By Karen Ravn, Special to the Los Angeles Times
May 30, 2011
If you answered no, hooray for you! (And, by the way, what planet are you from?)
But if you answered yes (like any normal member of the human race), you're likely heartened by the arrival of vacation season. Just the ticket for a little stress-reduction.
And that can have some big payoffs. It can lower your blood pressure, boost your immune system and help you live longer. It may even make you smarter.
"A vacation is not a luxury," says Jens Pruessner, an associate professor in the departments of psychology, psychiatry, neurology and neurosurgery at McGill University in Montreal. "It's an investment in your health."
Most of what scientists know about the brain and chronic stress comes from studies of rodents, whose response systems are very much like ours (perhaps disconcertingly so) and who therefore make good stand-ins for us. But rodents rarely pack their bags and head for the beach when summer rolls around, so it's harder to use them as models for vacationers.
Nonetheless, researchers have learned enough to make some useful suggestions:
A vacation is a chance to get away from many of the stresses you can't get away from in your everyday life (your boss, your commute, the chaos that is your home). Of course, it can also introduce new ones. But while some of these may be out of your control — bad directions, missed connections, loud neighbors in hotels with thin walls — planning ahead can forestall others. If it's stressful for you to be around your in-laws, don't arrange a monthlong camping trip with them. If you're afraid of airplanes, pick a destination you can drive to instead — and don't get talked into skydiving lessons. If you suffer from separation anxiety, don't go anywhere Spot can't go too.
Making your vacation as stress-free as possible pays off, according to a 2010 study in the Netherlands. When researchers looked at how happy people were after taking vacations, only those who felt very relaxed while they were away were happier than people who hadn't taken a trip at all.
But the same study found that people who were busy planning a vacation were happier than those who had no vacation to plan — so even when a vacation turned out to be a dud, the time spent planning it may have made it all worthwhile.
One caveat: For some people, going on vacation may be more stressful than not going — perhaps because of money concerns or because they're just not comfortable being away from home or from work. In such cases, it may be that no amount of planning can make a vacation a good idea.
Make sure it's fun
This is not exactly shocking news, but it is nice to know for a scientific fact that fun is good for you (and your brain). A study published last year in the Proceedings of the National Academy of Sciences found exactly that. In rats, anyway.
"It doesn't get rid of stress, just lowers it, across all aspects of the hormonal system," says study co-author James Herman, director of the Laboratory of Stress Neurobiology and professor of psychiatry and behavioral neuroscience at the University of Cincinnati.
Rats in the study had access to a sugar solution twice a day for two weeks. Then researchers tested their responses to stress by placing them in tubes that restricted their movements. Compared with controls, the rats who had had access to sugar had lower heart rates and levels of stress hormones. Other rats who received a saccharin-sweetened solution also had reduced stress responses, but rats who had sugar delivered directly to their stomachs did not. Researchers inferred that it was the pleasurable taste, not the calories in the solution, that produced the effect.
To confirm the pleasurability hypothesis — and to show that it held for more than just taste — other rats were allowed daily visits with "pliant females" for two weeks, Herman says, and they too showed the same stress reductions.
To travel or not?
Even if you love to travel, at times the hairy logistics can present you with plenty of opportunities to blow your cool. On the other hand, a situation is only stressful if you perceive it to be. "A lot depends on your appraisal of the evidence," says Carlos Grijalva, a professor of psychology and behavioral neuroscience at UCLA. "How you evaluate the situation is critical."
True, it's hard to put a positive spin on the situation if you're standing at the end of a mile-long line and your flight is due to take off in five minutes. But it may be possible to perceive an irritating seat mate as a chance to hone your social skills or lost luggage as an excuse to spiff up your wardrobe.
The post-vacation brain
Some studies with rats have shown that stress can actually shrink parts of their brains, and a 2009 study in the Proceedings of the National Academy of Sciences found that it probably shrinks your brain too.
But not to panic!
The rat studies found that three weeks of restraint-induced stress led to shrinkage of tree-like projections called dendrites in a part of the brain called the medial prefrontal cortex — and impaired performance on an attention task. Importantly, though, these chronic stress effects disappeared once the rats had been stress-free for four weeks.
In the parallel human study, medical students who'd spent a month preparing for stage one of the medical board exam were tested on an attention-shifting task as close to the day of their medical exam as possible. Then they were tested again a month after the test, when their sources of stress were way down.
They too performed relatively poorly the first time they did the task, when they were badly stressed, and much better — just as well as a control group — after an essentially stress-free month.
The researchers could not, of course, get direct evidence that there was dendrite shrinkage in the med students that was subsequently reversed. But they inferred that this happened, since the results of every other aspect of the studies were so parallel, says study lead author Dr. Conor Liston, a research fellow in the department of psychology at Weill Cornell Medical College in New York.
How long a vacation?
"How long it takes you to relax after a stressful period of time depends on how quickly you can reset your perspective on life," says George Slavich, an assistant professor at the UCLA Cousins Center for Psychoneuroimmunology. "Taking a relaxing trip to Hawaii can help, but it's not necessary, nor is it always sufficient. No tropical vacation can help if the stress is mostly in your head."
On the other hand, Pruessner says, when you're on vacation, you probably have more time than usual for self-reflective thought, which could help you recognize that your stress is mostly in your head — and maybe even work on getting it out of there.
In the medical student study, a month was enough to make stress-impaired brains get their groove back. But wait! Don't snort. Sure, a month off is inconceivable. But it's possible that less time could do the trick too.
Pruessner once did a simple experiment with a group that had come for a two-week meditation-and-yoga retreat at a hotel in Canada. He measured blood levels of the stress hormone, cortisol, twice: at the beginning of their stay and again at the end.
At the beginning, the group could be divided into three sets: those with normal cortisol levels, those with higher than normal levels and those with lower than normal levels. Pruessner inferred that the first set was not particularly stressed, the second set was somewhat stressed and the third was even more stressed. (Scientists believe that when stress gets really, really bad, the body's cortisol response can sometimes stop working.)
At the end of the two weeks, those in the first set still had normal cortisol levels; those in the second set had lower levels than before, implying that they had become less stressed; and those in the third set showed no change, implying that their blunted response systems had not improved.
Pruessner's interpretation? Two weeks of rest and meditation and yoga were enough to help those who were somewhat stressed but not enough to help those who were more stressed than that.
"Ideally, you don't want to wait too long to take a vacation," he says. "You don't want to get to that third stage."
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