did it!
What We Measured
To assess the outcomes, we tracked:
Addenbrooke’s Cognitive Examination (ACE-III)
Alzheimer’s Disease Cooperative Study – Activities of Daily Living
Quality of Life in Alzheimer’s Disease questionnaire
Cardiovascular risk factors
Adverse effects
The Results
Despite the short timeframe, the results were incredibly encouraging:
✅ Participants achieved nutritional ketosis
Compared to the standard diet, those on the ketogenic diet experienced:
Significant improvement in Activities of Daily Living
(A 3.13 point increase – considered “clinically meaningful,” whereas those on the standard diet declined)Significant improvement in Quality of Life
(A 3.37 point increase – again, “clinically meaningful”)Improved cardiovascular markers
Mild and manageable side effects
Cognition (ACE-III) also improved, though not significantly—possibly due to the short study period and COVID-19 lockdown, which occurred during weeks 7–11 and disrupted food access and routine.
Still, improved daily function and quality of life are incredibly important for people living with AD—and rarely achieved with medication.
Why This Matters
Our study has since been referenced globally and offers real hope—not only for supporting those already diagnosed with Alzheimer’s, but also for preventing cognitive decline before it starts.
While I don’t believe everyone needs to follow a ketogenic diet for prevention, it’s hard to ignore the impact of today’s processed, sugar-laden diets—especially when we consider the rise of type 2 diabetes and Alzheimer’s.
If more people simply embraced a whole foods lifestyle, I genuinely believe we’d see a massive decline in Alzheimer’s and many other chronic, lifestyle-driven diseases.
Final Thoughts
Being part of this research was such a rewarding experience and one I hope I can continue to pursue at some point. It proved that what we eat truly matters for our brains—and that change is possible, even in later stages of life. People often wait until something explodes in their health i.e. a diagnosis of sorts but my biggest hope is that people would make changes now so that they prevent disease and don’t have to go through the turmoil of these disease for themselves and their loved ones.
If you have thoughts or questions, I’d love to hear from you in the comments below!
