Food additives 'may fuel tumors'
2008-12-29 21:09
Washington - Common food additives
known as phosphates may help lung cancer tumors grow faster, at
least in mice, South Korean researchers reported on Monday.
Their tests in mice suggest the additives - found in many
soft drinks, baked goods and processed meats and cheese - may
also help tumors develop in the first place.
"Our study indicates that increased intake of inorganic
phosphates strongly stimulates lung cancer development in
mice," Myung-Haing Cho of Seoul National University, who led
the study, said in a statement.
A diet high in phosphates "significantly increased the lung
surface tumor lesions as well as the size," Cho's team wrote in
their study.
Cho said the research suggests that cutting back on
inorganic phosphates "may be critical for lung cancer treatment
as well as prevention."
Phosphates are critical to human nutrition and can be used
in compounds that enrich calcium and iron content and prevent
food from drying out.
But Cho said it is possible that some people get too much.
"In the 1990s, phosphorous-containing food additives
contributed an estimated 470mg per day to the average daily
adult diet," Cho said.
Food additives
Now, he said, people can get up to 1 000 mg a day.
Writing in the American Journal of Respiratory and Critical
Care Medicine, Cho and colleagues said they studied mice bred
to develop lung cancer.
For a month, half got diets equivalent
to a human diet high in phosphates and the other half got a
moderate dose.
The bred mice do not develop cancer in the same way as
humans do and the researchers stressed their study does not
show that the food additives contribute to cancer in people.
Instead, it points to questions for human cancer
researchers to study.
Lung cancer is by far the most common cancer killer around
the world, killing 1.2 million people a year. Smoking is the
most common cause but a majority of smokers do not develop lung
cancer, so scientists are looking for other factors that may
help tumors develop and spread.
Cho's team found phosphate-rich diets affected the Akt
gene, known to be involved in lung cancer, and suppressed
another gene that can help slow cancer's development.