Active brain and body associated with reduced risk of dementia

Greater lifetime cumulative cognitive reserve decreased the risk of dementia, according to a new study.

A team of researchers from Tianjin Medical University in China wanted to determine whether the lifetime accumulation of cognitive and social activities was related to a slower rate of memory loss, resulting in lower risk to develop dementia, despite cerebral pathologies.

The study, published in JAMA Neurology, shows that the risk of dementia was reduced by 39% among seniors with the greatest cognitive reserve in their lifetime, compared to those with the lowest scores. In spite of a vascular pathology or Alzheimer's disease (AD), the risk of dementia was lower if the older person had high scores on cognitive reserve over the course of life.

The cognitive reserve (CR) hypothesis is a compensatory mechanism for dealing with age-related brain damage. It has been proposed to explain why some people maintain better cognitive function, even with age-induced brain changes or any pathological process.

Alzheimer's disease in MRI. Image Credit: Atthapon Raksthaput / Shutterstock

The lifespan cognitive reserve score

To achieve their results and cumulatively measure cognitive reserves over the course of life, the researchers enrolled a total of 2,022 participants in the Rush Memory and Aging Project, which is currently a community-based cohort study.

The participants had an annual follow-up between 1997 and 2018. After excluding patients who were not qualified according to the study criteria, they were left with 1,602 patients without dementia, the majority are women and had a mean age of 80 years.

At follow-up, 747 people had died and 611 of them had undergone an autopsy. The researchers then examined the reports and data between May and September 2018. The cognitive reserve score for lifetime included education, social activities at the end of life, a social network at the end of life and the cognitive activities at the beginning of life, at mid-life and at the end of life. The team measured the CR lifespan score and divided them into tertiles, ranked lowest, highest and lowest.

The results of the study

Of the 1,602 participants, 389 developed dementia, of which 357 developed Alzheimer's disease.

Compared to those with high brain pathology but a lower CR Tertile, the dementia rate was approximately 38-55% lower in individuals with both tertiary and high-brain TBI pathologies.

The researchers found that the highest cognitive reserve score was linked to a reduced risk of dementia, even in patients with a high pathology of Alzheimer's disease.

This means that cognitive reserves, which include education, cognitive activities, social networks, and social activities, can reduce the risk of developing dementia.

"In this prospective community-based study of seniors without dementia, we found that a CR indicator of long-life accumulated by education, cognitive activities at the beginning of life, activities cognitive in mid-life, cognitive activities at the end of life and social activities at the end of life were badociated. with a reduced risk of dementia in a dose-dependent way, "the researchers explained.

They also stated that the cognitive reserve was not related to most cerebral pathologies and that the link between CR and dementia remained significant even after adjusting for these cerebral pathologies. Finally, they discovered that CR can be linked to a reduced risk of dementia, even in cases of severe Alzheimer's disease and vascular diseases such as heart attacks.

"Our results suggest that mentally cumulative educational and stimulating activities that improve lifelong CR may be a feasible strategy for preventing dementia, even in people with vascular disease or high AD. Other large population-based longitudinal studies are needed to establish strategies for participation in CD-related dementia prevention activities, "concluded the study's authors.

What is dementia?

Dementia is a syndrome and a generic term for many diseases that affect memory, cognitive abilities and behavior. These alternations in brain function significantly interfere with a person's ability to maintain activities of daily living (ADL).

Although age is the highest risk of dementia, it is not a normal part of aging. In fact, it is the loss of cognitive functioning, which includes the ability to remember, solve problems, think and reason. Functions affected by dementia include memory, problem solving, visual perception, language skills, ability to focus and focus, and self-management.

Worldwide, an estimated 50 million people with dementia represent a total cost of $ 818 billion in care provided by caregivers. This number is expected to triple in 2050. Dementia is now the 5th leading cause of death in the world.