New breast cancer alert

New research has revealed why British women are at much greater risk of breast cancer and heart disease.

Tests show that oestrogen is far more prevalent in modern Western women than in those from less developed societies.

Scientists warn today that high levels of the female hormone could be one reason why so many women in Britain develop breast cancer and heart disease.

Dr Tessa Pollard, a lecturer in biological anthropology at the University of Durham, suggests that affluent lifestyles and rich Western diets during pregnancy could be responsible for producing high levels of oestrogen in girls, who go on to keep those high hormonal levels for the rest of their lives.

By contrast, women in poorer African nations who have meagre diets during pregnancy bear children with lower oestrogen levels - and who go on to have correspondingly lower instances of heart disease and breast cancer.

One in nine women in the UK will suffer breast cancer in her lifetime and one in five deaths is linked to heart disease.

Oestrogen is known to fuel most types of breast cancer. It also protects women from heart disease up to the menopause. Oestrogen levels seem to vary depending on where in the world a woman is brought up, says Dr Pollard.

One study showed that Dogon women in Mali, west Africa, experienced an average of 109 periods in a lifetime, compared with a Western woman's 400. Menstrual cycles are known to boost oestrogen levels.

In addition, women in richer countries now have their first period earlier than those in poorer countries and have the menopause later.

Dr Pollard claims that those born in underdeveloped countries have more "normal" levels of oestrogen.

Speaking at the British Association Festival of Science at the University of Salford, Dr Pollard said: "Why do so many women in countries like the UK get breast cancer? It seems likely that oestrogen is a big part of the answer."

Dr Pollard said her work was looking at whether a woman's early environment in the womb and early childhood helped set her oestrogen levels for life.

Dr Pollard is carrying out a study in Newcastle upon Tyne, focusing on women from Pakistan, to prove her theory. She is also working with another researcher, in London to focus on Bangladeshi immigrant women.

Dr Pollard said: "In today's world women's environments are much more likely to change dramatically than in our evolutionary past."