Astaxanthin is a fat-soluble, xanthophyll carotenoid with antioxidant properties that are primarily synthesized by microalgae and accumulate in many marine organisms. The unique molecular structure astaxanthin is what allows for such high antioxidant activity. Although this compound may be most well-known for its application in supporting eye health, astaxanthin shows great potential for nutritional support for other conditions that are marked by increased inflammation.

According to a human clinical trial published in the May 2021 issue of the International Journal of Clinical Practice, astaxanthin supplementation may have a beneficial effect on individuals with type 2 diabetes (T2D) by downregulating pro-inflammatory markers and expression of specific microRNAs that are commonly seen upregulated in diabetic and hyperglycemic populations.

In this randomized, double-blind, placebo-controlled clinical trial, researchers analyzed the effects of supplemental astaxanthin on circulating malondialdehyde (MDA) and interleukin-6 (IL-6) levels, in addition to the expression of microRNA-146α and microRNA-126, in patients diagnosed with T2D. MicroRNA-146α is upregulated in individuals with diabetes and those with elevated blood sugar, whereas microRNA-126 is often reduced. MDA is a primary biomarker of oxidative stress and free radical-mediated lipid damage to cell membranes that is often elevated in diabetic patients. In this trial, 44 patients with T2D received either 8 mg per day of oral astaxanthin or a placebo for 8 weeks. At the end of the 8 weeks, researchers observed a significant reduction in plasma levels of MDA and IL-6, and downregulation of microRNA-146 expression levels in the treatment arm compared to the placebo group.

A similar trial of patients with T2D was conducted in 2018. In the previous randomized controlled trial, 8 mg per day of astaxanthin supplementation for 8 weeks improved glucose metabolism and decreased blood pressure in patients with T2D.

Results from the more current study are supportive of the previous research trial, suggesting that supplementation with astaxanthin may be beneficial for individuals with T2D due to its promotion of a healthy inflammatory response and antioxidative effects. Further investigations led with larger sample sizes are needed to confirm these results.

Patients should be encouraged to adopt a low-glycemic, anti-inflammatory diet along with increased resistance training (if possible) to support normal blood sugar metabolism. Supplementation with astaxanthin may also promote a healthy inflammatory response for those who have T2D. Shrimp, krill, wild-caught sockeye salmon, crab, trout, and crayfish are great dietary sources of astaxanthin. Since astaxanthin is a fat-soluble nutrient, its bioavailability is enhanced when taken with dietary fat or fish oil.

By Caitlin Higgins, MS, CNS, LDN