Focus on Astaxanthin antioxidant properties

Here’s a second post on health claims and oxidant properties. As commented earlier, EFSA is saying that an antioxidant property per se is not a health benefit, as long as it is not shown that there is a direct effect in the body, on proteins, DNA or lipids. EFSA also argues that only some markers have been validated to show this type of direct beneficial effect on the body’s antioxidant defence network. Astaxanthin is an interesting case-study caught in the middle. EFSA has rejected an application because ‘although astaxanthin has antioxidant properties in vitro, the human studies presented do not provide any evidence in support of an in vivo antioxidant effect in terms of lipid peroxidation following the consumption of astaxanthin’. A recent study, according to the authors, provided support to “benefical effects on the oxidative stress markers in overweight adults”. If we focus on markers, the authors have used: malondialdehyde (MDA), isoprostane (ISP), superoxide dismutase (SOD), and total antioxidant capacity (TAC). Changes in F2-isoprostanes (ISP) in 24-h urine samples in considered the gold standard as direct measurement of lipid peroxidation. TAC has not been evaluated by EFSA. MDA and SOD can be used as supportive evidence in addition to reliable in vivo techniques. The concept itself of “beneficial effects on oxidative stress markers” is rejected by EFSA; if there is no protection of macromolecules in the body, there is no benefit. Companies and scientists seeking to support health claims are warned. Of course science goes its own way.

Sport Nutrition Team

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