Lead author, Dr. Aron S. Buchman, said:
"The results of our study indicate that all physical activities including exercise as well as other activities such as cooking, washing the dishes, and cleaning are associated with a reduced risk of Alzheimer's disease. These results provide support for efforts to encourage all types of physical activity even in very old adults who might not be able to participate in formal exercise, but can still benefit from a more active lifestyle.
This is the first study to use an objective measurement of physical activity in addition to self-reporting. This is important because people may not be able to remember the details correctly."
Dr. Buchman and team set out to measure total daily non-exercise and exercise physical activities among 716 seniors, with an average age of 82 years. They were all from the Rush Memory and Aging Project. None of them had any signs of dementia. They all wore a device which monitors their physical activity, called an actigraph. The device is worn on the dominant wrist. The participants wore the actigraph for 10 days.
The researchers recorded data on all their exercise and non-exercise physical activities. The seniors also underwent yearly cognitive tests (the study was ongoing) to measure their thinking abilities and memory. The study-participants also reported on their social and physical activities.
Over an average period of 41 months, 71 seniors developed AD (Alzheimer's disease).
Total exercise as well as exercise intensity affect Alzheimer's riskThe authors found that the 10% least physically active seniors in their study were 2.3 times as likely to develop Alzheimer's disease, compared to the 10% most active.
They also found that exercise intensity impacted on Alzheimer's risk. Those in the bottom 10% of physical activity intensity were 2.8 times as likely to develop AD, compared to those in the top 10%.
Dr. Buchman said:
"Since the actigraph was attached to the wrist, activities like cooking, washing the dishes, playing cards and even moving a wheelchair with a person's arms were beneficial. These are low-cost, easily accessible and side-effect free activities people can do at any age, including very old age, to possibly prevent Alzheimer's."
The researchers said that by 2030, the number of people in the USA over 65 years of age will double to 80 million.
Dr. Buchman said:
"Our study shows that physical activity, which is an easily modifiable risk factor, is associated with cognitive decline and Alzheimer's disease. This has important public health consequences."
Written by Christian Nordqvist