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http://news.bbc.co.uk/2/hi/uk_news/northern_ireland/3513607.stm

Soya 'link' to male infertility

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 established 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 or your steak and kidney pies," Dr Anderson said.

"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 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.