trace mineral found in everyday foods could be the key to keeping cancer at bay.
Adding extra selenium which
is in Brazil nuts, bread, cereals, fish, poultry and meat to the diet has already
been proved to help cancer survivors by halving their risk of contracting the disease
Now British scientists are launching
a trial to discover if taking a daily supplement of the mineral could prevent healthy
people developing the disease.
Since the Sixties it has been
thought that selenium supplements might prevent dietary-linked cancers.
This is because some areas, where
people have a naturally high intake of the mineral, have lower than expected rates of the
The most promising evidence so far comes from a U.S. study which showed an
overall drop of 50 per cent in cancer deaths and a fall of 37% in new cases
especially lung, bowel and prostrate among 1,300 volunteers taking supplements for
But the small-scale research
involved people who had suffered skin cancer and there are still doubts over whether it
could help healthy people.
This has led to the launch by the
Cancer Research Campaign, supported by the supermarket chain Asda, of the most ambitious
study ever to investigate the trace elements cancer blocking potential.
Altogether 40,000 people from the
U.S., Britain and three other European countries will take part in the study, which will
start here as a pilot project involving 500volunteers.
Britain has been chosen because of
low levels of selenium consumption. The average intake of 34 micrograms a day is only half
the amount found in the diet 25 years ago. It is also less than half the 75 mcg a day
recommended for men and lower than the 80 mcg recommended for women.
Dr, Margaret Rayman, of Surrey
University Guildford, who is organising the study in Britain said Selenium intakes
have been falling for several years and thee is no sign of a change in the trend.
One of the key reasons is a major
reduction over the last 20 years in the use of North American wheat, which contains high
levels of selenium.
The pilot study will use GP
surgeries in Guisborough, Cleveland; Bungay, Suffolk; and Bromsgrove, Worcestershire, to
recruit volunteers aged between 60 and 74.
The trial aims to show not
only whether selenium has a protective effect against cancer, but also how much selenium
is needed to have this effect and which people will benefit most said Dr
Cancer Research Campaign director
general Professor Gordon McVie said If this study is successful, it will be the
first time in the UK that a nutritional supplement has been conclusively shown to have
beneficial health qualities.
Dieticians say assessing dietary
intake through foods is difficult as selenium differs from most other nutrients by varying
hugely in food stuffs you can never by sure how much you are getting. Doctors
assess levels by analysing toe clippings and taking blood.
Too much selenium is toxic and
consumers are advised to keep intake well below the toxic level of 800mcg a day.