An important new investigation has shown that the human brain experiences substantial immune and genetic alterations between ages 50 and 75, suggesting the existence of a unique period of healthy aging. This discovery throws new light on the increased prevalence of neurological diseases with advancing age and might cause novel strategies to maintain memory, cognition and brain health.
Scientists have known for some time that the brain slowly morphs as we get older, but the newest study indicates that the change isn’t entirely gradual.
Instead, researchers pinpointed a window of time in which immune function and gene activity seem to jump into new gear, which might have an effect on brain response to stress, inflammation, and aging. In the human brain, many of your thousands of genes can either increase or decrease activity (gene expression) with age. The authors found changes in the expression of these genes are concentrated in the cells of the brain tissue affecting information processing, cell repair, and neural network integrity.
They saw most significant changes in these processes as taking place in the years 50-75. During research, researchers made the surprising discovery that the immune system of the brain may also be aging. Microglia, cells that defend the brain while it is developing, may change their behavior during mid-to-late the life of the individual.
Maybe as individuals get older microglia become more reactive and result in higher levels of inflammatory activity within the brain. Although inflammation in the brain is a normal and necessary part of the immune response, chronic inflammation has been linked to pathologies including Alzheimer’s, Parkinson’s, and other neurodegenerative diseases.
Knowing when inflammation begins may provide an earlier target for intervention. A broad-scale alteration in gene expression was also seen related to this, with lower activity levels noted in genes involved in energy metabolism, cell repair, and transmitting signals between neurons. These changes might be what decides whether an individual suffers from subtle memory loss with minor aging or enjoys healthy cognition into very old age.
Instead of a cascade powered by one gene, healthy brain aging tends to be managed by many interdependent biological networks working in concert. These results seem to strengthen the trend among researchers that aging is a complex biological thing and not just ‘clock time.’ Experts suggest if we knew more about these stage changes, it may be possible to time interventions for the support of the brain before the effects of aging become apparent.
New technologies, like sophisticated genetic sequencing and high powered cellular imaging enabled scientists to look at each cell in the brain in new ways. “Every cell in the brain was analyzed in unique detail, ” this uncovered subtle changes at the molecular level that could not have been detected before. The authors do not imply that all individuals who are between the ages of 50 and 75 will be faced with memory impairment or neurological disease.
Rather, they merely point to a window of time in which the brain undergoes a series of crucial biological changes. Following this stage, studies show that many individuals stay mentally sharp into their seventies, Most of all if they are accompanied by healthful practices for diet, activity, and regular physician visits.