It is well known that type 2 diabetes affects blood circulation. The disease stiffens blood vessels and reduces the amount of oxygen that circulates throughout the body. This includes the brain as well.
When blood flow in the brain is impaired, it can affect the way we think and make decisions.
People with type 2 diabetes are often overweight or obese. These are conditions that may also be linked to cognitive problems (problems with thinking abilities). Lowering the calories intake and increasing physical activity can reduce the negative effects of type 2 diabetes. However, the effects of these interventions on cognition and the brain are not clear.
Recently, researchers have examined information from a 10-year-long study called Action for Health in Diabetes. In the study, participants learned how to adopt healthy, long-term behavior changes. What is more, in this study, researchers focused on whether participants with type 2 diabetes who lowered calories in their diet and increased physical activity had better blood flow to the brain.
These findings were published in the Journal of the American Geriatrics Society.
Researchers assigned participants to one of two groups. The first group was called the Intensive Lifestyle Intervention. In this group, participants were given a daily goal of eating between 1200 to 1800 calories in order to lose weight. They also had a goal of 175 minutes of physical activity during the week, through activities such as brisk walking.
Participants were seen weekly for the first six months, and three times a month for the next six months. During years 2 through 4, they were seen at least once a month and were regularly contacted by phone or email. Moreover, they were also encouraged to join group classes. When the study finished, participants were encouraged to continue individual monthly sessions and other activities.
The second group was called the “control group.” They attended Diabetes Support and Education classes. The researchers compared the control group to the group that participated in the lifestyle intervention.
About ten years after enrollment, 321 participants underwent an MRI brain scan. 97 percent of those MRIs met quality control standards set by the researchers for their study.
The researchers looked at the group of adults who were overweight or obese at the beginning of the study. They concluded that in that group, those who did the long-term behavioral intervention had greater blood flow in the brain. What is more, blood flow tended to be the greatest among those who did not do as well on tests of mental functions. This may show how the brain may adapt in response to cognitive decline.
However, the researchers also found that for the heaviest individuals, the intervention may have worked differently. The intervention may have been most effective in increasing or maintaining blood flow in the brain for individuals who were overweight but not obese.