Written by Luc Geeraert and the CAM-Cancer Consortium.
Updated January 20, 2017

Ornish diet and lifestyle modification programme

Does it work?

Only a limited number of studies have been carried out to date, with investigations limited by reliance on surrogate biomarkers (PSA, PSA doubling time, and serum-induced changes in growth and apoptosis of LNCaP prostate cancer cells), sample size, and duration. To determine the clinical relevance of the findings from these studies on disease-specific survival, and to help define optimal dietary patterns and lifestyle factors important for prostate cancer management, larger, well-designed, and longer-term studies are needed.

Clinical trials

The Ornish diet and lifestyle modification programme was tested in a randomized trial in 93 men with early biopsy-proven prostate cancer (PSA 4-10 ng/ml, Gleason scores less than 7) who had chosen not to undergo any conventional treatment 3. After 1 year, intensive lifestyle changes resulted in a PSA decrease of 4% and an inhibition of the serum-stimulated growth of LNCaP cells of 70%, compared to a 6% increase of PSA and only 9% LNCaP growth inhibition in the control group (not following the Ornish diet and lifestyle modification programme, but making lifestyle changes as advised by their physician). None of the 44 patients in the treatment group, but 6 of the 49 control patients had to undergo conventional treatment (e.g., radical prostatectomy, radiotherapy, or androgen deprivation therapy) due to an increase in PSA and/or progression of disease on magnetic resonance imaging. After 2 years, 2 of the 43 experimental patients and 13 of the 49 control patients had undergone conventional prostate cancer treatment; at this time point no significant differences in PSA change were found between the experimental and control patients (excluding patients who had undergone conventional treatment), and adherence to the intensive lifestyle changes remained high (95%) 10. Experimental patients showed greater improvements in cardiovascular health parameters than did control patients. Patients in the treatment group appeared to experience overall optimism and hope, make gains in their emotional availability, and highly value a peer/staff community experience 16. Patients in both the treatment and the control group who improved their lifestyle showed enhanced physical health-related quality of life and decreased perceived stress after 1 year, but no significant differences in quality of life were found between the groups 9. All recommended dietary reference intakes were met by the intervention, only vitamin D intake was less than adequate 17. After 1 year, the intake of several dietary constituents that may reduce the risk of many chronic diseases was increased, while the intake of constituents implicated with an increased chronic disease risk was decreased in the intervention group compared to controls 18. The levels of insulin-like growth factor 1 (IGF-1) increased in both groups over 1 year, whereas an increase in the levels of IGF-1 binding protein (IGFBP-1) and a trend towards lower fasting insulin levels were observed in the experimental group only 19.

In an uncontrolled pilot study in 30 men with biopsy-diagnosed low-risk prostate cancer under active surveillance, the Ornish diet and lifestyle modification programme was found to significantly modulate biological processes playing critical roles in tumorigenesis 11, and to significantly increase telomerase activity in PBMCs 12. Total PSA did not change significantly, although percent free PSA was improved 11. Overall, patients were able to adhere closely to the lifestyle modifications, a significant decrease in cardiovascular disease risk factors was found, and patients reported significant reductions in psychological distress associated with prostate cancer. The intervention was safe and no adverse events were observed. From the intervention group, 10 men were enrolled in a follow-up study where they continued the Ornish diet and lifestyle modification programme, and were compared to 25 external controls with biopsy-proven low-risk prostate cancer under active surveillance 21. After 5 years, the relative telomere length had increased in the intervention group and decreased in the control group; this difference between both groups was significant. A better adherence to lifestyle changes was significantly associated with more increased relative telomere length.

Citation Luc Geeraert, CAM-Cancer Consortium. Ornish diet and lifestyle modification programme [online document]. http://ws.cam-cancer.org/The-Summaries/Dietary-approaches/Ornish-diet-and-lifestyle-modification-programme. January 20, 2017.


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