Causal relationship between milk chocolate intake and calf pain: A Mendelian randomization analysis

Objective: This study aimed to examine the association between milk chocolate intake (MCI) and calf pain (CP). Method: We acquired data from the MR Base database and used Mendelian randomization (MR) to evaluate the causal association between MCI and CP. Results: We selected eight single nucleotide polymorphisms from genome-wide association studies that were significantly associated with both MCI and CP. Inverse weighted variance (IVW) and weighted median methods showed that MCI had a protective effect on CP (IVW: 13 = -0.360, odds ratio [OR] = 0.698, 95 % confidence interval [CI] = 0.502-0.969; Weighted median: 13 = -0.509, OR = 0.601, 95 %CI = 0.393-0.920). However, MREgger analysis suggested no causal association (13 = -0.315, OR = 0.729, 95 %CI = 0.231-2.299). The greater precision of weighted median estimator and IVW suggest our results may support a potential causal association between MCI and CP. Conclusion: The MR analysis demonstrated that MCI has a protective effect on CP.