GUELPH, Ont. - Researchers have long known that eating a variety of brightly coloured vegetables daily is good for health: red, orange, yellow, dark green — and purple?
New research by Agriculture and Agri-Food Canada scientists suggests that purple vegetables are associated with higher levels of antioxidants, which can help reduce the risk of some types of cancer and heart disease.
Dr. Rong Cao of AAAFC and a team at the Guelph Food Research Centre suggest vegetables high in anthocyanins have an even stronger antioxidant activity than other varieties of the same vegetable.
Anthocyanins are the phytochemicals responsible for purple (or blue or red) pigments in highly pigmented vegetables such as purple carrots, potatoes and tomatoes. Antioxidants are substances such as vitamin E and vitamin C, or beta carotene, thought to protect body cells from the damaging effects of oxidation.
Cao's team has the go-ahead to examine how anthocyanins in purple carrots and potatoes contribute to reducing blood sugar.
A previous study with Dr. Dan Ramdath, also of the Guelph Food Research Centre, showed that anthocyanins inhibit enzymes such as alpha-glycosidase, which is needed to metabolize sugar. Inhibiting this enzyme slows the rate of glucose production, which helps maintain blood sugar levels, crucial for those living with diabetes.
Root vegetables have an advantage over fruits because they can be a fresh staple in the diet year-round.
Cao's research will be done through collaborative animal and human clinical trials.
Which purple foods can benefit you? Check these out: