At 57, the human brain enters a first phase of biological aging that most of us ignore. Contrary to the received idea of a progressive decline, our nervous system would undergo three successive “waves” of degradation, at very specific ages. This is what a vast study published in the journal reveals Nature agingwhich upsets the perception of slow and linear aging.
Three peaks revealing in the blood
To achieve this conclusion, researchers from the University of Zhengzhou in China have studied the concentration of nearly 3,000 plasma proteins in 4,931 British adults aged 45 to 82 years, from the UK Biobank cohort. Their objective: to identify biomarkers linked to brain health and its decline. They thus identified 13 proteins particularly linked to the aging of the brain, whose concentration forms three net peaks over time: at 57, 70 and 78 years. Among them, two proteins attract the attention of scientists: Brevican (BCAN), associated with dementia, stroke and motor disorders, and GDF15, known to reflect cellular stress and chronic inflammation. According to the authors, these sudden variations are not trivial. “”The peaks of these 13 proteins could reflect changes in the health of the human brain at these specific ages“They explain in their study.
A new brain aging map
The study did not stop there. It was enriched by a cross -analysis with multimodal cerebral imaging data on more than 10,900 adults. Result: a strong correlation between protein peaks in the blood and the biological signs of brain aging observed at these three ages. “”We discovered that the end of the fifties is a potential moment in the trigger for brain aging“, Specify the authors. They add:”Our study suggests that the end of the fifties and the end of the seventh decade are also essential moments in the aging of the brain“. These results throw a new light on the internal functioning of the human brain, demonstrating that its aging could be closer to that of an organ with thresholds, with successive breaks rather than a constant crumbling.
Crucial issues for the decades to come
Far from being a simple theoretical observation, this cartography of aging could open the way to new medical strategies. By targeting these critical periods, researchers believe that it would be possible to better anticipate the appearance of neurodegenerative disorders. “”These could help delay the appearance of diseases such as dementia“, they underline. The demographic context strengthens the urgency of this work: according to their projections, the number of people aged 65 and over should exceed 1.5 billion in the world by 2050. Better understand how and when the brain changes could therefore become a key lever for global public health.”These results contribute to filling the essential gaps in knowledge in the clarification of the molecular mechanisms of brain aging“, conclude the authors. These discoveries could also promote the development of new biomarkers or personalized therapeutic targets, for early diagnostics and treatments adapted to critical ages.