A woman’s “body clock” might affect her dementia risk according to a new study. The timing of an older woman’s sleep/wake cycle (also known as circadian rhythms) and the levels of daily physical activity was also linked to odds for mental decline, the study found.
It found that the risk of dementia or "mild cognitive impairment" (a state that sometimes precedes dementia) was higher in older women with weaker circadian rhythms who are either less physically active or more active later in the day, compared to those who have a stronger circadian rhythm and are more active earlier in the day.
"We've known for some time that circadian rhythms, what people often refer to as the 'body clock,' can have an impact on our brain and our ability to function normally," lead author and scientist said. Findings suggest that future interventions such as increased physical activity or using light exposure to influence body clock cycles could help influence cognitive mental health in older women.
Data was analyzed from almost 1,300 healthy women, over age 75, who were followed for five years. At the end of that time, 15 percent of the women had developed dementia and 24 percent had some form of mild cognitive impairment. Women with weaker circadian rhythms who had lower levels of physical activity or who were most active later in the day were 80 percent more likely to develop dementia or mild cognitive impairment than those with stronger circadian rhythms who were active earlier in the day.
"To our knowledge this is the first study to show such a strong connection between circadian activity rhythm and the subsequent development of dementia or mild cognitive impairment," researchers said. The finding marks an association only, however, and cannot prove cause-and-effect. "The reasons why this is so are not yet clear," he added. "The changes in circadian rhythm may directly influence the onset of dementia or mild cognitive impairment, or the decrease in activity may be a consequence, a warning sign if you like, that changes are already taking place in the brain.
Identifying what the reason is could help us develop therapies to delay, or slow down, the development of brain problems in the elderly. In the new year, keeping busy and keeping your mind stimulated would be a good resolution for all! Happy New Year – I hope everyone has a healthy and safe 2012 – and surround yourself with caring people.