One-third of Alzheimer’s cases ‘may be preventable’

Around one-third of Alzheimer's disease cases worldwide can be attributed to potentially modifiable risk factors, according to a University of Cambridge study.

This is lower than the previous estimate of one in two cases, as – unlike a prior study conducted in 2011 – this takes into account the fact some of the risk factors used in previous studies are related.

The seven key risk factors for which there is consistent evidence of an association with the disease are diabetes, midlife hypertension, midlife obesity, physical inactivity, depression, smoking and low educational attainment.

By reducing the relative risk from each of these risk factors by 10 percent, it is estimated that it will be possible to reduce the prevalence of Alzheimer's in 2050 by 8.5 percent – equivalent to nine million cases.

Study leader Professor Carol Brayne, from the Cambridge Institute of Public Health, said: "Although there is no single way to prevent dementia, we may be able to take steps to reduce our risk of developing dementia at older ages."

Alzheimer's disease is the most common type of dementia, affecting almost 500,000 people in the UK.