Reducing stress can decrease short-term memory loss
Everyone knows that stress is bad for you. It has been linked to anxiety attacks, heart problems, digestion issues and psychological disorders. Now, researchers in the US say that stress can also escalate short-term memory loss in older individuals.
Researchers from the University of Iowa say they’ve found a link between high levels of cortisol – the stress hormone – and short-term memory loss.
“Stress hormones are one mechanism that we believe leads to weathering of the brain. Like a rock on the shoreline, after years and years, it will eventually break down and disappear,” said Jason Radley, assistant professor in psychology at UI and study author. The study was published in the Journal of Neuroscience1.
From where you put your glasses to the name of the neighbor from three doors down – everyone forgets things at times. There is a difference between age-related memory loss and short- and long-term memory problems.
As we get older, we forget more easily. Sometimes making a list can help. Other times, we just need a little reminder. As long as these changes in memory do not disrupt our ability to maintain an independent lifestyle, there is nothing to worry about.
When short-term memory loss becomes a part of our lives, knowing why it is happening, how to halt it and ways to address it is vital.
To figure out if their hypothesis was correct that stress may cause short-term memory loss, Radley’s team of researchers put rats of different ages in a T-shaped maze and tested the rodents’ short-term memory by hiding a treat for them to find. The rats had to remember which direction they had turned at the top of the T and were given 30-, 60- or 120-second intervals between turns.
The researchers used rats of different ages in this experiment. One study group included 21-month-old rats. They say that’s the rodent equivalent to 65-year-old humans. And, they say, 65 is the age that short-term memory lapses related to cortisol begin in healthy people.
The study also included 4-month-old rats – the equivalent to a 20-year-old person.
The rat groups were further separated into those with naturally high or naturally low levels of corticosterone, which is the hormone equivalent of cortisol in humans.
The results showed that memory declined across all groups as the time rats waited before running the maze again increased. But the older rats with high corticosterone levels consistently performed the worst. The older rats with high stress hormone levels chose the correct direction only 58% of the time while the older rats with low stress levels, chose it 80% of the time.
The researchers also took tissue samples from the rats’ prefrontal cortexes and found that the rodents who performed poorly had smaller and 20% fewer synapses, compared with all other groups. Synapses are the connections in the brain that help us process, store and remember information. When they shrink and disappear, it indicates memory loss.
Of course, this is not the first study to show cortisol’s effects in the aging brain. But this study examines its impact on the prefrontal cortex.
The important findings help researchers look to the future to find preventative treatments and try to halt memory loss.
Radley says that the research suggests there is a possibility that short-term memory decline in older adults could be slowed or prevented via treatments that decrease cortisol levels.
The researchers also explain that stress hormones are only one of a host of factors that cause mental decline and memory loss as we age.
How to keep stress out of your life:
• Eat healthy, well-balanced meals
• Exercise regularly
• Get plenty of rest
• Take a break
• Share your feelings
• Avoid drugs and alcohol