Extra Virgin Olive Oil Reduces Postprandial Glucose After High GI Meal in Type 1 Diabetes

Maintaining blood glu­cose con­trol is extremely impor­tant for both type 1 and type 2 dia­bet­ics. To do so it is often rec­om­mended that dia­bet­ics con­sume low glycemic index foods as a large pro­por­tion of their daily intake. And mon­i­tor­ing the quan­tity of car­bo­hy­drate con­sumed is com­mon prac­tice.

The glycemic index is a mea­sure of car­bo­hy­drate qual­ity and shows how quickly dif­fer­ent foods cause blood glu­cose to rise. Low glycemic index foods are those cat­e­go­rized as 55 or below. High glycemic foods are above 55. The higher the index, the more rapidly blood glu­cose is affected. To mea­sure the response to var­i­ous foods and meals, post­pran­dial, also known as post meal, blood glu­cose is com­monly recorded by dia­bet­ics.

A recent study by Bozzetto and Colleagues, from Federico II University in Naples, Italy, pub­lished in Diabetes Care, eval­u­ated whether fat qual­ity could influ­ence post­pran­dial glu­cose response in the con­text of high or low glycemic index meals in type 1 dia­betes patients.

The study recruited 13 type 1 dia­betic patients on insulin pumps in a ran­dom­ized crossover trial where they con­sumed two series of meals, high glycemic and low glycemic, com­posed of the same car­bo­hy­drate amount but with dif­fer­ing fat qual­ity — low fat, but­ter (sat­u­rated fat), or extra vir­gin olive oil (EVOO; monoun­sat­u­rated fat).

As was expected, there was a sig­nif­i­cant dif­fer­ence in post­pran­dial glu­cose in response to a high glycemic index meal com­pared to a low glycemic index meal, espe­cially in the first 3 hours where blood glu­cose was sig­nif­i­cantly higher after con­sum­ing the high glycemic meal.

However, after con­sum­ing the high glycemic meal it was shown that EVOO resulted in a sig­nif­i­cantly lower effect on post­pran­dial blood glu­cose than either but­ter or low fat. This result was par­tic­u­larly dif­fer­ent in the 0 – 3 hour incre­men­tal area under the curve. In this instance, they found no sig­nif­i­cant dif­fer­ences between the groups for low glycemic index meals.

The authors con­clud­ing that:

“Using EVOO in an HGI [high glycemic index] meal atten­u­ates the early post­pran­dial glu­cose response… Therefore, an opti­mal pran­dial insulin admin­is­tra­tion would require con­sid­er­ing, in addi­tion to the quan­tity of car­bo­hy­drates, the qual­ity of both car­bo­hy­drate and fat.”

This is only a small study but it does indi­cate that fat qual­ity could in fact be a very impor­tant con­sid­er­a­tion for the every­day diets of dia­bet­ics and may be par­tic­u­larly use­ful dur­ing dietary tran­si­tion when high glycemic foods may still be con­sumed more fre­quently.

• Glycemic Index: University of Sydney


• Diabetes Care: Extra-Virgin Olive Oil Reduces Glycemic Response to a High-Glycemic Index Meal in Patients With Type 1 Diabetes: A Randomized Controlled Trial