Vascular dementia is the second most common form of dementia after Alzheimer's disease, said study author Dr. Giovanni Ravaglia of the University Hospital S. Orsola Malpighi, in Bologna, Italy

The four-year study involved 749 men and women in Italy age 65 and over who did not have memory problems at the beginning of the study. Researchers measured the amount of energy exerted including: walking, climbing stairs, and other moderate activities, such as house and yard work, gardening, and light carpentry.

By the end of the study, 54 people developed Alzheimer's disease and 27 developed vascular dementia.

The study, published in the online issue of Neurology, found the top one-third of participants who exerted the most energy walking were 27 percent less likely to develop vascular dementia than those people in the bottom one-third of the group.

"Our findings show moderate physical activity, such as walking, and all physical activities combined lowered the risk of vascular dementia in the elderly independent of several sociodemographic, genetic and medical factors," Ravaglia said in a statement.