Blood sugar is the concentration of glucose in the blood. Glucose is the main source of energy for cells and, in a healthy person, it fluctuates throughout the day between 70 and 120 mg/dl. Glucose is found in carbohydrates, and therefore in bread, pasta, rice, potatoes but also honey, fruit and sugar. When we eat these foods, thanks to digestion, glucose enters the circulation and blood sugar increases. Even if this process is essential for life, it must be kept under control to avoid an excessive increase in blood sugar, which, in the long run, would increase the risk of type 2 diabetes, obesity, cardiovascular problems and inflammations. As for pasta, it is possible, by varying the cooking method, to reduce its glycemic index, and therefore its impact on blood sugar. This is what appears in a recent scientific research published in Foods magazine by a team from the University of Brighton (Hodges et al, Foods, 2020).
In order to understand how the method of cooking pasta can affect the glycemic index, the researchers recruited 45 volunteers aged between 20 and 24 years. The study participants were divided into three groups. To everyone was served a plate of pasta dressed with tomato sauce and basil, but to the first group was served freshly cooked pasta, to the second group pasta that was first cooked and then kept in the refrigerator for 24 hours at 4° C, to the third group pasta that was cooked, kept in the refrigerator for 24 hours and then cooked again for three minutes in the microwave. All the volunteers had their blood glucose measured before the meal and every 15 minutes for the following 120 minutes after the meal. What emerged was that both the cooled pasta and the cooled and reheated pasta resulted in a quick return to fasting blood sugar compared to freshly cooked pasta. The explanation for what was observed is that the cooling process has changed the structure of the starches, increasing their indigestibility. In fact, if starches cannot be digested they do not release glucose. The subsequent heating process of the pasta did not cause any reorganization of the carbohydrate structure, as this only occurs at temperatures above 145° C.
Therefore, both the cold pasta and the cooled and then reheated pasta helped to keep blood sugar under control with health benefits, both in terms of a reduction in inflammation and oxidative stress.