Is Astaxanthin in Salmon Safe? A Look at This Antioxidant Pigment

Astaxanthin is a reddish pigment that gives salmon and other seafood its distinctive color. It is also a potent antioxidant with emerging health benefits. But is consuming astaxanthin-rich salmon safe? In this article, we’ll explore the science on astaxanthin sources, benefits, risks and usage considerations.

What is Astaxanthin?

Astaxanthin is a reddish carotenoid pigment belonging to the terpenoid group It occurs naturally in certain algae, yeast, salmon, trout, krill, shrimp and other seafood that consume these microorganisms.

Astaxanthin gives salmon, lobster and other marine life their bright red-orange hue. It helps shield them from oxidation in the harsh ocean environment. This antioxidant is now being studied for potential benefits in humans.

Sources of Astaxanthin

The primary natural source is freshwater algae called Haematococcus pluvialis. Under stress they produce astaxanthin which accumulates in their cells. Algal astaxanthin is extracted and used in salmon aquaculture feed to pigment farmed fish.

Astaxanthin levels are higher in wild salmon than farmed. Wild sockeye salmon has about 4-5 mg of omega-3s per 4 oz, while farmed salmon only has 1-2 mg. Trout, shrimp, crab and krill also contain varying amounts.

Synthetic astaxanthin is also approved for fish feed. Nutritional supplements provide doses of 2-12 mg from natural or synthetic sources.

Potential Health Benefits

Emerging research suggests astaxanthin supports health via diverse mechanisms:

• Powerful antioxidant activity to relieve oxidative stress
• Reduces chronic low-grade inflammation
• Boosts skin health and provides UV-ray protection
• Enhances endurance, muscle recovery and heart health
• Improves brain function and may slow neurodegeneration
• Alleviates eye fatigue, enhances vision and prevents cataracts
• Boosts immunity and inhibits cancer cell growth

While promising larger human trials are needed to substantiate many of these benefits. But current evidence and safe profile suggests astaxanthin merits further research.

Is Astaxanthin Toxic?

Astaxanthin supplements are well tolerated with very few side effects at recommended doses. Studies found:

• Generally recognized as safe (GRAS) by the FDA
• European Food Safety Authority deems it safe for human consumption
• No documented toxicity or adverse effects in humans
• Very low toxicity in rodent studies – LD50 over 4000 mg/kg body weight

Research suggests astaxanthin may:

• Lower blood pressure (caution if on BP meds)
• Affect hormones like testosterone (needs more study)
• Reduce calcium absorption (a concern for osteoporosis)

While minor concerns exist, moderate supplementation appears safe. But consult a doctor before use in pregnancy, with autoimmune disorders or on medications.

Is Astaxanthin-Fed Salmon Safe?

Some people theorize that astaxanthin supplementation in farmed salmon feed might be harmful. However, research has found:

• Astaxanthin levels in fish fillets are far below amounts used in trials. A typical serving of salmon provides just a few milligrams.

• Salmonids require astaxanthin for proper pigmentation, growth, survival and reproduction. It’s a necessary nutrient, not just a cosmetic dye.

• Feeding approved astaxanthin to salmon has not been shown to pose any food safety risks.

• Wild salmon accumulate the same pigment naturally by consuming astaxanthin-rich prey.

Both farmed and wild salmon are nutritious choices providing this antioxidant carotenoid. While moderation is advised, current evidence indicates consuming astaxanthin via salmon is safe.

Retinal Toxicity Concerns

High-dose astaxanthin supplements as tanning pills were linked to retinal toxicity in the 1990s. This raised concerns about eye safety. However, research has now established that:

• Retinal issues were from megadoses of >20 mg/day. Typical supplementation is under 12 mg.

• Absorption from fish consumption is far lower than purified tablets.

• No case reports exist of retinal damage from eating salmon or shrimp.

• Astaxanthin may actually prevent retinal damage and eye problems.

While megadoses may be inadvisable, astaxanthin from seafood does not pose any ocular toxicity concerns. On the contrary, it likely supports eye health.

Astaxanthin vs Canthaxanthin

Some confuse astaxanthin with canthaxanthin, a related but different carotenoid:

• Canthaxanthin was used as a tanning agent and in higher amounts was linked to retinal crystal deposits.

• Astaxanthin has a very different safety profile and does not appear to accumulate in the eye.

• Research conclusively shows astaxanthin does not cause the same adverse effects at recommended doses.

The two should not be conflated when it comes to safety considerations. While canthaxanthin can be problematic in very high amounts, astaxanthin is well tolerated.

Bioavailability Considerations

Despite astaxanthin’s potency, optimal delivery to target tissues is challenging:

• Poor water and fat solubility makes systemic absorption in the gut limited.

• Encapsulation, emulsification and addition of oils during manufacturing aims to enhance bioavailability.

• Plasma uptake only reaches 0.2% of the oral dose from supplements.

• Absorption is higher from seafood matrixes than isolated compounds.

• Synergistic nutrients like omega-3s in salmon may boost astaxanthin absorption.

So while the pigment exhibits biological activity in vitro, sufficient delivery to exert systemic effects is difficult. Further work is required to optimize bioavailability.

Potential Benefits Outweigh Minimal Risks

Current evidence indicates potential health benefits of moderate astaxanthin intake:

• Powerful antioxidant and anti-inflammatory activities.
• Cardioprotective, neuroprotective and anti-diabetic effects.
• Improved immune function, endurance and muscle recovery.
• Enhanced skin and eye health.

Supplementation and consumption via seafood appear safe with a wide safety margin:

• Occasional mild side-effects like skin discoloration.
• Minimal concerns at recommended doses for healthy adults.
• No indication of organ toxicity or accumulation.

With a favorable risk-reward ratio, both supplementation and astaxanthin-rich salmon can be considered as part of an overall healthy lifestyle.

The Takeaway