Astaxanthin, a natural antioxidant, lowers cholesterol and markers of cardiovascular risk in individuals with prediabetes and dyslipidaemia.

AIM: To determine the effects of astaxanthin treatment on lipids, cardiovascular disease (CVD) markers, glucose tolerance, insulin action and inflammation in individuals with prediabetes and dyslipidaemia. MATERIALS AND METHODS: Adult participants with dyslipidaemia and prediabetes (n = 34) underwent baseline blood draw, an oral glucose tolerance test and a one-step hyperinsulinaemic-euglycaemic clamp. They were then randomized (n = 22 treated, 12 placebo) to receive astaxanthin 12 mg daily or placebo for 24 weeks. Baseline studies were repeated after 12 and 24 weeks of therapy. RESULTS: After 24 weeks, astaxanthin treatment significantly decreased low-density lipoprotein (-0.33 ± 0.11 mM) and total cholesterol (-0.30 ± 0.14 mM) (both P < .05). Astaxanthin also reduced levels of the CVD risk markers fibrinogen (-473 ± 210 ng/mL), L-selectin (-0.08 ± 0.03 ng/mL) and fetuin-A (-10.3 ± 3.6 ng/mL) (all P < .05). While the effects of astaxanthin treatment did not reach statistical significance, there were trends toward improvements in the primary outcome measure, insulin-stimulated, whole-body glucose disposal (+0.52 ± 0.37 mg/m(2) /min, P = .078), as well as fasting [insulin] (-5.6 ± 8.4 pM, P = .097) and HOMA2-IR (-0.31 ± 0.16, P = .060), suggesting improved insulin action. No consistent significant differences from baseline were observed for any of these outcomes in the placebo group. Astaxanthin was safe and well tolerated with no clinically significant adverse events. CONCLUSIONS: Although the primary endpoint did not meet the prespecified significance level, these data suggest that astaxanthin is a safe over-the-counter supplement that improves lipid profiles and markers of CVD risk in individuals with prediabetes and dyslipidaemia.