Middle-aged brain can predict your future brain health, new review finds

19 Mar 2024

Middle Age – between 40-60 years – marks a shift in brain ageing and the middle-aged brain could provide a window in your future brain health, a major academic analysis finds today.

The team led by University College Cork (UCC) researchers reviewed past evidence from human and animal studies to illustrate that during middle age the brain undergoes significant molecular, cellular, and structural changes, and many of these changes have been linked to cognitive decline, which has also been shown to accelerate during middle age.

The review published in the journal Trends in Neurosciences today states that structurally, middle age is associated with changes in the volume of several brain structures, shrinking of the hippocampus (a brain structure involved in memory and learning), and decreased connectivity between different parts of the brain.

Predicting future cognitive health

"In your 40s and 50s, the brain undergoes accelerating change, especially in its "wiring" and communication between cells. This particularly seems to affect everyday memory but also simpler things like reaction time. During middle age, the review highlights, the composition of your blood changes rapidly, and some of these changes (e.g. in your 40s) can predict future cognitive decline 20 years later (e.g. in your 60s)," states University College Cork (UCC) researcher Sebastian Dohm-Hansen.

"The fourth and fifth decades of life may be a turning point in the organization of brain networks, characterized by optimal efficiency, system segregation and modularity, followed by accelerated decay of these properties," the authors write.

Science of ageing long overlooked

Most studies of brain health and cognitive decline focus on older age groups, but by this time, interventions may have limited efficacy. Screening for risk of future cognitive decline could help by allowing treatment to begin earlier, when it might be more effective. A better understanding of brain shifts during middle age might also help identify novel targets for therapy, the researchers say.

"The science of ageing has long overlooked middle age because the effects of time are most easily seen in old age, but at that point, the time for intervention is quickly running out" states University College Cork (UCC) researcher Sebastian Dohm-Hansen.

"Middle age is associated with specific and modifiable risk factors for future dementia risk," write the authors, who include neuroscientist Professor Yvonne Nolan of APC Microbiome Ireland, a world leading Science Foundation Ireland research centre based at UCC in Ireland. "We encourage giving this previously understudied period of life renewed consideration."

Finding new interventions

There is some evidence that exercise might aid healthy cognitive aging, but more research is needed.

"A lot of what is good about healthy lifestyle choices like exercise is that it, too, can spread via the blood and slow down the ticking of the clock (or even reverse it). By looking for common but opposing effects of aging and exercise, we may be able to find new interventions to help us enjoy good health for longer. This will be important as the global population gets increasingly older" states Sebastian Dohm-Hansen.

This research was supported by the Science Foundation Ireland, the Irish Health Research Board and Alzheimer Nederland.

For more on this story contact:

https://www.ucc.ie/en/research/news/2024/middle-aged-brain-can-predict-your-future-brain-health-new-review-finds.html