The UK daily the Guardian reported on the 11th that research has found that reading, writing, and studying one or two foreign languages can lower the risk of dementia by nearly 40%.

Researchers at Rush University Medical Center in Chicago, United States, published a paper on the 11th in the American Academy of Neurology journal ‘Neurology’ stating that participation in intellectually stimulating activities is associated with a reduced risk of Alzheimer’s disease, the most common form of dementia, and with a slower rate of cognitive decline.

The researchers followed 1,939 participants with an average age of 80 who did not have dementia at the start of the study. During the study, 551 developed Alzheimer’s disease, and 719 were diagnosed with mild cognitive impairment (MCI). The Guardian reported that dementia is one of the world’s greatest health threats and that, by 2050, the number of people living with the condition worldwide is expected to triple to 150 million. It is also expected to pose a large and rapidly growing threat to future health and social care systems in all communities, countries, and continents.

The team tracked participants for an average of eight years and also administered a survey on cognitive activities and learning resources across three life-course stages. For the ‘early enrichment stage’ before age 18, they examined learning resources such as reading frequency, access to newspapers and maps at home, and whether participants had studied a foreign language for five years or more.

At age 40, in the ‘midlife enrichment stage’, they assessed, in addition to income level and household resources, the frequency of visits to museums or libraries, and in the ‘late-life enrichment stage’, which begins at an average age of 80, they assessed the frequency of participation in activities such as reading·writing·games and total income.

Based on the survey results, the researchers compared the top 10% group with the highest level of cognitive enrichment to the bottom 10% group with the lowest level. In the top group, 21% developed Alzheimer’s, whereas in the bottom group, the incidence was higher at 34%.

After adjusting for factors such as age, sex, and education, higher lifetime enrichment scores were associated with a 38% lower risk of Alzheimer’s disease and a 36% lower risk of mild cognitive impairment. Those with the highest lifetime enrichment levels developed Alzheimer’s disease at an average age of 94, whereas those with the lowest levels developed it at an average age of 88, indicating a delay of more than five years.

For mild cognitive impairment, the highest-level group developed it at an average age of 85, and the lowest-level group at an average age of 78, a difference of seven years.

Lead author Professor Andrea Zammit told the Guardian, “Our study shows that consistently engaging in a variety of mentally stimulating activities over the life course can make a difference in cognitive abilities.” He emphasized, “Public investments that expand access to enriched environments, such as libraries and early education programs that nurture a passion for lifelong learning, may help reduce dementia incidence.”