Hormone replacement therapy, often referred to as HRT, contains the hormone estrogen and sometimes progestin and is given to many women after menopause to relieve symptoms such as hot flashes and insomnia.

In 2002 a large study discovered a connection between taking estrogen and progestin for menopause and the risk of breast cancer. Later this study also presented some evidence that the combined hormone therapy may also increase the risk of stroke and heart disease.

At the time another large study – the Women’s Health Initiative – was in progress. It consisted of over 16,000 women between the ages of 50 and 79 who were using hormone replacement therapy. The study ended early because of the other results.

More recently there is evidence that the number of new breast cancer cases has gone down dramatically which many attribute to many less women using HRT. This study was lead by Donald Berry from the University of Texas M. D. Anderson Cancer Center. It reports a 7% decrease between 2002 and 2003 – with the largest difference seen in women from 50 to 69 years old – at 12%.

It is believed that it is related to estrogen receptor positive breast cancers which need the hormone estrogen to grow. There is still uncertainty however with this conclusion since the study relied on population statistics.

A new study called the Kronos Early Estrogen Prevention Study (KEEPS) headed by Virginia Miller of the U.S. Mayo Clinic College of Medicine is going to study over 700 women between 42 and 58 to see if HRT has a protective effect from heart disease if started at a younger age. It is believed by some researchers that if you start the hormone treatment at an earlier age it will benefit women. This could possibly be due to being able to prevent the plaque build up in arteries to begin with.

Other research paid for by the National Institutes of Health (NIH) has shown that black cohosh does not relieve hot flashes for women during menopause. It was headed by Katherine Newton of the Group Health Center for Health Studies in Seattle and the University of Washington. For this study, 351 women from 45 to 55 were given either black cohosh or one of four other possible treatments. The five different substances given were 1) black cohosh by itself, 2) a combination of black cohosh, alfalfa, licorice, oats, pomegranate, Siberian ginseng and 4 other things, 3) number 2 along with increased dietary soy, 4)hormone therapy or 5) a placebo. It was found that black cohosh only had their number of hot flashes reduced by as much as those taking the placebo. The women taking the hormones did however have their number of hot flashes reduced significantly.

Lastly, a study in Human Reproduction shows evidence that women who are twins have a greater chance of a premature menopause due to premature ovarian failure (POF) compared to other women. Around 800 twins in Australia and Britain were studied. It was discovered that twins were 3-5 times more likely to have POF between 40 and 45 years old.

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