Scientists have uncovered indicators of brain aging. The results of a 20-year study have been published

It turned out that people with type 2 diabetes and low levels of certain proteins in cerebrospinal fluid have faster changes in the brain and develop LCS earlier than others, according to a Phys.org article.

Progress of the study

As part of the BIOCARD (Biomarkers for Older Controls at Risk for Dementia) programme, which began in 1995, scientists followed 185 participants. The subjects had an average age of 55 and were all cognitively healthy at the start of the study. Over the course of 20 years, they underwent regular brain MRI scans and cerebrospinal fluid analyses, measuring changes in brain structures and levels of proteins associated with Alzheimer's disease.

Key findings of the study

• • White matter and brain ventricles: High rates of white matter contraction and brain ventricular enlargement were significant predictors of earlier onset of LCN. White matter contraction was associated with an 86% increased risk of developing LCN, and ventricular dilation was associated with a 71% increased risk of developing LCN.

  • Type 2 Diabetes: People with diabetes had a 41% higher risk of going from normal thinking to LCN than those without diabetes. So much for the sweet life!

  • Amyloid proteins: A low ratio of amyloid peptides Aβ42 to Aβ40 in cerebrospinal fluid is associated with a 48% increased risk of developing LCN. This ratio serves as a biomarker for Alzheimer's disease.

  • Combination of factors: Participants with diabetes and a low Aβ42/Aβ40 ratio had a 55% increased risk of developing LCN. That is, these two factors together significantly increase the likelihood of cognitive decline.

Significance of the study

Long-term studies tracking changes in the brain over many years are rare but extremely valuable. Most previous work has only provided snapshots that don't show how the brain changes over time. In this study, scientists followed participants for up to 27 years (an average of 20 years), providing new insights into how certain health conditions can accelerate brain aging.

The findings highlight the importance of early identification of people with accelerated brain atrophy and unfavourable biomarkers. This can optimise prevention strategies and possibly delay or prevent the development of mild cognitive impairment.

Additional information: Study: Yuto Uchida et al, Acceleration of Brain Atrophy and Progression From Normal Cognition to Mild Cognitive Impairment, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.41505

Invited Commentary: Shohei Fujita, Optimizing Strategies to Prevent Cognitive Decline With 20-Year Brain Imaging, JAMA Network Open(2024). DOI: 10.1001/jamanetworkopen.2024.41466