The top allele associated with lower diabetes risk has the highest frequency in European populations, whereas the top allele associated with later menopause has the highest frequency in African populations.<h4>Conclusions and implications</h4>Positive selection on <i>ACSL1</i> resulted in geographically varying genetic variants, which may contribute to differential phenotypes across human populations, including type 2 diabetes and age at menopause. Here, ACSL1 is linked to diabetes mellitus.