A large genetic study has found that sharp rises in blood sugar after meals could significantly heighten the risk of Alzheimer’s disease. Researchers from the University of Liverpool analyzed data from over 350,000 UK Biobank participants, revealing a 69% increased risk linked to postprandial hyperglycemia. The effect appears independent of visible brain damage, pointing to subtler biological mechanisms.
Researchers at the University of Liverpool have uncovered evidence that post-meal blood sugar spikes may pose a greater threat to brain health than previously recognized. In a study published in Diabetes, Obesity and Metabolism in 2025, the team examined genetic and health data from more than 350,000 participants in the UK Biobank, all aged between 40 and 69. The analysis targeted metrics like fasting glucose, insulin levels, and blood sugar two hours after eating, employing Mendelian randomization to determine causal links to dementia.
The results highlighted a strong association between elevated post-meal glucose—termed postprandial hyperglycemia—and Alzheimer’s disease. Participants with higher levels faced a 69% greater risk, a connection not attributable to brain atrophy or white matter lesions. This suggests underlying pathways, possibly involving hidden metabolic effects, that warrant further investigation.
Conditions like type 2 diabetes and insulin resistance have long been tied to cognitive decline, but this research isolates after-meal spikes as a distinct factor. Lead author Dr. Andrew Mason noted, "This finding could help shape future prevention strategies, highlighting the importance of managing blood sugar not just overall, but specifically after meals."
Senior author Dr. Vicky Garfield emphasized the need for validation: "We first need to replicate these results in other populations and ancestries to confirm the link and better understand the underlying biology. If validated, the study could pave the way for new approaches to reduce dementia risk in people with diabetes."
These insights build on prior knowledge of hyperglycemia's role in dementia, potentially informing targeted interventions to safeguard brain health amid rising diabetes rates.
