Reading can lower dementia risk by 40%

Public investments that expand access to enriching environments such as libraries may help to reduce the incidence of dementia, the study author said. Photograph: Westend61/Getty Images

From The Guardian

Reading, writing and learning a language or two can lower your risk of dementia by almost 40%, according to a study that suggests millions of people could prevent or delay the condition.

Dementia is one of the world’s biggest health threats. The number of people living with the condition is forecast to triple to more than 150 million globally by 2050, and experts say it presents a big and rapidly growing threat to future health and social care systems in every community, country and continent.

US researchers found that engaging in intellectually stimulating activities throughout life, such as reading, writing or learning a new language, was associated with a lower risk of Alzheimer’s disease, the most common form of dementia, and slower cognitive decline.

The study author Andrea Zammit, of Rush University Medical Center in Chicago, said the discovery suggested cognitive health in later life was “strongly influenced” by lifelong exposure to intellectually stimulating environments.

“Our findings are encouraging, suggesting that consistently engaging in a variety of mentally stimulating activities throughout life may make a difference in cognition. Public investments that expand access to enriching environments, like libraries and early education programs designed to spark a lifelong love of learning, may help reduce the incidence of dementia.”

Researchers tracked 1,939 people with an average age of 80 who did not have dementia at the start of the study. They were followed for an average of eight years. Participants completed surveys about cognitive activities and learning resources during three stages.

Early enrichment, before 18, included the frequency of being read to and reading books, access to newspapers and atlases in the home, and learning a foreign language for more than five years.

Middle-age enrichment included income level at 40, household resources such as magazine subscriptions, dictionaries and library cards and the frequency of activities such as visiting a museum or library. Later-life enrichment, starting at an average age of 80, included the frequency of reading, writing and playing games and total income from social security, retirement and other sources.

In total, 551 participants developed Alzheimer’s disease and 719 developed mild cognitive impairment (MCI) during the study, which was published in Neurology, the medical journal of the American Academy of Neurology.

Researchers compared those with the highest level of cognitive enrichment, the top 10%, with those with the lowest level, the bottom 10%. Of those with the highest level, 21% developed Alzheimer’s. Among those with the lowest, the figure was 34%.

After adjusting for factors such as age, sex and education, researchers found higher scores in lifetime enrichment were associated with a 38% lower risk of Alzheimer’s disease and a 36% lower risk of MCI.

People with the highest lifetime enrichment developed Alzheimer’s disease at an average age of 94, compared with 88 for those with the lowest level of enrichment – more than a five-year delay.

Researchers found people with the highest lifetime enrichment developed MCI at an average age of 85, compared with 78 for those with the lowest level of enrichment – a seven-year delay.

Researchers also looked at participants who died during the study and had autopsies. Those with higher lifetime enrichment had better memory and thinking skills and slower decline prior to death, the study found.

A limitation was that participants reported details about their early and midlife experiences later in life, so may not have remembered everything accurately. The study also did not prove that lifelong learning reduces the risk of dementia, as it only showed an association.

Dr Isolde Radford, a senior policy manager at Alzheimer’s Research UK, who was not involved with the study, said the findings 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 to reduce their risk of developing dementia.”

The factors that reduce or prevent dementia are becoming more and more clear:

• Use it or lose it.  Don't just sit there like a pudding watching TV or the internet.  Read, think, learn a language.
• Social contact is important.  Loneliness is lethal.  The authorities should be strongly encouraging meet-ups for older people, like coffee mornings at neighbourhood learning centres.
• Poverty in old age makes things worse because it narrows options available---and the mind.  It might work out cheaper for society to make sure the old can enjoy a rich social and intellectual life than to cut support and face subsequent huge health expenses.
• Omega-3 unsaturated fatty acids are essential, literally.  Don't heat them; they'll disintegrate if they're cooked.  You get them from fish, nuts and seeds, especially walnuts, (ground) linseed, pepitas (hulled pumpkin seed).
• Red and processed meat is bad for dementia (I'll be doing a post on this shortly).  A healthy diet helps keep your brain healthy.
• Exercise is good.  Surprisingly, weight-training seems to help a lot, but even a daily walk makes a difference.