Dietary patterns derived from principal component analysis (PCA) and risk of colorectal cancer: a systematic review and meta-analysis.

Vanessa Garcia-Larsen, Victoria Morton, Teresa Norat, André Moreira, James F Potts, Tim Reeves, Ioannis Bakolis

Journal: European journal of clinical nutrition 2020;73(3):366-386

PMID: 30050075

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Abstract

BACKGROUND AND AIM

Colorectal cancer (CRC) is highly prevalent worldwide, with dietary habits being a major risk factor. We systematically reviewed and meta-analysed the observational evidence on the association between CRC and dietary patterns (DP) derived from principal component analysis.

DESIGN

PRISMA guidelines were followed. Web of Science, Medline/PubMed, EMBASE, and The Cochrane Library were searched to identify all eligible papers published up to the 31st July 2017. Any pre-defined cancer of the colon was included, namely colon-rectal cancer (CRC), colon cancer (CC), rectal cancer (RC), or proximal and distal CC, if available. Western (WDP) and prudent (PDP) dietary patterns were compared as a proxy to estimate "unhealthy" (Rich in meat and processed foods) and "healthy" diets (containing fruits or vegetables), respectively. Meta-analyses were carried out using random effects model to calculate overall risk estimates. Relative risks (RR) and 95% confidence intervals were estimated comparing the highest versus the lowest categories of dietary patterns for any of the forms of colon cancer studied.

RESULTS

28 studies were meta-analysed. A WDP was associated with increased risk of CRC (RR 1.25; 95% CI 1.11, 1.40), and of CC (RR 1.30; 95% CI 1.11, 1.52). A PDP was negatively associated with CRC (RR 0.81; 95% CI 0.73, 0.91). Sensitivity analyses showed that individuals from North-and South-American countries had a significantly higher risk of CRC than those from other continents.

CONCLUSION

A PDP might reduce the risk of CRC. Conversely, a WDP is associated with a higher risk of disease.

Address: 2 Program in Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA. [email protected].; Population Health and Occupational Medicine Group, National Heart and Lung Institute, Imperial College London, London, UK. [email protected].; School of Public Health, Imperial College London, London, UK.; Immuno-allergology, Hospital São João & Immunology, Faculty of Medicine, University of Porto, Porto, Portugal.; Population Health and Occupational Medicine Group, National Heart and Lung Institute, Imperial College London, London, UK.; National Guideline Alliance (NGA), Royal College of Obstetricians and Gynaecologists, London, UK.; Department of Biostatistics and Health Informatics, Kings College London, London, UK.; Health Services and Population Research Department, Kings College London, London, UK.

DOI: 10.1038/s41430-018-0234-7