Pettersson, A., Johansson, B., Persson, C., Berglund, A., & Turesson, I. (2012). Effects of a dietary intervention on acute gastrointestinal side effects and other aspects of health-related quality of life: A randomized controlled trial in prostate cancer patients undergoing radiotherapy. Radiotherapy and Oncology, 103(3), 333–340.
To examine the effect of decreased intake of insoluble dietary fiber and lactose on acute gastrointestinal (GI) side effects and other aspects of health-related quality of life (QOL) in patients with localized prostate cancer receiving radiotherapy (either brachytherapy or proton therapy)
Patients in the intervention group were instructed to avoid foods high in insoluble dietary fiber and lactose and to consume foods higher in soluble fibers and low in lactose beginning at baseline and continuing for 24 months past the completion of radiotherapy. Patients in the standard care group were instructed to continue their normal diet during this time period. Data was collected at four time points: prior to randomization and initiation of radiotherapy, after four weeks of treatment, one week after radiotherapy completion, and two months after completion of radiotherapy.
This was a single-site, outpatient study conducted in Uppsala, Sweden.
Patients were undergoing multiple phases of care.
This was a randomized controlled trial.
Both the intervention group and the standard care groups followed dietary instructions as indicated by an interaction effect between randomization and time in the FFQ scores (p ˂ 0.001). The dietary intervention had no statistically significant effect on GI side effects or other aspects of QOL, although bowel symptoms were lower in the intervention group.
The dietary intervention of decreased intake of insoluble dietary fibers and lactose did not have an effect on acute GI side effects in patients with localized prostate cancer undergoing radiotherapy (either brachytherapy or proton therapy).
Although this study did not show that a diet with reduced intake of insoluble dietary fiber and lactose had a significant effect on GI side effects, it did show a tendency toward lower prevalence of bowel symptoms in the intervention group during radiotherapy, which suggests the intervention may have had a positive effect. Controlling for health status in future studies might lead to a different outcome. Also, patients in this study had localized prostate cancer where a small part of the rectum was in the field of irradiation. Future research should evaluate the effect of the diet intervention in patients with lymph node positive disease, which would involve a larger bowel volume in the radiation field and increase the possibility of GI toxicity.