Have you ever seen a purple carrot? How about white, yellow, or red? Most people haven’t, even though such carrots have existed for hundreds of years. You may see them in the future, however. Recent research at the University of Wisconsin-Madison suggests that pigments in these colorful carrots, which taste just like regular carrots, may help prevent heart disease and cancer, and reduce cholesterol.
Studies examining the health benefits of fruits and vegetables are revealing the disease-preventive powers of the pigments that give plants their distinctive colors.
Philipp Simon, a plant breeder and geneticist who directs the USDA”s vegetable breeding program at the UW-Madison”s College of Agricultural and Life Sciences, heads one of only three carrot research programs in the country. The program works to improve carrot quality for growers and consumers, says Simon, who sees the impact of this effort in the 20 percent growth in sales and production per capita over the last 10 years.
Simon”s research started with improving the appearance and flavor of orange carrots, but expanded to improving nutritional quality, too. Orange carrots get their color from beta carotene, a pigment the body converts to vitamin A. Vitamin A deficiency, although rare in the United States, poses a major public health problem in developing countries second only to protein malnutrition, says Simon.
According to the World Health Organization, vitamin A deficiency partially or totally blinds nearly 350,000 children from more than 75 countries every year. Roughly 60 percent of these children die within months of going blind. However, vitamin A deficiency is preventable.
Simon believes the development of new and more potent sources of beta carotene in horticultural crops, and the improvement of production, shelf life, and consumer acceptance of these crops, can make an important contribution to improved human health.
More recently, Simon recognized the potential nutritional value of the vegetable”s other pigments. Now Simon studies yellow, orange, red, purple, and white carrots. Yellow carrots contain xanthophylls, pigments similar to beta carotene, which help develop healthy eyes and may prevent lung and other cancers. Red carrots contain lycopene, a pigment also found in tomatoes and watermelon; lycopene helps prevent heart disease and some cancers including prostate cancer. Purple carrots contain anthocyanins, pigments that act as powerful antioxidants, grabbing and holding on to harmful free radicals in the body. Anthocyanins also help prevent heart disease by slowing blood clotting. White carrots lack pigment, but may contain other health-promoting substances called phytochemicals.
Surprisingly, purple and yellow carrots were grown and eaten as long ago as 900 AD in Afghanistan, says Simon. People began cultivating orange carrots only about 400 years ago, and most of the world eats them today.
Tracing the history of carrots is difficult since few written records exist. About 40 years ago, a Dutch researcher used paintings depicting vegetables to gather historical information about carrots. Although fragmented, written records show that early Iranians and Northern Arabians preferred purple carrots while Northern Europeans preferred yellow carrots, says Simon. The people of India prefer red carrots and grow them on a large scale, he adds.
Simon says carrot color preferences probably depend more on culture than on flavor since the different colored carrots taste the same. He should know.
“I”ve tasted hundreds of thousands of carrots,” he says. Pigments don”t appear to affect the flavor of carrots, but overcooking gives them an unpleasant “violet” taste, he notes.
Up to now, most seed companies seem hesitant to develop new and unusually colored carrot varieties with seed provided by Simon”s program. This is not surprising, says Simon, since there is no consumer demand for them. Yet.
The next step in Simon”s research involves scientifically evaluating the nutritional quality of these colorful carrots with the help of the nutritional scientists at the UW-Madison.
Perhaps a carrot a day will keep the doctor away.