Mental decline in the elderly is not inevitable, claims study

People grow just as many new brain cells in their old age as they do when they’re younger, according to new research. 

A study carried out by scientists at Columbia University has found that healthy participants as old as 79 can generate the same number of brain cells as a 14-year-old.

The question of whether adults can grow new neurons is one that has been contested in the scientific community for a long time. Previous studies have suggested that the brain is hard-wired and cannot regenerate after a certain age, but this new research refutes that claim.

Instead, it provides new hope for potential pathways to treatment for psychological and neurological conditions that typically affect the elderly. These include Alzheimer’s, which is the most common form of dementia in the UK.

Dr Maura Boldrini, associate professor of neurobiology at Columbia University, was the lead author of the study. She has explained that her team’s findings could suggest that many elderly people have better cognitive and emotional capabilities than is commonly believed.

Neurons are essential for the brain to process new memories, as they are the building blocks of the organ. They create complex circuitry, which needs to stay strong in order to function at its optimum levels.

Another key feature of the brain is the hippocampus, which is where emotions are controlled. New circuits in this region are necessary to ensure that psychological changes are processed correctly.

While the ability to build new circuits may deteriorate in people with psychological disorders, this should not be the case in the rest of the population as they age. Any decline in ability in terms of forming episodic memories has a different cause, the study suggests.

Dr Boldrini said: “We found that older people have similar ability to make thousands of hippocampal new neurons from progenitor cells as younger people do. We also found equivalent volumes of the hippocampus - a brain structure used for emotion and cognition - across ages.

“Nevertheless, older individuals had less vascularisation and maybe less ability of new neurons to make connections.”

The team did research into the proteins that signal the growth of new neurons and found that older people had the same number nearing maturation as younger participants. They conducted the study on the bodies of 28 people, ranging in age from 14 to 79, who had died suddenly, but were in good health up to their deaths.

None of the subjects had been cognitively impaired, suffered from depression or taken antidepressants during their lives. The results are in stark contrast to another study that was released recently, which stated neuron production just about comes to a halt by the age of 13.

Dr Boldrini commented on the fact that most people know someone in their nineties who is still sharp. Her research reveals why that is possible and that mental decline is not an inevitable part of the ageing process.

Environmental and lifestyle factors can help to prevent the deterioration of the brain, allowing for independent living for as long as possible. Future research will help to determine a clearer insight into the issues.