Beans, long touted for nutritional benefits, also may hold extra cancer-fighting properties due to the levels of antioxidants they contain. A Colorado State University study will investigate antioxidant properties of various varieties of beans, whether eating beans can fight cancer and possible anti-diabetic benefits humans can derive from eating beans.
The study, conducted by the Cancer Prevention Laboratory in the university’s Department of Horticulture and Department of Soil and Crop Sciences, will investigate the specific cancer-fighting and diabetes-prevention properties of 15 different types of beans common in the human diet.
The project, which recently was funded with $187,000 from the Bean Health Alliance, may serve as a future model for food and crop research that can be used by farmers to determine what varieties of crops to plant while also being used by consumers to help determine dietary preferences.
"Antioxidants are found to be important to people for fighting cancer and also for battling diabetes," said Henry Thompson, professor and director of the Cancer Prevention Laboratory. "We know that there is an association between cell oxidation and diabetes, because we’ve seen this behavior as part of the pathology of diabetes. Diabetes actually can increase cellular oxidation – and cellular oxidation is an event that may predispose some people to cancer."
Antioxidants protect against damage on the cellular level caused by derivatives of oxygen working within a cell. These derivatives, called free radicals, can damage cells when they bind to them, causing health complications. Antioxidants, which include vitamins and minerals, bind to free radicals and change them into compounds that are not harmful to the body. Fruits and vegetables, particularly those that are brightly colored such as spinach, carrots and tomatoes, are known to be good sources of antioxidants.
Previous studies have identified significant antioxidant properties in beans; in a recent study by the U.S. Department of Agriculture, three varieties of beans rank in the top four foods studied for these benefits. Red beans, such as those in red beans and rice, red kidney beans and pinto beans, beat other fruits and vegetables such as berries, apples and artichokes.
"We know that colored beans have been linked to higher antioxidant properties," said Mark Brick, professor in the Department of Soil and Crop Sciences. "Bean coats get their color from phenol and anthucyanins, and those chemicals have antioxidant properties. We believe that is because there is a link between the darker seed coats and higher phenol levels. Current research shows that red beans have the highest levels of antioxidants, followed by black beans and then beans with a lighter-colored seed coat."
In the study, Brick and Thompson will look at 15 market classes, or classes common to the consumer, of beans for their various antioxidant properties. The study will include beans pulled from different gene pools, including ancient varieties that have not been changed as much with breeding practices.
Among the beans in the study are navy beans; black beans; pinto beans native to two areas of the nation; great northern beans, including an original race grown by Native Americans; small red beans; pink beans; light and dark red kidney beans; white kidney beans; yellow beans, also known as canario or azufrado beans; Nuna (Nuňa) beans, also known as Pop beans; common red beans believed to have been grown by Native Americans; and black-eyed peas, known as cowpeas.
Each of these classes of beans will be evaluated for six different measure of antioxidant activity by identifying chemical properties of each type of bean. Once these beans are evaluated in a laboratory, they’ll be further tested in a laboratory model for cancer and diabetes-prevention and fighting properties, such as their impact on blood sugar levels and inflammation, two symptoms of diabetes, as well as their impact on cancer indicators.