Don't worry, be happy and, according to new research, you will also be healthy.

    It is estimated that over the course of one year, Americans suffer 1 billion colds. But new research shows that all it may take to avoid this common affliction is a positive and upbeat attitude.

    People who are energetic, happy and relaxed are less likely to catch a cold than those who are depressed, nervous or angry, finds a new study published in the journal Psychosomatic Medicine.

    Healthy volunteers first underwent an emotional assessment in which they were asked to rate their tendency to experience positive and negative emotions - how often they felt pleased, relaxed, happy, or anxious, depressed and hostile. The subjects were next given a squirt up the nose of a rhinovirus, the nasty little germ that causes colds.

    Researchers then watched the volunteers to see who came down with a cold and waited to see how the unlucky ill manifested their cold symptoms.

    "We found that people who regularly experience positive emotions, when exposed to rhinovirus, are relatively protected from developing illness," said Dr. Sheldon Cohen, lead author of the study and a psychology professor at Carnegie Mellon University.

    Although positive people showed a greater resistance to colds, negative people did not necessarily get sick more often.

    "Increases in positive emotional styles were linked with decreases in the rate of clinical colds, but a negative emotional style had no effect on whether or not people got sick," Cohen said.

    So how can your emotions influence your health? In simple terms, when the brain is "happy" it sends messages to our organs that help keep the body healthy and sound.

    "It's like a drug that is released by your state of mind and simply changing the state of mind can produce effects on the rest of the body through the nervous system and hormones," said Dr. Neil Shulman, associate professor of medicine at Emory University School of Medicine and author of Doc Hollywood. "Your chance of developing the common cold, pneumonia, or even cancer may very well be decreased by keeping your brain in a healthy state."

    In addition, happy and relaxed people are prone to better health practices than their negative and stressed counterparts. They are more likely to get plenty of sleep and to engage in regular exercise, and have been shown to have lower levels of certain stress hormones.

    Shulman says the study shows there are some simple things you can do to improve your chances of staying healthy.

    "The take-home message is that we have very healthy ways that we can improve our overall well-being that don't cost money and that don't require a wait in the doctor's office," he said.

    根據新的研究結果顯示，如果你心情愉快、無憂無慮，你就會身體健康。

    據估計，美國一年中有十億人患感冒。而新的研究表明只要有積極樂觀的態度，就可以避免這一常見的疾病。

    《心理醫學》雜志發表的一項新的研究表明：精力充沛、快樂輕松的人和沮喪、緊張、易怒的人相比不容易得感冒。

    身體健康的志愿者們首先接受了一次情緒測試，來測定他們的情緒是趨向于積極的還是消極的，也就是他們感到高興、舒適、快樂或是焦慮、沮喪、敵對的頻率。接著志愿者的鼻子上方被噴射一種能夠引起感冒的可惡的微小細菌-----鼻病毒。

    然后研究者們觀察那些志愿者，看誰先感染上感冒，并等著看那些不幸患病的人表現何種感冒癥狀。

    該研究的主要領導者、卡內基梅隆大學的心理學教授謝爾登·科恩博士說："我們發現情緒一貫積極樂觀的人遭受鼻病毒侵襲時，相對來說不太容易感染疾病。"

    盡管積極的人對感冒表現出較強的抵抗力，消極的人也不一定更容易經常感冒。

    "情緒越樂觀，感冒的幾率就越低，但是消極的情緒并不會對是否感冒產生影響。"科恩說。

    那么情緒到底是怎樣影響你的健康的呢？簡單的說，當大腦"輕松愉快"的時候，它會向各個器官發出有助于保持身體健康的信號。

    "這就像是你的情緒釋放的一種麻醉劑，只要改變情緒就可以通過神經系統和激素對身體的其他部分產生影響，" 埃莫里大學醫學院的醫學副教授、影片《好萊塢醫生》的作者尼爾·舒爾曼博士說，"保持健康的情緒可以有效地降低感冒、肺炎甚至癌癥發生的可能性。"

    另外，心情輕松愉快的人往往比消極緊張的人有更好的保健習慣。他們更容易有充足的睡眠，進行有規律的身體鍛煉，而且他們體內某種緊張激素的含量較低。

    舒爾曼說研究顯示你可以通過做一些簡單的事情來保持身體健康。

    他說："我們的建議是通過健康的方法來改善整個健康狀況，這不需要花錢也不需要在醫生的辦公室前等待。"