Myths vs facts: LCT and fertility

Claims that LCT variants (lactase persistence) directly affect fertility are not supported by robust evidence. LCT determines adult lactose digestion – there is no known causal link to reproductive function. Some studies explore associations between dairy intake and fertility (e.g., in PCOS or endometriosis), but results are inconsistent and not attributable to specific LCT SNPs. MyBody-X tests suggesting such connections rely on weak evidence or marketing. Fact: lactose intolerance is common but not a fertility marker. Anyone with fertility concerns should seek medical evaluation rather than rely on genetic tests for LCT. Evidence: unclear.