Adoption of a plant-based diet by patients with recurrent prostate cancer.
Study Goal
The researchers aimed to investigate whether adopting a plant-based diet could influence the rate of PSA rise in patients with recurrent prostate cancer.
Results Summary
The study found that increased intake of plant-based foods was associated with a decreased rate of PSA rise, suggesting potential therapeutic benefits for managing prostate cancer recurrence. However, the effect was not sustained at 6 months, indicating variability in long-term adherence or efficacy.
Population
Asymptomatic, hormonally untreated prostate cancer patients with rising PSA levels post-surgery or radiation therapy.
Effective Dosage
Not specified (servings per day of whole grains and vegetables increased, but exact dietary plan not detailed).
Duration
6 months
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
plant-based diet | decrease | prostate cancer incidence and risk of disease progression after treatment | - | - | have been associated with decreased risks | #1 |
plant-based diet | increase | median intake of whole grains | patients with recurrent prostate cancer | from 1.7 servings/d at baseline to 6.9 and 5.0 servings/d at 3 and 6 months, respectively | increased | #2 |
plant-based diet | increase | median intake of vegetables | patients with recurrent prostate cancer | from 2.8 servings/d at baseline to 5.0 and 4.8 servings/d at 3 and 6 months, respectively | increased | #3 |
plant-based diet | decrease | rate of PSA rise | patients with recurrent prostate cancer | from 0.059 (prestudy) to -0.002 (0-3 months) | decreased | #4 |
plant-based diet | increase | rate of PSA rise | patients with recurrent prostate cancer | from -0.002 (0-3 months) to 0.029 (3-6 months) | increased slightly, though not significantly | #5 |
plant-based diet | neutral | management of recurrent prostate cancer | patients with recurrent prostate cancer | - | may have therapeutic potential | #6 |
The Western diet has been associated with prostate cancer incidence as well as risk of disease progression after treatment. Conversely, plant-based diets have been associated with decreased risks. A pilot clinical trial of a 6-month dietary change and stress reduction intervention for asymptomatic, hormonally untreated patients experiencing a consistently rising PSA level, the first sign of recurrence of prostate cancer after surgery or radiation therapy, was conducted to investigate the level of intake of plant-based foods and the relationship between intake and the change in the rate of PSA rise. A pre-post design was employed in which each patient served as his own control. In this multifaceted intervention, patients and their spouses were encouraged to adopt and maintain a plant-based diet. The prestudy rate of PSA rise (from the time of posttreatment recurrence to the start of the study) was ascertained by review of patients' medical records. Dietary assessments were performed and prostate-specific antigen (PSA) levels ascertained at baseline, prior to the start of intervention, and at 3 and 6 months. Changes in numbers of servings of plant-based food groups were calculated and compared with rates of PSA rise over the corresponding time intervals. Median intake of whole grains increased from 1.7 servings/d at baseline to 6.9 and 5.0 servings/d at 3 and 6 months, respectively. Median intake of vegetables increased from 2.8 servings/d at baseline to 5.0 and 4.8 servings/d at 3 and 6 months, respectively. The rate of PSA rise decreased when comparing the prestudy period (0.059) to the period from 0 to 3 months (-0.002, P < .01) and increased slightly, though not significantly, when comparing the period from 0 to 3 months to the period from 3 to 6 months (0.029, P = .4316). These results provide preliminary evidence that adoption of a plant-based diet is possible to achieve as well as to maintain for several months in patients with recurrent prostate cancer. Changes in the rate of rise in PSA, an indicator of disease progression, were in the opposite direction as changes in the intake of plant-based food groups, raising the provocative possibility that PSA may have inversely tracked intake of these foods and suggesting that adoption of a plant-based diet may have therapeutic potential in the management of this condition.