Over 55 millionTrusted Source people live with dementia worldwide, and there are nearly 10 million new cases every year.
Previous studies have identified several potential risk factors for the condition, includingTrusted Source:
An increasingTrusted Source amount of evidence also demonstrates that maintaining physical activity in midlife and beyond may help preserve cognitive capacity and prevent dementia.
Which kinds and intensities of physical activity preserve cognitive capacity and prevent dementia most effectively, however, remains unknown.
Recently, researchers investigated the effects of different forms of physical and mental activity on dementia risk.
They found that activities including frequent exercise, household chores, and daily visits to family and friends lowered dementia risk.
The study appears in Neurology.
Activities tied to lower dementia risk
For the study, the researchers analyzed healthcare data from 501,376 participants in the UK Biobank cohort. Participants were an average of 56.5 years old at recruitment and were followed for an average of 10.7 years.
At the start of the study, the participants filled in questionnaires indicating their physical activity — such as housework-related activity and transportation — and mental activity, including the use of electronic devices, social contact, and attendance of adult education classes.
The researchers also examined participants’ genetic risk factors for developing dementia alongside their family history of the condition.
During the follow-up period, 5,185 participants developed dementia. Of these, the researchers reported that those most likely to develop dementia tended to be older, male, have a history of hypertension or hyperlipidemia, and have a lower socioeconomic status and higher body mass index (BMI).
After analyzing the data, the researchers found that more frequent engagement in physical and mental activity was linked to lower rates of dementia.
Those most engaged in frequent exercise, household chores, and daily visits by friends and family had a 35%, 21%, and 15% lower risk of dementia compared to those least engaged in these activities.
The researchers further found that physical and mental activity protected against dementia among all participants- regardless of their genetic risk or family history of the condition.
They also found that visiting the pub or social club and watching TV were linked to a higher risk of dementia.
Underlying mechanisms: What we know
The researchers noted that while the underlying mechanisms linking physical activity and a reduced dementia risk remain unknown, several possible explanations exist.
They wrote that regular aerobic exerciseTrusted Source might improve cerebral blood flow, thus reducing age-related cognitive decline, and that exercise has antioxidant effectsTrusted Source, which may delay oxidative damage in the brain.
They added that exercise could influence other modifiable factors for cognitive function, including:
When asked how physical and mental activities, including learning, exercising, and socializing, may reduce dementia risk, Prof. Gill Livingston, professor of psychiatry of older people at University College London, told Medical News Today that they may increase cognitive reserve — the brain’s resistance to structural damage from processes like aging.
To the same question, Dr. Dorina Cadar, senior lecturer in cognitive epidemiology and dementia at the University of Sussex, not involved in the study, told MNT:
“New evidence shows that you can grow new brain cells- the building blocks of our thinking skills- until later in life. It is really important to regularly feed the brain with new information and store this new content information in our brain. It could be by simply reading a book, a magazine, or listening to a podcast.”
“In this way, we are adding layers of knowledge and emotions. So, when we refer to ‘use it or lose it,’ we now know that these cells can be worked out and kept busy, whether you are in your 40s, 60s, 70s or older,” she added.
She continued to note that social interaction, a sense of belonging to a group, and having friends with common interests are key to psychological well-being and mental resilience.
“There is evidence showing that lacking social connections can damage a person’s health as much as smoking 15 cigarettes a day. Social isolation and loneliness present one of the most significant health and social care challenges of the 21st century, increasing one’s risk of dying by almost 30 percent,” she said.
“Half a million older people in the [United Kingdom] do not see or speak to anyone for more than 6 days a week. That has tremendous consequences on individual mental health and subsequent dementia risk,” she explained.
The researchers concluded that frequent mental and physical activity could be effective interventions for preventing dementia.
When asked about the study’s limitations, Dr. Livingston noted that although the UK Biobank has “excellent, detailed data,” it comes disproportionately from a high income and healthy population with few minority groups, and thus may not be fully representative.
She further noted that the cohort was also relatively young, given the mean age for developing dementia is around 80 years old.
Dr. Cadar added that the study did not accurately diagnose subtypes of dementia and that mental activities could have been investigated in more detail.