Smoking linked to earlier menopause: study

Women who smoke may hit menopause about a year earlier than those who don't light up, according to a study that also notes an earlier menopause may influence the risk of getting bone and heart diseases.

The 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.

Non-smokers hit menopause between age 46 and 51, on average. But in all but two of the studies, smokers were younger when they hit menopause, between 43 and 50 overall.

During menopause, a woman's ovaries stop producing eggs and she can no longer get pregnant.

"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 analysed 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 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," Dvornyk told Reuters Health in an email.

Smoking and Menopause

Cigarette smoking can 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.

Smoking's Effect on the Onset of Menopause

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.

Generally, women who smoke will enter menopause one to two years earlier. Early menopause has been seen to lead to heart disease, strokes, and osteoporosis; therefore, if a woman can prevent its early onset by stopping smoking, she needs to do so.