A new study suggests women who start hormone replacement therapy early are not boosting their risk of heart disease.

The study, which will be published in the Journal of the American Medical Association on Wednesday, is reassuring to women who many temporarily start hormone therapy to help them through menopause.

"What I say to younger women now is that this study tells us it is safe for them to use hormone replacement therapy for the relief of menopause symptoms," Dr. Jennifer Blake of Sunnybrook Health Sciences Centre told Â鶹´«Ã½.

Researchers studied data collected from over 27,000 women and found those who started the hormone therapy at a younger age, within 10 years of beginning menopause, had a reduced risk of heart disease.

The youngest women, aged 50 to 59, had an overall reduced risk of death on the therapy.

For most women, the hot flashes and night sweats disappear in two or three years, after which many discontinue taking hormones.

"Every study that comes out sheds a little light ... and it's important that these studies be reported to women," Blake said.

But the study did confirm a higher risk of heart disease in women who began HRT long after menopause, or those who were on the pills 20 or more years after their menopause began.

That's because some women seemed to have chronic menopausal symptoms, which may be a red flag for heart disease.

"There is something about hot flashes and night sweats at an older age which are linked to higher risk, and this risk is then further increased if those women take hormone therapy," Dr. Jacques Rossouw of the National Heart, Lung and, Blood Institute told Â鶹´«Ã½.

But the study isn't a licence for younger women to take HRT, researchers warned.

Other findings from the analyses of the combined trials suggested hormone therapy increases the risk of stroke, and also boosts the risk of breast cancer in women taking estrogen with a progestin.

Rossouw recommends that women considering hormone therapy should manage risk factors such as blood pressure and blood cholesterol, and that they should also get regular mammograms.

With a report by CTV's medical specialist Avis Favaro and medical producer Elizabeth St. Philip