Released: January 16, 2002
K-State Study: Choose Whole Wheat Products to Fight Cancer
MANHATTAN, Kan. – Consumers who can’t choose between white or whole wheat bread at the grocery store may be better off buying the latter, say researchers at Kansas State University.
A new study is finding that eating whole wheat products can prevent many common forms of cancer, and not just because of its higher fiber content. In fact, how much a wheat product can help prevent cancer may have more to do with how much that product is processed.
K-State Research and Extension biochemist Dolores Takemoto says a chemical component in whole wheat – called an orthophenol – is at work.
Orthophenols act as antioxidants to kill cancer cells. They’re most common in whole-wheat products and less common in highly-processed wheat products, such as white bread.
"Fiber is important," Takemoto said, "but at the end of our study, we gave different types of wheat to mice that were a model for tumors. We found that if we gave them different wheat diets that had equal fiber, some of those diets prevent cancer better than others."
Over a six-month period, the K-State researchers fed laboratory mice wheat diets that were low or high in orthophenols.
"We were able to reduce tumor size and number of tumors by about 60 percent in the animals that got the really good diets," Takemoto said. "In wheat, we found that the orthophenols were very high in the [diets] that killed cancer the best."
Human trials have not yet been conducted.
"We’re looking at orthophenols in wheat because wheat products are a major component of the American diet; bread, pasta...just so many things have wheat in them," Takemoto said. "It is much easier to identify the quality components in existing things than to revamp a person’s diet, as everyone who’s ever been on a diet knows. It’s much easier just to point to something that will be healthier for you."
Takemoto noted that the research team’s "ultimate goal" is to convince government agencies to approve food labels that include a product’s orthophenol content, particularly for bread.
"What is important is that you [eat wheat products] that are not highly processed," she said. "[Many people] are aware that brown rice is better than white rice; if you take a lot of things out of [rice] and process it, it’s not as good for you. It’s the same with wheat. Whole wheat is better than a processed wheat."
In Kansas, farmers have grown hard red winter wheat for over a century. Only recently have farmers begun growing large quantities of hard white wheat varieties. K-State’s research has not found any difference in orthophenol content between those two classes; instead, the most important factors they’ve found are how much a wheat is processed, and even the field in which it is grown.
For example, a wheat crop grown in different environmental conditions – affected by fertilizer, moisture, heat or soil type – will contain different levels of orthophenols. Knowing that, farmers may in the future grow crops to promote high orthophenol content, thus creating a value-added product.
In a related study, Takemoto and the K-State research group are now using animal models for diabetes, feeding those animals the same diets used in the cancer study. "We hope to find that [orthophenols] can help bring down the level of side effects for diabetics, as well," she said.
Takemoto’s research is a joint effort with Wichita State University. The study is funded by the Kansas Wheat Commission.
"The take-home message would be that when you go to the store, get whole grains rather than [products] that are processed, because you [increase] the possibility of having high antioxidants and high orthophenols in that grain-based product – be it bread or whatever. When you go to the bread market or the bakery of your grocery store, if [a product] says something like whole wheat, or if you see the grains in it, that will be the best thing for you."
K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.
Dolores Takemoto is at 785-532-7009