Astaxanthin: antioxidant, UV protector and more

There has been a fair amount of research indicating that astaxanthin can benefit various aspects of health.

Unfortunately, the majority of health-related astaxanthin studies have so far been in animals. In several species, including cats and dogs, dietary astaxanthin was shown to improve several aspects of the immune function: it increased production of antibodies, activated several types of immune cells and reduced inflammation. In rats, astaxanthin inhibited thrombosis (blockage by clots) in cerebral vessels. In mice, it prevented the formation of ethanol-induced gastric ulcer. In both cell culture and animal studies, astaxanthin was shown to reduce a number of negative effects of free radicals, including DNA damage. There is also considerable evidence of benefits of astaxanthin for the nervous system and the eyes. In many cell culture studies and some animal studies astaxanthin protected neurons and retinal cells from a variety of damaging factors ranging from oxidative stress to hypoxia to toxins. Importantly, astaxanthin crosses blood-brain barrier (as opposed to many of its cousins, such as beta-carotene and lycopene), which potentially makes it a promising neuroprotective agent for clinical use. When taken orally, it should still easily get to the cells of the nervous system and retina and thus be in a position to protect them.

Some of the above effects have been confirmed in human clinical studies. In a small but well-designed 2010 study (i.e. randomized double-blind and placebo-controlled), Dr Park and co-workers from Washington State University gave young women 0, 2, or 8 mg astaxanthin per day for 8 weeks. They reported that astaxanthin stimulated proliferation of several types of immune cells (such as T & B lymphocytes and natural killers) as well as enhanced their activity. Astaxanthin also increased the levels of interferon gamma and interleukine-6 (key molecular mediator of immunity). Furthermore, astaxanthin appeared to reduce general intensity of inflammation: “plasma C-reactive protein concentration was lower on week 8 in subjects given 2 mg astaxanthin". Dr Park and co-workers also reported that astaxanthin reduced the markers of DNA damage (possibly due to reduced DNA damage from free radicals).

Other human studies (unfortunately most of them relatively small) indicated the following potential benefits of astaxanthin: increase in HDL cholesterol (a.k.a. good cholesterol); improvement in male fertility (when combined with other infertility treatments); reduction of free radical damage (as evidenced by reduction in lipid peroxidation and other markers); enhanced physical performance (astaxanthin improved cycling time); partial protection from oxidative damage caused by smoking; and others.

All in all, astaxanthin appears to hold a considerable promise for a number of human conditions as well as anti-aging. Unfortunately, it will take a lot more human studies to determine the extent of its clinical benefits as well as optimal dosage and usage practices. In the few human studies conducted so far, the daily intake of astaxanthin ranged from 2 mg to 10 mg per day. (For reference, wild salmon contains between 3 and 11 mg of astaxanthin per kilogram.)

Astaxanthin and the skin

Astaxanthin may have a number of skin benefits, some more proven than others. In particular, astaxanthin appears to provide some degree of sun protection through multiple mechanisms. First, it blocks a modest amount of ultraviolet light directly (not enough to be an effective sunscreen by itself but still useful). Second, it neutralizes some of the free radicals induced by UV radiation and responsible for some of the sun damage. Third, astaxanthin appears to inhibit the induction of matrix metalloproteinases (MMP) by UV light. (MMP are an important factor in sun damage and skin aging.)

Astaxanthin is a potent fat-soluble antioxidant and thus should be able to protect fat-rich tissues (inluding the skin) particularly well. It is likely to be a useful skin protector from various types of skin damage, not just UV radiation. Another potentially useful property of astaxanthin is its ability to regulate so-call gap junctions, which are channels of cell-to-cell communication common in skin cells such as fibroblasts. Gap junctions tend to become disregulated with age and normalizing their function may help improve skin texture.

Unfortunately, the research into the skin benefits of astaxanthin is still in its early stages. There remains much uncertainly as to how to best utilize it in skin care. Notably, astaxanthin is a natural compound that has been consumed by humans for millenia (e.g. in salmon, shrimp and krill) and has a very good safety profile. For those who do not wish to wait for more conclusive research, trying astaxanthin as a part of their skin care regimen appears to pose a rather low risk.

The easiest way to get skin benefits of astaxanthin (as well as its other benefits) is to increase oral intake by consuming some astaxanthin-rich fish/sea food (e.g. wild salmon) and/or by taking a daily supplement (see typical dosage in the previous section).

However, dietary intake may not be sufficient to maximize skin benefits of astaxanthin. When ingested, astaxanthin is distributed throughout the entire body and only relatively small amount finds its way into the skin. Luckily, astaxanthin is well absorbed if applied topically (e.g. in a cream or lotion) because it is fat soluble and has relatively small molecules. The only possible downside of topical application is that astaxanthin may give your skin a bit of a tint (in the orange-red-bronze range). Some people enjoy this look as it resembles a light, fresh tan while others prefer to minimize it and therefore use astaxanthin lotions at night. The way astaxanthin looks on you may depend on your skin complexion as well as your choice of makeup. However, you will get the antioxidant, UV-protection and possibly other anti-aging benefits of astaxanthin regardless of your skin type or complexion.

Commercial skin care products with astaxanthin are available albeit not in a great variety (you can easily find some by googling). They tend to be more expensive that the cost of astaxanthin would justify -- perhaps due to perceived novelty. Another problem with the products containing topical astaxanthin or other antioxidants is that once a jar has been opened (or if it is intact but poorly sealed), the contents starts to degrade due to exposure to oxygen in the air. A viable alternative is to make your own cream or lotion with astaxanthin, which guarantees freshness and is far less costly. For specific instructions see DIY Anti-Aging Skin Care Infopack.

As I mentioned, astaxanthin is similar in many ways to its carotenoid cousin lycopene, which also has both skin and health benefits. On the other hand, there are some notable differences between the two indicating that they are not fully interchangeable. In fact, combining astaxanthin and lycopene may produce the best results. Whereas very few (if any) skin care products include both these agents, astaxanthin and lycopene are fully compatible and can be easily combined in a DIY formula (see DIY Infopack).