Note from the dietitian
Jane Dummer, RDA healthy diet is the first line of defence for prevention and treatment of many lifestyle related diseases and the nutritional profile of pulses can play an important role. Pulses provide slowly digestible carbohydrates, fibre, and vegetable protein. They are nutrient dense and low in fat. Research has shown that in the short term, pulses can increase satiety and lower the glycemic index (GI) of a meal, while regular consumption can improve blood glucose control and lower an individual’s LDL cholesterol level.
Obesity, Satiety and Weight ManagementThe prevalence of obesity has reached epidemic proportions, making the quest for effective solutions to reduce obesity a health priority. A recent review of 144 research studies related to pulse consumption, satiety and weight management reported that randomized controlled trials support the beneficial effect on weight loss, when pulse consumption is coupled with energy restriction1. The observational studies from this review consistently showed an inverse relationship between pulse consumption and increased BMI (>25) or the risk for obesity. However, many of the studies did not control for other confounding dietary and lifestyle factors. More long term (≥ one year) experimental trials are needed to investigate the optimal, daily intake of pulses for weight control.
Type 2 DiabetesType 2 diabetes is one of the fastest growing diseases in Canada, with more than 60,000 new cases yearly2. A recent meta-analysis of 41 randomized controlled experimental trials that involved 1,674 participants with and without diabetes provided scientific support that pulses, alone or in low GI or high fibre diets, improved the biomarkers of glycemic control in humans3. This included lower fasting glucose and insulin levels and improved glycosylated hemoglobin (HbA1c). The blood glucose lowering effect of pulses was strongest for chickpeas. The benefit was also seen with black beans, pinto beans and red and white kidney beans. Eating only a half cup (125 ml) of these pulses daily lowered fasting glucose and insulin levels. The researchers suggested, that when the type 2 diabetics consumed pulses as part of the low GI and high fibre diets, the improvement in the HbA1c levels were comparable to the lower limit of efficacy expected for oral medications3. Further research is necessary to explore this comparison of this diet intervention to drug therapy with type 2 diabetics.
Cardiovascular DiseaseOver the past 40 years, the rates of heart disease and stroke have steadily declined. However, heart disease and stroke are still two of the three leading causes of death in Canada and the cause of 31% of all female deaths4. Decreasing LDL cholesterol remains the primary target for treating dyslipidemia and preventing cardiovascular disease. A current meta-analysis evaluating data from 10 randomized clinical trials representing 268 participants found that eating pulses reduced total cholesterol levels by 12mg/dL (6%) and LDL cholesterol by 8mg/dL (7%) as compared to control diets5.
The pulse based intervention diets varied from the addition of mixed pulse meals, whole chickpeas, whole peas, whole pinto beans, whole navy beans and canned baked beans to field beans ground into flour. The participants (ages from 18 to 78 years with 70 % male) had high, borderline high or normal cholesterol and were not taking any cholesterol lowering medications. The control diets were calorie and macronutrient-matched, often with a wheat-based or canned vegetable substitutions and the studies ranged from three to eight weeks in duration. This meta-analysis provided strong evidence that non-soy legume consumption lowers total and LDL cholesterol and therefore, may lower the risk of CVD.
SummaryIn addition to including pulses in the diet for overall health, they have an integral part in chronic disease prevention and management. To benefit from the numerous nutritional features of pulses, encourage your clients to consume them in a variety of their every day recipes.
Here's a plan that's perfect for your clients
- Take a quick scan of the types and amounts of pulses your clients are consuming
- Set goals for increasing pulse consumption with your clients
- Create an adaptation plan for your clients to help their bodies adjust to the introduction of pulses:
- Start off consuming about ¼ cup (63 ml) pulses per day, 3 times per week
- Drink lots of water as pulse consumption increases
- Gradually increase pulses to ½ cup (125 ml) per day, at least 3 times per week (more often is even better)
- Add pulses to favourite recipes, or check out http://www.pulsecanada.com/recipes for new recipe ideas
- McCory MA, Hamaker BR, Lovejoy JC, Eichelsdoerfer PE. Pulse Consumption, Satiety, and Weight Management. Adv.Nutr. 2010; 1:12-30.
- Health Canada. Diabetes. November 25, 2010. Available from http://www.hc-sc.gc.ca/hc-ps/dc-ma/diabete-eng.php
- Sievenpiper JL, Kendall WC, Esfanhani A, Wong JMW, Carleton AJ et al. Effect of non-oil-seed pulses on glycaemic control: a systemic review and meta-analysis of randomised controlled experimental trials in people with and without diabetes. Diabetologia. 2009;Aug;52(8):1479-95.
- Statistics Canada. Mortality, Summary List of Causes: CANSIM Table 102-0529: Deaths, by cause, Chapter IX: Diseases of the circulatory system (I00 to I99), age group and sex, Canada, annual (number), 2000 to 2006. 2006 (Released May 4, 2010). Available from http://dsp-psd.pwgsc.gc.ca/collections/collection_2010/statcan/84F0209X/84f0209x2006000-eng.pdf
- Bazzano LA, Thompson AM, Tees MT, Nguyen CH, Winham DM. Non-soy legume consumptions lowers cholesterol levels: A meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis. 2011;21(2): 94-103.