A diet filled with meat and dairy raises levels of a hormone that promotes cell growth by 15%.

University of Oxford researchers found men with high blood levels of the specific hormone were 40% more likely to develop prostate cancer than those with low levels.

Researchers also say it can help the spread of tumours.

The hormone plays a key role in the growth and development of children and adolescents, but in adults it can inhibit the death cells which have come to the end of their natural life cycle.