九乡新闻网辛金生于戌月的八字:“性”福生活 有益健康
来源：百度文库 编辑：九乡新闻网 时间：2024/07/14 05:55:51
爱对你的健康有好处吗——抑或这只是一种空想？
一系列小规模的研究显示，性爱带来的健康益处就像是维生素D和花椰菜给身体带来的好处。它不仅可以缓解压力、改善睡眠、燃烧卡路里，还能减轻疼痛、舒缓沮丧情绪、增强血管弹性、提高免疫系统功能、降低罹患前列腺癌和乳腺癌的风险。
Ray Bartkus缓解压力：迅速上升的激素水平提振情绪，促进亲近感，帮助控制数天的压力。
Ray Bartkus体重：性行为能够每分钟燃烧掉5卡路里热量，这表示在大约12小时内即可减掉一磅。
Ray Bartkus心脏健康：性行为能够使心率提高到相当于爬两段楼梯的水平。
Ray Bartkus改善睡眠：劳累过后，催产素和催乳素带来饱食感和睡意－－尤其是对于男性而言。
Ray Bartkus延年益寿：更多的性行为对男性意味着寿命更长；女性获得性满足能长寿。然而这些研究中有许多都有赖于被研究者回忆并坦诚地讲述他们的性行为，而很多人无法区分因果，也就是说，究竟是性爱让人们变得更健康还是更健康的人会有更多的“嘿咻”行为？
要评估这些论断还需要进行更多的研究。《性医学杂志》(Journal of SexualMedicine)的主编、加州圣地牙哥阿尔瓦拉多医院(Alvarado Hospital)性医学部门主任、泌尿科医生戈尔茨坦(IrwinGoldstein)说，如果我跟你说我们已经对这些问题进行了随机双盲对照多中心试验，这是在骗人。他说，最大的阻碍在于研究资金的缺乏，如果在你的基金申请计划书中出现了“性爱”一词，它就很难获得批准了。
尽管如此，通过了解研究者已经掌握的性爱生理学知识可以知道，性爱让人享受鱼水之欢的同时至少可以带来一些健康益处。
即便没有科学依据，性爱所带来的一些好处——当然，除了能“造人”之外——也是显而易见的。戈尔茨坦说，当你享受了一次愉快的性生活后，你会体会到一种松弛和满足……你躺在那儿，感觉生活真美好。
这种感觉在很大程度上是由于身体内的化学反应造成的——“嘿咻”过程中会有大量荷尔蒙和神经递质迅速增加和减少。这种“觉醒”刺激了多巴胺的分泌，而多巴胺又启动了大脑的渴求中枢和奖赏中枢，印第安那大学(Indiana University)金赛研究所(KinseyInstitute)的资深科学家詹森(Erick Janssen)说，这种刺激作用就好像是吃巧克力或是赌赢了钱所产生的效果。
性爱还会提高催产素的水平，这种被称为“拥抱荷尔蒙”的物质能让人与人之间的关系变得亲密，还能减轻恐惧情绪，并刺激内啡肽这一人体天然止痛药的产生，这也是为什么性爱可以让背痛、偏头痛和其他身体疼痛得到暂时性缓解的原因。
性高潮过后，多巴胺水平迅速下降，催乳素水平上升，使人在产生满足感的同时也有了困意，这种现象在男人身上尤其明显。对性与健康的关系进行过大量研究的西苏格兰大学(University of the West of Scotland)心理学家布罗迪(StuartBrody)说，这是性爱过后愉悦而放松的感觉。当然，时间节点的掌握并不总是那么完美。在2006年一项对一万名英国男子的调查中，有48%的人承认他们在“嘿咻”的过程中就已经睡着了。
所有这些一连串的化学变化能产生一种持续性效果，帮助人们缓解压力，对此布罗迪在2005年发表于《生物心理学》(BiologicalPsychology)期刊的一项研究中有过阐述。他先是让24名女子和22名男子记录下他们在两个星期中的性行为，然后要求他们面对一群不友好的听众发表即兴演讲并进行数学题的快速心算，此时布罗迪测量了他们的血压。相比那些在前两周中有过其他形式性行为或是根本没有性行为的人，那些在此期间有过传统性行为的人在出现血压突然升高的情况时，血压升高幅度更小而且恢复得更快。
性爱还号称具有良好的锻炼效果——但实际上效果并不太大。虽然每一对夫妻都各不相同，但通常来说人们在“嘿咻”时每分钟估计会消耗掉五卡路里的热量，也就是总共燃烧掉50至150卡路里左右。换一种计算方式，性高潮需要三至四个单位的能量代谢当量（一种衡量体力劳动强度的指标）——相当于干了少量家务活。
性生活的确可以使心率加快、血压升高——每分钟心跳可高达125次，收缩压峰值可高达160——大致相当于爬一、两段楼梯的效果。数项研究显示，规律的性生活有助于预防心血管疾病。英国的一项研究发现，那些报告每周有三次或者更多次性高潮的男子发生心脏病的次数要比性生活相对不那么频繁的人少50%——这也许是因为性高潮刺激了脱氢表雄酮的产生，这种荷尔蒙有助于改善血液回圈和动脉扩张。
另一方面，勃起功能障碍也许是心血管疾病的早期征兆——当诸如“伟哥”(Viagra)这样的药物最初进入市场时，一些心脏病学家担心性生活可能会给男性潜在心脏病患者带来危险。总体来看，这种担忧已被证明是没有依据的。根据德国、日本以及韩国的研究，在性生活中发生猝死的情况实际上是极为罕见的。但这种情况在婚外性行为的过程中发生的可能性则要大一些。
规律的性生活或许还能从另一个方面有助于男性健康：刺激睾丸激素的分泌，这种激素反过来又能强健肌肉、增强男性活力、改善认知能力。（性生活对于睾丸激素的影响在1970年刊登于《自然》(Nature)杂志的一篇文章中得到了说明，这篇文章如今已是蜚声世界。一名男子被困在了一座没有女人存在的遥远岛屿上，后来他的胡子停止了生长。当他回到文明世界、再度过上性生活时，胡子重新开始生长。）
性爱还能改善女性的情绪——不过对于它究竟是如何产生这种效果的，人们说法不一。2002年对纽约州立大学奥尔巴尼分校(State University of New York in Albany)293名大学女生进行的研究发现，拥有性生活并且不采取保护措施的女性出现抑郁的可能性要小于其性伙伴使用安全套的女性或是根本没有性生活的女性。研究人员指出，精液中含有睾丸激素、雌激素、催乳素和前列腺素，它们通过阴道壁进入血液，令女性精神振奋。但提倡安全性行为的团体则补充说，由于性生活过程中没有采取防护措施而产生了意料之外的后果——怀孕以及性传播疾病——将会大大地挫伤情绪。
一些最令人振奋的研究结果显示，规律的性生活能降低罹患某些癌症的风险。《美国医学会杂志》(Journal of the American Medical Association)2004年刊登的一项针对2.9万名男性医疗保健从业人员进行的研究发现，射精次数最为频繁的男性——每月至少21次——患前列腺癌的风险要远远低于每月射精次数为四至七次的男性。
戈尔茨坦说，每隔一段时间让“容器”清空一次也许有利于前列腺的健康。不过上述文章的作者指出，研究数据可能存在某些误差，因为该项研究要求这些男性回忆的是四十年前他们每个月的射精次数，有些男性如今都已经八十多岁了。
同样，1989年法国的一项研究显示，性生活很少或是根本没有性生活的女性罹患乳腺癌的风险是性生活更加频繁的女性的三倍——但造成这种情况的潜在生物学机理尚不明了。
一些研究还显示，总体而言性生活可以延年益寿。《英国医学杂志》(British MedicalJournal)刊登的一项研究发现，相比起每周有一次性生活的男性，每月性生活次数不足一次的男性在未来十年中死亡的可能性是前者的两倍。杜克大学(DukeUniversity)在25年时间中对270名年龄在60至96岁的男性和女性进行了研究，结果发现男性的性行为越多，他们的寿命就越长。而那些说她们很享受性生活的女性要比性冷淡的女性多活七到八年。不过诸如智力、健康、运动等因素也对延年益寿有着影响。
那么，为了让身体更健康，人们应该让“嘿咻”变得更加频繁吗？
不一定。金赛研究所的詹森说，“多多益善”这种建议过于简单化了。我们从所有这些年来的研究中了解到，真正重要的在于那种满足感以及我们赋予性爱的意义。简言之，假如你的性生活频率和方式与你自身和谐相融，这种性生活就是健康的。
The Joy of Researching the Health Benefits of Sex
Is sex good for your health—or is that just a fantasy?
A flurryof small studies suggest that sex is as good for your health as vitamin Dand broccoli. It not only relieves stress, improves sleep and burnscalories, it can also reduce pain, ease depression, strengthen bloodvessels, boost the immune system and lower the risk of prostate andbreast cancer.
But many of those studies rely on people toremember and report their sexual activity honestly and many can'tdistinguish between cause and effect. That is, does sex make peoplehealthier or do healthier people have more sex?
More research isneeded to evaluate all these claims. 'If I told you we have randomizeddouble-blind placebo-controlled multi-center trials on these questions,there is no such a thing,' says Irwin Goldstein, a urologist and editorin chief of the Journal of Sexual Medicine. The biggest obstacle is lackof funding, he says. 'If 'sex' is in your grant proposal, it's veryhard to get it approved.'
Still, a look at what researchers doknow about the physiology of sex shows that at least a few healthbenefits may come along with that roll in the hay.
Some benefitsof sex—beyond producing a baby, that is—are obvious even withoutscientific evidence. 'When you have good sex, there's a relaxationresponse and a satiation response…you lie there and life is great,' saysDr. Goldstein, who is also the director of sexual medicine at AlvaradoHospital in San Diego, Calif.
Much of that is due tochemistry—the rush of hormones and neurotransmitters that rise and fallduring sexual activity. Arousal boosts dopamine, which activates thebrain's centers of craving and reward 'just like chocolate and winningat gambling,' says Erick Janssen, a senior scientist at the KinseyInstitute at Indiana University.
Sex also increases oxytocin,known as the 'cuddle hormone,' which promotes bonding, reduces fear andstimulates endorphins, the body's natural painkillers, which is why sexcan bring temporary relief from back pain, migraines and other bodyaches.
Dopamine levels plummet after orgasm, and levels ofprolactin rise, bringing on feelings of satisfaction and sleepiness,particularly in men. 'That's the nice, relaxed feeling afterwards,' saysStuart Brody, a psychologist at the University of the West of Scotlandwho has conducted numerous studies on sex and health. Of course, timingisn't always perfect. In a 2006 survey of 10,000 British men, 48%admitted to having fallen asleep during sex.
All together, thischemical cascade has a lasting effect that helps people handle stress,which Dr. Brody showed in a study in the journal Biological Psychologyin 2005. He had 24 women and 22 men keep diaries of their sexualactivities for two weeks, then took their blood pressure while they weretold to give an impromptu speech to a hostile audience and do rapidmath calculations in their heads. Those who had had traditional sexualintercourse during the fortnight had smaller blood pressure spikes andrecovered more quickly than those who engaged in other forms of sex ornone at all.
Sex is also touted as good exercise—but the effectis actually modest. Although couples obviously differ, sex generallyburns an estimated five calories per minute, or roughly 50 to 150calories total. Calculated another way, orgasm uses 3 to 4 METs(metabolic equivalent tasks, a measure of physical intensity)—theequivalent of light housekeeping.
Sex does increase heart rateand blood pressure—as high as 125 beats per minute and to 160 peaksystolic rate—about as much as walking up a flight or two of stairs. Andseveral studies suggest that having it regularly can protect againstcardiovascular problems. One British study found that men who reportedhaving three or more orgasms per week experienced 50% fewer heartattacks than those who engaged less frequently—perhaps because orgasmtriggers the release of the hormone DHEA (dehydroepiandrosterone), whichhelps with circulation and arterial dilation.
On the other hand,erectile dysfunction can be an early indicator of cardiovascularproblems—and when drugs such as Viagra first came on the market, somecardiologists feared sex could be dangerous to men with underlying heartproblems. In general, such fears have proven unfounded. Cases of suddendeath during sex are actually very rare, according to studies inGermany, Japan and Korea. But they are more likely to occur duringextramarital sex.
Frequent sex may benefit men's health anotherway: by boosting testosterone, which in turn is linked to strongermuscles, more energy and better cognition. (Sex's effect on testosteronewas shown in a now-famous article in Nature in 1970. A man stranded on aremote island with no women saw his beard stop growing. Then it resumedwhen he returned to civilization and sex again.)
Sex alsoimproves women's moods—although how it does is controversial. One 2002study of 293 college women at the State University of New York in Albanyfound that those who engaged in unprotected sex were less likely to bedepressed than those whose partners use condoms or who don't have sex atall. The researchers noted that semen contains testosterone, estrogen,prolactin and prostaglandins, which can pass through vaginal walls intothe bloodstream and elevate mood. But safe-sex groups add that theunintended results of unprotected sex—pregnancy and sexually transmitteddiseases—can put quite a damper on mood.
Some of the mostintriguing findings suggest that frequent sex can lower the risk of sometypes of cancer. A 2004 study of 29,000 male health professionals inthe Journal of the American Medical Association found that those whoreported having the most frequent ejaculations—21 or more a month—had amuch lower risk of prostate cancer than those reporting four to sevenper month.
'Emptying the tank every once in awhile is probablygood for the prostate,' Dr. Goldstein says. Still, the authors notedthat the data 'may have contained some inaccuracy' since it asked men,some in their 80s, to recall how often they ejaculated each month fourdecades earlier.
Similarly, a 1989 study in France found thatwomen who had sex infrequently or not at all had three times the risk ofbreast cancer compared to those who had sex more frequently—but thepossible biological mechanism is less clear.
Several studies alsosuggest that having sex extends life in general. A study in the BritishMedical Journal found that men who had sex less than once per monthwere twice as likely to die in the next 10 years than those who had sexonce per week. A 25-year study of 270 men and women aged 60 to 96conducted at Duke University found that the more men had sex, the longerthey lived. Women who said they enjoyed their sex lives lived seven toeight years longer than those who were indifferent. But factors such asintelligence, health and activities also played a role in living longer,too.
So should people ramp up their sexual activity to be healthier?
Notnecessarily. 'The 'more is better' prescription is too simplistic,'says the Kinsey Institute's Dr. Janssen. 'What we've learned from allour years of research is that what's important is the satisfaction andthe meaning we attach to sex.' In short, 'if you're having sex in afrequency and in a way that is compatible with who you are, then that'shealthy.'
一系列小规模的研究显示，性爱带来的健康益处就像是维生素D和花椰菜给身体带来的好处。它不仅可以缓解压力、改善睡眠、燃烧卡路里，还能减轻疼痛、舒缓沮丧情绪、增强血管弹性、提高免疫系统功能、降低罹患前列腺癌和乳腺癌的风险。
Ray Bartkus缓解压力：迅速上升的激素水平提振情绪，促进亲近感，帮助控制数天的压力。Ray Bartkus体重：性行为能够每分钟燃烧掉5卡路里热量，这表示在大约12小时内即可减掉一磅。Ray Bartkus心脏健康：性行为能够使心率提高到相当于爬两段楼梯的水平。Ray Bartkus改善睡眠：劳累过后，催产素和催乳素带来饱食感和睡意－－尤其是对于男性而言。Ray Bartkus延年益寿：更多的性行为对男性意味着寿命更长；女性获得性满足能长寿。然而这些研究中有许多都有赖于被研究者回忆并坦诚地讲述他们的性行为，而很多人无法区分因果，也就是说，究竟是性爱让人们变得更健康还是更健康的人会有更多的“嘿咻”行为？要评估这些论断还需要进行更多的研究。《性医学杂志》(Journal of SexualMedicine)的主编、加州圣地牙哥阿尔瓦拉多医院(Alvarado Hospital)性医学部门主任、泌尿科医生戈尔茨坦(IrwinGoldstein)说，如果我跟你说我们已经对这些问题进行了随机双盲对照多中心试验，这是在骗人。他说，最大的阻碍在于研究资金的缺乏，如果在你的基金申请计划书中出现了“性爱”一词，它就很难获得批准了。
尽管如此，通过了解研究者已经掌握的性爱生理学知识可以知道，性爱让人享受鱼水之欢的同时至少可以带来一些健康益处。
即便没有科学依据，性爱所带来的一些好处——当然，除了能“造人”之外——也是显而易见的。戈尔茨坦说，当你享受了一次愉快的性生活后，你会体会到一种松弛和满足……你躺在那儿，感觉生活真美好。
这种感觉在很大程度上是由于身体内的化学反应造成的——“嘿咻”过程中会有大量荷尔蒙和神经递质迅速增加和减少。这种“觉醒”刺激了多巴胺的分泌，而多巴胺又启动了大脑的渴求中枢和奖赏中枢，印第安那大学(Indiana University)金赛研究所(KinseyInstitute)的资深科学家詹森(Erick Janssen)说，这种刺激作用就好像是吃巧克力或是赌赢了钱所产生的效果。
性爱还会提高催产素的水平，这种被称为“拥抱荷尔蒙”的物质能让人与人之间的关系变得亲密，还能减轻恐惧情绪，并刺激内啡肽这一人体天然止痛药的产生，这也是为什么性爱可以让背痛、偏头痛和其他身体疼痛得到暂时性缓解的原因。
性高潮过后，多巴胺水平迅速下降，催乳素水平上升，使人在产生满足感的同时也有了困意，这种现象在男人身上尤其明显。对性与健康的关系进行过大量研究的西苏格兰大学(University of the West of Scotland)心理学家布罗迪(StuartBrody)说，这是性爱过后愉悦而放松的感觉。当然，时间节点的掌握并不总是那么完美。在2006年一项对一万名英国男子的调查中，有48%的人承认他们在“嘿咻”的过程中就已经睡着了。
所有这些一连串的化学变化能产生一种持续性效果，帮助人们缓解压力，对此布罗迪在2005年发表于《生物心理学》(BiologicalPsychology)期刊的一项研究中有过阐述。他先是让24名女子和22名男子记录下他们在两个星期中的性行为，然后要求他们面对一群不友好的听众发表即兴演讲并进行数学题的快速心算，此时布罗迪测量了他们的血压。相比那些在前两周中有过其他形式性行为或是根本没有性行为的人，那些在此期间有过传统性行为的人在出现血压突然升高的情况时，血压升高幅度更小而且恢复得更快。
性爱还号称具有良好的锻炼效果——但实际上效果并不太大。虽然每一对夫妻都各不相同，但通常来说人们在“嘿咻”时每分钟估计会消耗掉五卡路里的热量，也就是总共燃烧掉50至150卡路里左右。换一种计算方式，性高潮需要三至四个单位的能量代谢当量（一种衡量体力劳动强度的指标）——相当于干了少量家务活。
性生活的确可以使心率加快、血压升高——每分钟心跳可高达125次，收缩压峰值可高达160——大致相当于爬一、两段楼梯的效果。数项研究显示，规律的性生活有助于预防心血管疾病。英国的一项研究发现，那些报告每周有三次或者更多次性高潮的男子发生心脏病的次数要比性生活相对不那么频繁的人少50%——这也许是因为性高潮刺激了脱氢表雄酮的产生，这种荷尔蒙有助于改善血液回圈和动脉扩张。
另一方面，勃起功能障碍也许是心血管疾病的早期征兆——当诸如“伟哥”(Viagra)这样的药物最初进入市场时，一些心脏病学家担心性生活可能会给男性潜在心脏病患者带来危险。总体来看，这种担忧已被证明是没有依据的。根据德国、日本以及韩国的研究，在性生活中发生猝死的情况实际上是极为罕见的。但这种情况在婚外性行为的过程中发生的可能性则要大一些。
规律的性生活或许还能从另一个方面有助于男性健康：刺激睾丸激素的分泌，这种激素反过来又能强健肌肉、增强男性活力、改善认知能力。（性生活对于睾丸激素的影响在1970年刊登于《自然》(Nature)杂志的一篇文章中得到了说明，这篇文章如今已是蜚声世界。一名男子被困在了一座没有女人存在的遥远岛屿上，后来他的胡子停止了生长。当他回到文明世界、再度过上性生活时，胡子重新开始生长。）
性爱还能改善女性的情绪——不过对于它究竟是如何产生这种效果的，人们说法不一。2002年对纽约州立大学奥尔巴尼分校(State University of New York in Albany)293名大学女生进行的研究发现，拥有性生活并且不采取保护措施的女性出现抑郁的可能性要小于其性伙伴使用安全套的女性或是根本没有性生活的女性。研究人员指出，精液中含有睾丸激素、雌激素、催乳素和前列腺素，它们通过阴道壁进入血液，令女性精神振奋。但提倡安全性行为的团体则补充说，由于性生活过程中没有采取防护措施而产生了意料之外的后果——怀孕以及性传播疾病——将会大大地挫伤情绪。
一些最令人振奋的研究结果显示，规律的性生活能降低罹患某些癌症的风险。《美国医学会杂志》(Journal of the American Medical Association)2004年刊登的一项针对2.9万名男性医疗保健从业人员进行的研究发现，射精次数最为频繁的男性——每月至少21次——患前列腺癌的风险要远远低于每月射精次数为四至七次的男性。
戈尔茨坦说，每隔一段时间让“容器”清空一次也许有利于前列腺的健康。不过上述文章的作者指出，研究数据可能存在某些误差，因为该项研究要求这些男性回忆的是四十年前他们每个月的射精次数，有些男性如今都已经八十多岁了。
同样，1989年法国的一项研究显示，性生活很少或是根本没有性生活的女性罹患乳腺癌的风险是性生活更加频繁的女性的三倍——但造成这种情况的潜在生物学机理尚不明了。
一些研究还显示，总体而言性生活可以延年益寿。《英国医学杂志》(British MedicalJournal)刊登的一项研究发现，相比起每周有一次性生活的男性，每月性生活次数不足一次的男性在未来十年中死亡的可能性是前者的两倍。杜克大学(DukeUniversity)在25年时间中对270名年龄在60至96岁的男性和女性进行了研究，结果发现男性的性行为越多，他们的寿命就越长。而那些说她们很享受性生活的女性要比性冷淡的女性多活七到八年。不过诸如智力、健康、运动等因素也对延年益寿有着影响。
那么，为了让身体更健康，人们应该让“嘿咻”变得更加频繁吗？
不一定。金赛研究所的詹森说，“多多益善”这种建议过于简单化了。我们从所有这些年来的研究中了解到，真正重要的在于那种满足感以及我们赋予性爱的意义。简言之，假如你的性生活频率和方式与你自身和谐相融，这种性生活就是健康的。
The Joy of Researching the Health Benefits of Sex
Is sex good for your health—or is that just a fantasy?
A flurryof small studies suggest that sex is as good for your health as vitamin Dand broccoli. It not only relieves stress, improves sleep and burnscalories, it can also reduce pain, ease depression, strengthen bloodvessels, boost the immune system and lower the risk of prostate andbreast cancer.
But many of those studies rely on people toremember and report their sexual activity honestly and many can'tdistinguish between cause and effect. That is, does sex make peoplehealthier or do healthier people have more sex?
More research isneeded to evaluate all these claims. 'If I told you we have randomizeddouble-blind placebo-controlled multi-center trials on these questions,there is no such a thing,' says Irwin Goldstein, a urologist and editorin chief of the Journal of Sexual Medicine. The biggest obstacle is lackof funding, he says. 'If 'sex' is in your grant proposal, it's veryhard to get it approved.'
Still, a look at what researchers doknow about the physiology of sex shows that at least a few healthbenefits may come along with that roll in the hay.
Some benefitsof sex—beyond producing a baby, that is—are obvious even withoutscientific evidence. 'When you have good sex, there's a relaxationresponse and a satiation response…you lie there and life is great,' saysDr. Goldstein, who is also the director of sexual medicine at AlvaradoHospital in San Diego, Calif.
Much of that is due tochemistry—the rush of hormones and neurotransmitters that rise and fallduring sexual activity. Arousal boosts dopamine, which activates thebrain's centers of craving and reward 'just like chocolate and winningat gambling,' says Erick Janssen, a senior scientist at the KinseyInstitute at Indiana University.
Sex also increases oxytocin,known as the 'cuddle hormone,' which promotes bonding, reduces fear andstimulates endorphins, the body's natural painkillers, which is why sexcan bring temporary relief from back pain, migraines and other bodyaches.
Dopamine levels plummet after orgasm, and levels ofprolactin rise, bringing on feelings of satisfaction and sleepiness,particularly in men. 'That's the nice, relaxed feeling afterwards,' saysStuart Brody, a psychologist at the University of the West of Scotlandwho has conducted numerous studies on sex and health. Of course, timingisn't always perfect. In a 2006 survey of 10,000 British men, 48%admitted to having fallen asleep during sex.
All together, thischemical cascade has a lasting effect that helps people handle stress,which Dr. Brody showed in a study in the journal Biological Psychologyin 2005. He had 24 women and 22 men keep diaries of their sexualactivities for two weeks, then took their blood pressure while they weretold to give an impromptu speech to a hostile audience and do rapidmath calculations in their heads. Those who had had traditional sexualintercourse during the fortnight had smaller blood pressure spikes andrecovered more quickly than those who engaged in other forms of sex ornone at all.
Sex is also touted as good exercise—but the effectis actually modest. Although couples obviously differ, sex generallyburns an estimated five calories per minute, or roughly 50 to 150calories total. Calculated another way, orgasm uses 3 to 4 METs(metabolic equivalent tasks, a measure of physical intensity)—theequivalent of light housekeeping.
Sex does increase heart rateand blood pressure—as high as 125 beats per minute and to 160 peaksystolic rate—about as much as walking up a flight or two of stairs. Andseveral studies suggest that having it regularly can protect againstcardiovascular problems. One British study found that men who reportedhaving three or more orgasms per week experienced 50% fewer heartattacks than those who engaged less frequently—perhaps because orgasmtriggers the release of the hormone DHEA (dehydroepiandrosterone), whichhelps with circulation and arterial dilation.
On the other hand,erectile dysfunction can be an early indicator of cardiovascularproblems—and when drugs such as Viagra first came on the market, somecardiologists feared sex could be dangerous to men with underlying heartproblems. In general, such fears have proven unfounded. Cases of suddendeath during sex are actually very rare, according to studies inGermany, Japan and Korea. But they are more likely to occur duringextramarital sex.
Frequent sex may benefit men's health anotherway: by boosting testosterone, which in turn is linked to strongermuscles, more energy and better cognition. (Sex's effect on testosteronewas shown in a now-famous article in Nature in 1970. A man stranded on aremote island with no women saw his beard stop growing. Then it resumedwhen he returned to civilization and sex again.)
Sex alsoimproves women's moods—although how it does is controversial. One 2002study of 293 college women at the State University of New York in Albanyfound that those who engaged in unprotected sex were less likely to bedepressed than those whose partners use condoms or who don't have sex atall. The researchers noted that semen contains testosterone, estrogen,prolactin and prostaglandins, which can pass through vaginal walls intothe bloodstream and elevate mood. But safe-sex groups add that theunintended results of unprotected sex—pregnancy and sexually transmitteddiseases—can put quite a damper on mood.
Some of the mostintriguing findings suggest that frequent sex can lower the risk of sometypes of cancer. A 2004 study of 29,000 male health professionals inthe Journal of the American Medical Association found that those whoreported having the most frequent ejaculations—21 or more a month—had amuch lower risk of prostate cancer than those reporting four to sevenper month.
'Emptying the tank every once in awhile is probablygood for the prostate,' Dr. Goldstein says. Still, the authors notedthat the data 'may have contained some inaccuracy' since it asked men,some in their 80s, to recall how often they ejaculated each month fourdecades earlier.
Similarly, a 1989 study in France found thatwomen who had sex infrequently or not at all had three times the risk ofbreast cancer compared to those who had sex more frequently—but thepossible biological mechanism is less clear.
Several studies alsosuggest that having sex extends life in general. A study in the BritishMedical Journal found that men who had sex less than once per monthwere twice as likely to die in the next 10 years than those who had sexonce per week. A 25-year study of 270 men and women aged 60 to 96conducted at Duke University found that the more men had sex, the longerthey lived. Women who said they enjoyed their sex lives lived seven toeight years longer than those who were indifferent. But factors such asintelligence, health and activities also played a role in living longer,too.
So should people ramp up their sexual activity to be healthier?
Notnecessarily. 'The 'more is better' prescription is too simplistic,'says the Kinsey Institute's Dr. Janssen. 'What we've learned from allour years of research is that what's important is the satisfaction andthe meaning we attach to sex.' In short, 'if you're having sex in afrequency and in a way that is compatible with who you are, then that'shealthy.'