Entries in Testosterone (6)


Scientists Find 'Striking' Change in Sex Hormone When Friend Is Involved

Ingram Publishing/Thinkstock(NEW YORK) -- Hey brother, feel sexually drawn to your best friend's wife? Testosterone, the bad boy among male sex hormones, is supposed to make it easier for you to ignore your friendship and make your move.

However, scientists at the University of Missouri have found that men are biologically inclined toward avoiding a close encounter with the mate of a buddy, and it works the other way around if she is not committed to a friend.

Testosterone seems to be depressed if a friend is involved, but elevated if there is no close relationship, a condition the scientists describe as a "striking reversal" in the role of this powerful hormone. The study was published in the journal Human Nature.

"Men's testosterone levels generally increase when they are interacting with a potential sexual partner or an enemy's mate," anthropologist Mark Flinn, lead author of the study, said in releasing the report. "However, our finding suggests that men's minds have evolved to foster a situation where the stable pair bonds of friends are respected."

The findings should be regarded as tentative, because the number of participants was limited and some data may be compromised by the difficult circumstances under which it was collected, as the researchers note in their own study. The conclusions depend partly on data collected a few years ago in the Dominican Republic.

In some cases, for example, testosterone levels were not determined before the "interaction" with the female, so it's not known how much the level changed during the event, and it was not known if there were prior interactions with the same female.

"Even with these important limitations, the apparent dampening of androgen (sex hormones) levels when interacting with friends' mates is remarkable nonetheless, and consistent with mutual respect of mating relationships and enhanced cooperation among group males," the study notes.

The scientists see their study as much broader than just the sexual temptation involving a friend's mate, because additional research was carried out showing that testosterone is actively involved in a wide range of human activities, probably even international conflict.

They found, for example, that the level of testosterone soared in young men in a Dominican community when they competed in sporting events with a rival from another community, but it remained unchanged if the rival was a close neighbor. And that, they suggest, shows we are biologically determined to form relationships, or coalitions, with those around us -- so we will act less aggressively within our group -- but we are more willing to trample or attack outsiders.

"A victory against friends does not affect testosterone significantly, whereas a victory against outsiders results in elevated testosterone," the study concludes. "Likewise, a defeat by friends has little effect on testosterone, whereas a defeat by outsiders results in decreased testosterone from pre-competition levels."

The researchers take that a step further, suggesting that testosterone remains low to help members of a community work together and it rises to help defeat a threat from outside the community. Thus, they add, it may play a critical role in human interactions, even at the international level.

Copyright 2013 ABC News Radio


Woman Designs Diet for Men to Be Less Like Women

iStockphoto/Thinkstock(NEW YORK) -- Guys, eating like a real man might make a woman out of you.

That's the theory behind the Men Only Weight Loss program, concocted by founder Wendy Meyers who argues that certain things men eat regularly are "feminizing foods."

According to Meyers, stuff like processed foods with preservatives, dyes or soy and favorites including breads, desserts and beer are "the equivalent of several female birth control pills on a weekly or monthly basis."

She says these foods mimic estrogen, causing lower testosterone, not to mention lack of energy and weight gain.

If that isn't enough to make a guy break down and cry, Meyers believes that these "feminizing foods" are responsible for loss of sex drive and bigger breasts on men.

Meyers' Men Only Weight Loss program gets men to wean themselves off these foods, replacing them with proteins and produce, and it's supposedly done without calorie counting or portion control.

Registered dietician Penny Wilson isn't all that wound up about Meyers' theory that today's diet "is emasculating men," but she does think the alternate food choices are a step in the right direction.

Copyright 2012 ABC News Radio


Testosterone May Help Heart Failure Patients, Studies Suggest

iStockphoto/Thinkstock(PITTSBURGH) -- Testosterone can ease shortness of breath and improve exercise endurance among patients with chronic heart failure, according to a combined analysis of four clinical trials.

Some study participants experienced 50-percent improvements in their ability to walk, and in some cases, the muscle-strengthening effects lasted a year. Although 84 percent of the study subjects, with an average age of 67, were men, testosterone treatment with patches, gels or injections also produced improvements in women.

However, the pooled findings are from only 198 patients with chronic, stable heart failure, so they hardly provide the final word on treating the disorder with hormonal supplements, the study's lead author said. The observed improvements need to be reproduced in larger numbers of patients before testosterone can be recommended as therapy, said Dr. Justin Z. Ezekowitz, director of the Heart Function Clinic at the University of Alberta in Edmonton, Canada.

"We don't want patients and their loved ones rushing to buy testosterone supplements online, or physicians to misinterpret the findings," said Ezekowitz, who led the meta-analysis published Tuesday in the American Heart Association's journal Circulation Heart Failure.

The American Heart Association estimates that about 5.7 million Americans have congestive heart failure, about 2 percent of the population. The condition accounts for about a third of heart-related deaths.

When a person has heart failure, the heart cannot pump strongly enough to supply blood to the body, allowing fluids to build up in the lungs, arms and legs. It typically results from narrowed arteries (atherosclerosis), heart attack, heart valve diseases or infections that weaken the heart muscle.

Treatments include diuretics to eliminate fluid buildup, as well as several types of blood pressure drugs and others that also help reduce the heart's workload, and cardiac rehabilitation exercise programs. End-stage heart failure can be treated with heart transplants; occasionally, doctors implant a left ventricular assist device (LVAD), like the one that former Vice President Dick Cheney had before recently undergoing a transplant.

"These data are interesting," said Dr. Clyde W. Yancy, cardiology chief at Northwestern University in Chicago and a former American Heart Association president. Yancy's own research 20 years ago focused on exercise function in heart failure, a problem that he said remains pressing today.

Scientists have had several reasons to be curious about the use of testosterone in heart failure. Lower testosterone levels have been shown to be an independent risk factor for worse outcomes among men and women with heart failure. Low testosterone levels have been associated with decreased survival for men with coronary artery disease. And, testosterone supplementation has been associated with better cholesterol levels among men with heart disease, Ezekowitz and his colleagues noted in their study.

Despite interest in novel ways to improve exercise function in heart failure, "we should not yet view testosterone as the definitive answer," Yancy said, noting the lack of information about long-term cardiovascular effects of testosterone treatments. He called the small number of patients and limited follow-up in the four studies, in some cases just weeks to months, "insufficient to identify potential risks."

"As one assesses the magnitude of benefit observed, this is only a modest to moderate degree of improvement," Yancy said. "Finally, it is unfortunate but necessary to highlight that increased availability of testosterone as a therapeutic agent comes with significant abuse potential."

Abuse of testosterone, a steroid hormone that helps athletes and bodybuilders bulk up, has been associated with cardiovascular disease, increased risk of heart attack, and mood changes, as well as prostate cancer.

Copyright 2012 ABC News Radio


Study Suggests Men Are Wired to Nurture

David Sacks/Thinkstock(WASHINGTON) -- There’s a new study out that suggests men might actually be wired to nurture their children.

The research, published in The Proceedings of the National Academy of Sciences, followed 624 young men before and after they became fathers in and around the city of Cebu, in the Philippines. The researchers found that levels of testosterone actually decreased by about 34 percent in the men after fatherhood.

According to the study, men with newborn babies who were less than a month old had especially reduced levels of testosterone.

And the researchers believe lower testosterone levels might even protect against certain chronic diseases, which could explain why married men and fathers often enjoy better health than single men of the same age.

The study might also point to the idea that life and biology might be more adaptable than we previously thought, as the demands of fatherhood understandably require many emotional, psychological and physical adjustments.

Copyright 2011 ABC News Radio


Penis Size Linked to Finger Length, Researchers Find

BananaStock/Thinkstock(INCHEON, South Korea) -- The longer a man's index finger when compared with his ring finger, the longer the length of his penis, according to Korean researchers.

The research team, led by urologist Dr. Tae Beom Kim from Gachon University in Incheon, Korea, measured the fingers and penises -- both stretched-out and flaccid -- of 144 men who were anesthetized before undergoing urological surgery.

Men's ring fingers are usually longer than their index fingers.  But Kim and colleagues linked a larger gap in finger length -- a lower 2D:4D ratio -- to a longer stretched-out penis.

"Based on this evidence, we suggest that digit ratio can predict adult penile size, and that the effects of prenatal testosterone may in part explain the differences in adult penile length," the researchers reported Monday in the Asian Journal of Andrology.

The length of the penis when stretched is believed to correlate to its erect length, the team reported.

Earlier studies suggest the 2D:4D ratio is governed by prenatal exposure to the male and female sex hormones, testosterone and estrogen.  Women tend to have ring and index fingers of roughly equal length -- a result of less testosterone exposure in the womb, report the Korean researchers.

But men who have relatively long ring fingers are thought to have been exposed to high levels of testosterone in utero, and this has been linked to aggression, athleticism, sexuality, intelligence, and even the ability to trade high-stakes stocks.  It has also been linked to a higher risk for amyotrophic lateral sclerosis, or Lou Gehrig's disease, prostate cancer and arthritis.

Copyright 2011 ABC News Radio


Viagra Doesn't Work for Half of Those Who Have It Prescribed

Photo Courtesy - Getty Images(BRITAIN) -- Doctors say Viagra isn't effective for half the men who take the drug.  Britain's Daily Mail reports many men who are prescribed the little blue pill have low levels of testosterone.  The drug alone does nothing to treat this.  In fact, Viagra works by enhancing the effects of nitric oxide.  This chemical doesn't function unless a person taking the pill already has high levels of testosterone.

"Viagra will only work if there are sufficient levels of testosterone. Often men with low testosterone levels won't feel like sex at all," says Dr. Geoffrey Hackett, a consultant urologist at Good Hope hospital in Birmingham, England and former chairman of the British Society for Sexual Medicine.  "They will get repeat prescriptions for Viagra in the hope that it will eventually work. Everybody thinks that Viagra is the panacea for all sexual problems; it's not," he adds.

Low levels of testosterone, which affect 40 percent of men over the age of 40, can be detected with a simple blood test.  Once the condition is confirmed, treatment can commence with testosterone pills, patches or gels.

Copyright 2010 ABC News Radio

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