Experts have gathered the strongest evidence yet that a woman's lifestyle is linked to her risk of developing breast cancer. The biggest ever review of research into the issue has concluded that women should limit alcohol, take exercise and maintain a healthy weight. More than four out of 10 cases of breast cancer could be prevented if women adopted healthier lifestyles, experts have predicted. Breastfeeding babies is also an important factor in helping cut the chance of developing the disease, which kills around 12,000 women in the UK each year. The latest study, from experts at the World Cancer Research Fund (WCRF), is an update on its cancer prevention report published in 2007, which looked at many different types of the disease. That report drew on 873 breast cancer studies but now scientists at Imperial College London have added another 81 carried out in the last few years. These latest studies confirm the link between lifestyle and breast cancer. Professor Martin Wiseman, medical and scientific adviser for the WCRF, said the new report "represents the clearest picture we have ever had" on how lifestyle affects a woman's risk of breast cancer. He added: "This means we are now more sure than ever before that by limiting the amount of alcohol they drink, maintaining a healthy weight and being physically active, women can make a significant difference to their risk.
"We estimate over 40% of breast cancer cases in the UK could be prevented just by making these relatively straightforward changes. "About 45,000 women are diagnosed with breast cancer every year in the UK, so it is clear these changes could make a big difference. "As well as this, there is also convincing evidence that mothers who breastfeed reduce their risk and breastfeeding probably also reduces babies' chances of gaining excess weight as they grow." The charity recommends that both men and women aim to be as lean as possible without becoming underweight. A healthy body mass index (BMI) is between 18 and 25 and the WCRF encourages people to remain close to the lower end of the scale. The charity also recommends at least 30 minutes of exercise a day and, if alcohol is drunk at all, it is limited to two drinks a day for a man and one for a woman. The latest study on breast cancer is part of a Continuous Update Project run by the WCRF. The goal is to continuously update the findings of the WCRF's 2007 report so that experts draw on the latest research when advising people on cancer prevention. Bowel cancer and prostate cancer will now be studied, with updates on them available in 2010. Marilyn Gentry, chief executive of the WCRF, said: "As a charity we believe it is important that people have access to advice that is based on the latest scientific research and this is why we are proud to be funding the Continuous Update Project.
"When people read about new research it is impossible for them to take the findings and weigh them up against all the other research that has been done.
"The idea of this project is to do that job for them.
"These are still quite early stages in the project but once it is fully up and running it will mean that people all over the world will always have access to up-to-date advice about how they can make lifestyle changes that can reduce their risk of cancer," she added.
"We believe this can play an important role in the fight against cancer."
Arlene Wilkie, director of research and policy at Breast Cancer Campaign, said: "This review provides further evidence that maintaining a healthy weight throughout life along with regular physical exercise will reduce the risk of many health problems including breast cancer, heart disease, high blood pressure, diabetes, arthritis and other types of cancer.
"Although age is the biggest single risk factor -- 80% of breast cancers are diagnosed in women over the age of 50 -- being overweight after the menopause increases your risk even further."