According to estimates from the Centers for Disease Control and Prevention, one out of every six adults in the U.S. has genital herpes. Despite the long-term health consequences associates with the sexually transmitted disease, each year approximately 776,000 people in the U.S. get a new herpes infection.
While the outbreak of sores the disease causes remains its most well-known symptom, a new study suggests herpes could also affect memory in older adults. According to researchers, older adults who suffer from certain types of infections, such as herpes, may have a worse memory and poorer thinking abilities when compared to their peers.
While the results of the study, which were published in the March issues of Neurology, show a potential link between herpes and memory impairment, the study does not prove a conclusive link. However, despite the tenuous connection that researchers have found, herpes has long been known capable of spreading throughout the body, including to the brain where researchers have speculated that it might help contribute to dementia.
The results of this latest study only help to confirm the theory that the long-term effects of herpes on brain function are not fully understood, and that further study is needed.
A Growing Understanding
As part of the study, researchers at New York’s Columbia University College of Physicians and Surgeons used blood sampled from over 1,6000 senior adults with an average age of 69 to look for indicators of chronic infection with a few common pathogens including HSV-1 and HSV-2, the viruses responsible for oral and genital herpes, respectively; cytomegalovirus, a virus that’s part of the herpes family but usually doesn’t cause any symptoms; C pneumonia, a respiratory infection causing bacterium; and H. pylori, a bacterium that thrives in the stomach and can cause ulcers to develop.
On average, the more infections seniors suffered from, the poorer they performed on standardized tests that measured memory and thinking. These results were still found true even after researches considered additional factors that can affect a senior’s cognitive abilities, such as diabetes, heart disease, smoking, and level of education.
Researchers also determined that individuals who suffered from viral infections rather than bacterial infections seemed to suffer from greater mental decline. In total, 23 percent of individuals tested as part of the study showed signs of suffering from mental impairment at the beginning study, and the odds of impairment were 2.5 times higher among those who carried all three viruses researchers tested for – cytomegalovirus, and HSV 1 and 2- than in those who only carried one type of virus.
Infection by itself does not cover the entire story when it comes to linking dementia with herpes viruses. Most people, for example, carry at least one of the three virus types researchers tested for, with 80 percent of the U.S. population carrying cytomegalovirus by the age of 40. However, the vast majority of people don’t develop dementia. This suggests that researchers are just starting to uncover the role viruses play in the development of dementia.
Researchers at Columbia University have plans for future clinical testing that could provide further answers about the causes of dementia. However, if researchers can conclusively link viruses such as herpes to dementia and other mental impairments, this would add to the growing reasons why further progress needs to be made by in STD education and prevention.