Nutrition Notes (PCN Summer 2016) JUN 24 2016 | Consumers and Producers | Pulse Crop News
This article appeared in the Summer 2016 issue of Pulse Crop News.
Debra McLennan, RD, APG Food & Nutrition Coordinator
Everyone is talking about International Year of Pulses, especially the health benefits of eating pulses. Pulses contribute to bowel health/regularity and satiety, as well as reduce post-prandial glycemia and cholesterol levels. We talk a lot about these health benefits, but do we have the research to back up the claims? I’m happy to report that we do in some areas, but we need more research in other areas of pulse nutrition.
Dietary Pulses and Cardiovascular Disease
There is a growing body of evidence that shows eating 130 g (1/2 to 3/4 cup) of pulses daily can lead to a reduction in LDL cholesterol (“bad cholesterol”) and total cholesterol levels. This decrease can lower the risk of heart attack and stroke. This amount is equivalent to one meat and alternative serving, according to Health Canada’s Healthy Eating with Canada’s Food Guide.
The current evidence is showing that bean consumption appears to have a consistent beneficial effect on total and LDL cholesterol levels, but only a moderate effect on triglycerides and HDL cholesterol (“good cholesterol”). Further research is needed to provide more strength to the information that we currently have and to find out what the component is in beans/pulses that provides this effect.
Pulses and Diabetes
Pulses are a well-known low glycemic index food. Research with pulses and their effect on people with diabetes has shown a reduced rise in blood sugar levels after a meal when 1 cup (250 mL) cooked/canned pulses are eaten in place of low fibre starchy foods.
Much of this research has focused on lentils and beans, but all of the pulses have shown this positive effect on blood sugar levels after a meal. The pulse portion size of 1 cup (250 mL) was used as this provides the same amount of available carbohydrates as the other test foods in the studies, but this amount could be a barrier to people including pulses in their diet to improve their diabetic control.
Future areas to research include whether this same positive is seen with a smaller portion size and with pulse ingredients like the flours and if processing has any effect on the glycemic response. It would also be interesting to find out if the same effects are seen in people who do not have diabetes.
Pulses and Other Health Effects
There are only a few studies looking at the effects of pulses on satiety and appetite and the potential pulses could have for weight control. Short-term studies have shown decreased hunger and increased satiety 2-4 hours after eating pulses when the amount of calories is controlled between the pulse containing meal and the regular control meal.
There is some evidence from longer-term studies that found pulses had a positive effect on weight loss when the caloric intake is also controlled. Again, more research is needed to determine the mechanisms in pulses that have this effect on appetite, satiety and potentially weight control.
Gut health is another interesting area of research for pulses. Insoluble fibre improves colon health and pulses have high amounts of insoluble fibre as well as antioxidants that could play a role in promoting gut health. Since there aren’t very many studies looking at the role that pulses can have in gut health, more research is required before any health claims can be made.
Ultimately, to be able to make health claims about pulses, more research is needed in the areas of active components in pulses, if the effects are the same with all the pulses and pulse ingredients and if the effects are the same with different intakes of pulses. What we do know is that it only takes 1/2 cup of pulses to provide meaningful amounts of important nutrients like fibre, protein, folate, iron, magnesium, potassium and zinc, and that is a message that we can continue to share with consumers and health professionals alike!
Looking for pulse recipe inspiration? Check out the Alberta Pulse website www.pulse.ab.ca or the International Year of Pulses recipe website 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 firstname.lastname@example.org or 780-986-9398 ext. 6.