This should have been a good day for Joe Biden. After all, no charges should be brought against the US president after an investigation into his mishandling of classified files. But the official report from Robert Hur, special counsel to the Justice Department, was nonetheless devastating.
Hur’s description of Biden, 81, as an “elderly man with a poor memory” who had “diminished faculties as he aged” provoked an indignant defense from the White House.
The incident shed new light on the sensitive issue of older politicians and the risks associated with leaders who are long past what most countries consider the standard retirement age. The reality is that the brain is not spared from the physical decline that accompanies old age, although the degree of decline varies enormously.
Brain scans over the course of a human life reveal an increase and decrease in brain size. Starting in adulthood, the brain begins to shrink as people lose gray and white matter. Gray matter is made up largely of brain cell bodies, while white matter is made up of bundles of nerve fibers that connect neurons to functional brain circuits.
As people age in good health, the decline is gradual, although it tends to accelerate when individuals reach 70 or 80 years of age. In dementia, decline becomes rapid.
Even as we age in good health, this shrinkage has consequences. “If you have less brain matter, it’s going to affect cognition, because you’re losing neurons and the connections between them. The network will not be in as good a condition as it ages,” says Professor Tara Spires-Jones of the UK Dementia Research Institute at the University of Edinburgh.
“You don’t lose large numbers of neurons, but you lose the connections between them in various regions of the brain, and that probably plays a big role in why we don’t think as well.”
There is, however, no overall decline in mental abilities. Tests of memory and cognition paint a more nuanced picture. People vary wildly, but general knowledge tends to hold up. Vocabulary often improves after retirement age.
However, many other skills deteriorate. Working memory – tasks such as memorizing phone numbers – tends to weaken. People have a harder time learning new information. Old brains simply work slower.
The consequences can be more serious when people try to remember information. Knowledge is buried somewhere in the brain, but its retrieval can become slow with age. This sometimes happens when an older team plays a younger team in the University Challenge, says Dennis Chan, consultant neurologist and professor at the Institute of Cognitive Neuroscience at University College London. “We hear the groans of the elderly. They know the answer, but they don’t remember it,” he says.
Hur makes specific and unflattering mention of Biden’s memory in his 345-page report, emphasizing that it would be difficult to persuade jurors that Biden knew he was wrong, speculating that his lawyers would likely insist on the “limits of his reminder.”
Another skill that declines with age is attention; our ability to concentrate on a particular thought or task. Have you ever found yourself in the kitchen without remembering why you went there? Or have you forgotten where you put your car keys? Or put the milk back in the cereal cupboard instead of the refrigerator? Such errors tend to become more common in old age, although there may be reasons other than a failing brain.
“This may happen more often when you’re older, because you have more things to think about,” says Chan. “It may be linked to aging, but there are other factors, such as having a lot on your mind, stress or lack of sleep. It is not necessarily pathological.
Although some mental decline is on the horizon for most, research indicates a number of steps people can take to ensure their brains remain healthy into old age. Doctors say that what is good for the heart is good for the brain. This means not smoking or drinking excessively, eating a healthy diet, and exercising regularly. This helps keep the cardiovascular system healthy, which is crucial for a healthy brain.
But stimulation is also vital. Chan recommends people continue to challenge themselves mentally and encourages frequent social interactions, as social interactions are very mentally demanding. He emphasizes the importance of new activities because they force the brain to make new connections.
“Doing something different from the usual is much harder on the brain,” says Chan. “And the more we engage our brain, the more we encourage it to develop new synapses, new connections, and all of that will help.”
