Moderate exercise may stall vascular dementia


Older adults who regularly walk for exercise may help lower their risk of vascular dementia, the second-most common form of this disorder after Alzheimer's disease, a study published Wednesday suggests.
In a group of 749 adults who were 65 years of age or older, the Italian researchers found that those who regularly walked or got other forms of moderate exercise were less likely to develop vascular dementia over the next 4 years.
Compared with their sedentary counterparts, active adults had about one quarter the risk of developing vascular dementia. Vascular dementia is caused by an impaired blood flow to the brain. Blockages that narrow the blood vessels supplying the brain or complete blockages that cause a stroke, may also lead to vascular dementia. People with conditions that damage blood vessels throughout the body -- such as high blood pressure or diabetes -- are also at increased risk.
The new findings, published in the online edition of the journal Neurology, build on evidence that lifestyle habits are important in dementia risk. A number of studies have suggested that the same habits that are good for the heart -- such as a healthy diet and regular exercise -- may benefit the aging brain as well.
Although moderate exercise had no effect on Alzheimer's disease, the findings do not mean that exercise has no effect on the risk of Alzheimer's, according to the researchers, led by Dr. Giovanni Ravaglia of the University Hospital S. Orsola-Malpighi in Bologna.
The study included Italian adults with no evidence of mental decline at the outset. The patients were interviewed about their physical activity levels, medical history and any depression symptoms, among other health factors.
Over the next 4 years, 86 study participants were diagnosed with dementia, including 27 with vascular dementia.
Ravaglia's team found that, compared with participants who walked the least often at the study's start, those who logged the most miles were 73-percent less likely to develop vascular dementia.
Similarly, those who got the most moderate exercise of any type -- such as gardening, bicycling and housework -- had a 76 percent lower risk of vascular dementia.
Exercise may benefit mental functioning for a number of reasons, according to the researchers. Aside from improving blood from improving the blood flow to the brain, it may also stimulate the release of key brain chemicals, and enhance the development of new nerve cells or the connections among those cells.
It's also possible, Ravaglia and his colleagues note, that an active lifestyle helps protect the aging brain by keeping older adults mentally stimulated and socially active.
In general, experts advise that all healthy adults try to accumulate at least 30 minutes of moderate exercise on most, if not all, days of the week. Older adults who want to start a new exercise routine should talk with their doctors first.
SOURCE: Neurology, online December 19, 2007.