Exercise increases blood flow to the brain, aids neuroplasticity and reduces inflammation. All of those are factors in cognitive decline and dementia. So, it has been understood for years that exercise can help keep people sharp and lower the risk of dementia.
Studies from Johns Hopkins found that 35 minutes of vigorous exercise a week can lower the risk of dementia by 41 percent. The risk decreases by 60 percent for 36-70 minutes. Then the return on your energy investment goes down. Seventy-one to 140 minutes of vigorous exercise lowers the risk by 63 percent and 140 minutes or above lowers the risk by 69 percent.
But researchers have not known when we should exercise. Do we have to exercise when we’re young to reap the rewards later in life? And do our genes make exercise pointless? Now, researchers at the Framingham Heart Study have shed some light on the situation.
Exercising regularly at age 45 and above may help reduce the risk of dementia. The lower risk was seen even in people who were genetically predisposed to the condition.
The study used medical data from 4,290 people who participated in the Framingham Heart Study. The study began in 1948 with more than 5,000 people. In 1971, they added a second wave of participants — adult children of the original participants and their spouses.
This research used self-reported workout data collected from people in the study throughout their lives. They checked in with them when they were young adults in the ‘70s, then they were middle-aged in the ‘80s and ‘90s and when they were older in the 2000s.
They categorized people based on how much they exercised, if they were diagnosed with dementia and at what age, and if people were genetically predisposed to it. They found that 13.2 percent of the group developed dementia, mostly when they were older. People who were highly active when they were middle-aged or older were the least likely to develop the condition. Exercising when younger didn’t budge the needle.
When it came to people who were genetically predisposed to Alzheimer’s, the results were more nuanced. While exercising in middle age helped the general public lower their risk of dementia, it didn’t lower the risk for people genetically predisposed to Alzheimer’s. But, exercising over the age of 65 helped everyone — with or without the genetic risk.
