Many factors contribute to dementia — some of which are within your control, and others that are not. In the latest study published in Neurology, researchers focused on one thing that people may be able to do to lower their risk of developing dementia later in life: staying fit.
In the study, which involved nearly 1,500 women in Sweden who provided information on their physical activity levels and took cognitive tests for up to 44 years, scientists found that women with higher fitness levels were 88% less likely to develop dementia compared to women with average fitness. Women with lower fitness had a 41% higher risk of developing dementia than women with average fitness.
Fitness is not the same as exercise, however, and higher levels of physical activity don’t necessarily translate into improved fitness. Helena Horder, a physiotherapist from the Center for Aging and Health-AGECAP at the University of Gothenburg in Sweden, and her colleagues measured cardiovascular fitness, an indicator of how well the circulation of blood is feeding the heart and the brain. “If the small blood vessels and circulation in the heart are okay, then the brain is also affected in a positive way by good small vessel circulation,” says Horder.
While there is strong data showing that having low fitness is unhealthy for the heart and brain, “I was very surprised that high fitness was so protective,” Horder says, “and that so few developed dementia in the high fitness group.”
Current recommendations suggest at least 30 minutes of exercise at least two or three times a week, until people feel a little tired but not exhausted. For people who are not active, that could mean starting out with shorter sessions of 10 or 15 minutes, but getting 30 minutes of exercise total in a day. They could start with brisk walking on flat surfaces, and as that becomes easier, include some routes that require walking up hills. As you become more fit, you can include more intense interval training that intersperses a few minutes of intense activity with a few minutes of stretching or less intense exercise.
While the study focused on cardiovascular fitness, Horder says that as people get older, strength training and building muscle are also important. More research is needed to pinpoint when during midlife the fitness benefits start accruing to reduce dementia risk — in the current study, the women ranged in age from 38 to 60 when they began the trial — and also whether improving fitness can actually slow or prevent dementia.