Astaxanthin, a carotenoid belonging to the xanthophyll subclass, possesses numerous clinical benefits due to its unique cell membrane effects. It neutralizes free radicals and oxidants by accepting or donating electrons without becoming a prooxidant. Its linear structure and polar-nonpolar-polar layout allow it to be precisely inserted into cell membranes, with its polar structure scavenging free radicals in aqueous environments, and its nonpolar segment providing oxidation resistance and electron delocalization.
Clinical trials have demonstrated the efficacy and safety of astaxanthin. In double-blind, randomized controlled trials, it reduced oxidative stress and improved biomarkers of inflammation and immunity. It also decreased triglycerides, increased HDL cholesterol, and improved blood flow in microcirculation models. In a small clinical trial, astaxanthin improved cognition and neural stem cell differentiation and proliferation. It has also been shown to improve vision and eye adaptation in several studies.
Astaxanthin has been shown to have a positive impact on fertility and sperm function. In a clinical trial, men receiving 16 mg of astaxanthin daily for three months had increased sperm linear velocity and decreased sperm oxygen-free radical production, resulting in a significantly higher pregnancy rate compared to the placebo group.
In another trial, astaxanthin was evaluated for its effect on functional dyspepsia. While it did not significantly reduce overall symptoms, the higher dose of 40 mg/day did reduce acid reflux-related symptoms and improve well-being in quality of life questionnaires.
Astaxanthin is mainly obtained through the diet, with seafood being the primary source. It is also used as a feed additive for farmed seafood to enhance its color. Natural astaxanthin is mainly derived from the algae Haematococcus pluvialis, while synthetic astaxanthin is also available. Natural and synthetic astaxanthin differ in chemical composition, bioavailability, purity, and sensory quality.
Clinical studies have shown that natural astaxanthin has a good safety profile, with no serious adverse effects observed even at high doses. In one study, subjects experienced red-colored stools and increased bowel frequency at a dose of 30 mg, but no significant changes were observed in liver parameters at doses of 8 to 12 mg daily.
In Closing
Astaxanthin has been shown to have various benefits for human longevity due to its potent antioxidant and anti-inflammatory properties. It helps protect cells from oxidative stress, reduces inflammation, and improves immune function. Additionally, astaxanthin has been linked to improved cardiovascular health, cognitive function, and sperm quality, which are all important factors for overall longevity.
