Smoking and high blood pressure over the age of 50 lead to accelerated mental decline, research claims.
Scientists analysed risk factor data for more than 8,000 older adults taking part in the English Longitudinal Study of Ageing (Elsa).
Tests of memory, planning and overall mental ability were carried out after four and eight years.
The study showed that smoking consistently reduced all three performance measures after four years.
High blood pressure and high risk of stroke were associated with lower scores for memory and overall mental ability after eight years. Being overweight was linked to memory.
The findings appear in the journal Age And Ageing. They indicate that future trials should focus on combinations of risk factors rather than individual causes of mental decline.
Lead scientist, Dr Alex Dregan, from King's College London, said: “Cognitive decline becomes more common with ageing and for an increasing number of people interferes with daily functioning and well-being.”