A systemic review and meta-analysis of 6 RCTs examining the effects of pistachio nuts on glycemic control and insulin sensitivity in people with T2DM, prediabetes, or metabolic syndrome, reported a significant reduction in fasting glucose and IR, without differences from controls on HbA1c and fasting plasma insulin; the reported beneficial effects were possibly related to their high content of antioxidants (beta-carotene, lutein, proanthocyanidins, and vitamin E), anti-inflammatory compounds, fiber, and healthy fats, monounsaturated fatty acids [416]. This evidence concerns the gene INS and prediabetes syndrome.