When we think about supplements for immune support, a few generally come to the forefront: Vitamin C, vitamin D, zinc, selenium, and maybe a few herbs like echinacea and medicinal mushrooms. But one thing we rarely hear about for maintaining healthy immune responses is antioxidants.

Free radicals and reactive oxygen species are a double-edged sword; they play a dual role as both toxic and beneficial compounds in the body and, depending on the levels and situation, can be either harmful or helpful.

But free radical production isn’t something we can just turn on or turn off. They’re produced as a byproduct of normal cellular metabolism, as well as from external sources like environmental pollution, cigarette smoke, radiation, and medication.

But when free radicals levels become excessive, and the body can’t destroy or neutralize them, their accumulation generates a phenomenon called oxidative stress, which plays a major role in the development of various chronic and degenerative diseases like cancer, autoimmune (AI) disorders, premature aging, ocular diseases, rheumatoid arthritis, and cardiovascular and neurodegenerative diseases.

However, the good news is that the body naturally has several mechanisms to counteract oxidative stress, including antioxidants produced either endogenously or supplemented through diet.

If you’re not familiar with the world of antioxidants, we’re talking about two of the most powerful ones—glutathione and astaxanthin—and their roles in supporting immune function. We’re covering what they are, their roles in the body, and which ones take the reins for the best immune-supporter.

What Is Glutathione?

If you’ve heard about antioxidants before, chances are you’ve probably heard the word ‘glutathione’ come up a few times. It is an essential antioxidant and sulfur compound that’s composed of three amino acids—cysteine, glycine, and glutamic acid—and is the major non-protein thiol in most organisms, including humans 1.

Glutathione (GSH) is found in high concentrations in many tissues within the body and has been shown to play roles in mitigating oxidative stress and inflammation, maintaining redox balance, enhancing metabolic detoxification processes, and regulating immune function 2.

Although it’s an endogenous antioxidant, there is variability in an individual’s capacity to actually produce the compound, which means that levels may not be where they should.

And several chronic, age-related conditions have been linked to low levels of GSH, including neurodegenerative diseases, mitochondrial dysfunction, diabetes, and even some forms of cancer 2-4. But during times of high oxidative stress, malnutrition, or increased toxic burden, the demand for GSH increases, thereby diminishing levels further.

As we said, glutathione is one of the most potent antioxidants in the human body, so naturally, it plays a role in combating free radicals and reducing oxidative stress to prevent cellular damage. But that’s not all it does. Glutathione also plays key roles in 5:

  • Neutralizing reactive oxygen and nitrogen species (RONS)
  • Serving as a cofactor for antioxidant enzymes
  • Regenerating other antioxidants (vitamin C and E)
  • Removing toxins and heavy metals from cells and the brain
  • Regulating cell proliferation and apoptosis
  • Supporting mitochondrial function
  • Maintaining mitochondrial DNA

As for its role in the immune system, aside from protecting cells from free radical damage, it also protects the immune system in two key ways 6:

  1. Supports proper function of the T-cell lymphocytes to enable frontline soldiers of the immune system to increase in numbers
  2. Stimulates production and activation of natural killer (NK) cells

It’s also been shown to have a pivotal role in establishing innate immune responses to viruses, possibly acting as a signaling molecule with a mechanism different from simply scavenging reactive oxygen species 7.

What Is Astaxanthin?

At first glance, you’re probably thinking asta-what? Astaxanthin is another powerful antioxidant that’s been extensively studied for its role in skin health because of its powerful photo-protective, antioxidant, and anti-inflammatory properties, but more recently, it has been a lot of kudos for protecting the eyes and maintaining ocular health.

Unlike glutathione that’s synthesized endogenously, astaxanthin is a xanthophyll carotenoid that’s naturally produced in various types of bacteria, microalgae, and yeasts, but is also the dietary compound that gives certain aquatic life their characteristic pink color 8.

Because of its unique molecular structure, it’s been suggested to have strong antioxidant, anti-inflammatory, and anti-apoptotic activities 9, which gives it a key role in any conditions where inflammation and oxidative stress may underlie the pathology.

And what’s interesting is that some research suggests that its antioxidant capacity may be up to 10-times more powerful than zeaxanthin, lutein, and beta-carotene, and up to 100-times more powerful than vitamin E 10.

As for its role in immune function, astaxanthin has been shown to have three important roles 11:

  1. Modulating immune responses
  2. Inhibiting cancer cell growth
  3. Reducing bacterial load and gastric inflammation

Studies show that astaxanthin may be a powerful compound for regulating immune responses, oxidative damage, and inflammation in humans 11.

Dietary astaxanthin has been shown to enhance both cell-mediated and humoral immune responses, evident through enhanced T cell and B cell mitogen-induced lymphocyte proliferation, NK cell cytotoxic activity, IFN-γ and IL-6 production, and LFA-1 expression.

But there’s more. In rodent studies, astaxanthin has also been shown to be beneficial for ameliorating oxidative stress-induced inflammatory diseases like diabetic nephropathy, lipopolysaccharide-induced uveitis, and exercise-induced skeletal and cardiac muscle damage 11.

Which One’s A More Powerful Immune-Booster?

When we’re looking at what the better immune booster is out of two antioxidants, we first need to look at the role of oxidative stress in immune function.

As we said before, oxidative stress is a major player in developing various chronic diseases and degenerative conditions, but the body has mechanisms to combat excessive levels and resulting damage.

Endogenous and exogenous antioxidants act as free radical scavengers by preventing and repairing damage caused by reactive oxygen and nitrogen species (RONS).

In doing so, it can support and enhance immune defenses and lower the risk of diseases that develop from immunosuppression and excessive oxidative stress.

But the thing with immune cells is that they’re particularly sensitive to oxidative stress because of their high percentage of polyunsaturated fatty acids in the plasma membranes, along with naturally producing more oxidative products 12.

Overproduction of RONS can tip the oxidant to antioxidant balance, thereby destroying cell membranes, proteins, and DNA.

As such, under conditions of increased oxidative stress (e.g., during disease states or high-intensity physical activity), dietary antioxidants become essential for maintaining the proper balance 11.

While studies show major roles for both glutathione and astaxanthin in supporting immune function, which one is better?

It’s not to say that one is necessarily a stronger antioxidant than the other, but where the immune system is concerned, studies do support a greater role for glutathione in preventing oxidative damage and reducing inflammation, thereby bolstering appropriate immune responses and optimal immune function.

And although astaxanthin can support immune health, it has strong links to ocular and skin health, which may make it a better option for reducing antioxidant damage in the eyes, preventing visual impairments, and supporting proper function and health of the skin.

And if you want the best of the best, Setria Glutathione is it. It’s one of the most powerful forms of L-glutathione produced from a unique fermentation process, leaving you with the cleanest, purest, and most effective form of glutathione.

Studies show that supplementing with 1,000mg/day of Setria® Glutathione can increase whole blood levels by 30%, red blood cell levels by 35%, and buccal cell glutathione levels by 260%!

Not to mention that Setria® naturally works to increase NK cell activity two-fold for stronger and more efficient immune responses.

One study even found that after three months of supplementation with glutathione, there was a 2-fold increase in NK cell activity with 1,000mg of Setria®.

Basically, it’s a one-way ticket to a healthier and stronger immune system and the best defense you can get.

Final Thoughts

With all of that said, we can get behind both glutathione and astaxanthin. They’re both fantastic antioxidants on their own, but when it comes to supporting immune function and protecting your body against illness and infection, glutathione takes the crown.


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