One in three cases of Alzheimer's disease  could be prevented by increased activity levels and tackling rising obesity and diabetes cases, according to a recent study Blackmore Vale Magazine reported.

Researchers from Cambridge University in the United Kingdom  found that one hour of exercise per week may be able to reduce the risk of Alzheimer's disease by almost half.

"Simply tackling physical inactivity, for example, will reduce levels of obesity, hypertension and diabetes, and prevent some people from developing dementia as well as a healthier old age in general -- it's a win-win situation," Carol Brayne, lead author of the study, told The Daily Telegraph.

For the study, Brayne and her colleagues collected and analyzed almost a decade of studies on each of the risk factors for dementia, and calculated the overall proportion of dementia which could be prevented.

Based on the findings, people who do not achieve three 20-minute bursts of vigorous exercise per week, such as jogging or football, or five 30-minute sessions of moderate activity, such as walking are 82 percent more likely to go on to develop dementia.

People who were obese in mid-life increased their risk of developing dementia or Alzheimer's disease by 60 percent, while high blood pressure raised the threat by 61 per cent, the analysis found.

Smoking was also found to significantly increase dementia risks. Smokers increased their risk of the condition by 59 percent, while those with diabetes were 46 percent more likely to develop dementia.

The research team found that other factors found to sharply increase the risk of dementia included depression and lower levels of educational attainment.  They suggest that by reducing the relative risk posed by each lifestyle factor by just ten percent, it would be possible to reduce global prevalence rates by 8.5 percent by 2050.

The findings were recently published in the Lancet Neurology.