Greater adherence to diet lowers the risk for Alzheimer’s disease
Adherence to a Mediterranean diet has been associated with lower risk of various age-related diseases including dementia. A study which appeared in the journal Neurology 2007, had revealed adherence to the Mediterranean diet (MeDi) not only lowers the risk for Alzheimer’s disease but also consequent disease course.
Narrative reviews on the diet have been published however; no systematic review has incorporated studies on the link between adherence to the MeDi and cognitive function or dementia.
Researchers from the University of Exeter Medical School, supported by the National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care in the South West Peninsula (NIHR PenCLAHRC), has carried out the first such systematic review.
Lead researcher Iliana Lourida, MSc, PhD student, and colleagues reviewed 11 observational studies and one randomized controlled trial that examined the association between a Mediterranean diet adherence score and cognitive function or dementia.
The systematic review found a higher adherence to the Mediterranean diet was associated with better cognitive function, lower rates of cognitive decline, and reduced risk of Alzheimer disease in nine out of 12 studies, whereas results for mild cognitive impairment were inconsistent.
Mediterranean diet includes an abundance of food from plant sources such as fruits, vegetables, nuts and grains, consuming less processed foods, olive oil as the principal fat, fish , poultry, limited red meat consumption, moderate consumption of red wine and regular physical activity.
In their conclusion the researchers write “Published studies suggest that greater adherence to Mediterranean diet is associated with slower cognitive decline and lower risk of developing Alzheimer disease. Further studies would be useful to clarify the association with mild cognitive impairment and vascular dementia. Long-term randomized controlled trials promoting a Mediterranean diet may help establish whether improved adherence helps to prevent or delay the onset of Alzheimer disease and dementia.”
According to Lourida "Mediterranean food is both delicious and nutritious, and our systematic review shows it may help to protect the ageing brain by reducing the risk of dementia. While the link between adherence to a Mediterranean diet and dementia risk is not new, ours is the first study to systematically analyse all existing evidence."
In conclusion she adds "Our review also highlights inconsistencies in the literature and the need for further research. In particular research is needed to clarify the association with mild cognitive impairment and vascular dementia. It is also important to note that while observational studies provide suggestive evidence we now need randomized controlled trials to confirm whether or not adherence to a Mediterranean diet protects against dementia."
The findings of the review are published in Epidemiology.
More information on the Mediterranean diet can be found online at Oldways.