28 August 2012

Does gender really affect dementia?

Research shows that female hormones could be the reason for the increase risk of dementia, which could mean that hormone replacement therapy could be a possible treatment for the condition.

For years scientists have known that men and women’s brains function differently, for example women are more likely to suffer from depression but less likely to get the kind of brain damage you get in a car accident.

It has been pointed out that there has not been enough research into the gender differences and, in fact, many studies have focused purely on the male brain, leaving women even more vulnerable.

Glenda Gillies, professor of neuroendocrine pharmacology at Imperial College London, studies the effects of drugs and hormones on the brain and is concerned about the neglected area of research. She said, ‘We need much better data about gender differences. It’s women who are losing out because of this, and because they live longer, at any one time significantly more women will have the disease than men, so we need to know a lot more about what works for them.’

Gender also affects the types and location of the harmful proteins that infect the brain, causing dementia. Professor of neurobiology at the University of California, Larry Cahill found that about 90 per cent of male sufferers have the proteins in the central area of the brain which controls hunger and eating while only 10 per cent of women experience proteins in this region.

A study from the University of Hertfordshire reported that women felt the effects of Alzheimer’s much more than men. Research from Kansas University found that if your mother had the disease, it doubles your risk of developing the condition compared to having a father who had it.

The failure to investigate gender differences in diseases isn’t a new issue. Lynn Posluns, founder of the charity, Women’s Brain Health Initiative said, ‘Twenty years ago, doctors were less likely to spot a woman was having a heart attack because they misinterpreted symptoms. Doctors were trained that the classic symptom of a heart attack — a stabbing pain in the heart and pain down the left arm — applied to women, too. However, female heart attack symptoms can include nausea, breathlessness, an upset stomach and a feeling of exhaustion. As a result, women took longer to get vital treatment. We are determined not to let it happen all over again with Alzheimer’s.’

As yet, no research has been conducted into the contribution of gender to developing dementia but Professor Walter Rocca, a neurologist at the Mayo Clinic in Minnesota, found that, ‘When a woman has a hysterectomy, often because of fibroids or pain, the surgeon often removes the ovaries as well.” He found that this increased the risk of Alzheimer’s by 140 per cent but by replacing the oestrogen the risk returned to normal. He added that, “Doctors have been nervous of giving oestrogen to protect the brain because of the link with cancer and heart disease but the latest finding is that there is a therapeutic window between 50 and 60. The danger doesn’t seem to be there if oestrogen is given close to the menopause.”

‘Sex differences in Alzheimer’s hasn’t become much of a live issue in Britain yet,” says Professor Gillies, “But it is certainly an area that needs more attention.”