This chemical has been shown to reduce the number of mammary tumors in rats. How phytic acid works is unclear but it may act through changes in liver metabolism, as an antioxidant, as an agent to eliminate harmful metals, or by action on the communication between cells. Grains, fruits and vegetables are all good sources of chemically complex molecules, known as flavonoids. Flavonoids from grains have been studied very little. Nonetheless, flavonoids from other plants limit the growth of breast tumor cells, and a large cohort study found a decrease in all types of cancer with higher levels of flavonoids in the diet.
Grains also contain phenolic acids.
These chemicals are also found in fruits and vegetables and are often responsible for their flavor. Phenolic acids have been shown to limit tumor formation in animals. These compounds may act by preventing the activation of cancer-causing chemicals in the body. Short Chain Fatty Acids. Some of the carbohydrates in grains are broken down by the bacteria in the intestines producing short chain fatty acids.