February 11, 2026
People who have abnormally high elevations in blood sugar after meals may be at increased risk of developing Alzheimer’s disease, according to a new report. The findings add to growing evidence linking metabolic disorders like diabetes and poor blood sugar control to dementia risk.
Prior research has shown a strong link between Type 2 diabetes and an increased risk of Alzheimer’s disease and other types of dementia. Most of these studies were observational, following large groups of people over time to see how various aspects of health, diet or behavior are tied to disease. While such studies can identify links between specific health or behavioral traits, they cannot prove cause and effect.
For this study, researchers at the University of Liverpool in Britain used a technique called Mendelian randomization, which aims to better pinpoint the underlying causes of disease. The statistical method involves identifying small snippets of genes that we inherit at birth and that are tied to specific health markers or behaviors. By identifying which of these risk genes people carry, researchers are better able to untangle how certain behaviors may lead to illness.
For the current study, the researchers analyzed genetic data from more than 350,000 men and women who were part of the U.K. Biobank, a long-running study of aging and health. They ranged in age from 40 to 69. The researchers focused on genes related to various components of blood sugar control, including fasting glucose levels, insulin levels, and blood sugar levels two hours after eating.
Their analysis found that spikes in glucose levels after eating were most closely tied to dementia. People who tended to have abnormally high elevations in blood sugar levels two hours after eating had a 69 percent higher relative risk of developing Alzheimer’s disease than their peers who didn’t have these post-meal blood sugar spikes. The increased risk was independent of other Alzheimer’s risk factors, such as decreased overall brain volume or damage to the brain’s white matter.
“This finding could help shape future prevention strategies, highlighting the importance of managing blood sugar not just overall, but specifically after meals,” said Andrew Mason, the study’s lead author. The study was published in the journal Diabetes, Obesity and Metabolism.
The results provide new insights into how diabetes and poor blood sugar control may raise Alzheimer’s risk. Diabetes may contribute to poor memory and diminished mental function in various ways. The disease damages tiny blood vessels throughout the body, including the brain. Diabetes and other metabolic imbalances can also contribute to high levels of body-wide inflammation, which researchers increasingly believe is tied to Alzheimer’s disease and other chronic diseases of aging.
While some people are genetically predisposed to having elevated blood sugar spikes after eating, the foods you eat can also make a difference. Nutrition experts say that balanced meals that include vegetables and protein and that are high in whole grains, nuts and seeds, fiber and complex carbohydrates can help to keep blood sugar levels in check. Avoid added sugars, sweet desserts and sugary beverages. Taking a brisk walk or other short bursts of activity after eating can also help to keep blood sugar levels in check.
If you already have diabetes, it is important to maintain tight control of blood sugar, using medications and regular medical check-ups. Other studies have shown that those with diabetes who are not taking medicines for their disease are more likely to progress to Alzheimer’s disease than those who were not taking drugs for the condition.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D. Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Andrew C. Mason, PhD; Nasri Faith, PhD; Reecha Sofat, PhD; et al: “Disentangling the relationship between glucose, insulin and brain health: A UK Biobank study.” Diabetes, Obesity and Metabolism, December 12, 2025
