Healthy living may enhance memory

AS PEOPLE reach their senior years, they can tell that memory fails them more often. This is a generally accepted fact brought about ageing. But no one is quite sure about the relationship between ageing and loss of memory, and what can be done to slow the decline.

Gathering evidence suggests that the brain’s ability to make new neurons in a region called the hippocampus – specifically in a sub-region called the dentate gyrus – is important for the acquisition of memories. Studies show that this capacity for neurogenesis declines as we age, and the result is a decline in at least one kind of memory.

As neuroscientists develop a more complex understanding of how memory works and the impact of ageing, they’re learning how an improved diet, exercise and staying mentally active may boost our ability to make new neurons where they’re needed to preserve and maintain memory.

Three neuroscientists spoke with The Kavli Foundation about this emerging consensus, and what they hope to learn in coming years about the changing landscape of memory as we age.

“Along with gaining a better understanding of the different types of memory, we’re getting a better understanding of how we acquire, store and retrieve information. … And that gives us a lot more confidence about understanding something about the mechanisms involved in memory and age-related memory decline,” explains Fred Gage of the Salk Institute for Biological Studies.

Scott Small of Columbia University and a member of the Kavli Institute for Brain Science, says, “It’s an especially exciting time because of the technologies we use to image the brain in living human beings. … There is really very good evidence that different regions do slightly different things, and that's important.”

“Researchers have tried to look at what’s going on at the level of an individual neuron and relate that to a behaviour or dysfunction. … When we study the hippocampus and the dentate gyrus in particular – brain structures that are so important for memory – there’s been a lot of progress in this area,” says Craig Stark of the Center for the Neurobiology of Learning and Memory, University of California, Irvine.

Regarding how we might slow the decline of age-related memory loss, Mr Gage adds, “The things we do, how we behave, what we eat and what we do physically all can play a role in how well the brain functions. Our memories are formed in the brain, and the brain is an organ. Just like other organs that deteriorate with age, the brain is going to deteriorate with age in a global sense. But what we do as individuals can impact the rate of that decline.”