Vargas AJ¹, Ashbeck EL², Wertheim BC², Wallace RB³, Neuhouser ML⁴, Thomson CA⁵, Thompson PA⁶.

• ¹Departments of Nutritional Sciences, ashley.vargas@nih.gov.
• ²The University of Arizona Cancer Center, Tucson, AZ;
• ³University of Iowa College of Public Health, University of Iowa, Iowa City, IA; and.
• ⁴Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA.
• ⁵Departments of Nutritional Sciences, College of Public Health, The University of Arizona, Tucson, AZ; The University of Arizona Cancer Center, Tucson, AZ;
• ⁶Departments of Nutritional Sciences, Molecular and Cellular Biology, and The University of Arizona Cancer Center, Tucson, AZ;

Abstract

BACKGROUND:

Putrescine, spermidine, and spermine (i.e., polyamines) are small cationic amines synthesized by cells or acquired from the diet or gut bacteria. Polyamines are required for both normal and colorectal cancer (CRC) cell growth.

OBJECTIVE:

We investigated the association between dietary polyamines and risk of CRC incidence and mortality.

DESIGN:

The study was a prospective analysis in 87,602 postmenopausal women in the Women's Health Initiative Observational Study. Multivariate Cox regression was used to calculate HRs and 95% CIs.

RESULTS:

Total dietary polyamine intake (mean ± SD: 289.2 ± 127.4 μmol/d) was not positively associated with CRC in fully adjusted models. Instead, intake ≥179.67 μmol/d was associated with reduced risk of CRC [HR (95% CI): 0.82 (0.68, 1.00), 0.81 (0.66, 0.99), 0.91 (0.74, 1.12), and 0.80 (0.62, 1.02) for quintiles 2-5, respectively, compared with quintile 1]. Reduced risk was not significant across all quintiles. Polyamines were not significantly associated with CRC-specific mortality in fully adjusted models. When stratified by risk factors for CRC, only body mass index (BMI) and fiber intake significantly modified the association between polyamine intake and CRC. In women with BMI (in kg/m²) ≤25 or fiber consumption above the median, polyamine intake was associated with significantly lower risk of CRC.

CONCLUSIONS:

No positive association between dietary polyamines and CRC or CRC-specific mortality risk in women was observed. Instead, a protective effect of dietary polyamines was suggested in women with some CRC risk-lowering behaviors in particular. These results are consistent with emerging evidence that exogenous polyamines may be beneficial in colon health and warrant additional study.