Carbohydrate intake, glycemic index and prostate cancer risk

• Published in: The Prostate 2015-03, Vol.75 (4), p.430-439
• Main Authors: Vidal, Adriana C., Williams, Christina D., Allott, Emma H., Howard, Lauren E., Grant, Delores J., McPhail, Megan, Sourbeer, Katharine N., Hwa, Lin Pao, Boffetta, Paolo, Hoyo, Cathrine, Freedland, Stephen J.
• Format: Article
• Language: English
• Subjects: African Continental Ancestry Group; Aged; carbohydrates; Case-Control Studies; Diet; Dietary Carbohydrates - administration & dosage; Dietary Carbohydrates - adverse effects; European Continental Ancestry Group; Glycemic Index; Humans; Male; Middle Aged; prostate cancer; Prostatic Neoplasms - etiology; Risk; Surveys and Questionnaires
• ISSN: 0270-4137; 1097-0045
• DOI: 10.1002/pros.22929

BACKGROUND Reported associations between dietary carbohydrate and prostate cancer (PC) risk are poorly characterized by race. METHODS We analyzed the association between carbohydrate intake, glycemic index (GI), and PC risk in a study of white (N = 262) and black (N = 168) veterans at the Durham VA Hospital. Cases were 156 men with biopsy‐confirmed PC and controls (N = 274) had a PSA test but were not recommended for biopsy. Diet was assessed before biopsy with a self‐administered food frequency questionnaire. Logistic regression models were used to estimate PC risk. RESULTS In multivariable analyzes, higher carbohydrate intake, measured as percent of energy from carbohydrates, was associated with reduced PC risk (3rd vs. 1st tertile, OR = 0.41, 95% CI 0.21–0.81, P = 0.010), though this only reached significance in white men (p‐trend = 0.029). GI was unrelated to PC risk among all men, but suggestively linked with reduced PC risk in white men (p‐trend = 0.066) and increased PC risk in black men (p‐trend = 0.172), however, the associations were not significant. Fiber intake was not associated with PC risk (all p‐trends > 0.55). Higher carbohydrate intake was associated with reduced risk of high‐grade (p‐trend = 0.016), but not low‐grade PC (p‐trend = 0.593). CONCLUSION Higher carbohydrate intake may be associated with reduced risk of overall and high‐grade PC. Future larger studies are needed to confirm these findings. Prostate 75:430–439, 2015. © 2014 Wiley Periodicals, Inc.