Men need the 'female' hormone oestrogen to maintain their sex drive and avoid obesity, new research suggests
Men need the ‘female’ hormone oestrogen to maintain their sex drive and avoid obesity, new research suggests.
Men who have too little oestrogen in their bodies can develop certain ‘male menopause’ symptoms – such as diminished libido.
They are also more likely to put on weight.
‘A lot of things we think are due to testosterone deficiency are actually related to the oestrogen deficiency that accompanies it,’ said Dr Joel Finkelstein of Massachusetts General Hospital.
Testosterone is the main male sex hormone.
Men's bodies convert some of it into oestrogen, and levels of both decline with age.
However, it is usually thought that the problems some men experience as they age are caused by a lack of testosterone when, actually, it could be their falling oestrogen levels that are to blame.
The study involved 400 healthy male volunteers, aged 20 to 50, who were given monthly injections of a drug to temporarily reduce their testosterone production to pre-puberty levels.
They were then given various doses of testosterone gel or a dummy gel to use. Half were also given another drug to prevent testosterone's conversion into oestrogen.
Designing the study this way allowed researchers to compare the effects of different levels of each hormone on things like strength and body composition.
After 16 weeks, researchers saw that muscle size and strength depended on testosterone, body-fat mass depended on oestrogen, and both hormones were needed to maintain normal sex drive and performance.
The results mirror animal research – mice that are altered so they do not make oestrogen become fat and have no sex drive.
And in male-to-female transsexuals, ‘there's actually evidence that when those men are given oestrogen, it helps their libido,’ Dr Finkelstein said.
The new study was too short to see long-term benefits or risks, such as the effect of testosterone supplements on the heart, mental sharpness, prostate enlargement or cancer.
Men who have too little oestrogen in their bodies can develop certain 'male menopause' symptoms such as diminished libido. They are also more likely to put on weight
Also, abruptly and artificially depriving men of testosterone the way the study did may not be the same as when it falls naturally and gradually over time.
Further research is needed, but the results may boost the case for giving testosterone to prevent frailty in older men, the authors write.
Low testosterone may contribute to less muscle and bone strength and mobility, impaired thinking skills, heart disease and other problems.
‘This is a big public health issue,’ Dr Finkelstein said. ‘If the changes with aging are due to these things, then potentially replacing these hormones in men might ameliorate these changes.’
Read more: http://www.dailymail.co.uk/health/article-2418956/Why-men-need-womens-hormones-Oestrogen-vital-sex-drive-avoiding-obesity-say-doctors.html#ixzz2emqTZvXt
Follow us: @MailOnline on Twitter | DailyMail on Facebook
