A VICTORIAN psychiatrist has accused Ian Gawler's foundation of denigrating conventional cancer treatments and encouraging people to use harsh and unjustified lifestyle changes to combat cancer.

After attending several Gawler Foundation programs last year, Dr Tanya Hall said she was troubled by the strict diet and excessive juicing regime taught to cancer patients and was surprised to hear a program leader say there was no evidence to show chemotherapy was effective.

Ian Gawler. Credit:Joe Armao

''This was nothing less than astonishing, patently untrue, and highly disrespectful to those of us undergoing chemotherapy,'' she wrote of her experience in the Medical Journal of Australia.

''In fact, while criticism of conventional medicine is noticeable, there is an almost complete lack of critical analysis among participants of Gawler's methods - which are supported in a quasi-religious fashion.''