In their current research, they are experimenting with ways to increase the bioactive components in these foods in order to test the efficacy of enriched broccoli and tomatoes in a new prostate cancer study.
Rats were fed diets with food powders containing 10 percent of either standard broccoli; standard tomato; lycopene-enriched tomato; tomato enriched with lycopene and other carotenoids; broccoli sprouts, which contain very high levels of cancer-fighting compounds; or broccoli grown on soil treated with selenium.
The scientists found that greater amounts of bioactive components in the food powders translated into increased levels of the compounds in body tissue and increased bioactivity in the animals.
Carotenoid-enriched tomatoes produced more bioactivity in the liver than lycopene-enriched or standard tomatoes, yielding the most cancer-preventive benefits.
"Carotenoids, which are phytochemical pigments found in fruits and vegetables, are thought to be excellent antioxidants and effective in cancer prevention," said Ann G. Liu, a U of I graduate student who worked on the study.
"A good rule is: the brighter the color, the higher the carotenoid content. If you're growing or buying tomatoes, select plants or produce that are a very bright red. High-lycopene tomatoes are now available through garden catalogs," she added.
"This research shows that you can greatly increase a food's bioactive benefits through normal farming practices, without resorting to genetic engineering. Farmers have traditionally been more concerned about yield than nutritional composition. Now we're asking, can we grow more nutritional broccoli and tomatoes? And the answer is a definite yes," said Jeffery.
|Contact: Phyllis Picklesimer|
University of Illinois College of Agricultural, Consumer and Environmental Sciences