A new report by the Lancet Commission on dementia prevention, intervention and care, concludes that addressing 14 modifiable risk factors, starting in childhood and continuing throughout life, could prevent or delay nearly half of dementia cases.
The report adds two new risk factors, vision loss and high cholesterol, to a list of 12 previously identified by the Commission in 2020.
On the report, Prof David Attwell, Director of the BHF-UK DRI Centre for Vascular Dementia Research, and Jodrell Professor of Physiology at UCL, said:
“I welcome this updated version of earlier Lancet Commission reports on dementia. Vascular contributions to dementia are given higher prominence compared to the 2020 report, with the recognition that vascular health and hence dementia risk can be negatively affected by diabetes, cholesterol level, hypertension, smoking, obesity, air pollution and head injury.
More mechanistic assessment of how vascular dysfunction leads to dementia (beyond correlations between vascular dysfunction and stroke) could have been included, and could aid prediction of interventions that might prevent or slow dementia onset.
Key questions remain over whether a decrease of cerebral blood flow or a breakdown of blood-brain barrier function makes a larger contribution to dementia.
In Alzheimer’s disease, affected parts of the brain suffer a 45% decrease in cerebral blood flow (1) which is expected to impair cognition, and this is generated by constriction of capillaries by a specialised cell type known as pericytes (2). Consistent with this, use of drugs that dilate the blood vessels may delay the onset of Alzheimer’s disease (3) and similarly delay vascular dementia caused by cerebral small vessel disease (4). In contrast, drugs correcting blood-brain barrier dysfunction have yet to reach routine clinical use (but see 5), making it hard to assess the contribution of the blood-brain barrier to dementia onset.”
Prof Tara Spires-Jones, Group Leader at the UK DRI at Edinburgh, said:
“This study by Livingston and colleagues is an excellent up-to-date analysis of the research from around the world examining risk factors for developing dementia. The data in the paper add compelling evidence for the ability to prevent dementia by addressing some of the 14 identified risk factors.
This type of research cannot conclusively link any of these factors directly to dementia, but contribute to the growing evidence that a healthy lifestyle including keeping your brain engaged through education, social activities, exercise, and cognitively stimulating activities, and avoiding things like head injury and factors that are bad for your heart and lungs can boost brain resilience and prevent dementia.
There are new links in this report with vision loss and high cholesterol associating with dementia risk, which broadly fit with the previous research indicating that keeping your brain active and avoiding vascular risk factors that come with a sedentary lifestyle and poor diet is good for reducing dementia risk. This study is important as it gives insight into ways that both individuals and governments can help reduce dementia risk. It also helps guide more fundamental neuroscience research into how these factors influence brain vulnerability to the diseases that cause dementia.
While this excellent study estimates that up to half of dementia cases could be prevented by changing modifiable risk factors, it is important that we keep in mind that the other half of people with dementia likely developed brain disease for unavoidable reasons related to factors beyond their control like genetics.”
Article published: 31 July 2024
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