Antioxidants: We Hardly Knew Ye continued...
Researchers have long thought that fruits and vegetables were the primary sources of antioxidants in the diet. But new research presented this year suggests that a different type of antioxidant and other phytochemicals may also be found in whole grains.
"Phytochemicals seem to be in what we call the free form in fruits and vegetables, and when we looked for these in whole grains they weren't found," says Polk. "What researchers have now discovered is that they were in different form in whole grains. They are attached to cell walls of the plant and don't get absorbed into the blood until bacteria act upon them during digestion."
"We didn't know about this bound form of phytochemicals until recently, and so the benefits of whole grains are even greater than what we thought before," says Polk.
Polk says these findings may also help explain why studies that have looked at the potential anti-cancer properties of the fiber found in whole grains have produced conflicting results.
"We know diets that are high in fiber are cancer protective, but there has been some question about whether or not it is the fiber itself," Polk tells WebMD. "It may not be fiber but maybe something else in high-fiber foods."
Confused? Mix It Up
If the conflicting research about the health benefits of different foods has you confused, researchers say the best recipe is to mix it up.
Researchers say every time they try to isolate one of the components behind the potential health benefits of a food, it doesn't seem to work.
"We have been so unsuccessful in finding that perfect food or that perfect nutrient that if you just pop a supplement you're going to have decreased risk," says Lichtenstein.
In contrast, new research suggests that it may be the ways various phytochemicals and ingredients in different foods work together that produce the biggest health benefits.
For example, a recent study showed that mice with prostate cancer fed a diet rich in both broccoli and tomatoes experienced much less tumor growth than those fed either food alone.