Abstract

Introduction: Emerging evidence supports that increased consumption of dry beans (Phaseolus vulgaris L.) reduces both the incidence and recurrence of adenomatous polyps or precancerous growths. Navy beans have been studied for dietary colorectal cancer (CRC) chemoprevention in animal models. Our main objectives were to assess the feasibility of increased navy bean consumption in adults with and without history of CRC and to achieve intake amounts associated with chemoprevention.

Methods: Seven meals and six snacks were developed for both the absence and inclusion of cooked navy bean powder (35grams/day). Sixteen healthy adults (7 non-cancer and 9 CRC survivors) completed the placebo-controlled, randomized, single-blinded dietary intervention trial. Participants consumed one study-provided meal and snack daily for 28 days, which accounted for approximately one-third of their total recommended caloric intake (meals = 202-483 kcal and snacks = 194-401 kcal). Participants also recorded three-day dietary food logs each week.

Results: The addition of 35g of cooked navy bean powder (NBP) into foods provided 5-8% daily caloric intake. The compliance to the meal and snack intervention ranged from 89-100%. Non-cancer participants in the NBP group had a significant decrease in total caloric intake after week 4 (p0.0001). CRC survivors in the NBP group significantly increased total fiber intake by week 4 (p0.0001).

Conclusions: NBP are feasible to include in meals for increased total fiber intake and for consuming the amount that is associated with CRC chemoprevention outcomes. These findings warrant further evaluation of NBP consumption in clinical nutrition trials for CRC control and prevention.

Keywords: Colorectal cancer, dietary fiber, dietary practices, functional foods, legumes, navy beans, nutrition, Phaseolus vulgaris L.