November 14, 2017
We know that stroke is associated with an extreme increase in dementia risk. But now, heart attacks have been found to increase risk, too—even decades after the fact. A new study has found that patients who experienced heart attacks were 35 percent more likely to develop dementia in the following years. The increased risk effect did not fall off or decrease in the 35 years patients were followed after the heart attack, suggesting the damage that is caused during the cardiac arrest has lasting effects on the factors that cause vascular dementia.
Dr. Jens Sundbøll, MD, Ph.D, from the Department of Clinical Epidemiology at Aarhus University looked at 200,000 people who survived a heart attack from the years 1980 to 2012. The patients, sourced from the Danish National Patient Register and the Danish Psychiatric Central Research Register, were checked for every type of dementia diagnosis before they were compared to a control group consisting of one million people from the background population.
An interesting finding, though, was that heart attack was not associated with an increase in Alzheimer’s, one type of dementia, but just vascular dementia. Symptoms-wise, vascular dementia patients often decline suddenly and then plateau; in Alzheimer’s, patients gradually decline over time. Vascular dementia accounts for one-fifth of total dementia cases worldwide. Vascular dementia damage in the brain can often be pinpointed to a specific cardiac event like a heart attack or stroke, whereas scientists still aren’t sure what might trigger the plaques and tangles they believe cause Alzheimer’s.
This discovery is important because it emphasizes how important preventing heart attack can be for brain health over a lifetime. “A thirty-five per cent increased risk is in itself an argument for examining the possibilities for preventive measures such as relevant medications and healthier lifestyle. The importance of prevention is underscored by the fact that, for the majority of dementia diseases, there is no good treatment once the dementia has set in,” said Sundbøll.
Sundbøll says the findings are significant because as time passes, more people are living longer than ever before, which means vascular dementia is inevitably on the rise. “As opposed to most other dementia subtypes, vascular dementia is likely preventable,” he said.
Last week, a report was released that indicated lupus, an autoimmune disease that causes inflammation, also increases the risk for dementia. The risk increase for lupus patients was 51 percent when compared to those without lupus, which held true across all age groups. We also know that diabetes can increase the risk of dementia by 75 percent.
So, what can we do to prevent disease associated with dementia? Doctors suggest the first step is a healthy diet and aerobic exercise three times per week. You can read more about lifestyle studies and dementia here.