One of the hallmarks of aging is a gradual loss of muscle.
This leads to a host of risks, including loss of mobility, bone-breaking falls, and — perhaps most commonly — loss of independence, which relies on mobility and strength.
Age-related muscle loss, known as sarcopenia, is characterized by the replacement of muscle tissue with fat, giving your muscles a marbled appearance and less strength.
About half of all adults over 80 suffer from sarcopenia, which usually starts, unnoticed, at around age 40 and accelerates after age 65.
Previous research indicates that the reduced endurance and strength can be slowed or reversed with a combination of resistance (strength) and aerobic workouts.
Proper nutrition — including ample protein intake — can also help halt or slow age-related muscle loss.
Now, the results of a pilot clinical trial see some promise in astanxanthin: the antioxidant, anti-inflammatory pigment that turns shrimp shells and salmon flesh red.
What is astaxanthin?
In addition to omega-3 fatty acids and vitamin D, wild salmon is the leading source of astaxanthin (asta-zan-thin), which is a carotenoid-class antioxidant and red-orange pigment.
As a carotenoid, astaxanthin is a close cousin to plant-source antioxidants such as beta-carotene, which gives carrots their orange color.
Astaxanthin is created by many algae to protect themselves from harmful UV sunrays, and lends its red-orange-pink colors to anything that eats such algae.
It works its way up the food chain from algae to zooplankton (like krill) and the larger creatures that eat zooplankton, including salmon, lobster and shrimp.
In the body, astaxanthin works as a powerful antioxidant, protecting cells from damage caused by an excess of the unstable oxygen molecules called free radicals.
In test tube experiments, astaxanthin is displays a free-radical-fighting capacity about 500 times greater than vitamin E's.
Astaxanthin’s antioxidant power can — largely via its effects on our working genes — protect and optimize cell functions and may thereby reduce the risk or severity of “degenerative” conditions such as osteoarthritis, dementia, and cardiovascular disease.
Just as importantly, astaxanthin moderates inflammation — a key promoter and driver of degenerative diseases — also effects via its effects on our working genes.
Wild salmon — especially sockeye or “red” salmon — is the leading food source of astaxanthin, but it contains very small amounts, measured in micrograms (millionths of a gram).
For example, wild sockeye salmon contains about 12 micrograms per 6 oz serving and krill oil contains about 100 micrograms per 1000 mg capsule.
In contrast, astaxanthin supplements provide much larger amounts, measured in milligrams.
Accordingly, it makes sense to consume astaxanthin as a dietary supplement, as in all the studies described below.
Astaxanthin may help seniors with age-related muscle loss
A newly published study from the University of Washington, Seattle examined the effects of supplemental astaxanthin on muscle loss in older adults.
The research was based on previous findings that showed astaxanthin supplementation increased strength and endurance.
For example, one prior study showed that six months of astaxanthin supplementation in healthy young men resulted in strength-endurance gains of 55%.
For the new study, the researchers wanted to see how supplemental astaxanthin plus exercise affected muscle mass, compared to exercise alone (Liu SZ et al. 2018).
The four-month-long randomized, double-blind, clinical trial involved 42 older adults, ranging from 65 to 82 years.
All the volunteers participated in an interval-exercise program that lasted for three months and involved walking on an increasingly steep treadmill, three times per week for 40-60 minutes.
Each of the two randomly-assigned groups received a different daily regimen:
• Placebo capsules
• Astaxanthin (12 mg) capsules that also provided tocotrienol* (10 mg) and zinc (6 mg)
*Tocotrienol is one of the compounds that constitute the nutrient complex called vitamin E. Most vitamin E supplements feature only its tocopherol components.
After the four-month trial, both groups experienced improvements in endurance. On average, both groups were able to spend 50% more time on the treadmill and walked 8% longer.
However, only the astaxanthin group displayed three other significant benefits:
• 8% increase in mobility
• 40% increase in endurance
• 14% increase in muscle strength
As the study’s authors concluded, “… the AX [astaxanthin] formulation in combination with a functional training program uniquely improved muscle strength, endurance, and mobility in the elderly.”
Lead author Kevin Conley, Ph.D., expressed the practical implications of their findings: “This gives clinicians an option for their patients who cannot make the substantial lifestyle changes required to halt the crippling impact of muscle loss.”
Astaxanthin may also protect brain function
Previous research indicates that astaxanthin may also help to protect the brain from the effects of aging.
Your brain is carefully protected from damage by a membrane known as the blood-brain barrier, which bars entry to pathogens and toxins circulating in the bloodstream.
However, this extra layer of protection also blocks some nutrients and antioxidants, rendering them less able to protect or enhance brain functions.
Astaxanthin is unusual in that it can cross the blood-brain barrier, and the results of animal research suggest that it may indeed help guard brain health.
In a 2016 rodent study, supplemental astaxanthin boosted the creation of new brain cells (i.e., neurogenesis) while enhancing learning and memory capacity (Yook JS et al. 2016).
Those effects matter because the age-related drop in the ability to create new brain cells — and connections between brain cells — exacerbates memory and mental-function problems.
Astaxanthin's broad spectrum of benefits
Evidence from animal studies and preliminary human trials indicate that astaxanthin may help protect against cataracts, sun damage to the skin, support immunity, and help prevent or ameliorate the effects of cancer, diabetes, hypertension, stroke, and vascular dementia (Hussein G et al 2006).
And the results of a clinical trial published two years ago revealed adaptogen-like effects from supplemental astaxanthin: see Salmon's Bold Color Boosts Energy & Slows Aging.
(The term “adaptogen” was coined to describe the herbs that fight mental and/or physical fatigue and/or bolster endurance, such as ginseng, schisandra, ashwagandha, and rhodiola.)
Further, supplemental astaxanthin may improve blood-fat profiles and burn body fat:
See Salmon’s Red-Orange Hue Helps Hearts & Fights Belly Fat and Salmon Pigment Shows Weight Control Potential.
Astaxanthin in wild vs. farmed salmon
Farmed salmon get astaxanthin as a feed additive, for two reasons.
Astaxanthin is essential for salmon's growth and overall health, and consumers will not buy grey-fleshed salmon.
It’s important to note that the astaxanthin in most farmed salmon chow is a synthetic form or “isomer” whose health effects in humans remain untested.
And wild salmon contains 40% to 400% more astaxanthin, compared with farmed fish (Turujman SA et al. 1997).