Exploring exercise and nutrition interventions for dementia prevention

Dr Helen Macpherson investigated strategies for protection against the development of dementia in older people.

Dementia represents a major cause of disability and is the second leading cause of death in Australia.  Prevention strategies are essential, given that around 40 per cent of dementia risk is potentially modifiable. 

Diet and physical activity are important targets for intervention because they influence cardio-metabolic and psychosocial risk factors for cognitive decline, Alzheimer’s disease, and other forms of dementia. 

For her National Health and Medical Research Council (NHMRC) and Australian Research Council (ARC) Dementia Research Development Fellowship, Dr Macpherson focused on understanding the role of diet and exercise in dementia prevention as well as testing a combination of exercise with a specific formulation of nutrients, to explore potential benefits in both cognition and physical function. 

As part of her research Dr Macpherson explored the impact of individual nutrients in older people who were still healthy but concerned about their memory.  She showed that habitual intake of omega 3 was related to better cognitive and physical function amongst participants.  

 This is important as it confirms the importance of having a healthy diet rich in omega 3 as people get older,” Dr Macpherson said. 

 Dr Macpherson then conducted a randomised controlled trial in 147 older people with memory concerns.  

 Participants took part in a six-month exercise program run in gyms around Melbourne, which focussed largely on resistance training. They were also required to take a daily supplement drink which contained omega 3, vitamin D and protein.  

 “These are nutrients which if depleted, or not consumed at adequate levels, have been implicated in declining memory and strength as people age,” Dr Macpherson explained.   

 The control group also took part in a gym-based stretching and flexibility program to control for the social benefits that people receive from exercising in a group setting, and consumed a daily placebo supplement drink.  

 While the intervention improved the primary outcome of executive function after 6 months, this effect did not reach statistical significance compared to the control group.  

This intervention was implemented in people prior to the onset of cognitive impairment. Even though the combination of exercise and the dietary supplement only demonstrated small benefits in executive function, the important message is that exercise and diet are still important for brain health.  

Dr Macpherson said that future interventions should adopt a tailored approach, adapting exercise and diet intervention components based on participants individual needs as recommended by the WHO guidelines for the risk reduction of cognitive decline and dementia.