While short term memory lapses in older adults are commonly attributed simply to advanced age, research shows that it does not have to be this way. In fact, chronic stress may have a lot to do with it.
A new study performed at the University of Iowa has linked chronically high levels of cortisol (the ‘stress hormone’) to impaired short term memory in older individuals. The study found that having high levels of cortisol over the long term actually shrinks synapses (the connectors which aid in recalling information) in the prefrontal cortex, the part of the brain that governs short term memory.
For their experiment, researchers analyzed the ability of rats, both young and old, and with either low or high measured cortisol levels, to escape a ‘T-shaped’ maze which relied on their short term memory to recall turns that they had just taken. While the younger rats completed the maze similarly regardless of their cortisol levels, the older rats with high cortisol only identified the right way out of the maze 58 percent of the time.
However, the older rats with low cortisol levels remembered the correct direction to go about 80 percent of the time, almost as well as the younger rats. This result is quite encouraging, indicating that older individuals may be able to retain short term memory by mitigating stress throughout their lives.
When researchers sampled the brain tissue of the rats, they found that the older rats with high cortisol levels had 20 less synapses in the prefrontal cortex than the other groups. On the results of the study, Jason Radley, an assistant professor in psychology and corresponding author on the study, wrote, “stress hormones are one mechanism that we believe leads to weathering of the brain.”
Chronic stress, also known as long-term stress, has been associated with many other negative health effects. It can cause systemic inflammation which paves the way for many illnesses, including high blood pressure and heart disease. It is also linked to weight gain, digestive disturbances, compromised immune system function, high blood sugar and belly fat.
Also, stress can affect sleep quality and duration. Since insufficient sleep can in turn spike cortisol, sleeplessness and stress may become a perpetual cycle.
Our natural stress responses are key to our survival as a species and help us in emergency situations. On a short term basis, elevated cortisol contributes to us acting quickly and efficiently to deal with the urgent situation at hand. When cortisol does not go back down, however, detrimental effects begin.
This study provides one more reason to keep our stress in check on a regular basis, starting as early in life as possible. While many of us lead stressful lives, taking the time to unwind is essential. Aerobic exercise, deep breathing and meditation are all time-tested methods. It may also do you worlds of good to take a day of the week (or a few hours at least) for yourself to do something you really enjoy with no disruptions.
Even if you think you don’t have the time, some creative scheduling can help you make the time. Your memory – and overall health – will be all the better for it.
-The Alternative Daily