Omega-3 fatty acids: a nutritional lever against prostate cancer

By Lila Rouland | Published on November 3, 2025 | 3 min read


Prostate cancer is the second most common malignant tumor in men and the fifth leading cause of cancer-related death worldwide. Despite therapeutic advances, prevention and mortality reduction strategies remain limited. Among modifiable factors, diet has attracted growing interest. In particular, polyunsaturated omega-3 fatty acids (EPA, DPA, DHA) have potential anti-inflammatory and anticancer properties.

However, previous studies have reported contradictory results, and there are few large-scale longitudinal data on the dose–response relationship between omega-3 intake and prostate cancer outcomes. The aim of this study was to evaluate the impact of dietary omega-3 consumption on the incidence and mortality of prostate cancer, using data from the PLCO Cancer Screening Trial, a major U.S. prospective cohort.  

What dose of Omega-3 truly protects the prostate?  

The study included 30,552 men aged 55 to 74 years, followed for a median of 7 years. Omega-3 intake (EPA, DPA, DHA) was assessed using a validated dietary questionnaire (DHQ), and risks were analyzed with Cox regression models, adjusted for major confounding factors (age, medical history, BMI, PSA, lifestyle, etc.).  
Results showed a linear inverse relationship between omega-3 consumption and overall prostate cancer risk (highest vs. lowest quintile: HR = 0.90, 95% CI: 0.81–1.00; p = 0.053), though this association lost significance after full adjustment.  

For prostate cancer mortality, a U-shaped nonlinear relationship was observed (p for nonlinearity = 0.009). The risk of death decreased significantly for intakes between 0.15 and 0.40 g/day, with an HR of 0.67 for the 2nd vs. 1st quintile (p = 0.011). However, intakes above 0.4 g/day appeared to increase risk again, with an HR of 0.70 in the 5th quintile (p = 0.021).  

These findings suggest a protective effect at moderate doses, but potentially harmful effects at high doses, possibly due to hormonal interactions or an imbalance between omega-3 and other lipids (such as omega-6).    

What nutritional strategy against prostate cancer?  

This work confirms the potential protective role of moderate omega-3 intake on prostate cancer–related mortality, while advising caution with high doses. The anti-inflammatory effects of omega-3s, their modulation of COX-2 and NF-κB pathways, and their ability to induce apoptosis and autophagy support these biological observations.  

However, the study has limitations: self-reported dietary data, analyses based on a single measurement, a predominantly older white population, and no distinction between food sources and supplements. The authors recommend randomized controlled trials to clarify clinical recommendations.  

In practice, moderate omega-3 consumption (especially from fatty fish and marine oils) may help reduce the risk of prostate cancer progression and death, particularly among at-risk individuals (older age, family history, overweight). However, intake above 0.4 g/day does not appear beneficial and may warrant individualized monitoring.  

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