Whole grain phytochemicals and health

Phytochemicals and antioxidants in whole grains have not received as much attention as the phytochemicals in fruits and vegetables although the increased consumption of whole grains and whole grain products has been associated with reduced risk of developing chronic diseases such as cardiovascular disease, type 2 diabetes, some cancers and all-cause mortality. Recent research has shown that the total phytochemical content and antioxidant activity of whole grains have been commonly underestimated in the literature, and that whole grains contain more phytochemicals than was previously reported. Most whole grain phenolics are in bound form, 85% in corn, 76% in wheat, and 75% in oats. In addition, whole grains contain unique phytochemicals that complement those in fruits and vegetables when consumed together. The beneficial effects associated with whole grain consumption are in part due to the existence of the unique phytochemicals of whole grains. The majority of phytochemicals of whole grains that are beneficial for health are present in the bran/germ fraction. In whole wheat flour, the bran/germ fraction contributed 83% of total phenolic content, 79% of total flavonoid content, 78% of total zeaxanthin, 51% of total lutein, and 42% of total beta-cryptoxanthin. The bran/germ fraction of whole wheat may therefore impart greater health benefits when consumed as part of a diet, and help reduce the risk of chronic diseases. This paper will review recent research on the phytochemicals and antioxidant activity of whole grains and their unique contribution to the health benefits of whole grains. (c) 2007 Elsevier Ltd. All rights reserved.