Exercise the key to a robust brain
Here’s one more reason to get off the couch and lace up your sneakers: it will pump up your brain volume as well as your muscles.
In one of the latest studies to come out of the Framingham Heart Study, researchers showed a correlation between levels of fitness in middle age and brain volume 20 years later. Those who were the least physically fit in middle age actually had smaller brains later in life.
The study, led by Nicole Spartano, PhD, a post-doctoral fellow at Boston University School of Medicine, included 1,583 participants. Their average age at the beginning of the study was 40 years old and none had any signs of dementia or heart disease. Participants were given before and after treadmill tests and MRIs to compare their level of physical fitness and the size of their brain.
“This Framingham study like many other studies suggests that healthy living with regular exercise – in particular cardiovascular exercise – really helps to maintain brain volume,” said Hyannis neurologist Sean Horrigan, DO. “And if you maintain brain volume as you age then this should translate to maintaining brain health and overall function.”
The functioning of the brain that is most affected by shrinking volume is short-term memory and other cognitive skills such as attention, decision-making, language and visual spatial intelligence, Dr. Horrigan said.
“When the brain shrinks, particularly the pre-frontal cortex and the hippocampus, those are areas that are really important for learning, for memory, for planning and other complex mental tasks,” he explained. “Those are all things in particular that get smaller just with normal aging. The brain also gets smaller because there is a breakdown in the chemical signaling between the neurons and the chemicals the neurons share with one another.”
Brains shrink as people age – even those of healthy people – as part of the aging process, Dr. Horrigan said. Our brains continue to grow in volume until our late 20’s and then from about the age of 30 on, they begin to shrink ever so slightly with each passing decade.
With that in mind, he said that it’s not really fair to compare one person’s brain to another person’s brain. What you should do, instead, is focus on the brain you have with the goal of trying to make sure that its volume at the age of 75 is as close to what it was at 25 as you can.
More and more studies show that regular exercise is the key to improving memory performance later in life. One of the biggest reasons exercise helps with brain health is that blood flow is extremely important for all organs to function properly, including the brain. If you don’t exercise, over time your arteries can narrow and you begin growing fewer new capillaries to feed organs like the brain, Dr. Horrigan said.
“That’s why exercise is so beneficial in general because what you are really trying to promote and strengthen is your vascular system,” he said. “If you can keep challenging your vascular system to stay open and keep a really good blood flow to your brain and other organs, they’re going to work better for you.”
One of the things the Framingham Study looked at was how well the brain was perfused with blood. Brain perfusion, which is the passage of blood and other fluids through an organ, is important for two reasons.
“The brain is a very fussy organ,” Dr. Horrigan said. “It needs oxygen and nutrition in high demand on a second to second basis to work well. Blood flow to the brain is essential for supplying oxygen and for supplying nutrition.”
The second important part of brain perfusion and blood flow is that it carries away cellular waste and contributes to good metabolic management, he said.
Even though this study focused on the middle-aged versus older brain, other smaller studies indicate that it’s never too late to start exercising. One study of 59 healthy but sedentary people aged 60 through 79 placed half of the participants in an aerobic training program and the other half in a toning and stretching program. After six months, the people in the aerobic program showed significant increases in volume of both grey and white matter in the brain.
Another study of 37 sedentary adults between the ages of 57 and 75 showed cognitive gains and improved neuroplasticity after just three months of aerobic exercise.
Neuroplasticity is your brain’s ability to recognize and create new pathways to meet the body’s needs. The process happens very quickly in babies and children, whose brains are constantly rewiring and networking to create new connections. Now doctors know that ability is not limited to the young.
“For years we thought that once all that wiring is done, it’s all set and established,” Dr. Horrigan said. “But the truth is the brain keeps creating pathways and the only thing that has been proven to do so at this point is exercise. It’s not Sudoku and it’s not crossword puzzles – not that I ever discourage people from doing those things. I think all those mental exercises are great, but they are not going to add up to as much if you are not exercising several days a week.”