Dementia can be avoided or delayed, even among those more pre-disposed to the condition, claims a new study based on researching people in the UK over 60 years.
The study, published in Neurology®, the medical journal of the American Academy of Neurology, on 3 August, 2022, shows for the first time that building mental resilience across a lifetime – a ‘cognitive reserve’ – through education, socialising, jobs and having several leisure activities, can reduce the risk of dementia, even among those with low childhood cognition or a genetic predisposition to the condition.
Previous studies have shown that people with low cognitive scores in childhood are more likely to have a steeper cognitive decline in old age than people with high scores.
“These results are exciting because they indicate that cognitive ability is influenced by various factors throughout our lifetime and taking part in an intellectually, socially and physically active lifestyle may help ward off cognitive decline and dementia,” said study author Dorina Cadar, PhD, Brighton and Sussex Medical School. “It’s heartening to find that building up one’s cognitive reserve may offset the negative influence of low childhood cognition for people who might not have benefited from an enriching childhood and offer stronger mental resilience until later in life.
“Considering that we struggle to successfully treat dementia, this study is promising that we could and should build our mental resilience throughout our entire life before it’s too late.”
The study involved 1,184 people who were born in 1946 in the UK. Participants took cognitive tests when they were eight years old and again when they were 69 years old. A cognitive reserve index combined people’s education level at age, participation in enriching leisure activities at age 43 and occupation up to age 53. Their reading ability at age 53 was also tested as a measure of overall lifelong learning separate from education and occupation.
The cognitive test participants took at age 69 has a maximum total score of 100. The average score for this group was 92, with the lowest score of 53 and the highest score of 100.
The researchers found that higher childhood cognitive skills, a higher cognitive reserve index and higher reading ability in midlife were all associated with higher scores on the cognitive test at age 69. For every unit increase in childhood test scores, the old-age cognitive test score increased by 0.10 points on average. For every unit increase in the cognitive reserve index, cognitive scores increased by 0.07 points on average, and for every unit increase in reading ability, cognitive scores increased by 0.22 points on average.
People with a bachelor’s degree or other higher education qualifications scored 1.22 points more on average than those with no formal education. People who engaged in six or more leisure activities such as adult education classes, clubs, volunteer work, social activities and gardening scored 1.53 points more on average than people who engaged in up to four leisure activities. Those with a professional or intermediate level job score 1.5 points more on average than those with partly skilled or unskilled occupations.
The study also found that for people with a higher cognitive reserve index and reading ability, their scores on cognitive tests did not decline as rapidly as people with lower scores, regardless of their test scores at age eight.
Katherine Gray, Research Communications Manager at Alzheimer’s Society, said “This long-term Alzheimer’s Society funded study adds to a popular theory that the more you regularly challenge your brain, the less likely you are to experience memory and thinking problems in your later years.
“From childhood to adulthood, participants who kept their brain active, whether it’s in education, their career or by taking part in complex hobbies, had better thinking abilities by the age of 69.
“It’s estimated that the number of people with dementia in the UK is set to rise to 1.6 million by 2040. While there are many risk factors related to developing dementia, it is hopeful to know that engaging in mentally stimulating activities and finding ways to regularly challenge your brain can help reduce the development of memory and thinking problems in the future.”
A limitation of this study is that the people who remained involved in the study until age 69 may be more likely to be healthier, have better overall thinking skills and be more socially advantaged than those who did not complete the study, so the results may not reflect the general population.
The study was supported by the UK Alzheimer’s Society, UK Medical Research Council, US National Institute on Aging and UK Economic and Social Research Council.
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Moderating Role of Cognitive Reserve Markers Between Childhood Cognition and Cognitive Ageing: Evidence From the 1946 UK Birth Cohort
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