Whether it's
jogging around the park, pumping
iron or swimming, an hour of
vigorous exercise a day can
lower the risk of bowel cancer,
a study said.
Even cleaning the house, or two hours
of less strenuous activity can make
a difference, according to the study
of more than 413,000 people in 10
European countries.
"This study is significant because
of its very large sample size and
the different levels of activity that
were observed across the European
countries," said Dr Christine Friedenreich,
lead author of the research, from
the International Agency for Research
on Cancer (IARC) in Lyon, France.
"This allowed a more in-depth analysis
of how physical activity influences
colon cancer risk," she added.
The research was published by scientists
working for the European Prospective
Investigation into Cancer and Nutrition
(EPIC), which was designed to investigate
the relationships between diet, nutrition,
lifestyle and environmental factors
and cancer.
A team of international scientists
analyzed the impact of physical activity
on the risk of colon cancer and found
people with the highest levels of
exercise were 22 percent less likely
to develop it. The reduced risk was
higher, up to 35 percent, for tumors
on the right side of the colon.
Although exercise had the biggest
impact in cutting cancer risk in people
of normal weight, it was also beneficial
to a lesser extent in men and women
who were overweight or obese.
But exercise did not have a protective
effect against rectal cancer.
Colon and rectal are among the most
common cancers in developed countries.
More than 940,000 cases are diagnosed
each year and about 492,000 people
die from the illness, according to
IARC.
Health experts estimate about 70
percent of cases could be prevented
by changes in diet and exercise.
Professor Elio Riboli, the coordinator
of EPIC from Imperial College London,
said the large number of people included
in the research was important.
"We were particularly interested
in the results that we found for different
parts of the colon and rectum which
were not feasible in previous studies
because of the smaller sample sizes
and lack of data on the position of
the tumors," he said in a statement.
