We all know that smoking is bad for us, leading to a host of problems such as lung cancer and heart disease. We also know it’s bad for children developing in their mother’s womb, leading to birth defects and childhood leukemia.
However, according to a new study published in the American Association of Cancer Research, medical researchers believe that even smoking outside before pregnancy can cause genetic changes that cause childhood leukemia.
How Smoking Causes Cancer in Children
In the past, researchers have linked smoking tobacco by parents to incidents of leukemia in children. In the current study, researchers led by Adam J. de Smith of the University of California San Francisco have been able to link toxic effects from tobacco exposure in parents to the leukemia cells in their children.
Acute lymphoblastic leukemia (ALL) is a cancer that causes the bone marrow of a child to make irregular lymphocytes with errors known as deletions in their DNA. This causes abnormal growth that crowds out healthy cells.
As part of the study, the researchers examined tumor samples from 559 patients with ALL in California. The researchers checked for specific gene deletions and compared these to the smoking habits of the parents.
Smoking Increases the Risk of Childhood Leukemia
Researchers found a 22 percent increase in the number of deletions for each five cigarettes smoked during pregnancy. A 74 percent increase in the number of deletions was associated with every five cigarettes smoked while breastfeeding.
Smoking five cigarettes a day by either the mother or father before conception was associated with a 7 percent to 8 percent increase in the number of deletions, showing that even smoking tobacco causes problems even before pregnancy.