Clinical study shows beans enhanced vascular health, with positive implications for coronary heart disease
by Craig Weatherby
The unique, bountiful health benefits of beans, peas, lentils, and their cousins in the legume family often get overlooked in the public focus on vegetables and whole grains.
All beans help greatly with blood sugar and appetite control… and colorful varieties are rich in some of the same beneficial antioxidants found in veggies, fruits, chocolate, and tea.
For more on those topics, see “Beans and Lentils May Deter Diabetes.”
The highly processed, calorie-dense, nutrient-depleted diet characteristic of modern America frequently leads to sudden spikes in blood glucose (sugar) and fat levels.
This phenomenon, which researchers call “post-prandial dysmetabolism”, generates free radicals and resulting oxidative damage to tissues, which increases in direct proportion to increases in blood sugar and triglyceride levels after a meal.
The transient increase in free radicals triggers inflammation, artery stiffness, blood clotting, and other “atherogenic” changes.
By definition, atherogenic changes are ones that promote the buildup of arterial plaque that characterizes atherosclerosis: the progressive narrowing and hardening of coronary arteries and other blood vessels.
Each of these physiological responses to junky meals is an independent predictor of adverse cardiovascular events, even in healthy, non-diabetic individuals.
And as a research team wrote last year, the converse is true: “…a diet high in minimally processed, high-fiber, plant-based foods such as vegetables and fruits, whole grains, legumes [beans/lentils], and nuts will markedly blunt the post-meal increase in glucose, triglycerides, and inflammation” (O'Keefe JH et al. 2008).
Now, a new clinical study suggests that eating beans, lentils, and peas daily can help fight off cardiovascular disease, which remains the number one cause of death worldwide.
Beans found to help vascular health
Researchers at the Canadian Center for Agri-Food Research in Health and Medicine (CCARM) conducted a small clinical study in 26 people with peripheral arterial disease (PAD)
—a form of atherosclerosis in which blood flow to the limbs is reduced.
More than 10 million people in North America suffer from PAD and many more are undiagnosed. PAD causes pain, cramping or numbness when walking and, in severe cases, can lead to amputation.
The CCARM team set out to test the effects in PAD patients of daily consumption of legumes such as beans, peas, lentils, and chickpeas.
The clinical results show that a daily legume routine leads to major improvements in blood vessel function in people with PAD.
Eating half a cup of beans or other legumes a day for eight weeks improved participants' arterial function significantly, including eaiser blood flow and less arterial stiffness.
“Eating pulses [beans] brings back arterial flexibility and may actually reverse the disease process,” said team leader Dr. Peter Zahradka. “We were astonished when we saw the results… the improvement in vessel function through diet was much greater than our best expectations” (PC 2009).
Regular bean consumption also reduced the body mass index of study participants and significantly reduced their total and LDL cholesterol levels.
“The study tells us that by making a few simple changes in your diet, you can improve your health significantly, potentially reducing the need for expensive pharmaceuticals,” said co-author Dr. Carla Taylor. “Pulses [beans] are a true functional food—they may offer significant protection against cardiovascular disease, are readily available and the amount can be easily integrated into an everyday diet” (PC 2009).
The study was one of seven clinical trials funded by Pulse Canada—the national association representing growers, processors and traders of beans and other legumes—with support from Agriculture and Agri-Food Canada (AAFC) and Canada's pulse grower associations.
- O'Keefe JH, Gheewala NM, O'Keefe JO. Dietary strategies for improving post-prandial glucose, lipids, inflammation, and cardiovascular health. J Am Coll Cardiol. 2008 Jan 22;51(3):249-55. Review.
- Pulse Canada (PC). New study shows eating pulses every day improves blood vessel function and fights heart disease. April 20, 2009. Accessed online at http://media.prnewswire.com