Debra McLennan, RD, APG Food & Nutrition Coordinator

Did you know that pulses can have a positive impact on the management of diabetes? Many people aren’t aware of the positive benefits pulses can have in the diet of people with diabetes and it doesn’t take a large quantity to see these benefits.
Statistics from Diabetes Canada indicate that there are 11 million Canadians living with diabetes or prediabetes and someone is diagnosed with diabetes every three minutes in Canada. Diabetes is a chronic health condition where the body either doesn’t make insulin or can’t properly use the insulin that it does make. Insulin is a hormone that is produced in the beta cells of the pancreas and is released into the bloodstream when blood glucose (sugar) levels increase, like after eating a meal. Our cells use glucose for energy and require insulin to get the glucose from the bloodstream into the cell. It’s like our cells have specific doors on them to let glucose in and insulin acts like a key to unlock those doors.
There are different types of diabetes and each has a different type of management. In Type 1 diabetes, little to no insulin is produced, so glucose builds up in the blood instead of moving into our body’s cells to be used for energy. About five to ten per cent of people with diabetes have Type 1 diabetes and it typically occurs in childhood or adolescence but can also develop in adulthood. Type 1 diabetes is treated with insulin in combination with meal planning.
In Type 2 diabetes, the body isn’t properly using the insulin that’s being produced by the pancreas or enough insulin isn’t being made. Instead of glucose being used for energy, it builds up in the blood leading to elevated blood glucose levels. Type 2 diabetes typically occurs in adults, but it can also occur in children. About 90 per cent of people with diabetes have Type 2 and management depends on the severity of the Type 2 diabetes. Sometimes, just meal planning and physical activity are enough to control blood glucose levels, but medications and/or insulin may also be required.
Another type of diabetes is Gestational diabetes. This temporary condition happens during pregnancy and affects approximately two to four per cent of all pregnancies in the non-Aboriginal
population. Management is specific in each case to promote better blood glucose control. Once the baby is born, blood sugar levels often return to normal, but there is an increased risk of developing diabetes in the mother and child later in life.
One of the key principles to diabetes management is maintaining good blood glucose control. When blood glucose levels are consistently too high, there is a higher risk of developing diabetes- related complications that can affect the eyes, feet, kidneys and heart potentially leading to blindness, nerve damage, stroke and heart attack. Pulses can play a role in the management of blood glucose levels which in turn can reduce the risk of developing diabetes-related complications.
How can pulses help manage blood glucose levels? The 2013 Clinical Practice Guidelines from Diabetes Canada recommend including carbohydrate from high fibre, low glycemic index (GI) foods. Gl is a system that ranks food based on their effect on blood glucose levels. The system ranks foods on a scale of 1 to 100 and typically foods that contain carbohydrates that break down quickly during digestion and release their glucose rapidly into the bloodstream have a high GI, closer to 100. Foods that have carbohydrates that breakdown more slowly and release their glucose gradually into the bloodstream have a low GI, closer to 1. The GI of pulses varies from 39-55, making them a low GI food that can be included more often in the diet to help promote better blood glucose control.
Pulses contain fibre, complex carbohydrates like oligosaccharides, slowly digestible and resistant starches as well as protein which can contribute to reducing the GI of the diet. Pulses have both soluble and insoluble fibre that can have a positive effect on blood glucose levels as well as bowel regularity and improve cholesterol levels. Oligosaccharides and resistant starch are types of complex carbohydrates that are not absorbed during digestion in the small intestine and have similar beneficial health effects as fibre such as improved gut digestion and blood glucose management. Slowly digestible starch is digested completely in the gut, but at a slower rate, which can have a beneficial effect on blood glucose management as well.
Looking at the 2013 Clinical Practice Guidelines from Diabetes Canada, the diet recommendations include replacing high GI foods/ carbohydrates with low GI foods/carbohydrates in a mixed meal as well as choosing low GI (55 or less) foods/ carbohydrates more often to help improve post-meal (also known as post-prandial) blood glucose response. Pulses definitely fit into this recommendation and in more than 30 published postprandial studies where pulses or pulse products were compared to potatoes, rice, white bread, pasta, etc. (the control), about 83 per
cent of these studies found significant reductions in postprandial peak glucose or area under the curve with pulses compared to the control. Another meta-analysis of longer term, randomized controlled experimental trials found that pulses significantly lowered fasting blood glucose levels as well as insulin levels when the pulses were eaten on their own.
So how much are we talking about? The studies typically use a one cup measure of pulses with their protocols and current studies are underway to see if a smaller portion of pulses has the same beneficial effects. Current diet recommendations for people with diabetes include following the guidelines set out by Eating Well with Canada’s Food Guide as well as individualized recommendations from a registered dietitian. According to Eating Well with Canada’s Food Guide, pulses are considered a meat alternative at a portion of ¾ cup (175 mL) and recommends that meat alternatives like lentils, beans and tofu be included more often.
What’s the takeaway? Including pulses in the diet of someone with diabetes can have a positive effect on their ability to control their blood glucose levels both at meal time and over the long term with improved blood glucose control. Good news for pulses and people with diabetes!
Looking for pulse recipe inspiration? Check out the Alberta Pulse website, www.pulsepledge.com or www.pulses.org for great ways to use pulses everyday!
Have you got a question about pulse nutrition? I would love to hear from you! You can contact me at debramc@pulse.ab.ca or (780) 986-9398 ext. 6.