Common Infections Explain Fading Memory and Slower Brain

Common infections may slow brain function later in life, according to a new study.

The study, which was presented at the American Stoke Association meeting in San Diego yesterday, claims that exposure to common bacterial and viral infections may play a role in cognitive decline as we age.

According to the researchers, the infection doesn't even necessarily have to make you ill. Some of the infections seen to have an impact on memory and brain functions include c. pneumonia, which leads to bronchitis and pneumonia, as well as herpes simplex viruses 1 and 2, which lead to common cold sores, and helicobacter pylori, which leads to stomach ulcers.  All three of these illnesses can infect people without causing them to feel sick.

During the study, researchers took blood samples from 588 people and closely analyzed each participant's medical history. These participants were asked to take several tests which measured memory and brain function. Five years later, half the participants came back -- the average age being 71 years old -- for more blood and cognitive testing.

What researchers found was that increased antibodies in the blood, or signs of an increased number of infections fought off, were associated with a drop in mental performance.

The researchers also noted that they took average mental decline due to aging factors into account, saying that study participants of same age and mental capacity on initial testing often varied in cognitive ability five years later due to differing antibody counts.

So what does this really mean? While it explains why, as we age, some of us slip away faster, the study doesn't really offer any solutions. All we can do, the researchers said during their presentation, is try to stay healthy.

Because the study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal. It should also be noted that the study did not establish a cause-and-effect relationship, but only presented evidence of numerical correlations.

An abstract of the presentation can be found published online through the American Heart Association.