A case–control study carried out in 2021 evaluated how, in a pool of 152 people over the age of 65 and with fasting blood sugar between 100 and 124 mg/dL, those who followed a balanced diet enriched with two weekly portions of sardines showed, in one year, a greater decrease in blood pressure, an increase in the omega-3 index, an increase in circulating metabolites considered protective against T2DM, an increase in adiponectin, and an improvement in IR assessed by HOMA-IR [66]. This evidence concerns the gene ADIPOQ and type 2 diabetes mellitus.