Intellectually stimulating activities pursued throughout life, such as reading, writing or learning languages, are linked to a significantly lower risk of developing dementia, according to a new US study. Researchers found the practices were associated with a near 40% reduction in the risk of Alzheimer’s disease.
Study Details and Findings
The research, which tracked 1,939 people with an average starting age of 80 for eight years, assessed cognitive enrichment across three life stages. Early enrichment, before age 18, included factors like being read to, access to books and newspapers at home, and studying a foreign language for over five years. Middle-age enrichment covered household resources like magazine subscriptions and library cards, while later-life enrichment measured the frequency of activities like reading and writing.
Of the participants, 551 developed Alzheimer’s disease and 719 developed mild cognitive impairment (MCI) during the study period. When comparing the top 10% for lifetime cognitive enrichment with the bottom 10%, researchers found 21% of the high-enrichment group developed Alzheimer’s, versus 34% in the low-enrichment group.
After adjusting for age, sex and education, higher lifetime enrichment scores were associated with a 38% lower risk of Alzheimer’s and a 36% lower risk of MCI. The study also found a delay in onset: those with the highest enrichment developed Alzheimer’s at an average age of 94, compared to 88 for those with the lowest—a delay of over five years. For MCI, the delay was seven years.
Implications and Limitations
The study’s lead author, Andrea Zammit of Rush University Medical Center in Chicago, said the findings suggest cognitive health in later life is “strongly influenced” by lifelong exposure to stimulating environments. “Our findings are encouraging,” Zammit stated, adding that public investments in libraries and early education programmes designed to spark a lifelong love of learning “may help reduce the incidence of dementia.”
Autopsies on some participants who died during the study found those with higher lifetime enrichment had better memory and thinking skills and a slower decline prior to death. The research, published in the journal Neurology, did have limitations: participants reported early and midlife experiences later in life, so memories may not have been entirely accurate, and the study showed an association rather than proving causation.
Commenting on the findings, Dr Isolde Radford, a senior policy manager at Alzheimer’s Research UK who was not involved in the study, said it highlighted that dementia was not an inevitable part of ageing. “This new research shows that staying mentally active throughout life can cut the risk of Alzheimer’s disease by nearly 40%,” she said. “This supports what we already know about the preventive steps people can take.”
The research emerges against a backdrop of growing concern over dementia, which is forecast to affect more than 150 million people globally by 2050, presenting a major threat to health and social care systems worldwide, as detailed by The Guardian.
