Written by Jessica Patella, ND. In a study with 2818 participants, research showed that polyps were reduced by 24%, 26%, and 40% thru the use of cooked vegetables, dried fruit, and brown rice, respectively. 

While colorectal cancer has decreased over the past 20 years, it is still the second leading cause of cancer death and the third most common cancer in both men and women (2). Routine colonoscopy screenings result in early detection and removal of colorectal polyps before they progress to cancer (3). Along with routine screenings, many studies suggest dietary factors play a large role in decreasing the risk of colorectal cancer (1). A recent study found eating cooked green vegetables, dried fruits, legumes and brown rice frequently was associated with a decreased risk of colorectal polyps (1).

The recent research included 2,818 participants that responded to two questionnaires (1). The first questionnaire was given from 1976-1977 and the second questionnaire was given to survivors from 2002-2004.  The first questionnaire was used to examine the risk of cancer, coronary heart disease and all-cause mortality among non-Hispanic California Seventh-day Adventists (4). The second questionnaire was used to provide more precise results investigating the relationship between selected foods and the risk of cancer (5).

After the 26-year follow-up, 441 cases of rectal/colon polyps were identified (1). These participants tended to be older, had higher body mass indices (BMI), tended to be more educated (college graduates or more) and a high proportion had a positive family history of colorectal cancer in a first-degree relative (1). There was no difference found between cases of polyps and non-cases for physical activity, constipation, use of pain medication or use of multivitamins (1).

In the population studied, Seventh Day Adventists, 60% were vegetarians or nearly vegetarians (eating meat less than once per week). The more cooked green vegetables, legumes, dried fruit and brown rice the participant ate, the lower the incidence of polyps (1). Eating cooked green vegetables once per day (or more) was associated with a 24% decreased risk of rectal/colon polyps when compared to consumption less than five times per week (P trend=0.03).  Eating dried fruit three times per week or more decreased the risk of polyps 26% when compared to consumption less than once per week (P trend=0.03). Consumption of brown rice at least once per week reduced the risk of polyps by 40% (P trend=0.02). A similar effect was seen for consumption of legumes (P trend = 0.02) (1).

About 80% of the participants did not make major changes in their diet from baseline to 26-years later (1). The lifestyle of the Adventist population has a low percentage of alcohol and smoking, which reduces the number of variables in the study (1).

In conclusion, cooked green vegetables, legumes, dried fruit and brown rice are associated with a decreased risk of rectal/colon polyps (1).

Source: Tantamango, Yessenia M., et al. “Foods and food groups associated with the incidence of colorectal polyps: the Adventist Health Study.” Nutrition and cancer 63.4 (2011): 565-572.

Copyright © 2011 Routledge

Posted August 22, 2011.  

References:

    1. Tantamango Y.M.; et al (2011): Foods and Food Groups Associated With the Incidence of Colorectal Polyps: The Adventist Health Study, Nutrition and Cancer, 63:4, 565-572.
    2. American Cancer Society: Cancer Facts and Figures 2010. American Cancer Society:Atlanta,GA, 2010.
    3. Edwards BK, et al.: Annual report to the nation on the status of cancer, 1975–2006, featuring colorectal cancer trends and impact of interventions (risk factors, screening, and treatment) to reduce future rates. Cancer 116, 544–573, 2010.
    4. Beeson WL, et al, Chronic disease among Seventh-Day Adventists, a low risk group. Rationale, methodology, and description of the population. Cancer (Phila) 64, 570–581, 1989.
    5. Butler TL, et al.: Cohort profile: the Adventist Health Study-2 (AHS-2). Int J Epidemiol 37, 260–265, 2008.