Researchers report that swapping just half of a portion of starchy side dishes with lentils can significantly improve your body’s response to carbohydrates. Replacing half a serving of rice with lentils caused blood glucose to drop by up to 20 percent, and replacing potatoes with lentils led to a 35 percent drop.
Lentils are an extremely nutrient-dense food with the potential to reduce chronic diseases associated with mismanaged glucose levels, according to lead researcher, Prof. Alison Duncan.
The study involved 24 healthy adults fed four dishes – white rice only, half white rice and half large green lentils, half white rice and half small green lentils, and half white rice and half split red lentils. Researchers measured glucose levels in the participants’ blood before they ate and during two hours afterward. They repeated the process for white potatoes alone and the same combinations of potatoes and lentils.
“We mixed the lentils in with the potatoes and rice because people don’t typically eat lentils on their own, but rather consume them in combination with other starches as part of a larger meal, so we wanted the results to reflect that.”
Blood glucose fell by similar amounts when half of the starch was replaced with each of the three types of lentils.
Blood glucose comprises sugar found in the blood during digestion in the upper digestive tract and depends on the starch content of foods consumed. Lentils slow digestion and inhibit the release of starchy sugars into the bloodstream, ultimately reducing blood glucose levels.
“This slower absorption means you don’t experience a spike in glucose. Having high levels over a period of time can lead to mismanagement of blood glucose, which is the hallmark of Type 2 diabetes. Essentially, eating lentils can lower that risk.”
Lentils contain compounds that inhibit enzymes involved in absorption of glucose, as well as fiber that encourages the production of short-chain fatty acids, which can also help to reduce blood glucose levels.
Source: Dita Moravek, Alison M Duncan, Laura B VanderSluis, Sarah J Turkstra, Erica J Rogers, Jessica M Wilson, Aileen Hawke, D Dan Ramdath. Carbohydrate Replacement of Rice or Potato with Lentils Reduces the Postprandial Glycemic Response in Healthy Adults in an Acute, Randomized, Crossover Trial. The Journal of Nutrition, 2018; 148 (4): 535 DOI: 10.1093/jn/nxy018.