Cognitive decline with age might not be inevitable.
As we grow older, there is an inevitable decline in many of our body's functions. This includes cognitive ability.
Memory can suffer as we enter the later years of life. However, some are affected by this slide more than others.
Because the population of the United States is living longer, it is more important than ever to understand what mechanisms are behind cognitive decline.
Is it possible to maintain good memory into old age? Researchers in Swinburne University's Centre for Human Psychopharmacology in Melbourne, Australia, are trying to answer this question.
Their results were published in the Journal of Alzheimer's Disease.
The role of the aorta
In particular, the team is interested in the potential relationship between cognitive decline and the elasticity of the aorta. The aorta is the main artery in the body, carrying blood from the heart and down through the abdomen before splitting off into smaller arteries.
It is a huge blood vessel with walls so thick they need their own blood supply. It is also particularly elastic, allowing it to swell with each heartbeat, thereby helping to maintain a consistent blood pressure. However, with age, the aorta, along with the other arteries, become less supple.
Lead author Greg Kennedy explains why elasticity in the aorta may yield clues about age-related decline in memory function:
"A healthier, more elastic aorta is also theorized to protect cognitive function by reducing the negative effects of excessive blood pressure on the brain."
Fitness, elasticity, and memory
The team wanted to see whether a more elastic aorta would mean better memory performance in older adults.
So, they recruited 102 people aged 60–90. They rated their fitness levels using a simple 6-minute walking test, and they assessed their aortic flexibility and memory performance.
As expected, they found that higher fitness levels and more flexible aortas predicted better performance in a memory test.
"People generally are less fit and have stiffer arteries as they age, which seems to explain the difference in memory ability that is usually attributed to 'getting older.'"
Interestingly, however, the level of fitness did not correlate with the participants' aortic flexibility. According to the study authors, this might be because the study only measured current fitness.
But, lifetime fitness levels are likely to play a significant role in how the arteries perform over time. More work will be needed to dig into this a little deeper.
Kennedy says, "The results of this study indicate that remaining as physically fit as possible, and monitoring central arterial health, may well be an important, cost-effective way to maintain our memory and other brain functions in older age."
These findings are in line with a huge body of research into age-related cognitive decline: remaining physically fit is likely to keep us mentally fitter for longer.