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One More Reason to Listen to Mom’s Advice

It’s probably more effective to get vitamins and nutrients by eating fruits and vegetables than by taking dietary supplements, according to a University of Wisconsin-Madison researcher. And what’s more, your vegetable options may soon expand as lines of specialty red, yellow and purple carrots begin appearing in stores.

“I like to say that it’s important to do all things in moderation–except eating vegetables!” says Sherry Tanumihardjo, a nutritional scientist in the College of Agricultural and Life Sciences. “There is a broad array of nutrients in fruits and vegetables that you cannot get from other foods.”

Vitamin A, which plays a key role in maintaining healthy vision and reproductive and immune systems, is one example, she says. It is present in liver, and also found as beta-carotene in foods like carrots, spinach and corn. Tanumihardjo is working on new methods to assess vitamin A status in at-risk populations, as well as studying the delivery and uptake of beta-carotene and lutein, a related compound thought to be important for eye health.

While it’s important to eat a balanced diet, Tanumihardjo is quick to point out that many people don’t–and that sometimes people take dietary supplements to make up for not eating enough fruits and vegetables. However, this strategy may not be effective, she says.

“In a recent study in my lab, we found that the body may not absorb lutein very well when it’s taken in pill form,” Tanumihardjo says. “Instead, people would be better off obtaining lutein through a balanced diet, or taking lutein dissolved in oil in a softgel capsule.”

Tanumihardjo’s lab is also examining the value of colored carrots as vehicles for lutein, beta-carotene and lycopene, all of which are antioxidents that may help prevent cancer. She’s working with CALS horticulturalist Phil Simon, who develops the yellow, purple, and red vegetables, to determine the health benefits of eating carrots that are bred to contain high levels of certain compounds.

Tanumihardjo fed muffins and smoothies containing the colored carrots to volunteer subjects–including UW-Madison students eager for free food and a little compensation–and measured the levels of lutein, beta-carotene and lycopene in the subjects’ blood. “We found that colored carrots can provide important health benefits,” she explains.

Yellow carrots turned out to be a good source of lutein and beta-carotene, while red carrots make a good alternative to tomato paste when it came to delivering lycopene. Furthermore, carrots that are specially bred to contain high levels of beta-carotene might be a good way to supply vitamin A to people that are at risk for nutrient deficiency.

Colored carrots are starting to show up in farmers markets and even in some grocery stores, Tanumihardjo says–and you can use a red or yellow carrot just as you would a regular orange carrot. Whether you munch on it raw, grate it into a slaw or chop it for a salad, the important thing is to eat it.

“Dietary change–eating more fruits and vegetables–almost always improves overall health more than intervening with drugs,” she says. “People who eat lots of fruits and vegetables tend to be healthier.”