The 93 study participants were men with early-stage prostate cancer who had chosen "watchful waiting" instead of active treatment for their prostate cancer.
During the one-year study, six men in the usual care group underwent conventional treatment because of rising prostate specific antigen, known as PSA, or evidence of progression from magnetic resonance imaging. In contrast, none of the men in the comprehensive lifestyle group, who followed a very-low-fat diet of 10 percent or less of daily calories, needed treatment. PSA levels decreased 4 percent in the lifestyle group, whereas PSA levels increased 6 percent in the usual-care group.
In addition, cell-culture studies showed that blood from men in the lifestyle group inhibited the growth of prostate-cancer cells by 70 percent, compared to 9 percent for men receiving usual care, according to the study published in the Journal of Urology.
The findings were reported in The Johns Hopkins Health Alerts.