INS and Insulin resistance: Despite 1 short-term study (6 wk) showing that blueberries (668 mg anthocyanins) improved insulin sensitivity in obese patients with insulin resistance (15), others have reported increased HbA1c and HOMA-IR following 8-wk blueberry intake [742 mg anthocyanins (17)] in hypertensive postmenopausal women, and no effect on insulin sensitivity in patients with MetS (581 mg anthocyanins) (16).