Brain patterns from a patient suffering from Alzheimer’s disease. A U.S. study found that diet, exercise, cognitive activity and managing heart health can improve old age cognition.Denis Balibouse/Reuters
Slowing or preventing cognitive decline and dementia is a major public-health priority because of the growing number of people affected globally.
In Canada, the prevalence of dementia is expected to increase 187 per cent from 2020 to 2050. The Alzheimer Society of Canada projects more than 1.7 million Canadians will be living with dementia by 2050.
The 2024 report of the Lancet Commission on dementia prevention identified 14 modifiable risk factors – many related to lifestyle – that, if addressed, could reduce or delay 45 per cent of dementia cases.
Now, a new U.S. study found that a combination of four lifestyle changes involving diet, exercise, cognitive activity and managing heart health can improve cognition in a large population of older adults.
Here’s what to know about the study, plus its key message that can make a meaningful difference to brain health later in life.
About the latest research
The large-scale randomized controlled trial, named the U.S. Study to Protect Brain Health Through Lifestyle Intervention to Reduce Risk, or US POINTER, was published July 28 in the journal JAMA.
The two-year trial enrolled 2,111 adults, aged 60 to 79, from five different regions in the U.S., who were at risk of cognitive decline and dementia.
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Participants were cognitively healthy, but they were sedentary and ate a poor diet.
As well, they had at least two other risk factors for late-life cognitive decline including a family history of memory impairment (mother, father, brother or sister), suboptimal cardiometabolic health (hypertension, high LDL cholesterol or elevated blood sugar), older age (70 to 79 years), or they were male.
Participants were assigned to one of two lifestyle interventions that focused on improving brain health through exercise, diet, cognitive activity, social engagement and heart health.
‘Structured’ versus ‘self-guided’
Participants in the structured lifestyle group attended 38 group meetings over two years, led by trained professionals, for motivation, accountability and goal-setting.
They engaged in regular physical activity – 30 to 35 minutes of moderate to intense aerobic exercise four times a week, resistance training twice a week, and stretching and balance exercises twice a week.
They also adhered to the MIND diet, an eating pattern that includes daily servings of leafy greens, berries, whole grains and olive oil, five one-ounce servings of nuts each week, and three or more weekly half-cup servings of pulses (beans, chickpeas, lentils). The MIND diet also limits red and processed meats, sweets, fried and fast food, full fat cheese, as well as butter and margarine.
At least three times a week, participants in the structured group did web-based cognitive training using a program called BrainHQ. They were asked to perform specialized tasks involving memory, attention, brain speed, people skills, decision-making and navigation; tasks were easy to complete and adaptive in difficulty.
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The structured group also regularly set goals to increase intellectual and social stimulation. Their cardiometabolic health was monitored every six months (blood pressure, LDL cholesterol, blood glucose, waist circumference).
The self-guided group was given publicly available education materials about health, exercise and diet, and were encouraged to make lifestyle changes that suited their personal needs and schedules.
They received encouragement during six group meetings over the two-year study and had their health checked annually during clinic visits.
Participants in both groups took cognitive tests at the start of the study and every six months thereafter.
Both lifestyle intervention groups improved
After two years, both groups showed cognitive improvement, which was measured using a global cognitive score. The score combines test results of episodic memory (recollection of past experiences), executive function (mental skills used in planning, problem-solving, achieving goals) and processing speed (how quickly the brain processes information).
Compared to participants in the self-guided group, cognitive improvements happened slightly faster for those in the structured program.
The benefit was consistent regardless of age, sex, genetic risk and cardiovascular risk.
The structured group showed greater improvement for executive function than the self-guided group. Processing speed showed a similar trend, but it was not statistically significant, meaning it could have occurred by random chance. Increases in episodic memory did not differ between the two groups.
Study strengths and limitations
The study is notable for its randomized design, its diverse group of participants and their high adherence to each lifestyle intervention group.
Longer-term follow-up is needed, however, to determine if the observed cognitive improvements last after the study ends and translate into a lower risk of dementia.
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The researchers noted they are planning future studies of US POINTER participants, using data from an extended follow-up to gain insight into the long-term impact of the lifestyle interventions.
This will include analyses of brain scans and blood tests, which would indicate whether cognitive improvements are associated with measurable changes in brain health.
Takeaways
While the more rigorous lifestyle program showed slightly greater cognitive benefits, the study also demonstrated that even small self-guided lifestyle changes can benefit brain health in older adults.
According to the 2024 Lancet Commission report, actions that decrease dementia risk – including healthy eating, regular exercise, cognitive stimulation and managing cardiovascular risk factors – should begin early and continue throughout life.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on X @LeslieBeckRD
