You don’t need to eat a lot of beans to benefit from their nutritional qualities, research released at a recent health symposium here shows.
Results of six clinical research trials released at Pulse Canada’s second annual food and health symposium show pulses’ can help ward off a range of chronic diseases.
Regular consumption of pulses can help manage diabetes and significantly lower cholesterol, a major risk factor for developing heart disease. They can help people lose weight too.
Pulse Canada received a $3.2 million grant from Agriculture and Agri-Food Canada in 2005 to come up with the hard evidence of pulse benefits, which have been widely recognized by medical professionals, but not among the general public.
Two of the six research trials took place in Manitoba.
Carla Taylor, a professor in the department of human nutritional sciences at the University of Manitoba, reported on an eight-week study there examining the impact of eating pulses on persons with restricted blood flow to the legs, a condition which makes walking even short distances difficult and increases risk of heart disease and stroke.
Their study gave participants a half-cup daily of various types of beans incorporated into specially prepared foods that were consumed at home.
Participants showed significant reductions in blood cholesterol levels. Total cholesterol decreased by five per cent and low-density lipoprotein (LDL), or “bad” was reduced by 9.5 per cent.
Another finding was weight loss. “Over the eight-week period there was a half-kilogram decline in body weight,” she said.
Another study conducted at the Richardson Centre for Functional Foods and Nutraceuticals reveals that the dietary fibre content of peas can play an important role in insulin management for those who are overweight and hyper-cholesterolemic.
Participants in that study ate pea flour or pea fibre muffins while a control group ate muffins made strictly with wheat flour. Those eating the pea fibre muffins had fasting insulin levels which were 15 per cent lower than participants consuming the wheat flour muffins, Peter Jones, director of the Richardson Centre for Functional Foods and Nutraceuticals told the symposium. The research also showed consuming pea fibre significantly decreases insulin resistance – by up to 18 per cent. Insulin resistance is when the body is no longer using the insulin it produces properly, creating risk for developing diabetes.
Presently, some two million Canadians are affected with diabetes.
Research undertaken at University of Toronto looked at what, if any effect pulses could have on body weight.
One group of subjects eating pulses was compared with another group eating no pulses but on a calorie-reduced diet. The latter group was also counselled in how to reduce how much they ate.
Both groups lost weight and waistlines shrank, said Harvey Anderson, a professor of nutritional sciences and physiology in the department of nutritional sciences faculty of medicine.
“The subjects (in the restricted energy diet) reported almost a 500-calorie reduction as a result of the dietary advice,” he said. “But the pulse group also spontaneously reduced caloric intake by almost 300 calories, and also carb intake.”
Their conclusion is that eating pulses, with no other dietary guidance, has the same beneficial effects as dietary counselling to reduce energy intake, said Anderson.
The study additionally found evidence that blood sugar and hunger are reduced after eating pulses.
Researchers at Purdue University in Indiana and at Bastyr University in Washington also report consuming pulses appears to contribute to weight loss. Those who consumed a half cup a day of pulses lost more weight than those eating just a tablespoon, reported Megan McCrory, assistant professor of foods and nutrition and physiological sciences at Purdue. Participants eating larger amounts – as much as 2-1/2 cups per day – had lowered blood pressure and improved fasting insulin levels.
More research is yet needed to determine the prebiotic effect of pulses, that is, how they improve gut health, according to Wendy Dahl, an assistant professor in the food science and human nutrition department at University of Florida.
A collaborative research project with University of Saskatchewan suggests regular consumption of pulses may aid in increasing levels of beneficial gut bacteria while reducing levels of harmful bacteria, Dahl said. The research which focused on chickpeas also looked at how well pulses are tolerated.
So did another project undertaken at the University of Guelph, which reports that subjects who ate pulses at the daily recommended levels – a half cup per day – don’t experience nearly the amount of tummy upset popular opinion might assume. “Introducing pulses into your diet at a moderate level, following the dietary guidelines of half-cup a day is not, from our data, showing that it will have any gastrointestinal effects,” reported Alison Duncan, an associate professor in the department of human health and nutritional sciences at Guelph.
PULSE RESEARCH NETWORK
Three other clinical trials are currently underway investigating how eating pulses influences satiety, and how they impact metabolic control, glycemic response, cardiovascular disease risk factors and hypertension. The effectiveness of eating pulse-based foods in combination with exercise is also being studied.
The research findings come at a pivotal time, as countries falter under a growing burden of health-care costs, much of it related to poor diet. Pulse Canada’s work now is to develop marketing messages that expose these findings to consumers, said Chantal Dupasquier, Pulse Canada’s acting manager of market innovation.
“Science-based knowledge is key to getting consumers to ask for pulse-based products,” she said. “And that’s key to getting companies to reformulate existing products or creating new products (to include pulses.)”
Health fact sheets will be created to use for promotion at conferences for health professionals and consumers, she said. Plans are also underway to have these and other pulse-focused study results published in food science journals.
The two-day symposium attracted more than 140 participants from across North America and Europe, including food processors, ingredient suppliers, health professionals, farmers and government policy-makers.