ISLAMABAD: Tobacco smoke might do more than cause cancer, heart disease and lung damage. It might also injure fertility in women, researchers reported Tuesday.
Women who smoked the most, and who started at the youngest ages, went through menopause almost two years earlier than women who never smoked, Danielle Smith of the Roswell Park Cancer Institute in Buffalo and colleagues reported.
Women who remembered breathing in the most secondhand smoke went through menopause an average of 13 months earlier than women who didn't think they'd ever breathed any in, the team reported in the journal Tobacco Control.
The team studied more than 93,000 women taking part in the Women's Health Initiative Observational Study between 1993 and 1998. They filled out very detailed questionnaires on lifestyle habits, health problems and medical diagnoses.
They found that women who smoked 100 cigarettes or more in their lives had a 14 percent greater risk of infertility and a 26 percent greater risk of going through menopause before they turned 50.
"Tobacco toxins also seem to lower the age of natural menopause by reducing circulating estrogen."
The study helps confirm other studies that have linked smoking with early menopause.
Women who grew up with a smoker in the house for 10 years or more, those who lived with a spouse who smoked for 20 years or more, and those who worked with smokers for 10 years or more were 18 percent more likely to have had infertility problems than women who had never been passive smokers.
Overall, about 15 percent of the women said they had struggled to conceive for a year at a stretch or more, and 45 percent said they went through menopause before they turned 50.
There's a debate over whether fertility rates have fallen, and many people have blamed chemicals known as endocrine disruptors in cans, bottles and in water supplies. But tobacco also contains these.
The toxins in tobacco smoke can interfere with the production of hormones related to fertility cycles, they can damage the production of egg cells, they can hurt the embryo before it gets implanted in the wall of the uterus, and they can restrict the processes that prepare a womb for pregnancy, the researchers said.
"Tobacco toxins also seem to lower the age of natural menopause by reducing circulating estrogen," they wrote.
Smoking can also affect men in specific ways. For instance, it seems to damage the male Y chromosome especially badly.
Smoking is on the wane in the U.S. Last month, the Centers for Disease Control and Prevention reported the percentage of U.S. adults who smoke cigarettes declined from 20.9 percent in 2005 to 16.8 percent in 2014.
And smoking bans have made secondhand smoke in the workplace and public areas a thing of the past in most states.