A combination of healthy activities including exercise, nutritious diet, computer brain games and socialising can improve cognitive performance in people at risk for dementia, according to a large new US study.
The study, conducted in five locations across the US over two years, is the biggest randomised trial to examine whether healthy behaviours protect brain health.
“It confirms that paying attention to things like physical activity and vascular risk factors and diet are all really important ways to maintain brain health,” said Dr Kristine Yaffe, an expert in cognitive ageing at the University of California, San Francisco, who was not involved in the study.
The results were presented last week at the Alzheimer’s Association International Conference in Toronto and published in the journal JAMA.
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The study involved 2,111 people, aged 60 to 79, from diverse racial and ethnic backgrounds. None were cognitively impaired. All had sedentary lifestyles, suboptimal diets and two other dementia risk factors, such as a family history of cognitive decline and high blood pressure.
Half of the participants followed a structured programme. They were prescribed a healthy diet, socially engaging activities, and a weekly regimen of eight exercise sessions and three sessions of computerised cognitive training. They attended 38 meetings with facilitators and fellow participants.
The other participants followed a self-guided programme. They were given educational materials and resources, and were regularly encouraged to engage in healthy behaviours. They attended six team meetings during the study.
Cognitive scores for both groups improved considerably, with the high-intensity group improving somewhat more than the other group. “The structured intervention had an extra benefit over and above the self-guided,” said Laura Baker, a professor of gerontology, geriatrics and internal medicine at Wake Forest University School of Medicine and a principal investigator of the study.
Still, the study left many questions unanswered.
We should have more aggressive targeting of interventions for people who have lower cognition, who are more at risk, and less intense or less expensive interventions for those with higher cognition
— Kaarin Anstey
Dr Lon Schneider, an Alzheimer’s expert at the University of Southern California and a member of the Lancet Commission on dementia prevention, was impressed that “both groups improved quite significantly”. But he noted that the difference in performance between the high-intensity and self-guided groups was “very small”, raising questions about how beneficial an intensive programme truly was.
It was also unclear how much of the cognitive improvement reflected a “practice effect”, a common phenomenon whereby participants learn to do better on assessments simply by taking them several times, Schneider and other experts said.
“This does not demonstrate that any of the lifestyle changes in and of themselves, or the combination of them, is responsible for this level of improvement,” Schneider said. “Or that it is necessarily related to neurodegeneration or Alzheimer’s disease.”
The results cannot be compared with the general population, as the study did not include a group that received no intervention.
“We didn’t believe that it was ethical” to have a “group that would not get anything”, said Heather M Snyder, senior vice-president for medical and scientific relations at the Alzheimer’s Association, which spent $50 million as the lead funder of the study.
Baker said that even if the structured intervention was only modestly more effective than the self-guided one, “I don’t think we can say a small difference for an at-risk group is not meaningful.” She estimated that, compared with the self-guided group, the structured intervention “slowed the cognitive ageing clock by one to two years”, which might “increase resilience against cognitive decline”.
But several outside experts said that estimating any real-world advantage was difficult. They also questioned whether many people could realistically adopt an intense programme.
“One of the big questions is how much do you need to do, and what’s cost-effective,” said Kaarin Anstey, director of the Ageing Futures Institute at the University of New South Wales in Australia. “If we only have very intensive interventions only a few people can afford, that’s not actually going to address the bigger issue of population ageing and lots of people developing cognitive impairment.”
The study, called US POINTER, was modelled after the first large randomised trial of lifestyle changes, called FINGER and conducted in Finland a dozen years ago. That study’s intensive group showed 25 per cent greater cognitive improvement than a group receiving minimal intervention.
The goal was to “see if it can work” in a more diverse nation with different health and lifestyle issues, Baker said.
The participants lived in North Carolina, Rhode Island, northern California, Houston and Chicago. More than two-thirds were women and 31 per cent were from racial or ethnic minority groups.
Most had first-degree relatives with memory loss, and 30 per cent had the APOE4 gene mutation, which increases Alzheimer’s risk. All of those subgroups experienced the same degree of cognitive improvement.
Most people participated for the full two years, an indication that they were highly motivated whether or not they received intensive supervision.
Phyllis Jones (66) of Aurora, Illinois, enrolled partly because her mother and grandmother had suffered from vascular dementia. Before the study, she said, stress from being laid off from a software engineering position and other job difficulties sent her to the emergency room with blurry vision and a racing heart. “I was in really bad shape,” Jones said. Participating in the structured intervention “woke me up”.
At first, just 10 minutes of aerobics was exhausting, but she now exercises daily and has lost 30lb, she said. Buoyed by social support from the peer meetings, she found a new job as a software tester.
She befriended another participant, Patty Kelly (81). They encouraged each other, and Kelly overhauled her own diet, sharply limiting sweets, cheese and fried food.
Both women perceived some cognitive benefit, although they have not been told their scores. Jones felt more able to plan home projects and follow messaging chains at work. Kelly, who retired from a non-profit serving homeless families, said her driving had improved. “I don’t run into the side of the garage any more,” she said.
The computer brain games were “the hardest thing for us to get on board with”, Jones said. That was true for other participants, too, Baker said. “Is it practical to expect people to do this day after day?” Baker said about computerised brain training. “Based on our experience, I’m going to say no.” But she said that any kind of intellectual stimulation could be helpful.
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Since the trial ended last year, Jones has maintained many practices, she said, but found herself backsliding with sugar, and her cholesterol climbed. “I think the structure is important, the accountability,” she said.
The study found that participants who started with lower cognitive scores benefited more. It is unclear why, Anstey said, but could suggest that “we should have more aggressive targeting of interventions for people who have lower cognition, who are more at risk, and less intense or less expensive interventions for those with higher cognition”.
For both groups, the biggest cognitive improvement involved executive function – skills like planning and organising. Memory initially improved in both groups, but then declined, with no significant difference in the groups’ ultimate memory scores. Memory loss is a core Alzheimer’s symptom, Yaffe noted, so cognitive improvements in the trial were likely “less related to Alzheimer’s disease and more related to vascular changes in the brain”.
The researchers will analyse blood, brain scans and other data to see if the activities spurred brain changes, reductions in Alzheimer’s-related proteins or other biological factors, Snyder said. The US Alzheimer’s Association will spend $40 million to follow the participants and help communities adopt locally tailored programmes.
“We now need to translate this and to turn brain health interventions into public health outcomes and solutions,” Snyder said. – This article originally appeared in The New York Times.
