Can olive oil protect against pancreatic cancer?

Takeaway

• Increased dietary oleic acid (OA) intake was inversely associated with the development of pancreatic ductal adenocarcinoma (PDA).
• Highest intake (>23.7 g/d; equivalent to 2 tablespoons olive oil) was associated with 84% reduction in risk after excluding those diagnosed within 5 years.

Why this matters

• OA is the most common naturally-occurring fatty acid and is particularly abundant in olive and rapeseed oils.
• Increased OA consumption in the population may reduce PDA incidence.

Key results

• 88 participants out of 23,658 developed PDA over the 17-year follow-up period.
• At diagnosis, 14.9% had disease localised, 30.1% had locally advanced disease, and 46.6% had metastatic disease.
• Average daily intake of OA significantly lower in cases (16.9 g/d) vs controls (18.7 g/day).
• Risk of PDA was inversely associated with higher OA intake (highest vs lowest quintile HR  0.29; 95% CI  0.10-0.81; P<0.05).
• Excluding participants diagnosed within 5 years of enrolment, top 4 quintiles had significantly reduced PDA risk (highest vs lowest quintile HR  0.16; 95% CI  0.05-0.52; P<0.005).
• Excluding participants with known diabetes did not alter the magnitude of associations.
• Elevated HbA1c was associated with significantly increased risk (highest vs lowest quintiles HR  6.32; 95% C I 1.38-28.89; P=0.004).
• Analysing dietary oleic acid intake by BMI, BMI >25  kg/m2 had a significant trend across quintiles (HR  0.67; 95% CI 0.47-0.95; P=0.022).

Study design

• 23,658 participants from the European Prospective Investigation of Cancer-Norfolk (EPIC-Norfolk) study completed 7-day food diaries between 1993 and 1997 which recorded foods, brands, and portion size.
• Funding: Big-C cancer charity.

Limitations

• Case-cohort analysis method.
• 35% of cases histologically confirmed.