The link between heart disease risk factors and a greater chance of developing dementia is well-known, but this is the first time reducing these risk factors has been shown to slow down cognitive decline.
A total of 1,260 people over 60 years old who were at risk of dementia took part in the study at the University of Eastern Finland. Half were assigned to an intensive programme involving a number of lifestyle changes, while half received general health advice.
Those in the intensive intervention group undertook exercise regimes including muscle strength training and aerobic exercise, as well as brain training.
They also saw nutritionists and were put on a diet where 15% of calories were from proteins, 30% from fat, and 50% from carbohydrates.
After two years, neuropsychological tests showed that those who had followed the strict regime had 25% better cognitive functioning than the control group.
Those who took part in the regime had 83% higher executive functioning scores, which measure the brain's ability to organise and regulate thought processes. The programme did not seem to improve memory.
However, 5% of the participants had musculoskeletal pain compared to none in the control group, possibly as a result of the exercise programme.
The study participants will be followed up for a further seven years to see if dementia diagnoses drop.
Dr Simon Ridley, from Alzheimer’s Research UK, said: ‘The initial results are promising and suggest that a combination of improving cardiovascular health and keeping mentally active could slow decline in some aspects of our thinking, but it’s unclear which of the interventions carried the greatest benefit.
‘Benefits on memory were not so clear from this study and we await the findings from the longer follow-up period to see whether this intervention also has long-term benefits in reducing the risk of dementia.'