Positive Health Online

Abstract

WILLIAMS and COLLEAGUES, Division of General Internal Medicine, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA. christina.williams@duke.edu examined the association between n-3 and n-6 PUFA and prostate cancer risk and determine if these associations differ by race or disease aggressiveness.

Background

Experimental studies suggest omega-3 (n-3) polyunsaturated fatty acids (PUFA) suppress and n-6 PUFA promote prostate tumour carcinogenesis. Epidemiologic evidence remains inconclusive.

Methodology

The objectives of this study were to examine the association between n-3 and n-6 PUFA and prostate cancer risk and determine if these associations differ by race or disease aggressiveness. The authors hypothesized that high intakes of n-3 and n-6 PUFA will be associated with lower and higher prostate cancer risk, respectively. A case-control study comprising 79 prostate cancer cases and 187 controls was conducted at the Durham VA Medical Center. Diet was assessed using a food frequency questionnaire. Logistic regression analyses were used to obtain odds ratios (ORs) and 95% confidence intervals (95% CI) for the associations between n-3 and n-6 PUFA intakes, the dietary ratio of n-6/n-3 fatty acids, and prostate cancer risk.

Results

The results showed no significant associations between specific n-3 or n-6 PUFA intakes and prostate cancer risk. The highest dietary ratio of n-6/n-3 was significantly associated with elevated risk of high-grade (OR, 3.55; 95% CI, 1.18-10.69; P(trend) = 0.03), but not low-grade prostate cancer (OR, 0.95; 95% CI, 0.43-2.17). In race-specific analyses, an increasing dietary ratio of n-6/n-3 fatty acids correlated with higher prostate cancer risk among white men (P(trend) = 0.05), but not black men.

Conclusion

In conclusion, the authors findings suggest that a high dietary ratio of n-6/n-3 fatty acids may increase the risk of overall prostate cancer among white men and possibly increase the risk of high-grade prostate cancer among all men.

References

Williams CD, Whitley BM, Hoyo C, Grant DJ, Iraggi JD, Newman KA, Gerber L, Taylor LA, McKeever MG and Freedland SJ. A high ratio of dietary n-6/n-3 polyunsaturated fatty acids is associated with increased risk of prostate cancer. Nutrition Research. 31(1): 1-8. Jan 2011.

Comment

The above study points to the complexity regarding discovering causes and effects of essential fatty acids, prostate cancer risk and race (genetics).