A causality between fruit consumption and colorectal cancer: a two-sample Mendelian randomization analysis

Area of Science:

• Genetics
• Nutritional Epidemiology
• Oncology

Background:

• Colorectal cancer (CRC) presents a significant global health challenge with rising incidence and mortality rates.
• The role of dietary habits, specifically fruit consumption, in CRC development remains a subject of ongoing scientific debate.
• Understanding the causal link between diet and cancer is crucial for public health interventions.

Purpose of the Study:

• To investigate the potential causal relationship between overall fruit consumption and the risk of developing colorectal cancer.
• To employ a robust two-sample Mendelian randomization (MR) approach for assessing this association.
• To differentiate the effect of general fruit intake versus specific fruit types on CRC risk.

Main Methods:

• Utilized summary statistics from large-scale genetic datasets (UK Biobank for fruit consumption, FinnGen Consortium for CRC).
• Applied multiple Mendelian randomization methods, including Inverse-Variance Weighted (IVW), MR Egger, and weighted median, to estimate causal effects.
• Assessed potential confounding factors such as heterogeneity and horizontal pleiotropy, and performed sensitivity analyses like leave-one-out analysis for result validation.

Main Results:

• A statistically significant inverse association was found between genetically predicted fruit consumption and colorectal cancer risk (IVW, P = 0.021).
• This protective association was predominantly observed in males, with a notable reduction in CRC risk.
• No significant causal effect was detected when analyzing individual fruit types, and results were robust against heterogeneity and pleiotropy.

Conclusions:

• Genetic predisposition towards higher fruit consumption may confer a protective effect against colorectal cancer, particularly in males.
• The lack of association with individual fruit types suggests a potential complex interplay of factors or a need for further detailed analysis.
• Further research is warranted to elucidate the specific mechanisms and dietary patterns underlying this protective association.