Lentils significantly reduce blood glucose levels, study reveals

June 13, 2018, University of Guelph
Lentils significantly reduce blood glucose levels, U of G study reveals
Dan Ramdath of Agriculture and Agri-Food Canada, U of G Ph.D. student Dita Moravek and U of G Prof. Alison Duncan. Credit: University of Guelph

Replacing potatoes or rice with pulses can lower your blood glucose levels by more than 20 per cent, according to a first-ever University of Guelph study.

Prof. Alison Duncan, Department of Human Health and Nutritional Sciences, and Dan Ramdath of Agriculture and Agri-Food Canada, found that swapping out half of a portion of these starchy side dishes for can significantly improve your body's response to the carbohydrates.

Replacing half a serving of rice with lentils caused to drop by up to 20 per cent. Replacing potatoes with lentils led to a 35-per-cent drop.

"Pulses are extremely nutrient-dense food that have the potential to reduce chronic diseases associated with mismanaged glucose levels," said Duncan, who worked on the study with Ph.D. student Dita Moravek and M.Sc. students Erica Rogers, Sarah Turkstra and Jessica Wilson.

Yet very few Canadians eat lentils, she added.

"Canada has a huge production of lentils, but we export most of it and only 13 per cent of Canadians eat them on any given day," said Duncan. "We are hoping this research will make people more aware of the health benefits of eating pulses."

Published and specially featured in the Journal of Nutrition, 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 because people don't typically eat pulses 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.

Pulses, such as lentils, can slow digestion and the release of sugars found in starch into the bloodstream, ultimately reducing blood glucose levels, said Duncan.

"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."

Pulses contain components that inhibit enzymes involved in absorption of glucose, and fibre contained in these foods can encourage the production of short-chain fatty acids, which can also help to reduce blood glucose levels, added Duncan.

Health Canada requires a 20-per-cent reduction in before a health claim about lowering can be approved, said Duncan.

"We are hoping that building evidence for approval of a health claim for pulses will further encourage people to add pulses to their side dishes."

Explore further: Consumption of legumes associated with lower risk of diabetes

More information: Dita Moravek et al, 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). DOI: 10.1093/jn/nxy018

Related Stories

Consumption of legumes associated with lower risk of diabetes

March 30, 2017
Legumes are a food group rich in B vitamins, contain different beneficial minerals (calcium, potassium and magnesium) and sizeable amounts of fibre and are regarded as a low-glycemic index food, which means that blood glucose ...

Lentils: the forgotten legumes

June 2, 2017
(HealthDay)—Lentils may be the least well known members of the legume family.

Eating beans, peas, chickpeas or lentils may help lose weight and keep it off

March 30, 2016
Eating one serving a day of beans, peas, chickpeas or lentils could contribute to modest weight loss, a new study suggests.

Research suggests benefits of canola oil for people with Type 2 diabetes

June 14, 2014
Canola is Canada's oil and new research from St. Michael's Hospital suggests it should also be one of the oils of choice for people with Type 2 diabetes. Dr. David Jenkins, head of the hospital's Clinical Nutrition and Risk ...

Expert discusses whether avoiding gluten offers health benefits to the general population

September 25, 2017
Sales of gluten-free foods continue to soar, reflecting a widespread belief that eliminating gluten from a person's diet can produce health benefits, even for those without gluten sensitivity or celiac disease.

Enzyme in saliva helps regulate blood glucose

April 4, 2012
Scientists from the Monell Center report that blood glucose levels following starch ingestion are influenced by genetically-determined differences in salivary amylase, an enzyme that breaks down dietary starches. Specifically, ...

Recommended for you

Engineered enzyme eliminates nicotine addiction in preclinical tests

October 17, 2018
Oct. 17, 2018—Scientists at Scripps Research have successfully tested a potential new smoking-cessation treatment in rodents.

A novel insulin accelerant

October 17, 2018
Insulin levels rise after eating a meal, signaling uptake of circulating glucose by skeletal muscle. In individuals with diabetes this process is often impaired—a condition known as insulin resistance.

Self-lubricating latex could boost condom use: study

October 17, 2018
A perpetually unctuous, self-lubricating latex developed by a team of scientists in Boston could boost the use of condoms, they reported Wednesday in the journal Royal Society Open Science.

How healthy will we be in 2040?

October 17, 2018
A new scientific study of forecasts and alternative scenarios for life expectancy and major causes of death in 2040 shows all countries are likely to experience at least a slight increase in lifespans. In contrast, one scenario ...

Study finds evidence of intergenerational transmission of trauma among ex-POWs from the Civil War

October 16, 2018
A trio of researchers affiliated with the National Bureau of Economic Research has found evidence that suggests men who were traumatized while POWs during the U.S. Civil War transmitted that trauma to their offspring—many ...

Father's nicotine use can cause cognitive problems in children and grandchildren

October 16, 2018
A father's exposure to nicotine may cause cognitive deficits in his children and even grandchildren, according to a study in mice publishing on October 16 in the open-access journal PLOS Biology by Pradeep Bhide of Florida ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.