October 17, 2011
Women Who Smoke May Experience Earlier Menopause
Experts warn that women who smoke can go through menopause about a year earlier than those who don´t, and also note that an earlier menopause may influence the risk of bone and heart disease.
The warnings are based on a study of about 6,000 women from the United States, Poland, Turkey and Iran that was carried out by the University of Hong Kong and published in the journal Menopause. The study researchers found that smoking women reach menopause between the ages of 43 and 50, compared to non-smoking women, who normally hit menopause between the ages of 46 and 51.“Our results give further evidence that smoking is significantly associated with earlier (age at menopause) and provide yet another justification for women to avoid this habit,” study leader Volodymyr Dvornyk, of the University of Hong Kong, told Reuters Health by email.
Dvornyk and his colleagues also analyzed five other studies that used a cut-off age of 50 or 51 to group women into “early” and “late” menopause. In those studies, findings showed that 43 percent of the more than 43,000 women studied were more likely to have premature menopause.
During menopause, a woman´s ovaries stop producing eggs and she can no longer get pregnant.
“General consensus is that earlier menopause is likely to be associated with the larger number and higher risk of postmenopausal health problems, such as osteoporosis, cardiovascular diseases, diabetes mellitus, obesity, Alzheimer's disease, and others,” noted Dvornyk, adding that premature menopause is also thought to increase a woman´s risk of death.
Late menopause is thought to increase the risk of breast cancer because one of the risk factors for the disease is more time exposed to estrogen.
Jennie Kline, an epidemiologist from Columbia University's Mailman School of Public Health in New York, told reporters from Reuters and the UK's Daily Mail that there are two theories for why smoking could mean earlier menopause.
One theory is that smoking could have an effect on how women´s bodies make, or get rid of, estrogen. The other is that certain components of cigarette smoke might kill eggs, said Kline, who was not involved in the study.
The research team did not have information on how long women had been smoking or how much they smoked per day, so they could not determine how either of those factors may have affected age at menopause.
Based on the lack of data on women´s smoking habits and other health and lifestyle factors linked to menopause, Dvornyk said the analysis may not be enough to resolve any questions on the link between smoking and menopause.
Kline noted that alcohol, weight and whether women have given birth or not may also play a role in when they go through menopause, but said that those factors have had mixed results.
It is also possible that the same factors that influence age at menopause may determine whether women have trouble with infertility or not, or how late they can get pregnant.
“There are way better reasons to stop smoking than worrying about menopause,” added Kline.
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