Engaging in stimulating hobbies in midlife tends to protect brain health more than just minimizing medical risks, providing evidence of strong protection against cognitive decline. Activities such as playing the piano, traveling abroad and socializing with friends are powerful ways to reduce the risk of memory loss, according to new research from Trinity College, Dublin. The study was published in the journal Alzheimer’s disease and dementia: diagnosis, evaluation, and disease monitoring.
Alzheimer’s disease is a progressive brain disease that slowly destroys memory, thinking, and the ability to perform simple tasks. This is the most common cause of dementia and is a broad term that refers to a decline in mental capacity severe enough to interfere with daily life. The physical changes in the brain associated with this condition begin decades before visible symptoms appear, making midlife a key time for potential prevention.
Dementia currently affects around 48 million people around the world, including nearly 1 million in the UK and 65,000 in Ireland. The number of people living with dementia worldwide is predicted to reach 150 million by 2050, and associated costs are expected to triple to €3 trillion. Because of this major global impact, scientists want to find accessible and cost-effective lifestyle interventions to help adults strengthen their cognitive health early on.
One of the key concepts that scientists have focused on is cognitive reserve. Cognitive reserve is essentially the brain’s ability to improvise and find alternative ways to accomplish tasks. It acts as a mental shock absorber that helps the brain cope with injury and illness without immediately showing signs of decline. People with high cognitive reserve tend to maintain normal memory and thinking skills, even if their brains begin to develop physical markers of Alzheimer’s disease.
Researchers drew data from the Dementia Prevention Program, a large longitudinal study investigating the early causes of memory loss. This project evaluates healthy people over a 10-year period. Lorena Naci, Professor in the Trinity College Neuroscience Institute and Global Brain Health Institute, leads the research site at Trinity College, Dublin. Her research team works closely with collaborating centers at the universities of Cambridge, Oxford, Edinburgh and Imperial College London.
The authors analyzed a final sample size of 587 participants. Initially, 700 people participated in the study, but scientists excluded people with incomplete medical or cognitive test data. Participants ranged in age from 40 to 59 years and all were cognitively healthy at the time of the first clinical visit. About one-third of the participants had a genetic risk of developing Alzheimer’s disease later in life.
To measure cognitive abilities, participants completed 13 different brain tests. These assessments assessed multiple mental domains, including attention, language, and working memory. Working memory is the ability to hold and manipulate information in your mind for short periods of time. Participants also took a visual memory test in which they memorized complex shapes and color combinations.
Scientists collected data on 10 modifiable risk factors, which are elements of a person’s life and health that can be changed or controlled. Modifiable factors include high blood pressure, high cholesterol, obesity, diabetes, hearing loss, depressive symptoms, smoking, alcohol use, traumatic brain injury, and poor sleep quality.
In addition to these, the authors recorded non-modifiable risk factors such as age, biological sex, family history of dementia, and genetic makeup. Specifically, the researchers tested the participants’ blood for a specific genetic mutation known as apolipoprotein E epsilon 4, a well-known risk factor for late-onset Alzheimer’s disease.
Finally, the scientists measured protective factors that contribute to cognitive reserve. These include total years of formal education and occupational attainment, which examines the complexity of an individual’s work. The researchers also used a questionnaire to measure engagement in stimulating activities. These activities include socializing with family and friends, practicing a musical instrument, artistic entertainment, exercise, reading, practicing a second language, and traveling.
To understand all these variables, researchers used advanced statistical methods to find the strongest mathematical relationships between risk factors, protective factors, and cognitive test scores. They found that participating in physically, socially, and intellectually stimulating activities during midlife is one of the most powerful ways to boost cognition. This positive association also applies to people who have a high genetic or familial risk of developing Alzheimer’s disease. In fact, stimulating activity played a larger role in shaping mental health than the most powerful common genetic risk factor, the apolipoprotein E epsilon 4 gene.
Simply put, the positive psychological benefits found from these lifestyle activities outweighed the negative effects of carrying high-risk genes. Nasi noted that the research team did not expect such a strong effect at this early stage. “We’ve known for some time that lifestyle activities such as exercise can protect against cognitive decline in older adults,” Dr. Nashi says. “We were surprised to see that stimulating daily activities during midlife significantly improved cognitive function, decades before age-related cognitive decline began.”
Scientists also found that participating in these different activities appears to produce a cumulative protective effect. Engaging in multiple different hobbies improved cognitive performance more than any single medical risk factor decreased it. “Importantly, we found that a combination of activities, rather than a single activity, provides greater benefits,” Nasi said. “Our results suggest that variety is key and that a combination of physical, social and mental stimulation is most effective in boosting brain health.”
On the downside, depressive symptoms and traumatic brain injury emerged as the most detrimental modifiable risk factors for mental performance. Participants who reported higher levels of depression and previous head trauma had significantly lower scores on tests of memory and attention. Other medical conditions, such as diabetes, high blood pressure, sleep deprivation, and hearing loss, also showed negative associations with cognitive performance.
The study found that men generally performed slightly worse on cognitive tests than women. Older participants, ages 40 to 59, also showed decreased mental performance. Surprisingly, participants with high-risk genetic mutations actually performed better on many memory tasks in midlife. The scientists noted that while this gene increases the risk of Alzheimer’s disease in old age, it may confer some psychological benefits in early adulthood and middle age.
Nasi suggested that these findings move dementia prevention from a distant medical concern to an immediate and actionable opportunity for young adults. “This research is empowering. It shows that engaging in a variety of stimulating activities, such as socializing, learning new skills, staying physically active, and fostering mental health, can actively strengthen cognitive resilience decades before symptoms appear, even in people with genetic risk or a family history of dementia,” Nasi said.
There may be some misconceptions or limitations to keep in mind. Because this study took a snapshot of the first clinical visit, causality cannot be definitively proven. People who naturally have strong cognitive skills may simply be more likely to seek out engaging hobbies.
Additionally, the scientists relied on self-report questionnaires to obtain information on lifestyle activities and sleep quality. People sometimes misremember or overestimate their healthy habits, leading to some degree of bias in the data. Another limitation is the demographic composition of this study. Approximately 95% of participants were Caucasian. This means that the findings may not fully apply to people from other racial and ethnic backgrounds.
Future research will follow this group of participants throughout the 10-year study period to uncover how this positive association changes over time. By tracking them as they age, scientists will be able to learn exactly how midlife habits influence the actual onset of memory loss. The authors hope that these future studies will guide health professionals in designing better prevention programs.
“This reframes brain health as something people can shape through achievable lifestyle choices, encouraging early and sustained engagement in enjoyable activities,” Nasi said. “It also shows that governments serious about reducing the future burden of dementia need to prioritize midlife lifestyle interventions, including mental health support, cardiovascular risk management, brain injury prevention, and access to lifelong learning and community engagement programmes.”
The study, “The relative contributions of modifiable and non-modifiable factors in determining cognition in middle-aged individuals at risk for late-life Alzheimer’s disease,” was co-authored by Bolin Kao, Chin Chi, Siobhan Hutchinson, Damian Ferguson, Paresh Malhotra, Ivan Koichev, John T. O’Brien, Katie Bridgman, Craig W. Ritchie, Brian Lawler, and Lorena Nasi.
