May 3, 2017 | 3 minute read

AICR’s latest report on colorectal cancer found that processed meat and alcohol are a few of the factors linked to increased colorectal cancer risk, while whole grains lower the risk. Research published this month now confirms and reinforces these findings, as part of AICR’s ongoing review of the research.

The study was published in the Annals of Oncology.

Aside from skin cancers, colorectal cancer is the third most common cancer diagnosed in both men and women in the United States.

In 2011 AICR and the World Cancer Research Fund (WCRF) International published a report on colorectal cancer as part of the Continuous Update Project (CUP). WCRF/AICR–funded scientists at Imperial College London conducted the systematic review, which an independent CUP expert panel then analyzed and made judgments.

For this paper, Imperial scientists updated the 2011 CUP analysis, including articles published up to May 2015. The paper included 400 individual study estimates from 111 unique population groups.

Foods associated with an increased risk of colorectal cancer included:

• Red and processed meats: Risk increased 12% for each 100 grams/day increase of red and processed meat. A hot dog is about 50 grams.
• Alcohol: Risk increased 7% for every 10 grams/day  of ethanol intake. A standard alcoholic drink contains 14 grams of ethanol.

Foods associated with an decreased risk of colorectal cancer included:

• Whole grains: Risk decreased 17% for each 90 grams/day increase of whole grains.
• Total dairy products: Higher intake of dairy products was associated with a decreased risk of colorectal and colon cancer, not rectal cancer independently. (This could be due to the smaller number of cases of rectal cancers.)

Lower risk of colorectal cancer was also seen with consuming higher amounts of vegetables and fish, but here the link was weaker and possibly driven by a single study. More research is needed.

There are several limitations to the findings, such as some studies may not have published their results on all food types or cancer subtypes. And the questionnaires may not have accurately reflected the foods participants eat.

AICR estimates that almost half – 47 percent — of US colorectal cancer cases are preventable each year through diet, physical activity and staying a healthy weight.

Note: The work was funded by the World Cancer Research Fund as part of the Continuous Update Project. The views expressed in this review are the opinions of the authors.

Source: A R Vieira, L Abar, DSM Chan, S Vingeliene, E Polemiti, C Stevens, D Greenwood, T Norat; Foods and beverages and colorectal cancer risk: a systematic review and meta-analysis of cohort studies, an update of the evidence of the WCRF-AICR Continuous Update Project. Ann Oncol 2017 mdx171. doi: 10.1093/annonc/mdx171

World Cancer Research Fund/American Insitute for Cancer Research. Food, Nutrition, Physical Activity and the Prevention of Colorectal Cancer. 2011