Thiamine, brain glucose and Alzheimer's disease
What it found
People with Alzheimer's disease often have lower thiamine activity in their blood and brains, and thiamine deficiency in animals causes memory problems and Alzheimer's-like brain changes.
The authors suggest thiamine supplements might help, but say proper trials are needed.
What they found
Studies in people
Thiamine deficiency in people
In people, severe thiamine deficiency causes Wernicke-Korsakoff syndrome, with memory loss and confusion. Giving thiamine can resolve acute symptoms and may save lives.
Thiamine status in Alzheimer's
In studies of people with Alzheimer's, a blood test of thiamine-dependent enzyme activity was 12% higher than in controls, and plasma thiamine was about one-third lower. This suggests many Alzheimer's patients are thiamine deficient.
Brain enzymes in Alzheimer's
The activity of three thiamine-dependent enzymes in the brain is reduced by 50 to 100% in Alzheimer's patients compared with controls, with no studies showing the opposite.
Previous trials in people
Small, short trials of thiamine or its analogues in Alzheimer's patients have been underpowered, so results are not reliable. Some showed mild benefits on memory or attention, but a one-year trial failed to replicate earlier positive findings.
Animal and lab studies
Animal memory and thiamine
In rats and mice, thiamine deficiency impairs performance on memory tasks like water maze and passive avoidance. Giving thiamine back can reverse these learning problems if done early.
Plaques and tau in animals
In mice engineered to make plaques, ten days of thiamine deficiency produced plaques throughout the brain and increased tau phosphorylation. A thiamine compound, benfotiamine, reduced plaques, tau and memory deficits.
What the authors conclude
“The safety of thiamine and its analogues suggests that a carefully designed trial of thiamine analogues, with appropriate power, should be conducted in AD patients.”
Also in their conclusions
- They conclude that a carefully designed trial of thiamine analogues, with appropriate power, should be conducted in Alzheimer's patients.
- They note that the safety of thiamine and its analogues supports this next step.
How it was done
The authors wanted to explore whether thiamine deficiency could be an early trigger for Alzheimer's disease, since both conditions involve memory loss and reduced glucose use in the brain.
They reviewed studies in people, animals and cells that looked at thiamine levels, thiamine-dependent enzymes, brain glucose metabolism, and memory in Alzheimer's disease and thiamine deficiency. They also examined previous trials of thiamine and its analogues in Alzheimer's patients.
What it can’t tell you
- Most of the evidence linking thiamine deficiency to Alzheimer's-like brain changes comes from animals, so it cannot prove what happens in people.
- The previous trials in people were too small and too short to show whether thiamine or its analogues truly help Alzheimer's patients.
- This review cannot show whether thiamine deficiency causes Alzheimer's disease or is just a consequence of it.
Who paid
- Funding
- Funded by NIA NIH HHS (from the PubMed record).
- Conflicts
- Conflicts of interest . The authors declare no conflicts of interest.
- Authors work at
- Brain and Mind Research Institute, New York; Burke Rehabilitation Hospital, New York
The paper
- Title
- Vitamin B1 (thiamine) and dementia
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Gibson GE, Hirsch JA, Fonzetti P, Jordan BD, Cirio RT, Elder J (2016). Vitamin B1 (thiamine) and dementia. Annals of the New York Academy of Sciences. doi:10.1111/nyas.13031Free full textPubMed 26971083DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error