Researchers have found that high blood glucose (sugar) levels may be a major factor in accelerating brain aging, increasing the risk of dementia, Parkinson's, and other neurological and psychiatric disorders.
The human brain naturally ages with time, beginning to shrink after the age of 30 or 40. However, in some cases, this process accelerates abnormally, leading to premature memory loss, cognitive decline, and an increased susceptibility to neurodegenerative diseases.
Despite this knowledge, the precise factors that control the rate of brain aging remained a mystery until this study.
Researchers from Guilin University and China Medical University used the massive UK Biobank database, which contains health, genetic and imaging data for more than 37,000 people.
By analyzing MRI scans of their brains, they identified 1,079 measurable brain features, such as brain region size and tissue characteristics. They then trained machine learning algorithms to predict brain age based on these features. The most accurate statistical model was the LASSO regression model, which was able to estimate brain age with an average error of only 3.26 years, meaning the error in the estimate was only about 3 years.
The team then applied this model to thousands of participants to calculate the "brain age gap" (BAG) - a value that indicates whether the brain appears younger or older than a person's chronological age, and by how many years.
By analyzing participants' blood samples, they identified nine molecules strongly associated with gap values, with glucose showing the strongest correlation of all. They found that higher blood sugar levels were linked to brains that showed more signs of aging in imaging, appearing older than their actual age.
But that's not all. High glucose levels have also been linked to an increased risk of seven brain conditions: dementia of all causes, Alzheimer's disease, vascular dementia, Parkinson's disease, stroke, depression, and anxiety. They have also been associated with reduced cognitive performance, motor function, and mental health, as well as decreased brain volume in 80 different regions.
Commenting on the findings, the researchers wrote in their paper published in the journal Molecular Psychiatry: "These results suggest that glucose metabolism represents a modifiable pathway in brain aging, with implications for early intervention strategies aimed at preserving brain health throughout life."
The researchers hope that their findings will contribute to the development of practical strategies for monitoring brain health and early intervention to reduce the risk of neurological diseases by controlling blood sugar levels as one of the modifiable factors, which may open new horizons in the prevention of dementia and age-related brain disorders.
