戴玉强为什么转业:性交促进健康，还是健康促使性交（图）

一些小的研究表明，性交就像维他命D和花椰菜一样对人的健康有益。性交不仅能够减少压力、增进睡眠、消耗卡路里，而且还能够减轻疼痛、缓解抑郁 、强化血管、增强免疫系统和减少前列腺癌和乳腺癌的风险。

But many of those studies rely on people to remember and report their sexual activity honestly and many can't distinguish between cause and effect. That is, does sex make people healthier or do healthier people have more sex?

但是，许多这方面的研究主要依靠人们去回忆，然后真是的诉说他们的性生活实现的。很多人根本就分不清其中的因果关系。也就是搞不清楚到底是性交促进健康，还是健康促使性交。

More research is needed to evaluate all these claims. "If I told you we have randomized double-blind placebo-controlled multi-center trials on these questions, there is no such a thing," says Irwin Goldstein, a urologist and editor in chief of the Journal of Sexual Medicine. The biggest obstacle is lack of funding, he says. "If 'sex' is in your grant proposal, it's very hard to get it approved."

需要进一步调查研究来验证这些观点。埃尔文·戈登斯坦是一名泌尿科医生，同时也是《性医药》杂志的总主编，他说“我们曾经随机进行了一个用安慰剂控制的多中心的双盲实验，结果表明根本就不存在这回事。”“我们面临的最大困难是资金不足。如果性交就是你们所认为的那些观点，那么是很难让人信服的。

Still, a look at what researchers do know about the physiology of sex shows that at least a few health benefits may come along with that roll in the hay.

 调查人员对性生理学的研究表明至少上面所说的众多益处中还是有几个是正确的。

 

Stress relief: The rush of hormones boosts mood, fosters feelings of closeness and helps manage stress for days

减少压力：荷尔蒙的大量分泌能够改善心情，增强彼此间的亲密感，能够在好几天帮你缓解压力。

 

Weight: Sex burns about five calories per minute, meaning it would take roughly 12 hours to lose a pound                                                                                                    

体重：性交过程中，每分钟大概消耗5个卡路里。也就意味着大约12小时的性交能够减少一斤的体重。

Better Sleep: After exertion, oxytocin and prolactin bring on satiation and sleep—especially in men

良好的睡眠：消耗体力过后，后叶催产素（脑下垂体后叶荷尔蒙的一种）和催乳激素给人一种满足感、催人入睡——尤其对于男人。

Longevity: More sex means longer lives for men; women live longer when they are sexually satisfied                                                                                                            

长寿：多进行性交对于男性意味着长寿。当女性在性生活上得到满足，也会长寿。

Heart health: Sex raises heart rates about as much as climbing two flights of stairs         

良好的心脏：性交和爬两层楼增加的心率相当。

Some benefits of sex—beyond producing a baby, that is—are obvious even without scientific evidence. "When you have good sex, there's a relaxation response and a satiation response…you lie there and life is great," says Dr. Goldstein, who is also the director of sexual medicine at Alvarado Hospital in San Diego, Calif.

除了能够繁衍后代这一益处外，性交的其他益处很明显，尽管没有科学方面的证据来证明这些益处。“当你尽情享受性交的时候，你会感到非常放松、满足---你躺在那里，感觉生活是那么美好”，身兼也是加利福尼亚州圣·迭戈阿尔瓦拉多医院性医药主管的戈登斯坦医生说。

Much of that is due to chemistry—the rush of hormones and neurotransmitters that rise and fall during sexual activity. Arousal boosts dopamine, which activates the brain's centers of craving and reward "just like chocolate and winning at gambling," says Erick Janssen, a senior scientist at the Kinsey Institute at Indiana University.

“这种现象是由于化学因素引起的——性交过程中荷尔蒙的分泌和神经传传递素的增减。”这些化学反应促进多巴胺的产生。多巴胺就像是巧克力和赌博赢钱时那样，可以激活大脑的渴望和回报中心。”印第安纳大学金赛研究中心的高级科学家艾瑞克·乔因森说。

Sex also increases oxytocin, known as the "cuddle hormone," which promotes bonding, reduces fear and stimulates endorphins, the body's natural painkillers, which is why sex can bring temporary relief from back pain, migraines and other body aches.

性交也可以促进一种被称为 “温馨荷尔蒙”的催生素的分泌。这种催生素有助于改善人际关系、减少恐惧，促进内啡呐（体内产生的一种有镇痛作用的荷尔蒙）的产生。内啡呐是人体天然的镇痛良药。这也是性交能够暂时减轻背部疼痛、偏头痛和其他身体疼痛的原因

Dopamine levels plummet after orgasm, and levels of prolactin rise, bringing on feelings of satisfaction and sleepiness, particularly in men. "That's the nice, relaxed feeling afterwards," says Stuart Brody, a psychologist at the University of the West of Scotland who has conducted numerous studies on sex and health. Of course, timing isn't always perfect. In a 2006 survey of 10,000 British men, 48% admitted to having fallen asleep during sex.

性高潮过后，人体多巴胺的含量迅速减少，催乳激素含量开始上升，给人带来一种满足感，催人入睡，尤其对于男性。“然后便是一种美好、轻松的感觉” 西英格兰大学一位在性和健康方面做了很多研究的生理学家斯都阿特·布兰迪说。当然，时机尚未成熟。2006年一项对一万名英国男性的调查显示，48%的人承认在做爱的过程中曾经睡着过。

All together, this chemical cascade has a lasting effect that helps people handle stress, which Dr. Brody showed in a study in the journal Biological Psychology in 2005. He had 24 women and 22 men keep diaries of their sexual activities for two weeks, then took their blood pressure while they were told to give an impromptu speech to a hostile audience and do rapid math calculations in their heads. Those who had had traditional sexual intercourse during the fortnight had smaller blood pressure spikes and recovered more quickly than those who engaged in other forms of sex or none at all.

 总而言之，2005年布兰迪医生在《生物生理学》杂志上的一个研究表明，这种化学反应在很长的一段时间内能有效的帮助人们处理好压力。他让24位女性和22位男性对两周内的性生活进行记录，然后让他们对着一些态度很差的听众进行即兴演讲和快速心算算数的情况下测量他们的血压。那些在过去两两周内进行传统性交的人要比那些采用多种方式或者不进行性交的人的血压要低，而且血压恢复的特别快。

Sex is also touted as good exercise—but the effect is actually modest. Although couples obviously differ, sex generally burns an estimated five calories per minute, or roughly 50 to 150 calories total. Calculated another way, orgasm uses 3 to 4 METs (metabolic equivalent tasks, a measure of physical intensity)—the equivalent of light housekeeping.

性交被吹捧为一种有效的锻炼方式，但是实际上效果并不明显。尽管男女在消耗能量方面有明显的差异，性交一般每分钟消耗5个卡路里或者总共消耗50-150个卡路里。用另一种计算方法，性高潮时大概使用3-4METS（MET表示新陈代谢等量任务，是测量体能强度的一种方法）----和干轻家务活所消耗的能量差不多

Sex does increase heart rate and blood pressure—as high as 125 beats per minute and to 160 peak systolic rate—about as much as walking up a flight or two of stairs. And several studies suggest that having it regularly can protect against cardiovascular problems. One British study found that men who reported having three or more orgasms per week experienced 50% fewer heart attacks than those who engaged less frequently—perhaps because orgasm triggers the release of the hormone DHEA (dehydroepiandrosterone), which helps with circulation and arterial dilation.

 性交确实起到增加心率、升高血压的作用-----一次性交能使心跳可达到最高每分钟125次，心脏收缩率最高可达160次。大致相当于登上一家飞机或两层楼所达到的效果。一些研究表明经常性交能够预防心血管疾病。英国的一项调查显示那些一周能有3次或者更多性高潮的男性要比那些性高潮较少的男性的心血管疾病发病率少50%。可能是因为性高潮可以促进一种叫DEHA的荷尔蒙的分泌，这种荷尔蒙有助于循环和动脉扩张。

On the other hand, erectile dysfunction can be an early indicator of cardiovascular problems—and when drugs such as Viagra first came on the market, some cardiologists feared sex could be dangerous to men with underlying heart problems. In general, such fears have proven unfounded. Cases of sudden death during sex are actually very rare, according to studies in Germany, Japan and Korea. But they are more likely to occur during extramarital sex.

另一方面，阴茎勃起障碍是心血管疾病的前兆。当像伟哥这样的药品进入刚进入市场时，一些心脏病学家担心一些有潜在心脏病的男性在性交的时候存在危险。总的来说，这些忧虑是不必要的。根据德国、日本、韩国的一些研究，性猝死的案例非常少。但是在婚外性交过程中易发生。

Frequent sex may benefit men's health another way: by boosting testosterone, which in turn is linked to stronger muscles, more energy and better cognition. (Sex's effect on testosterone was shown in a now-famous article in Nature in 1970. A man stranded on a remote island with no women saw his beard stop growing. Then it resumed when he returned to civilization and sex again.)

 频繁性交可以以另一种方式促进男性健康：那就是促进睾丸素的分泌来 增强肌肉、增加能量、提高认知。（性生活对于睾丸素的影响可见于1970年《自然》杂志上的至今仍然很出名的文章，文章的主要内容介绍一个男人被困在一个没有女人的偏远的岛屿上，他的胡子停止生长。当他重返人类文明，进行性生活过后，胡子又开始重新生长。）

Sex also improves women's moods—although how it does is controversial. One 2002 study of 293 college women at the State University of New York in Albany found that those who engaged in unprotected sex were less likely to be depressed than those whose partners use condoms or who don't have sex at all. The researchers noted that semen contains testosterone, estrogen, prolactin and prostaglandins, which can pass through vaginal walls into the bloodstream and elevate mood. But safe-sex groups add that the unintended results of unprotected sex—pregnancy and sexually transmitted diseases—can put quite a damper on mood.

 性交也有助于女性改善心情——尽管性交是怎样改善女性心情仍饱受争议。2002年一项对奥尔巴尼纽约州立大学的293位在校女学生的调查显示，在性交中男性伴侣使用安全套和没进行过性交的女性要比那些不采取任何措施进行性交的人更容易心情低落。研究人员注意到含有睾丸素、雌激素和催乳激素和前列腺激素的精液可以经女性阴道壁进入血管，从而改善女性心情。安全性交群体补充道，没有采取任何措施而怀孕或染了性疾病很让人扫兴。

Some of the most intriguing findings suggest that frequent sex can lower the risk of some types of cancer. A 2004 study of 29,000 male health professionals in the Journal of the American Medical Association found that those who reported having the most frequent ejaculations—21 or more a month—had a much lower risk of prostate cancer than those reporting four to seven per month.

Emptying the tank every once in awhile is probably good for the prostate," Dr. Goldstein says. Still, the authors noted that the data "may have contained some inaccuracy" since it asked men, some in their 80s, to recall how often they ejaculated each month four decades earlier.

一些很有趣的研究表明，经常进行性交可以减少患上某种类型癌症的风险。2004年，美国医药协会对29000名男性健康专家的调查显示，那些经常射精的人（每月21次甚至更多的人）要比那些每月只射精3-4次的人患上前列腺癌的风险要小的多"