Cigarette smoking is bad for the health. But for women, it may cause additional negative side effects, associated with triggering the earlier onset of menopause. Multiple studies have confirmed that tobacco smoking can actually affect the timing of the onset of menopause, the intensity of the symptoms of menopause, and the incidence of osteoporosis after menopause.
Women who smoke need to recognize these risks and do their best to kick the habit.
Massachusetts General Hospital Study
Menopause occurs when the ovaries cease to produce estrogen. A gene, Bax, and a genetic receptor, Ahr, are responsible for the onset of menopause when they become activated. Researchers at Massachusetts General Hospital have discovered that the chemicals in smoking directly activate these genetic components, creating what they call a “specific pathway” to killing ovarian cells.
It has been found that women who smoke more than ten cigarettes a day are 40 percent more likely to go into menopause early than nonsmokers. As was generally observed by the result of the study, women who smoke will enter menopause one to two years earlier.
University of Oslo, Norway, Study
Some interesting results were received by Norwegian scientists, who tried to review multiple factors as potential triggers for the menopause to strike earlier than expected statistically. Here are the important findings of the study:
- The study showed substantial association between current smoking and early onset of menopause, and that the earlier a woman stops smoking, the more protection she derives with respect to an early onset of menopause.
- While female smokers increase their risks to escalate the menopause onset, the study did not find any relationship between passive exposure to smoking and early menopause.
- No association was revealed between early menopause and alcohol or coffee consumption.
University of Hong Kong Study
The most recent study, which was carried in the journal Menopause, pooled data from several previous studies that included about 6,000 women in the United States, Poland, Turkey and Iran.
The researchers concluded that while non-smokers hit menopause between age 46 and 51, on average, in all but two of the reviewed previous studies, smokers were younger when they hit menopause, between 43 and 50 overall.
"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," wrote study author Volodymyr Dvornyk, from the University of Hong Kong.
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. Out of more than 43,000 women in that analysis, women who smoked were 43 percent more likely than nonsmokers to have early menopause.
Both early and late menopause factors have been linked to health risks. Women who hit menopause late, for instance, are thought to be at higher risk of breast cancer because one risk factor for the disease is more time exposed to estrogen.
"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," explained Dvornyk. Overall, he added, early menopause is also thought to slightly raise a woman's risk of death in the years following.
There are two theories for why smoking might mean earlier menopause, said Jennie Kline, an epidemiologist from Columbia University's Mailman School of Public Health in New York. Smoking make have an effect on how women's bodies make, or get rid of, estrogen. Alternatively, some researchers believe certain components of cigarette smoke might kill eggs, added Kline, who was not involved in the study.
Dvornyk's team did not have information on how long women had been smoking or how many cigarettes they smoked each day, so his team could not determine how either of those factors may have affected age at menopause. For that reason, and a lack of data on other health and lifestyle factors linked to menopause, the analysis may not be enough to resolve lingering questions on the link between smoking and menopause, they said.
Alcohol, weight and whether or not women have given birth may each also play a role in when they hit menopause, but the evidence for everything other than smoking has been mixed, Kline said. 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.
While there is a definite connection between smoking and menopause, but can smoking indeed cause early menopause? "Smoking can cause a woman to go through menopause a year or two earlier, but it isn't going to push a woman into menopause before the age of 40," says Geoffrey Redmond, MD, director of the Hormone Center of New York. So, in other words, smoking may cause the earlier menopause, but is unlikely to cause the early menopause in strict scientific terms.
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