Women on HRT stay clever and alert for longer

Women with high levels of the female hormone oestrogen in their blood stay smarter for longer, scientists have found.

Women with high levels of the female hormone oestrogen in their blood stay smarter for longer, scientists have found.

In a further boost for advocates of hormone replacement therapy (HRT), researchers have discovered that women with the highest levels of oestrogen are least likely to suffer problems with memory or concentration as they age.

British researchers described the study, conducted at the University of California and published in The Lancet medical journal, as "very encouraging".

HRT, used by women after the menopause to replace declining levels of oestrogen, has been the favoured drug of many high-powered women, including the Billericay MP, Teresa Gorman, and the author and broadcaster Dr Miriam Stoppard, for more than a decade.

Others said to have begun using the treatment include the actress Lauren Hutton, the Bodyshop's Anita Roddick and the presenters Sue Lawley and Valerie Singleton. Women who take it have long been observed to be at lower risk of Alzheimer's disease, and several trials to test its preventive effect against dementia are underway.

Kristine Yaffe and colleagues at the University of California measured the level of oestradiol, the principal form of oestrogen which is naturally produced from puberty until the menopause, in 425 women over 65. Their cognitive performance was assessed on a standard scale when the study began, between 1986 and 1988, and again six years later.

All the women showed a slight decline in cognitive function but among those with the lowest levels of oestradiol, 16 per cent (17 of 106) suffered a significant decline six years later. For those with the highest levels, only 5 per cent (5 of 94) showed a similar decline.

Previous studies, including one by Dr Yaffe, have failed to find a link between oestradiol and cognitive function. In this study, the effect was noted only for free oestradiol in the blood, which is active, not for that bound to protein. The researchers say: "A possible explanation is that unbound or loosely bound oestradiol crosses the blood brain barrier more readily than total oestradiol." There was no link with circulating levels of testosterone, the male hormone, which were also measured.

David Purdie of the Centre for Metabolic Bone Disease at Hull Royal Infirmary, and a former chairman of the British Menopause Society, said: "This is very encouraging. As the population ages the progressive loss of neurones goes on apace and dementia will rise unless some intervention can be devised. The hope is that either natural oestrogen or HRT will contribute to preserving the network of neurones.

"Maybe in the future we will be able to examine the amount of free oestradiol circulating in a woman's blood and if it is low give her HRT to restore the level... If their mother suffered from Alzheimer's disease that may be an added reason to take HRT," Professor Purdie added.

* Heart disease among women declined by 31 per cent between 1980 and 1994 in the US, as a result of the reduction in smoking, better diet and increase in the number on HRT. But the rising level of obesity slowed the declining trend, according to a study in the New England Journal of Medicine.