Smoking may pose a bigger health threat to women than men, say researchers.
Women who smoke have a higher risk of cancer than men, Norwegian investigators found.
They looked at the medical records of 600,000 patients and discovered the bowel cancer risk linked to smoking was twice as high in women than men.
Female smokers had a 19% increased risk of the disease while male smokers had a 9% increased risk, Cancer Epidemiology, Biomarkers & Prevention reports.
In the study, nearly 4,000 of the participants developed bowel cancer. Women who started smoking when they were 16 or younger and those who had smoked for decades were at substantially increased risk of bowel cancer.
Experts already know that women who start smoking increase their risk of a heart attack by more than men who take up the habit, although it is not clear why.
/BBC/