The Science of Antioxidants: Astaxanthin- the Soldier
We all know we need oxygen. Why do we need antioxidants?
Oxygen is “missing” 2 electrons from its outer orbit making it one of the more reactive atoms in the periodic table. It will seek out partners that can donate electrons to help fill the gap. O2 is two Oxygen atoms sharing electrons with each other. Water (H20) is two hydrogen atoms sharing electrons with one oxygen. Carbon Dioxide is one carbon atom sharing electrons with two oxygens. The list of possible combinations is extensive with many forms like water safe or even required for humans but add an extra oxygen making H202 vs. H2O and you make hydrogen peroxide, a reactive a reactive oxygen species (ROS) that can burn and destroy healthy cells.
Antioxidants bind with and neutralize RoS hence why we need them in our diet. 
Water Hydrogen peroxide
How does RoS get into our bodies?
We make it.
Plants convert light into energy. Animals evolved to used chemistry to make power. Our chemical power plant is located in the mitochondria that live in the cells throughout our body.
Mitochondria create energy using glucose and enzymes like CoEnzyme Q10 (CQ10) to add a phosphate to a compound called ADP (Adenosine di-phosphate) to make ATP (Adenosine tri-phosphate). Energy is released by the reverse process of ATP->ADP using the oxygen in the watery plasma to break off the phosphate that was added. This complex chemistry is not perfect. ROS is made naturally. If we alter the chemistry for example by consuming too much glucose in our diet, then the power plant is less efficient and produces more RoS.
How do we get rid of ROS? Antioxidants!
Vitamin C, enzymes like CQ10, minerals and metals (zinc, iron, magnesium ..) folate(vitamin B) , arachidonic acid and other compounds like glutathione are all antioxidants in their own right and are widely sold as antioxidant supplements.
I think about these antioxidants as the villagers in a medieval castle. Each villager has specific duties to perform to contribute to the fabric and health of the local economy.
Vitamin C makes collagen used to make our bones. CQ10 helps the mitochondria make energy, iron is used to carry and distribute oxygen throughout the town and folate is essential for replicating DNA and growing children into adults.
If it takes a village to raise a child, it takes soldiers to protect the village.
Enter astaxanthin: the soldier guarding the gates.
Multicellular life evolved about 600M years ago. To make complex living organisms requires tremendous amounts of energy hence more ROS.
Fortunately Mother Nature figured out how to make a highly specialized soldier that is 5000X more powerful than the villagers in protecting the castle from incoming invaders such as viruses & bacteria as well as neutralizing the ROS running around inside the castle walls.
Astaxanthin is unique. Its sole purpose is to stand on the wall, exchange electrons with incoming bacteria/viruses and ROS until it becoming saturated then it dies. Unlike the other antioxidants in the village. It has no role outside of defending and protecting the villagers.
Let’s come back to the villagers.
If the foot soldiers are overwhelmed, the villagers stop what they are doing and take up arms and fight. These antioxidants directly attack ROS or can be used to make white blood cells to attack viruses and bacteria that have gotten inside.
Minor breaches are neutralized but not without a cost to the community that survives. Major breaches of course wipe the entire village out.
We replenish our astaxanthin by eating a diet that of wild fish, shellfish, “barnyard” eggs/chickens and wild game. If you can’t source natural astaxanthin in your diet consider taking astaxanthin supplements such as https://www.adjuvia.life/products/astaxanthin (Footsoldiers) or https://www.adjuvia.life/collections/wellness-beauty/products/adjuvia-immune-system-booster (Footsoldiers plus 7 Villagers to back them up).