Health Benefits of Astaxanthin

Red pigment found in seafood may be a potent antioxidant

Salmon is high in asthaxanthin.
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Astaxanthin is a reddish pigment that belongs to a group of nutrients known as carotenoids. It is a compound found in algae and yeast and the one responsible for giving salmon, shrimp, trout, and other seafood their reddish coloration.

Carotenoids are plant-based compounds that also include vitamin A, beta-carotene, lutein, and lycopene. As with the other carotenoids, astaxanthin is believed to have antioxidant and anti-inflammatory effects. These can prevent or slow the progression of certain diseases by reducing the oxidative and inflammatory stress placed on cells.

Population-based studies have shown that people who eat diets rich in carotenoids tend to have a lower risk of cardiovascular disease. Whether any of these benefits can be directly attributed to astaxanthin is unknown. The current body of evidence is inconclusive at best.

Health Benefits

Alternative practitioners believe that astaxanthin supplements may prevent or treat a host of ailments, including heart disease, diabetes, high cholesterol, liver disease, and aging-related vision loss.

Others have made far-ranging (and sometimes exaggerated) claims, suggesting the astaxanthin can treat Alzheimer's disease, male infertility, rheumatoid arthritis, and even cancer. Few of these claims are supported by research.

With that being said, a number of smaller studies have suggested that astaxanthin may offer genuine health benefits when used as a supplement.

Heart Disease

Some scientists strongly believe that the antioxidant properties of astaxanthin may be cardioprotective. By eliminating the free radicals that damage vascular tissues at the genetic level, the risk of atherosclerosis (hardening of the arteries) may be greatly reduced.

Some test tube studies have suggested that astaxanthin may be no less than 500 times more effective in clearing free radicals than either vitamin C or vitamin E.

The interest in astaxanthin began in 2000 when a study from Japan reported that 24 adults prescribed astaxanthin in doses ranging from 1.8 to 21.6 milligrams daily experienced reductions in "bad" low-density lipoprotein (LDL) cholesterol after a year. Moreover, the degree of LDL reduction directly corresponded to increases in astaxanthin doses.

A 2016 review of studies further concluded that astaxanthin not only exerts a positive influence on cholesterol but also triggers reductions in blood sugar and generalized inflammation as well. All of this translates to an overall reduction in cardiovascular risk.

What is not known is how much the risk is reduced and whether the antioxidative effects of astaxanthin are enough to be considered therapeutic.


Insulin resistance is a condition in which your body does not respond to insulin in the way that it should. The condition, also known to as impaired glucose tolerance, often occurs before prediabetes and the onset of type 2 diabetes. Astaxanthin may help improve your body's insulin response and reduce the risk of type 2 diabetes.

A 2018 study in the Asia Pacific Journal of Nutrition reported 8 milligrams of astaxanthin taken daily for eight weeks reduced abdominal fat, LDL, blood pressure, triglycerides, and fructosamine in people with diabetes but not blood glucose.

What this suggests is that astaxanthin may have little impact on the treatment of type 2 diabetes but may mitigate many of the risk factors that can lead to the disease.

Macular Degeneration

Macular degeneration is an aging-related eye condition characterized by progressive damage to the central part of the retina (known as the macula), resulting in blurring and vision loss. Antioxidants like vitamin C, vitamin E, and beta-carotene are known to slow the progression of macular degeneration. Astaxanthin may also play a part.

According to a 2008 study published in Ophthalmology, people with macular degeneration provided a daily supplement of vitamin C (180 mg), vitamin E (30 mg), zinc (22.5 mg), copper (1 mg), lutein (10 mg), zeaxanthin (1 mg), and astaxanthin (4 mg) experienced significant improvements in the function of the central retina after six and 12 months.

A similar study in 2012 reported that the combination of lutein (10 mg), zeaxanthin (1 mg), astaxanthin (4 mg), and an antioxidant supplement improved visual sharpness and contrast perception in people with moderate macular damage.

Despite the positive findings, it is unclear how much of a role, if any, astaxanthin played when compared to the other antioxidants used in the regimens.

Possible Side Effects

Astaxanthin appears to be safe and well tolerated. Side effects tend to be mild and may include increased bowel movements and an otherwise harmless red stool color. High doses may cause stomach pain.

The long-term safety of astaxanthin supplements in children, pregnant women, and nursing mothers is unknown. It is also unknown what, if any, drugs astaxanthin may interact with. To avoid problems, speak with your doctor before taking an astaxanthin supplement to fully understand the possible risks and benefits.

Dosage and Preparation

There are no guidelines directing the appropriate use of astaxanthin supplements. Most are sold in gel cap form in doses ranging from 4 milligrams to 12 milligrams. As a general rule, never exceed the dose listed on the product label.

Astaxanthin gel caps are sensitive to high temperatures and sun exposure. Store them in a cool, dry room in their original light-resistant containers. Keep an eye on the use-by date and dispose of any expired supplements.

What to Look For

Dietary supplements are not subject to rigorous regulation in the United States. As long as they adhere to standard manufacturing practices and make no unqualified medical claims, they can be sold in drugstores with no little, if any, testing. To ensure safety and quality, opt for brands that have been voluntarily submitted for testing by an independent certifying body like the U.S. Pharmacopeia (USP), ConsumerLab, and NSF International.

Many astaxanthin products are derived from marine algae called Haematococcus pluvialis, a species known to produce high quantities of astaxanthin. In addition to supplements, the extracted pigment is approved for use as a cosmetic colorant or as an ingredient in fish feed to enhance the redness of farmed fish. When used in dietary supplements, the astaxanthin is suspended in a carrier oil.

Some astaxanthin supplements are produced synthetically in the lab. While some manufacturers will claim that algae-derived astaxanthin is superior, nothing in the body of research has shown that one is better than the other.

When buying an astaxanthin supplement, don't mistake a krill oil supplement (made from the bodies of tiny sea crustaceans) for the real deal. Many krill oil manufacturers will claim that their products are rich in astaxanthin, but the amount delivered is usually far less than that found in an astaxanthin supplement.

Other Questions

Which foods are highest in astaxanthin?

As a general rule of thumb, any fish or seafood that is red contains astaxanthin. With that being said, the amount can vary considerably. Wild sockeye salmon, for example, can contain as much as 3.2 milligrams per 3-ounce serving, while farmed Atlantic salmon delivers around 0.8 milligrams per 3-ounce serving.

While some people will tell you that the redness of a fish in an indication of its astaxanthin content, this is not always true. Many farmed fish, including salmon and rainbow trout, are fed astaxanthin-enriched fish feed to enhance their coloration.

By and large, the fish and seafood richest in astaxanthin are crawfish, crab, lobster, shrimp, red snapper, salmon, rainbow trout. and char.

Do I need an astaxanthin supplement?

Ataxanthan is not an essential nutrient, and there is no recommended daily intake. However, it is possible that an increased intake of astaxanthin could provide health benefits.

As with all other nutrients in your diet, always opt for food sources over dietary supplements. Astaxanthin is only one reason to add salmon to your diet. Even in canned form, salmon delivers a healthy dose of omega 3 fatty acids that are known to reduce cholesterol and the risk of heart disease.

If you don't eat fish, an astaxanthin supplement may be a reasonable option. But remember: the health benefits of astaxanthin supplementation are largely presumed, and taking a daily supplement in no way guarantees a result.

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