Study Reveals Surprising Link Between Stress And Memory Loss

When we are in survival mode, optimal amounts of cortisol -- commonly known as the stress hormone -- can be life saving. But abnormally high or prolonged spikes in cortisol -- like what happens when we are constantly stewing over a problem -- can lead to serious health issues such as weight gain, digestive troubles and high blood pressure.

Now a new study out of the University of Iowa has discovered a possible link between stress hormones and short-term memory loss in older adults. The study, published in the Journal of Neuroscience, revealed that having elevated levels of cortisol -- a natural hormone produced by the adrenal glands -- can result in memory lapses as we grow older.

In this study, researchers linked high amounts of cortisol to the gradual loss of synapses in the prefrontal cortex, the region of the brain that houses short-term memory. Synapses are the connections that help us process, store and recall information. And when we get older, repeated and long-term exposure to cortisol can cause them to shrink and disappear.

"Stress hormones are one mechanism that we believe leads to weathering of the brain," Jason Radley, assistant professor in psychology, said in a press release. Like a rock on the shoreline, after years and years it will eventually break down and disappear.

While previous studies have shown cortisol to do the same in other regions of the aging brain, this was the first study to examine its impact on the pre-frontal cortex.

And although preliminary, the findings raise the possibility that a person's short-memory decline may be slowed or prevented by decreasing levels of cortisol, Radley added. That could mean treating people who have naturally high levels of cortisol -- such as those who are depressed or experiencing stress due to a traumatic event.

According to Radley and Rachel Anderson, the paper's lead author, short-term memory lapses related to cortisol start around age 65. That's about the equivalent of 21-month-old rats, which the pair studied to make their discovery.

Still, researchers say it's important to remember that stress hormones represent only one factor when it comes to mental decline and memory loss as we age.

For example, a study out of the University of California found that sleep deprivation is connected with brain degeneration and memory loss in older adults.

When it comes to middle-aged men, another study found that those who drink more than two and a half drinks per day are likely to show signs of memory loss and cognitive decline up to six years sooner than men who are light drinkers or who don't drink.