Healthy lifestyle, “cognitive reserve” to prevent dementia.

Eating well, sleeping well, exercising, drinking little alcohol and avoiding cigarettes: these will, surprisingly, be the lifestyle choices that best help prevent the risk of dementia with age, starting with Alzheimer’s disease. This has been revealed in a new study published in the journal JAMA Neurology, confirming what other work here and there had already shown. But how can healthy living have such a decisive effect on the brain?

Healthy living provides a “cognitive reserve” that protects against the risk of dementia

To find out, researchers at Rush University Medical Center in Chicago (United States) examined the brain autopsies of 586 people who had donated them before death at an average age of 91. After following them over a period of 24 years, they compared the lifestyle habits and cognitive abilities of the participants during their last years of existence with the classic neurological signs of dementia. such as the accumulation of amyloid protein plaques in the brain, or changes in cerebral blood flow that may have been caused by stroke-type events.

As expected, the research team found that people who led very healthy lifestyles “As they approach the end of their lives, they are more likely to retain their spirit”, we can read in the press release. In detail, each one-point increase in a person’s “lifestyle score” was thus associated with an increase in their “global cognitive score” at the end of life. And for good reason: a healthy life – in terms of diet, exercise, sleep, excess, etc. – can “Provide cognitive reserve”

which protects against negative changes in the aging brain, allowing older people to “Maintain their cognitive abilities” over time.

Lifestyle can mimic the brain changes associated with dementia

On the other hand, the link with brain changes observed during autopsy was not so clear: if plaques of amyloid protein or changes in cerebral blood flow can be seen in the brain of a person who has led a healthy life, his scores on cognitive abilities. This guy stayed tall. “The only effect, very small, was seen for the accumulation of amyloid plaques in the brain: plaque reduction could account for 11.6% of the lifestyle/cognition relationship.”

In other words, this cognitive reserve provided by a healthy life will allow the brain to function better at the end of life, even in the presence of brain changes commonly associated with dementia. “If you take two people with equal amounts of these bad proteins in their brains, the person with the healthy lifestyle is more likely to have better cognitive function.”

Summarize the researchers. Conclusion: “You can almost fool biology a little.”