Exploring meat intake and varicose veins: insights from a Mendelian randomization study

Introduction: Background and objectives: the causal relationship between meat intake and the development of varicose veins remains unclear. Therefore, we employed Mendelian randomization to investigate the causal associations between the consumption of 10 different types of meat and the risk of varicose veins. Methods and study design: we selected a sample size as large as possible, consisting of independent individuals of European ancestry, for a meta-analysis of genome-wide association studies (GWAS). We conducted Mendelian randomization analysis with 10 dietary factors as exposure factors and varicose veins as the outcome. The Instrumental Variable Weighting (IVW) method was used to assess the heterogeneity of the instrumental variables (IVs), while MR-Egger regression was employed to evaluate the horizontal pleiotropy of the IVs. Results: the IVW method indicated that meat consumption (OR = 0.68, 95 % CI [0.47-0.98], p = 0.039) and beef intake (OR = 0.5, 95 % CI [0.30-0.86], p = 0.012) were protective factors against varicose veins. Conversely, the intake of oily fish was associated with a higher risk of developing varicose veins (OR = 1.42, 95 % CI [1.01-2.00], p = 0.043). However, there was no evidence to suggest that the consumption of other types of meat has a causal relationship with varicose veins. Conclusion: our findings suggest that oily fish intake increases the risk of varicose veins, while overall meat consumption and beef intake reduce the risk. Other dietary factors do not appear to be associated with the risk of varicose veins.