The antioxidant content of wholegrains is of worthy note, with research showing the in vitro antioxidant activity of whole grain foods is on par with, or higher than that of vegetables and fruits.
A 2007 study by the Agricultural Research Service of the United States Department of Agriculture ranked foods for their antioxidant capacity.
Cereal based foods including ready-to-eat cereals, oats, wholegrain breads and legumes were found to be amongst the highest antioxidant containing foods by ORAC (oxygen radical absorbance capacity) score.
Table 1: ORAC Antioxidant Capacity of Selected Fruits, Vegetables, Grains and Legumes (μmolTE/100g)
Rice bran 24287
Blueberries 6552
Cornflakes 2359
Blackberries 5347
Granola 2294
Strawberries 3577
Oat bran 2183
Apples 2828
Rolled oats 2169
Avocados 1933
Pumpernickel 1963
Oranges 1819
Popcorn 1743
Spinach 1515
Mixed grain bread 1421
Broccoli 1362
Shredded wheat cereal 1303
Green tea, brewed 1253
Mangoes 1002
Carrots 666
Legumes
Chickpeas 847
Green peas 600
Lima beans 243
Pinto beans 904
Antioxidant vitamins such as vitamin E and its isomers (tocopherols and tocotrienols) and minerals such as selenium contribute to the antioxidant activity, as do phytochemicals like phytates, phenolics, and lignans or alkylresorcinols.
Grain-specific antioxidants exist, such as oryzonol in rice, avenanthramides in oats and ferulic acid in corn and wheat. Some of these phenolics have anti-atherogenic activity. Certain other phenolics, phenolic lipids, flavonoids, tocopherols and dietary fibers (e.g. beta-glucan) found in grains are anti-mutagenic and anti-inflammatory.
Choline, betaine and alkylresorcinols (which is particularly abundant in rye) are other important compounds found in wholegrains which play a role in the prevention of cell mutations and tumor formation.
Research has shown (and continues to bring to light) the many nutritional and functional components of whole grain cereals that work alone and/or in synergy to promote human health and offer significant protection against many of the lifestyle diseases that plague our world today. More detailed information on the health attributes of wholegrains can be found in the section – ‘Grains and Health’.