Lentils significantly reduce blood glucose levels. Replacing potatoes or rice with pulses can lower your blood glucose levels by more than 20 per cent, according to a new study. Researchers found that swapping out half of a portion of these starchy side dishes for lentils can significantly improve your body's response to the carbohydrates. Replacing half a serving of rice with lentils caused blood glucose to drop by up to 20 per cent. Replacing potatoes with lentils led to a 35-per-cent drop. Source 6y.