New methods in breast cancer investigations

Monday 10 November 2003

New methods which may help prove that eating high-fibre foods such as strawberries, lentils and soy and can help prevent or influence the treatment of breast cancer, have been developed by scientists at the University of St Andrews.

The researchers are the first in the world to have developed methods of measuring the effects of chemicals called phyto- oestrogens on humans. These plant hormones – similar to the female sex hormone oestrogen – are found most commonly in soy beans and other high-fibre foods.

Previous research has found that women with high levels of phyto- oestrogens in their bodies are less susceptible to cancer. This is partly due to the effect they have on lowering natural production of oestrogen – high levels of which have been linked to breast cancer.

Recent research has reported that breast cancer is less prevalent in Asian women, who have a high- fibre, phyto-oestrogen containing diet. Until now, however this research has not been properly validated (tested for accuracy) nor tested on humans; previous researchers have used rats or mice.

The work of the St Andrews-based researcher, Dr Margaret Ritchie, has been described as ‘exceptionally important’ and ‘invaluable’ by independent academics, and has been causing excitement at cancer conferences in America and Europe this summer.

Dr Ritchie, a chemistry graduate and honorary lecturer at the University of St Andrews, has spent the last 3 years constructing and validating a database of foods which contain phyto-oestrogens. The database can be used to investigate the effects of human exposure to these compounds.

“So far, nobody in the World can accurately monitor human exposure to phyto-oestrogens, or how people respond to such exposure. This is a major breakthrough we are leading and is a massive step forward”, she said.

Phyto-oestrogens are found in around 300 foods, including many fruits and vegetables, sunflower and sesame seeds and rye, but most of all soybeans – good sources of which include tofu, soya milk and soya flour. Their potential anti- oxidant and anti-cancer properties have made these compound central to extensive research in phytochemical and nutritional studies.

A fundamental factor in phyto- oestrogen research is the absence of a ‘biomarker’ – a reliable biochemical snapshot of human exposure (or effects of exposure) to a particular pollutant or compound. Under the guidance of Professor John Cummings, a biomarker expert at Dundee’s Ninewells Hospital, Dr Ritchie set about identifying and validating several suitable biomarkers of phyto-oestrogen exposure. Biomarkers, which have long-term reliability and accuracy, can be used to measure exposure to a compound and the effect of such exposure on the risk of developing diseases.

“It was a case of going back to basics,” said Dr Ritchie. “It’s amazing that no-one has developed a biomarker of phyto-oestrogen exposure before,” she said.

In recent years, it has been claimed that phyto-oestrogens can also help prevent prostate cancer as well as alleviate the symptoms (mood swings, hot flushes) of the menopause, though this has yet to be proved. Dr Ritchie’s database however, will assist researchers in painting a clearer picture of the use and effects of these plant hormones, which could be invaluable for the future prevention of breast cancer or assistance in its treatment.

The database – which will be made freely available to researchers across the World via the University of St Andrews’ website – is already being used in an Edinburgh-based prostate cancer study.

To build the database and validate biomarkers of phyto-oestrogen exposure, Dr Ritchie enlisted almost ninety volunteers from all over Scotland; healthy, cancer- free women aged between 18 and 81, who each kept a food diary for up to six months. They returned their food diaries and diets to Dr Ritchie and supplied her with over 500 blood, urine and diet samples so that she could measure exposure to phyto-oestrogens. Some men were included in the research to prove that the biomarkers were reliable regardless of gender.

Dr Ritchie has presented her research at conferences in Scotland, the US, Germany and Ireland this year and will publish the results an upcoming issue of the prestigious British Journal of Nutrition. The research is also currently under review by the European Journal of Clinical Nutrition and the new Journal of Evidence-Based Integrative Medicine.

Dr Ritchie, who trained and worked as a Chemistry teacher before returning to full-time research, is an advocate of Complementary Medicine, and has assisted in the treatment of patients with cancer and with the care of babies in special care units using such therapies.

During the course of her research, Dr Ritchie collaborated with colleagues at the University’s Schools of Medicine and Chemistry, including Professor Michael Steel, an expert in breast cancer; Dundee’s Ninewells Hospital and the Scottish Crop Research Institute.

ENDS DR RITCHIE IS AVAILABLE FOR INTERVIEW ON (01382) 534206 or [email protected]


Issued by Beattie Media On behalf of the University of St Andrews Contact Gayle Cook on 01334 467227, mobile 07900 050 103, or email [email protected] Ref: M Ritchie Breast Cancer pr 071103 View the latest University news at

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