Obesity, vitamin D and coffee consumption – they’ve all been shown to affect how our brains work. But could their association with cognitive function help to prevent dementia?
That’s what UniSA population health expert Professor Elina Hyppönen is hoping to find out in her latest research project titled ‘Nutritional factors and cognitive function: examining evidence for a causal association’, with help from a recently secured Mason Foundation grant.
Prof Hyppönen says obesity, low vitamin D status and coffee consumption are all common in contemporary populations so understanding the causal link between each of these nutritional factors and cognitive function could have a significant impact on public health.
And in countries with an ageing population like Australia, uncovering new ways to prevent dementia is even more critical as dementia – a collection of symptoms affecting people’s ability to think and perform everyday tasks – is more common in people aged 65 and above.
“We selected these nutritional factors because all of them are associated with cognitive function, but the associations remain controversial and we don’t know whether these represent true causal effects,” Prof Hyppönen says.
“There is still a lot we don't know about the effects of these nutritional factors on cognitive function, which includes even whether they are beneficial or harmful.
“For example, obesity has been typically associated with poorer cognitive function and increased dementia risk, but a recent retrospective cohort study of nearly two million individuals reported reductions in dementia risk even for the severely obese individuals.
“The study noted that compared to those with a heathy weight, dementia risk was increased by 34 per cent for the underweight individuals with a body mass index (BMI) of under 20kg/m2.
“Perhaps most interesting though was that the study showed that dementia risk continued to fall with increasing BMI, and compared to those with a healthy weight, severely obese people with a BMI above 40 kg/m2 had 29 per cent lower dementia risk.
“With vitamin D, we have found evidence for lower memory function for individuals with both very low and high concentrations.
“And anyone who has felt that burst of energy from their morning cup of coffee will know that coffee consumption stimulates cognitive function in the short-term but we do not know if it has any long-term effects.
“Could these nutritional factors play a role in preventing dementia? That’s what we want to find out.”
The Professor of Nutritional and Genetic Epidemiology says approaching the study from a population health perspective is cost-effective while still providing important insights into new ways to prevent dementia in the future.
“This project aims to inform non-invasive ways to prevent dementia,” Prof Hyppönen says.
“From past experience we know that evidence from observational studies can be misleading, and even very promising nutritional factors may fail to deliver the promised benefits when tested in clinical trials. Clinical trials are also typically very expensive and time consuming.
“This makes the genetic approach we are using for this project very attractive, as it allows us to establish likely causal effects by modest life-long differences in exposure levels in a very cost-effective way without any risk of harm to patients.”
The field of population health uses and interprets population data to inform health and social policy.
Prof Hyppönen’s project will contribute to establishing a large-scale project with up to 150,000 participants form various European universities including the University of Exeter, University College London and University of Bristol among others.