Letting rice cool before eating can help prevent blood sugar spikes, small study suggests
- Cooling rice may help reduce blood sugar spikes after eating, a new study suggests.
- A type of carbohydrate called resistant starch develops as high-carb foods sit after cooking.
Eating reheated rice instead of freshly-cooked may slow spikes in blood sugar for people with diabetes, according to a small study published April 16 in Nutrition and Diabetes.
A group of Polish researchers from the Poznan University of Medical Sciences studied 32 patients with type 1 diabetes, comparing their blood sugar levels after eating two different test meals. One meal was long-grain white rice, about 46 grams of carbohydrates, prepared and served immediately. The other was the same portion of rice, but allowed to cool in a refrigerator for 24 hours, then reheated and served.
They found that when participants ate the cooled rice, their blood sugar levels were significantly more stable, with less of an increase overall, and a shorter time to peak than when they ate the fresh rice.
The results suggest cooled carbs like rice may help control blood sugar, according to the researchers, thanks to a specific type of carbohydrate called resistant starch. The chilled portion of rice in the study contained significantly more resistant starch than the fresh rice.
Evidence suggests resistant starch is digested more slowly. As a result, resistant starch may help balance out the absorption of other carbs to balance blood sugar, similar to fiber.
While the study is small and focused on a specific population, previous research supports the idea that cooling carb-rich foods can change how they're absorbed.
A similar 2015 study, conducted on people without diabetes, found comparable results, with the chilled rice causing less of a spike in blood sugar.
Experts say getting more resistant starch from cooled carbs has other benefits, too, such as regulating appetite to keep you full after meals, preventing energy dips, or even aiding in weight loss.
"If people are on a body fat loss mission and they're looking at leveling their blood sugar levels, or if they're looking at their productivity and avoiding afternoon slumps, it could be beneficial to try and consume more resistant starch," registered nutritionist Rhiannon Lambert previously told Insider.