When prostate cancer recurs, eating a plant-based diet and reducing stress may help slow progression of the disease, a new study shows.

Writing in the journal Integrative Cancer Therapies, Dr. Gordon A. Saxe of the Moores UCSD Cancer Center in La Jolla, California and colleagues note that hormone treatment may be used to extend survival when prostate cancer returns. However, they add, the treatment reduces sex drive, causes hot flashes and weakens bones.

The researchers investigated whether a plant-based diet might be another way to slow the advance of recurrent prostate cancer, because the typical "Western" diet high in animal protein and low in plant foods has been seen to boost the progression of the disease.

Because changing dietary habits can be stressful, the researchers note, they included stress reduction techniques in their intervention.

Fourteen men with recurrent prostate cancer participated in the study. They were instructed in how to raise their consumption of whole grains, vegetables, fruits, and legumes, and taught how to meditate and do several yoga and tai chi exercises. 

Just ten of the patients could be evaluated after the 6-month intervention, because two dropped out and two opted for hormone therapy.

Compared to the 6 months before the study, the average rate at which the patients' PSA levels rose slowed down during the dietary modification programs. Four patients actually showed a drop in PSA levels.

The rate of PSA rise is the best predictor of survival and cancer spread, Saxe and his team note.

"Our findings suggest that the intervention we employed may have resulted in a slowing of disease progression and, in a few patients, possibly disease reversal," they write, concluding: "These results provide preliminary evidence that adoption of a plant-based diet, in combination with stress reduction, may attenuate disease progression and have therapeutic potential for clinical management of prostate cancer."

SOURCE: Integrative Cancer Therapies, September 2006