Hormone therapy 'could help prevent strokes'

Hormone therapy can make the brain “younger” – and could protect against strokes, scientists said today.

Tests on postmenopausal women taking hormone therapy (HT) suggest the drugs can make their brains function more like those of younger women.

A study by Durham University in the UK found that, when women taking HT were asked to complete tasks of fine motor co-ordination, such as sequential finger tapping, the left and right sides of the brain worked more closely together than women of the same age who were not taking the sex hormone drugs.

Researchers say this mirrors the brain activity of younger women who naturally produce the sex hormones in their bodies.

The results contribute to a better understanding of the influence of sex hormones on the brain, although more research is needed to show how this affects the tasks carried out by women in their everyday lives.

Ultimately, researchers hope to find out if sex hormones can make the brain more resistant to damage through stroke or other injuries.

Previous studies have shown that women tend to use both halves of their brain more equally compared to men who tend to have a more dominant side.

The Durham researchers suggest the extent to which this is the case is influenced by the level of sex hormones.

Their studies, conducted over 10 years, show variations in brain organisation at different times of a woman’s menstrual cycle and under the influence of hormone therapy drugs.

The study findings suggest HT helps to open the gateway between the left and right side of the brain and encourages interaction between the two halves.

Lead researcher, Durham University psychologist Dr Markus Hausmann, said: “Sex hormones are powerful in changing the way the brain is organised, and can affect not only sexual and reproductive behaviour but also cognitive functioning.

“The tests with postmenopausal women show that HT can help both sides of the brain pull their weight, much in the same way as the brain organises itself in younger women.

“We hope to establish whether sex hormones can make the brain less vulnerable to the effects of stroke and other injuries by ’sharing’ the load between the two hemispheres as women get older.

“However, more research is needed on this.”

The study group of 62 postmenopausal women were split into three: one group taking hormone therapy with only oestrogen, one with a combination of oestrogen and synthetic gestagens, and one without HT. All women were asked to tap buttons with their fingers in certain orders of varying difficulties.

They were asked to complete any given sequence five times on each hand within 10 seconds.

An example of a relative complex sequence would be index finger, ring finger, middle finger, small finger.

Dr Ulrike Bayer, research fellow at Durham’s psychology department and author of the paper, said: “Right-handers usually perform better with their dominant right hand compared with the left hand.

“The relative difference between hands, however, is reduced when the task is rather complex.

“When both hands perform more equally, it is a sign that the two brain halves are interacting more and this was found to be more pronounced in women taking HT than in those not using HT.”

It is thought that HT is used by about a million women aged over 50 in the UK.

It can be taken to reduce the symptoms of menopause, such as hot flushes, mood changes and loss of sex drive.

HT has also been linked to adverse side effects.

Studies have shown that HT slightly increases the risk of developing breast cancer, ovarian cancer, stroke and heart attacks.

The study is published in the academic journal Hormones and Behavior and was funded by the German Research Foundation (Deutsche Forschungsgemeinschaft).