The claimEvidence C · limited
'Superfoods' are antioxidant cure-alls
The evidence
'Superfood' has no scientific definition; its core ORAC in-vitro basis was withdrawn by USDA in 2012, and human-endpoint evidence for any single star food is sparse.
The mechanism, in brief
The main scientific support for 'superfood' claims rested on a metric called ORAC — Oxygen Radical Absorbance Capacity. In the 1990s, a USDA laboratory developed the ORAC assay, and a ranked list of foods by ORAC value became the bible of superfood marketing: whichever berry scored higher was deemed more 'super'.
Sources (2)
- U.S. Department of Agriculture, Agricultural Research Service. (2012). Withdrawal of the USDA ORAC (Oxygen Radical Absorbance Capacity) database for selected foods. ARS stated ORAC values are biologically misleading because in-vitro antioxidant capacity does not predict in-vivo health effects.
- Prior, R. L., Wu, X., & Schaich, K. (2005). Standardized methods for the determination of antioxidant capacity and phenolics in foods and dietary supplements. Journal of Agricultural and Food Chemistry, 53(10), 4290-4302. Describes the ORAC assay and its in-vitro limitations.