Dr. Matthew Phillips is a neurologist and researcher in New Zealand who studies metabolic therapies—including ketogenic diets and fasting—for neurological diseases. His research has included Alzheimer’s disease, Parkinson’s disease, and brain cancer. He describes this emerging approach as metabolic neurology.
Phillips led a randomized clinical trial of a ketogenic diet in people with Alzheimer’s disease. Participants experienced significant improvements in daily functioning and quality of life while following the ketogenic diet. Cognitive scores also improved, but the difference was not statistically significant.
He has also conducted clinical research using ketogenic diets in Parkinson’s disease. His work explores whether changing the body's metabolism can improve brain energy and influence neurological disease. The studies are small, but they provide intriguing evidence for further research into metabolic therapies.
Dr. Phillips views many neurological diseases through the lens of metabolism and mitochondrial function. The brain requires enormous amounts of energy, and disturbances in the way brain cells produce and use energy may contribute to neurodegenerative disease.
Ketogenic diets and fasting change the body’s metabolism, reducing reliance on glucose and increasing the production of ketones. Ketones can provide the brain with an alternative source of energy.
Phillips is investigating whether these metabolic changes can improve brain function and potentially influence the course of neurological diseases.
Phillips and his colleagues conducted a randomized crossover trial involving 26 people with clinically confirmed Alzheimer’s disease.
Participants followed a modified ketogenic diet for 12 weeks and their usual diet supplemented with standard healthy-eating advice for another 12 weeks, with a washout period between them.
Twenty-one participants completed the ketogenic diet. Compared with the usual diet, participants experienced statistically significant improvements in measures of daily functioning and quality of life.
Cognitive test scores also improved, but the improvement was not statistically significant.
The study was small and relatively short, but it provided clinical evidence supporting further research into ketogenic diets for Alzheimer’s disease.
Dr. Phillips has also studied ketogenic diets in people with Parkinson’s disease. In a randomized clinical trial, participants followed either a ketogenic diet or a low-fat diet for eight weeks.
Both groups improved, but the ketogenic group showed greater improvement in non-motor symptoms, including problems such as daytime sleepiness and cognitive difficulties.
The study was small and short, so the results were preliminary. But it provided additional evidence that metabolic interventions may have applications beyond Alzheimer’s disease.
A ketogenic diet substantially reduces carbohydrate intake, causing the liver to produce ketones from fat. These ketones can provide an alternative source of energy for the brain.
Fasting can produce a similar metabolic shift. Phillips is interested in how both dietary ketosis and periods of fasting may influence cellular energy metabolism, mitochondrial function, and the brain’s resilience to disease.
Ketogenic diets have a long-established role in treating some forms of epilepsy, and their use in Alzheimer’s, Parkinson’s, and other neurological diseases remains an active area of research.
Phillips’s research is important because it moves metabolic therapies beyond laboratory studies and theory into human clinical trials.
His studies do not demonstrate that ketogenic diets or fasting can prevent, stop, or reverse Alzheimer’s or Parkinson’s disease. The trials have been relatively small and short.
However, the improvements observed in some measures of daily functioning, quality of life, and Parkinson’s symptoms provide a reason for larger and longer clinical trials.
A randomized crossover trial found that a modified ketogenic diet was feasible and produced improvements in daily function and quality of life in people with Alzheimer’s disease, although the study was small and short-term.
A small randomized controlled trial found that both low-fat and ketogenic diets were feasible in people with Parkinson’s disease, with the ketogenic group showing greater improvement in several nonmotor symptoms.
Dr. Phillips discusses his clinical research on ketogenic diets in people with Alzheimer’s disease and the evidence that ketosis may improve some measures of cognition and daily function.
Dr. Phillips explains why fasting and ketogenic diets are being studied for dementia and how ketones may provide an alternative source of energy when the brain has difficulty using glucose.
Dr. Phillips explains his view that neurodegenerative diseases may develop from underlying metabolic dysfunction long before symptoms appear and discusses the potential for metabolic therapies to intervene earlier.
Dr. Phillips explains how ketosis changes the brain’s energy metabolism and discusses why ketogenic diets and fasting are being studied for Alzheimer’s, Parkinson’s, and other neurological diseases.
Dr. Phillips explains how fasting, exercise, and ketosis may create beneficial metabolic stress that strengthens mitochondria and could potentially improve resilience in Parkinson’s disease.
Dr. Phillips discusses a striking individual case of neurological improvement and explores whether ketogenic diets and other metabolic stresses that stimulate mitohormesis could contribute to recovery.