Wild blueberries take antioxidant crown compared to commonly consumed fruit
Blueberries have greater antioxidant content than common fruits such as apples, bananas, and more commonly consumed fruits according to Cornell University researchers. They measured the ability of the fruits to protect the cell in a test they developed known as CAA (Cellular Antioxidant Activity); this moves the measure out of the test tube (the ORAC level of protection) and beyond into the realm of the effects in the body. Pomegranates, blackberries, raspberries and cranberries also performed well in the tests that measured cellular antioxidant activity in 25 fruits. Super-fruits known to be loaded with antioxidant protection such as Acai. Aronia, Mangosteen and Goji were not compared in the study.
“The CAA assay is a more biologically relevant method than the chemistry antioxidant activity assays as it accounts for uptake, metabolism, distribution and activity of antioxidant compounds within cells versus solely looking at antioxidant value,” said lead Cornell scientist Rui Hai Liu, PhD. Antioxidant activity of selected compounds is typically measured using a range of lab-based assays, including the ferric reducing ability of plasma (FRAP) assay, the oxygen radical absorbance capacity (ORAC) and Trolox equivalent antioxidant capacity (TEAC).
In addition to CAA, the researchers also measured total phenolic content, and oxygen radical absorbance capacity (ORAC) values (a test tube measure). These are more typical ‘in-the-fruit’ readings but the researchers wanted to test the levels of antioxidants in fruits in a more biologically representative manner, hence their application of the CAA method which measures antioxidant activity ‘in-the-cell’. The research is published in the recent issue of the Journal of Agricultural and Food Chemistry.
Note; Free radicals react with and attack lipids, proteins, carbohydrates, and DNA and have been linked to a number of oxidative stress conditions including heart disease, diabetes, accelerated aging and some common and dangerous cancers. The CAA test was developed at Cornell last year. CAA seeks to “move beyond the test tube” to determine how antioxidant compounds perform in cells – in this case human liver cells.