http://news.bbc.co.uk/2/hi/uk_news/northern_ireland/3513607.stm
Soya 'link' to male infertility
Researchers investigated soya in the diet
The humble soya bean may play a role in the problem of male
infertility, a team of researchers in Belfast has found.
Soya contains the female hormone oestrogen and too much of it is
being linked to poor quality sperm.
Dr Lorraine Anderson says she found the link in research carried
out at the Royal Victoria Hospital in Belfast.
"What many men do not realise is that soya is not just consumed by
vegetarians, it is contained in a lot of everyday processed
foods.
"It is contained in foods such as pizzas, any of those foods that
you add hot water to, to reconstitute them, or some of the
pre-packaged dinners like steak and kidney pies," Dr Anderson
said.
If men are consuming large amounts of soya products, for example,
there is a negative relationship between that and the quality of
their sperm
Dr Sheena Lewis
Queen's University, Belfast
"You'll find that a lot of the meat is not really meat, it is soya
protein because it is cheaper and soya has the highest percentage
of oestrogens compared to any other foods."
The director of reproductive medicine at Queen's University,
Belfast, Dr Sheena Lewis, said the findings were clear.
"What we have shown is that if men are consuming large amounts of
soya products, for example, there is a negative relationship
between that and the quality of their sperm.
"If they already have a slight problem in that area, then it might
be better for them not to consume so much."
Dr Lewis said that the way to avoid excess oestrogen was to eat
fresh produce.
"In our fast food diets, we are inclined to eat lots of meals and
we really don't know what the ingredients are," she said.
"If we eat fresh fruits, if we make fresh food at home ourselves,
which I know is very difficult in today's busy lifestyle, then we
are really aware of what the ingredients are."
However, the research does not simply have implications for men who
wish to start a family.
Dr Anderson said if boys eat a lot of soya when they are growing
up, it can damage their reproductive capability.
"The key time for that is when a male foetus is developing and in
the early toddler years and up to puberty.
"All through that period, if you alter the oestrogen that a man is
exposed to, you can not only affect their sperm quality but affect
the development of their reproductive tract, so that you can get an
increase in structural abnormalities like undescended testes and
you can also get other problems later in life, such as testicular
cancer."
Dr Anderson recently came runner-up in a prestigious competition
for her work on the link between male fertility and oestrogen in
the diet.
