Science: Why female hormones are vital for a red-blooded man

Do men have any use for female hormones, known as oestrogens? Yes, say scientists - the tiny amount produced naturally keeps them fertile. This could also shed new light on fears over 'environmental oestrogen'. Charles Arthur investigates.

Fears that man-made chemicals which mimic female hormones are causing a loss in male fertility may be misplaced, following new research which shows that sperm actively need the female hormone, oestrogens, to thrive.

Since sex hormones were discovered earlier this century, oestrogens have been regarded as an intrinsically female hormone, and androgens (such as testosterone) the essence of masculinity. Oestrogens regulate the menstrual cycle in women, and cause the changes in female body shape at puberty. Androgens cause hair growth and the deepening of the voice in boys. Limited versions of the same change can be induced in the opposite sex by administering those hormones.

However, men and women naturally both produce small quantities of both hormones, which scientists now think are "sides of the same coin" in regulating many body functions. They now know, for example, that it is oestrogen, not testosterone, which determines when the bones stop growing. Men who do not produce any oestrogen keep growing.

The essential role of oestrogen in male fertility was discovered by a team at the University of Illinois, which found that mice genetically engineered to have no cells which are sensitive to oestrogen are sterile.

This finding, reported today in the science journal Nature, has important implications for worries about "environmental hormones" such as phthlates, found in some plastics packaging, and other pollutants.

Earlier this week a survey suggested that global male fertility - measured in sperm counts - has halved over the past 50 years. This has been ascribed to increasing amounts of "oestrogen mimics" which were blamed for affecting males.

Richard Sharpe, of the Medical Research Council's Reproductive Biology Unit in Edinburgh, commenting on the latest work, said that this would at last give scientists some basis for future work to see how solidly based these claims are.

"The huge, but exciting, task that we now face is to discover what oestrogens are doing at their many different sites of action in the male," Mr Sharpe said.

Rex Heff, who led the Illinois scientists, wrote in Nature: "This finding is important given the recent concerns over reported declines in human sperm counts and speculation that exposure to environmental oestrogens may be the cause of this."

Suggested Topics
Start your day with The Independent, sign up for daily news emails
Arts and Entertainment
filmPoldark production team claims innocence of viewers' ab frenzy
Life and Style
Google marks the 81st anniversary of the Loch Ness Monster's most famous photograph
techIt's the 81st anniversary of THAT iconic photograph
News
Katie Hopkins makes a living out of courting controversy
people
News
General Election
Have you tried new the Independent Digital Edition apps?
ebooks
ebooksA special investigation by Andy McSmith
  • Get to the point
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Ashdown Group: HR Assistant - Immediate Start - Central Manchester - £20K

£18000 - £20000 per annum + Benefits: Ashdown Group: HR Assistant - Immediate ...

Recruitment Genius: Senior Development Engineer

£28000 - £32000 per annum: Recruitment Genius: This leading manufacturer of fl...

Recruitment Genius: Field Sales Operative - Oxfordshire / Worcestershire - OTE £30k

£12000 - £30000 per annum: Recruitment Genius: A Field Sales Operative is requ...

Recruitment Genius: Office Administrator

£14000 - £18000 per annum: Recruitment Genius: An Office Administrator is requ...

Day In a Page

Revealed: Why Mohammed Emwazi chose the 'safe option' of fighting for Isis, rather than following his friends to al-Shabaab in Somalia

Why Mohammed Emwazi chose Isis

His friends were betrayed and killed by al-Shabaab
'The solution can never be to impassively watch on while desperate people drown'
An open letter to David Cameron: Building fortress Europe has had deadly results

Open letter to David Cameron

Building the walls of fortress Europe has had deadly results
Tory candidates' tweets not as 'spontaneous' as they seem - you don't say!

You don't say!

Tory candidates' election tweets not as 'spontaneous' as they appear
Mubi: Netflix for people who want to stop just watching trash

So what is Mubi?

Netflix for people who want to stop just watching trash all the time
The impossible job: how to follow Kevin Spacey?

The hardest job in theatre?

How to follow Kevin Spacey
Armenian genocide: To continue to deny the truth of this mass human cruelty is close to a criminal lie

Armenian genocide and the 'good Turks'

To continue to deny the truth of this mass human cruelty is close to a criminal lie
Lou Reed: The truth about the singer's upbringing beyond the biographers' and memoirists' myths

'Lou needed care, but what he got was ECT'

The truth about the singer's upbringing beyond
Migrant boat disaster: This human tragedy has been brewing for four years and EU states can't say they were not warned

This human tragedy has been brewing for years

EU states can't say they were not warned
Women's sportswear: From tackling a marathon to a jog in the park, the right kit can help

Women's sportswear

From tackling a marathon to a jog in the park, the right kit can help
Hillary Clinton's outfits will be as important as her policies in her presidential bid

Clinton's clothes

Like it or not, her outfits will be as important as her policies
NHS struggling to monitor the safety and efficacy of its services outsourced to private providers

Who's monitoring the outsourced NHS services?

A report finds that private firms are not being properly assessed for their quality of care
Zac Goldsmith: 'I'll trigger a by-election over Heathrow'

Zac Goldsmith: 'I'll trigger a by-election over Heathrow'

The Tory MP said he did not want to stand again unless his party's manifesto ruled out a third runway. But he's doing so. Watch this space
How do Greek voters feel about Syriza's backtracking on its anti-austerity pledge?

How do Greeks feel about Syriza?

Five voters from different backgrounds tell us what they expect from Syriza's charismatic leader Alexis Tsipras
From Iraq to Libya and Syria: The wars that come back to haunt us

The wars that come back to haunt us

David Cameron should not escape blame for his role in conflicts that are still raging, argues Patrick Cockburn
Sam Baker and Lauren Laverne: Too busy to surf? Head to The Pool

Too busy to surf? Head to The Pool

A new website is trying to declutter the internet to help busy women. Holly Williams meets the founders