If you needed one more reason to take your daily steps, science has just taken you one. A new study shows that walking every day can reduce the risk of cognitive decline – especially among people with genetic predisposition to Alzheimer.
Almost 3,000 participants, aged 70 to 79 years, reported their daily walking habits over 10 years, according to a survey that will be presented on Tuesday (29) at the International Conference of the Alzheimer’s Association.
Those who have maintained or increased their walking levels over the years have had more significant improvements in processing and in.
The benefits of the walk were especially visible among those who have genetic predisposition to develop according to the preliminary study, which has not yet been reviewed by peers or published in a scientific journal.
“We know that sedentary behavior tends to increase with age, while physical activity decreases,” said senior author of the study, Dr. Cindy Barha, assistant professor of kinesiology at Calgary University in Alberta.
“Therefore, we recommend reducing the time sitting by introducing small walks throughout the day, among the periods when you need to sit.”
How does Alzheimer’s disease work?
Alzheimer’s disease is a serious form of dementia, which is believed to be caused by the accumulation of harmful plaques in the brain. These plates interfere with communication between neurons, which eventually leads to the death of these nerve cells, explained Barha.
As nerve cells die, people with Alzheimer’s can develop progressive memory loss, confusion, personality changes and physical decline. Over time, the disease can be fatal – and so far there is no known cure.
Genetics is believed to have an important role in the development of the disease. In particular, genotypes called support affect the metabolism of signs and other blood fats. A specific variation, APOE4, makes it difficult to eliminate these plaques by the brain and is associated with a higher risk of cognitive decline.
About 15% to 25% of the population has this version of the APOE gene, and the only way to know is through a genetic test, according to data from the US National Health Institutes.
The Mind-Body Connection
Although the new study has not followed a standardized walk, Barha recommends walking several times a day to interrupt sedentary behavior and maintain this habit consistently over the years as a way to prevent cognitive decline.
“We need more research to determine how many steps would be really needed, but in general, it is always better,” he said. “The next steps include finding the minimum amount of walking ideal for different groups, such as women versus men, or people with the APOE4 gene versus those without this variant.”
A 2022 study found that even people who walked about 3,800 steps a day – at any pace – reduced the risk of dementia by 25%.
What may be happening between the brain and the rest of the body? Experts have several theories.
One is that regular physical exercise stimulates the body to produce a protein called the brain -derived neurotrophic factor, or BDNF – compared to a “fertilizer” to the brain, as it helps in the growth of new cells and the formation of new neural connections, Barha explained.
“We believe that proteins released by the muscles travel to the brain and, when crossing or acting in the hematoencephalic barrier, begin a reaction that eventually leads to increased BDNF levels within the brain,” she said.
Another theory is that exercise helps reduce neuroinflamation, a common symptom of Alzheimer’s disease. The brain sends immunological cells called microglia to attack plates accumulation, but this may have a opposite effect, explained Dr. Christiane Wrann, an associated medical professor at the Massachusetts General Hospital and Harvard Medical School.
Chronic inflammation can cause microglia to begin to attack healthy brain cells, damaging brain connections.
“When you exercise, it actually strengthens the genetic expression program that microglias need to function properly,” Wrann said.
Greater risk, greater benefit?
The researchers were surprised to find that the walk has brought greater benefits to people with the APOE4 gene compared to those who do not have it. To better understand this phenomenon, more studies will be necessary – but Barha already has a hypothesis.
“Before the study began, we believe that the APOE4 bearers had more room to evolve cognitively, as they were possibly already having some degree of cognitive decline,” said Barha. “They also had more room to demonstrate improvements.”
It is possible that the study itself motivated the participants with the APOE4 gene to walk more than they did before, thus slowing down the rhythm of cognitive decline.
“This is a clear example that it is never too late to start exercising,” said Wrann. “Each step counts, and it’s much better to adopt an exercise routine that you really like and can keep up.”
