Diets
intensive lifestyle program slows-progression-of early-stage prostate cancer
In plain terms: Can this lifestyle program slow early prostate cancer so men can avoid treatment?
Part of: 🥗 intensive lifestyle program
Weak and unconfirmed: Ornish's own small trial showed lower PSA and less treatment, but the one large independent diet RCT found no effect on progression, and no trial shows the vegan diet component alone matters.
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Human trials (RCT / n-of-1)
How the studies fall
The evidence (7)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Dewell 2008 · J Am Diet Assoc | RCT | supports | low | Same cohort mechanism paper: confirms large shifts in protective/pathogenic nutrients — shows adherence, not clinical progression. |
| Parsons 2020 · JAMA | RCT | contradicts | high | MEAL RCT n=478 active surveillance: vegetable-enriched diet did NOT reduce prostate cancer progression vs control (HR ~0.96). |
| Ballon-Landa 2018 · Curr Opin Urol | observational | mixed | moderate | Independent review concludes nutrition/lifestyle evidence for altering prostate-cancer course is suggestive but inconclusive, with few adequately powered trials. |
| Zuniga 2020 · Urol Oncol | observational | mixed | moderate | Review of diet/lifestyle RCTs+cohorts: evidence for slowing progression remains limited and inconsistent; recommendations largely observational/expert-opinion. |
| Ornish 2013 · Lancet Oncol | RCT | supports | moderate | 5-year follow-up of the lifestyle-intervention pilot found increased telomerase/telomere length, a surrogate marker, same PCLT cohort and Ornish group. |
| Saxe 2001 · J Urol | n-of-1 | mixed | low | Small independent diet+stress-reduction study: slowed rate of PSA rise after biochemical recurrence; tiny, uncontrolled-grade. |
| Ornish 2005 · J Urol | RCT | supports | low | 93 men, watchful waiting, 1yr: PSA -4% intervention vs +6% control; 0/44 vs 6/49 underwent conventional treatment; serum inhibited LNCaP growth 8x more. |
Disagree, or know a study we missed?
We grade by evidence, not opinions. The way to weigh in is to point us to a study we haven't cited (check the evidence table above first), or to flag a problem with one we have. Every submission is reviewed; if it holds up, the grade updates and shows in Science Changes Its Mind.
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.