Dietary, supplement, and adipose tissue tocopherol levels in relation to prostate cancer aggressiveness among African and European Americans: The North Carolina-Louisiana Prostate Cancer Project (PCaP)

Prostate. 2015 Sep;75(13):1419-35. doi: 10.1002/pros.23025. Epub 2015 Jun 5.

Abstract

Background: Controversies remain over the safety and efficacy of vitamin E (i.e., α-tocopherol) supplementation use for the prevention of prostate cancer (CaP); however, associations of different tocopherol forms and CaP aggressiveness have yet to be examined.

Methods: This study examined whether food intake of tocopherols, vitamin E supplement use, and adipose tissue biomarkers of tocopherol were associated with CaP aggressiveness among African-American (AA, n = 1,023) and European-American (EA, n = 1,079) men diagnosed with incident CaP. Dietary tocopherols were estimated from a food frequency questionnaire, supplement use from questionnaire/inventory, and biomarkers from abdominal adipose samples measured using high-performance liquid chromatography. Odds ratios (ORs) and 95% confidence intervals (95%CIs) were estimated from logistic regression comparing high-aggressive CaP to low/intermediate aggressive CaP, adjusting for covariates.

Results: Dietary intakes of α-and δ-tocopherol were related inversely to CaP aggressiveness among EAs [OR (95%CI), highest versus lowest quartile: α-tocopherol, 0.34 (0.17-0.69), P(trend) = 0.006; δ-tocopherol, 0.45 (0.21-0.95) P(trend) = 0.007]. Inverse associations between dietary and supplemental α-tocopherol and CaP aggressiveness were observed among AAs, though these did not reach statistical significance [OR (95%CI), highest versus lowest quartile: dietary α-tocopherol, 0.58 (0.28-1.19), P(trend) = 0.20; supplemental α-tocopherol, 0.64 (0.31-1.21) P(trend) = 0.15]. No significant association was observed between adipose tocopherol levels and CaP aggressiveness [OR (95%CI), highest versus lowest quartiles of α-tocopherol for EAs 1.43 (0.66-3.11) and AAs 0.66 (0.27-1.62)].

Conclusions: The inverse associations observed between dietary sources of tocopherols and CaP aggressiveness suggests a beneficial role of food sources of these tocopherols in CaP aggressiveness.

Keywords: adipose tissue; diet; nutritional biomarkers; prostate cancer; supplement; tocopherols; vitamin E.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism*
  • Aged
  • Black or African American
  • Dietary Supplements*
  • Humans
  • Louisiana
  • Male
  • Middle Aged
  • Neoplasm Invasiveness / pathology*
  • North Carolina
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / prevention & control
  • Tocopherols / administration & dosage
  • Tocopherols / metabolism*
  • White People

Substances

  • Tocopherols