Almost half of all dementia cases could be prevented by targeting 12 key lifestyle factors outlined in a landmark review.
Major factors include drinking more than ten pints or two bottles of wine a week, head bangs such as those suffered in sports, and pollution from living on a busy road.
The Lancet Commission on dementia prevention has been compiled by 28 leading global experts and identified the ways 40% of the devastating diagnosis could be avoided.
Lead author Prof Gill Livingston, of University College London, said there are opportunities to make an impact “at each stage of a person’s life.”
She said: “Our report shows it is within the power of policy-makers and individuals to prevent and delay a significant proportion of dementia.”
Hearing loss in mid-life (8%) was followed by leaving school early (7%) and smoking (5%).
Then came loneliness and depression (both 4%), high blood pressure and physical inactivity (both 2%) and obesity and diabetes (both 1%).
It estimated that 2% of cases were linked to exposure to pollution in our twilight years and 1% to downing more than 21 units of alcohol a week in middle age.
Head injuries between the age of 30 and 50 were linked to 3% of cases.
Actions recommended included using hearing aids, taking actions to avoid head injuries and moving away from polluted areas in later life.
Prof Huw Williams, of Exeter University, said: “This analysis shows how the two big neuro-health conditions – Traumatic Brain Injury and dementia - are intricately linked.
"We’ve known for years that repeated brain injury links to dementia, which makes sense, but the global evidence around brain injury was very mixed.
“This link is particularly worrying as research shows head injuries are increasing. Many result from car crashes, violence, assaults and falls.”
