Omega-3 & -6 and Gleason at Radical Prostatectomy

[pjoshea13]

New study below.

"Epidemiological data suggest that omega-6 (ω-6) fatty acids (FAs) may be associated with cancer incidence and/or cancer mortality, whereas ω-3 FAs are potentially protective."

"Sixty-nine men were included in the study." "35 men with low grade disease (Gleason ≤3+4) and 34 men with high grade disease."

"FAs were extracted from membranes of RBCs obtained from fasting blood draws performed at the preoperative visit within one month of surgery."

"There was no significant association of ω-6:ω-3 with high grade disease ..."

However, here are the risk factors for individual components:

- total omega-6 = 3.37

- linoleic acid (omega-6) = 3.33

- arachidonic acid (omega-6) = 2.93

- dihomo-γ-linolenic acid (DGLA) (omega-6) = 3.21

- total omega-3 = 3.47

- docosahexaenoic acid (DHA) (omega-3) = 3.13

- eicosapentaenoic acid (EPA) (omega-3) = 1.57

Not quite what I expected.

There seems to have been no reading for alpha-linolenic acid (ALA) - the bad omega-3 - but the risk factor for total omega-3 (3.47) was much higher than for a combined EPA-DHA (1.57-3.13), which suggests that ALA risk is significantly larger than any of the numbers above.

I'm not sure what this means.

The men were from Georgia, U.S. How did their omega-6 & omega-3 status compare with the U.S. as a whole? Or with those following a Mediterranean diet, where the omega-6:3 ratio would presumably be much smaller?

The period from diagnosis until treatment is a time when many men make substantial changes to diet & supplements. Blood was drawn within the month before surgery. How can we be sure that the results reflect the FA status as of diagnosis? Higher omega-3 might be a recent event.

-Patrick

{FULL text: journals.plos.org/plosone/a...

ncbi.nlm.nih.gov/pubmed/278...

PLoS One. 2016 Nov 23;11(11):e0166594. doi: 10.1371/journal.pone.0166594. eCollection 2016.

The Association of Fatty Acid Levels and Gleason Grade among Men Undergoing Radical Prostatectomy.

Zhao Z1, Reinstatler L2, Klaassen Z2, Xu Y3, Yang X3, Madi R2, Terris MK2, Qian SY3, Kelavkar U4, Moses KA5.

Author information

1Department of Biostatistics, Vanderbilt-Ingram Cancer Center, Nashville, TN, USA.

2Department of Surgery, Section of Urology, Medical College of Georgia-Augusta University, Augusta, Georgia, USA.

3Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, USA.

4Nutechbiomarkers LLC, Savannah, Georgia, USA.

5Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.

Abstract

BACKGROUND:

Epidemiological data suggest that omega-6 (ω-6) fatty acids (FAs) may be associated with cancer incidence and/or cancer mortality, whereas ω-3 FAs are potentially protective. We examined the association of the ratio of ω-6 to ω-3 FA (ω-6:ω-3) and individual FA components with pathological results among men with prostate cancer (PCa) undergoing radical prostatectomy.

METHODS:

Sixty-nine men were included in the study. Components of ω-6 (linoleic acid (LA), arachidonic acid (AA), and dihomo-γ-linolenic acid (DGLA)) and ω-3 (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) were analyzed by liquid chromatography/mass selective detector separation. Logistic regression analysis was performed to determine association of FA with pathological high grade (Gleason ≥4+3) disease.

RESULTS:

The were 35 men with low grade disease (Gleason ≤3+4) and 34 men with high grade disease. Men with low grade disease were significantly younger (58y vs 61y, p = 0.012) and had lower D'Amico clinical classification (p = 0.001) compared to men with high grade disease. There was no significant association of ω-6:ω-3 with high grade disease (OR 0.93, p = 0.78), however overall ω-6, ω-3, and individual components of ω-6 and ω-3 FAs except EPA were significantly associated with high grade disease (ω-6: OR 3.37, 95% CI: 1.27,8.98; LA: OR 3.33, 95% CI:1.24,8.94; AA: OR 2.93, 95% CI:1.24,6.94; DGLA: OR 3.21, 95% CI:1.28,8.04; ω-3: OR 3.47, 95% CI:1.22,9.83; DHA: OR 3.13, 95% CI:1.26,7.74). ω-6 and ω-3 FA components were highly correlated (Spearman ρ = 0.77).

CONCLUSION:

Higher levels of individual components of ω-6 and ω-3FAs may be associated with higher-grade PCa.

IMPACT:

Studies into the causative factors/pathways regarding FAs and prostate carcinogenesis may prove a potential association with PCa aggressiveness.

PMID: 27880795 DOI: 10.1371/journal.pone.0166594

[PubMed - in process]