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[Katy Hall,Jan Diehm 日本語版：ガリレオ]
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A recent animal study conducted by Wake Forest University researchers showed that <a href="http://www.huffingtonpost.com/2013/01/28/stress-prostate-cancer-mice_n_2569256.html?1359412688">stress could help cancer cells survive</a> against anti-cancer drugs. The study, published in the Journal of Clinical Investigation, was done on mice induced to experience stress by being exposed to the scent of a predator. When experiencing this stress, an anti-cancer drug administered to the mice was <a href="http://www.huffingtonpost.com/2013/01/28/stress-prostate-cancer-mice_n_2569256.html?1359412688">less effective at killing cancer cells</a>, and the cancer cells were actually <em>kept</em> from dying because of the adrenaline produced by the mice, Everyday Health reported.
Even for healthy people, stressful moments can take a toll on the brain, a new study from Yale University suggests. Researchers reported in the journal Biological Psychiatry that stressful occasions -- like going through a divorce or being laid off -- can <a href="http://www.huffingtonpost.com/2012/01/10/extreme-stress-shrinks-brain-gray-matter_n_1197437.html">actually shrink the brain</a> by reducing gray matter in regions tied to emotion and physiological functions. This is important because these changes in brain gray matter could signal future psychiatric problems, researchers warned.
The extreme duress that a child experiences when exposed to violence early on could lead to <a href="http://healthland.time.com/2012/04/24/how-bullying-and-abuse-may-age-children-prematurely/">premature aging of his or her cells</a>, according to research in the journal Molecular Psychiatry. The study, which followed 236 children born in England and Wales between the ages of 5 and 10, showed that those who had been bullied, as well as those who were witnesses of violent acts or victims of violence by an adult, had shorter telomeres -- a sign that they <a href="http://healthland.time.com/2012/04/24/how-bullying-and-abuse-may-age-children-prematurely/">were aging faster</a>, TIME reported.
The <a href="http://www.newscientist.com/article/dn23109-stress-can-affect-future-generations-genes.html">effects of stress on a person's genes</a> may be passed on from generation to generation, according to a recent Science study -- suggesting stress's effects may not just take a toll on the person itself, but the person's progeny, too. New Scientist reported on the research, which was conducted in mouse germ cells (before they become eggs or sperm) by University of Cambridge researchers. They reported that certain markings to the genes, influenced by outside factors like stress, are generally thought to be erased in the next generation. But the new study shows that some of these markings to the genes <a href="http://www.newscientist.com/article/dn23109-stress-can-affect-future-generations-genes.html">still exist in the next generation</a>. "What we've found is a potential way things can get through, whereas before, everything was considered to be erased," study researcher Jamie Hackett told New Scientist.
A study in mice suggests stress could play a role in the <a href="http://healthland.time.com/2011/08/03/study-how-chronic-stress-can-lead-to-depression/">development of depression</a>. Researchers at the U.S. National Institute on Mental Health conducted several experiments on mice, where they noted how stress affected their behavior. They found that stress was linked with <a href="http://healthland.time.com/2011/08/03/study-how-chronic-stress-can-lead-to-depression/">depression-like behaviors</a>, such as giving up swimming in a plastic cylinder and lengthening the response time it took to eat food, TIME reported. "I think the findings fit well with the idea that <a href="http://healthland.time.com/2011/08/03/study-how-chronic-stress-can-lead-to-depression/">stress can cause depression</a> or that stressful situations can precipitate depression," study researcher Heather Cameron, chief of neuroplasticity at the NIMH, told TIME.
It's not just the stress, but <a href="http://www.huffingtonpost.com/2012/11/05/stress-reactions-health_n_2078919.html">how you react to it</a>, that could have an impact on your health down the road, according to a new study from Pennsylvania State University researchers. Published in the journal Annals of Behavioral Medicine, the study found that people who were more stressed out and anxious about the stresses of everyday life were, in turn, <a href="http://www.huffingtonpost.com/2012/11/05/stress-reactions-health_n_2078919.html">more likely to have chronic health conditions</a> (such as heart problems or arthritis) 10 years later, compared with people who viewed things through a more relaxed lens.
Stressed-out people may have a <a href="http://jnnp.bmj.com/content/83/11/1104">higher stroke risk</a> than their more mellowed-out peers, according to an observational study published in the Journal of Neurology, Neurosurgery and Psychiatry. "Compared with healthy age-matched individuals, <a href="http://jnnp.bmj.com/content/83/11/1104">stressful habits</a> and type A behavior are associated with high risk of stroke. This association is not modified by gender," the researchers, from the Hospital Clinico Universitario San Carlos in Madrid, wrote in the study.
Feeling anxious and stressed is linked with a 27 percent <a href="http://www.nydailynews.com/life-style/health/chronic-stress-equals-smoking-cigarettes-day-study-article-1.1224293">higher risk of heart attack</a> -- the same effect smoking five cigarettes a day has on the heart, the New York Daily News reported. "These findings are significant because they are applicable to nearly everyone," study researcher Safiya Richardson, of Columbia University Medical Center, told the Daily News. "The key takeaway is that how people feel is important for their heart health, so anything <a href="http://www.nydailynews.com/life-style/health/chronic-stress-equals-smoking-cigarettes-day-study-article-1.1224293">they can do to reduce stress</a> may improve their heart health in the future." And not only could chronic stress raise a person's heart attack risk, but it might also affect how well he or she <a href="http://www.nbcnews.com/id/49304726/ns/health-heart_health/t/chronic-stress-tied-worse-heart-attack-prognosis/#.UQwcWFqOjKo">survives after a heart attack</a>. Reuters reported on another study, conducted by researchers at St. Luke's Mid America Heart Institute, that showed that stress is linked with a 42 percent higher risk of dying in the two years after being hospitalized for a heart attack.
If you always suspected that <a href="http://abcnews.go.com/Health/ColdandFluNews/chronic-stress-feeds-common-cold-study-finds/story?id=16054304">stress was making you sick</a>, you might be on to something. Research shows that stress has an impact on our immune systems, with one recent study in the Proceedings of the National Academy of Sciences even showing it can make colds worse. That's because when you are stressed, your body produces more cortisol, which can then wreak havoc on your <a href="http://abcnews.go.com/Health/ColdandFluNews/chronic-stress-feeds-common-cold-study-finds/story?id=16054304">body's inflammatory processes</a>. The researcher of the study, Carnegie Mellon University's Sheldon Cohen, explained to ABC News: <blockquote>"You have people whose immune cells are not responding to cortisol and, at the same time, they're exposed to a virus system creating an inflammatory response. But the body doesn't have the mechanism that allows it to turn off the inflammatory response, which manifests as cold symptoms," said Cohen.</blockquote>
Cancer -- the diagnosis, treatment, and even the time after it's been "beaten" -- is a stressful process, and research shows that managing that stress could improve outcomes of the disease. Researchers at the University of Miami found that undergoing a Cognitive-Behavioral Stress Management program seemed to have a positive effect on <a href="http://www.miami.edu/index.php/news/releases/stress_management_improves_breast_cancer_outcomes/">breast cancer patients' immune system cells</a>. "For the women in the CBSM groups, there was better psychological adaptation to the whole process of going through treatment for breast cancer and there were physiological changes that indicated that the <a href="http://www.miami.edu/index.php/news/releases/stress_management_improves_breast_cancer_outcomes/">women were recovering better</a>," study researcher Michael H. Antoni, a professor of psychology and psychiatry and behavioral sciences at the university, as well as program leader of biobehavioral oncology at the Sylvester Comprehensive Cancer Center, said in a statement. "The results suggest that the stress management intervention mitigates the influence of the stress of cancer treatment and promotes recovery over the first year."
In this video, we discuss how does stress impact your health