High cholesterolHigh levels of ‘bad’ LDL cholesterol puts you at a 30 per cent increased dementia risk. MIXED DEMENTIA: At least one in ten people with dementia have more than one type: most commonly, Alzheimer’s and vascular dementia. AdvertisementThese repeated interruptions can also trigger stress responses in the body, leading to increased blood pressure, another dementia risk. This may lead to brain tissue damage and is linked with the build-up of amyloid proteins – that both raise dementia risk. BLOOD PRESSURE: NHS advises monitoring every five years, especially if over 40.