Healthy Heart Could Prevent Alzheimer's Disease
"Heart function could prove to be a major risk factor for dementia and Alzheimer's disease," says Angela Jefferson, PhD, director of the Vanderbilt Memory & Alzheimer's Center, and principal investigator of the study published in the journal Circulation.
"A very encouraging aspect of our findings is that heart health is a modifiable risk. You may not be able to change your genetics or family history, but you can engage in a heart healthy lifestyle through diet and exercise at any point in your lifetime," Jefferson explains.
For this research, Jefferson and colleagues used data from the Framingham Heart Study, an effort that began in 1948 to identify risk factors for heart disease. They followed 1,039 participants from Framingham's Offspring Cohort for up to 11 years to compare cardiac index to the development of dementia.
Cardiac index is a measure of heart health. It indicates cardiac output or the amount of blood that leaves the heart and is pumped through the body taking into consideration a person's body size. "A low cardiac index value means there is less blood leaving the heart," Jefferson says.
Over the study period, 32 participants developed dementia, including 26 cases of Alzheimer's disease. Compared to normal cardiac index, individuals with clinically low cardiac index had a higher relative risk of dementia. "We thought heart disease might be driving the increased risk of dementia and Alzheimer's disease. When we excluded participants with heart disease and other heart conditions, we were surprised that the risk of dementia and Alzheimer's disease got even worse," Jefferson points out.
Although the research community has long associated heart health with brain health, cardiac index has not been previously recognised as a risk factor for significant memory loss or dementia.
"For the average adult, the brain accounts for two percent of overall body weight but receives as much as 15 percent of blood leaving the heart. If there are changes in the heart's ability to pump blood, the brain is resilient and does a great job at regulating blood flow to maintain a consistent level to support brain tissue and activity. But as we age, our vessels tend to be less healthy. They become less adaptable to blood flow changes, and those changes may affect brain health and function," Jefferson says.
She emphasises that this research points only to a risk factor.
"At present, there is no proven method for preventing dementia or Alzheimer's disease. But leading a heart healthy lifestyle could help. When 30 percent of the population is exposed to a potential risk factor, like low cardiac index, that suggests it may be of significant public health concern."
Source: Vanderbilt University Medical Center
Image Credit: Vanderbilt University Medical Center
Published on : Thu, 5 Mar 2015