Antioxidants In Purple Vegetables High, Say Scientists June 10 2016
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:
Probably the first purple food most think of, eggplants have plenty of antioxidants, as well as potential cholesterol fighting and brain enhancing properties. However, because of the oxalates naturally found in eggplants (which can crystallize in the body), people with kidney and gallbladder problems may want to avoid them.
Hugely popular blueberries are rich antioxidants, can help with memory, cardiovascular health and boast a low glycemic index. Opt for organic blueberries, as the berries do get a high pesticide rating.
Freshly harvested blueberries are pictured on June 28, 2009 on a farm in Klaistow, eastern Germany. (MICHAEL URBAN/AFP/Getty Images)
We hear a lot about the resveratrol in grapes (and wine), and its role in increasing longevity, but these grapes also help with blood sugar balance and pump up the immune system.
Merlot grapes sit in bunches after being freshly picked during a night harvest for Artesa Winery October 1, 2007 in Napa, California. (Justin Sullivan/Getty Images)
A bit more rare than the usual red variety (which already has benefits from lycopene), purple tomatoes are usually heirloom and thanks to their hue, rich in those helpful anthocyanins.
Put a cherry on top! In addition to their anthocyanins, cherries have also been found to help with arthritis pain (thanks to their anti-inflammatory qualities) and sleep (thanks to their natural melatonin).
Like purple tomatoes, purple carrots can be a bit harder to find, even though they date back to 2000 B.C.E. They taste sweeter than their orange cousins, and are high in fiber. Their anthocyanins can also help with the effects of diabetes.
Like sweet potatoes, purple potatoes are rich in colour, which helps lead to their numerable health benefits. These pretty spuds help lower blood pressure, have tons of fiber, and of course, fight free radicals like all these purple foods.
Delicious and nutritious -- what more can you ask for from a berry? In addition the anthocyanins, blackberries are also rich in vitamin C (for eyes), vitamin K (for bones) and ellagic acid (for sun damage).
Though it's traditionally known as "red" cabbage, the leaves of this vegetable are no less rich in anthocyanin -- and as a bonus, cabbage is well known for its help with healing stomach ulcers.