Managing lifestyle factors such as smoking, hypertension and depression could prevent one-third of the world's dementia cases, a Lancet study has claimed.

The findings showed that better management of nine risk factors (that included smoking, hypertension and depression) in early, mid- and late life could reduce the increased likelihood of developing dementia in about 35 per cent cases."The potential magnitude of the effect on dementia of reducing these risk factors is larger than we could ever imagine the effect that current, experimental medications could have," said Lon Schneider, Professor at the University of Southern California. "Mitigating risk factors provides us a powerful way to reduce the global burden of dementia," Schneider added.By increasing education in early life and addressing hearing loss, hypertension and obesity in midlife, the incidence of dementia could be reduced by as much as 20 per cent.

In late life, stopping smoking, treating depression, increasing physical activity, increasing social contact and managing diabetes could reduce the incidence of dementia by another 15 per cent, the researchers said.Nearly 47 million people across the world have dementia and by 2030, the number is expected to climb as high as 66 million and by 2050, it will reach 115 million.The study also highlighted the beneficial effects of nonpharmacologic interventions such as social contact and exercise for people with dementia.

Psychological, social and environmental interventions such as social contact, group cognitive stimulation therapy and exercise were found superior to antipsychotic medications for treating dementia-related agitation and aggression. They also conferred some benefit in improving cognition."Antipsychotic drugs are commonly used to treat agitation and aggression, but there is substantial concern about these drugs because of an increased risk of death, cardiovascular adverse events and infections, not to mention excessive sedation," Schneider noted.