The role of dietary patterns in colorectal cancer: a 2019 update

ABSTRACT

Introduction: Colorectal cancer (CRC) is a major public health problem, both in terms of incidence and mortality. Lifestyle, particularly diet, plays an important role in the development of this cancer.

Areas covered: The aim of the present review was to provide an overview of systematic reviews/meta-analysis published in the last 10 years regarding the association between dietary patterns and CRC risk. Three databases were explored (Pubmed, Scopus, and Web of Science), and 13 articles were finally included. The most common a priori methods used were Healthy Eating Index, Mediterranean diet, and Dietary Inflammatory Index, while factor or principal component analyses, cluster analysis, and reduced rank regression were the most frequent a posteriori methods used. All the studies analyzed in the present review showed that a diet characterized mainly by a high intake of fruits and vegetables and low intake of red and processed meats decreased the risk of CRC.

Expert opinion: Important nutritional health campaigns and CRC screening programs are being done across the globe; nevertheless, we believe that those strategies are still inadequate as CRC incidence is increasing worldwide More effort is required at different institutional levels and public health policy advice to help the population shift toward healthier dietary habits.

KEYWORDS:

• Colorectal cancer
• dietary patterns
• review
• umbrella

Article Highlights

• This review provides an overview of the last 10 years of influence of dietary patterns in the development of CRC, as well as their evaluation methods.

• Of the 13 reviews included in the present review, 10 presented results obtained from a priori or hypothesis-oriented dietary pattern approach and 9 from a posteriori or data-driven dietary pattern approach (6 of the 13 evaluated both dietary a priori and a posteriori pattern approaches).

• Although among the a priori methods, the Healthy Eating Index (HEI) and the Meditarrenean Diet (MedD) were two of the most frequently investigated patterns, recent studies indicate that the Dietary Inflammatory Index (DII) emerges as a good tool for evaluating the association between dietary patterns and the development of colorectal cancer.

• Factor analysis, principal component analysis and cluster analysis are the most frequently used a posteriori methods; however, some investigators used a different third method, the reduced rank regression (RRR), which combines the characteristics of both the data-driven and the hypothesis oriented approaches to study dietary patterns.

• Both approaches lead to similar conclusions: a diet characterized mainly by a low intake of red and processed meats and a high intake of fruits and vegetables decreases the risk of CRC, consistent with the World Cancer Research Fund (WCRF) recommendations.

Declaration of Interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This research was partially funded by the public grants from the Spanish Association Against Cancer (AECC) Scientific Foundation – grant GCTRA18022MORE, and Spanish Ministry for Economy and Competitivity, Instituto de Salud Carlos III, co-funded by FEDER funds –a way to build Europe– (FIS PI17/00092). The authors thank the CERCA Program/Generalitat de Catalunya for their institutional support. M Obón-Santacana received a post-doctoral fellowship from the Spanish Association Against Cancer (AECC) Scientific Foundation. M Obón-Santacana and V Moreno are part of the group 55 of CIBERESP and AGAUR 2017SGR723. None of the funding agencies had a role in the design, implementation, analysis, or interpretation of study results.