Research to probe soy's positive effects on prostate cancer

Researchers at the University of Ulster in Northern Ireland and Belfast City Hospital are to launch a study on the link between dietary intake of soy and the prevention of prostate cancer.

There is already significant evidence to suggest that diet may have a role to play in preventing cancer.

Professor Ian Rowland from the University of Ulster said: "The incidence and mortality rate of certain cancers such as colorectal and prostate cancers, is much higher in western countries than in the East.​

"It is thought that this may be due to the differences in the foods people eat in different parts of the world. Studies suggest that it is the high amounts of soy food that people eat in eastern countries, such as Japan and China, that helps protect them against prostate cancer."​

Rowland noted that people in western countries, such as Northern Ireland, do not eat much soy and therefore could be missing out on a protective effect.

"This link between high soy consumption and low prostate cancer mortality is backed up by studies using animal fed high soy diets and by laboratory research using prostate cancer cells treated with compounds extracted from soy beans. Now what we need is evidence that soy can help to prevent the onset of prostate cancer, or, slow its progression, in humans. This is the primary aim of the new research project."​

The study will be carried out in collaboration with Dr Patrick Keane at Belfast City Hospital. Men attending the hospital for a biopsy of the prostate will be invited to take part.

Participants will be given milk drinks containing soy compounds over a four month period. Biological markers that indicate prostate cancer risk will then be measured to see whether the soy-rich diet had any beneficial effects. Any changes in the prostate cells themselves can also be detected.

Professor Rowland highlighted the worrying number of cases of prostate cancer in Northern Ireland - statistics from the Northern Ireland Cancer Registry show that at least 470 new cases of prostate cancer are reported in the province each year, and that the cancer causes around 200 deaths annually.

"It is the second most common cause of cancer death in males in Northern Ireland, and is catching up with lung cancer. Both incidence and mortality are increasing. That is why investigating new ways to prevent, or minimise the effects of the disease is so crucial,"​ concluded Rowland.