Fish oil has been shown to be an effective supplement for improving various cardiovascular and muscular benefits. Krill Oil is lesser known but with promise as an alternative to Fish Oil.
What did they test? Changes in muscle strength a leg extension test performed after 6 months of Krill oil or a control supplement.
What did they find? Six months of supplementing with 4 g/day of Krill Oil led to significantly improved muscle function in older healthy adults when compared to a placebo.
What does it mean for you? Regular intake of long-chain n-3 polyunsaturated fatty acids through Krill or Fish oil supplements, or any other fatty fish consumption promotes maintenance of muscle mass and function. This is especially important for those with age-related declines in muscle mass (sarcopenia).
What’s the Problem?
Sarcopenia, the phenomenon of muscle wasting with aging, is a genuine health concern for the world’s growing elderly population. Every year in the United States, 40 billion dollars go towards Sarcopenia healthcare costs 2. Moreover, sarcopenia significantly contributes to mortality risk in the elderly 3. Even more concerning, the hospitalized elderly are at a 2-3x greater risk for mortality and a 6x greater risk for those with type 2 diabetes and sarcopenia 4 5 . Sarcopenia also increases the risk of disability and functional decline by 2-3-fold compared to the elderly without sarcopenia 6 7. Sarcopenia typically begins around age 40 and results in a reduction in lean mass of approximately 0.5-1% per year 8. A few different factors likely drive sarcopenia. Metabolically, our muscle protein metabolism changes as we age, driving us towards catabolism. Research has demonstrated that anabolic signaling is impaired in elderly adults with a decreased muscle protein synthesis (MPS) to meal feeding compared to young subjects 9. It’s important to note that it appears the elderly can achieve a similar anabolic response to a meal as young adults, but it does require additional protein at that meal 10. However, when examining myofibrillar MPS specifically, there appears to be a reduced response to anabolic stimuli like essential amino acids (EAAs) even at higher doses 9. The decreased anabolic response may be partly explained by a reduced expression and activation of several key regulators of MPS, including the mammalian target of rapamycin (mTOR) and the ribosomal protein p70 S6K (S6K) 9. These complexes are phosphorylated when provided with sufficient nutrition (Leucine/EAAs/Protein) or mechanical (i.e., lifting) stimulus 11. Unfortunately, in the elderly, these anabolic signaling pathways appear to be dampened.
Not only is MPS in response to nutrition reduced in the elderly, but so is the anabolic response to resistance exercise. However, like nutrition, this suppressed response can be restored but requires a greater dosage of resistance exercise 12. Because aging promotes a catabolic, muscle-wasting environment, exploring treatment methods that could combat sarcopenia is crucial. One proposed treatment uses omega-3 fatty acids such as EPA and DHA found in fish oil and krill oil. Several studies indicate that EPA and DHA may increase lean mass in the elderly, MPS, and, the MPS response to a meal 13 14 15. Moreover, some studies have also demonstrated that these omega-3 supplements may help reduce the rate of muscle protein breakdown during wasting conditions 16. However, data are mixed on the effectiveness of these omega-3 fatty acids for increasing lean mass as some studies have demonstrated no effect 17. Krill oil is unique, containing choline and asaxanthin, which could improve muscle health 18 19. This leads to interest in Krill oil as an effective supplement for improving muscle size and strength. A recent study tested this idea in elderly individuals, keep reading to see if this could be a beneficial supplement for you!
Purpose & Hypothesis
Investigators aimed to determine the effect of krill oil supplementation, on muscle function and size in healthy older adults. They expected krill oil to increase muscle function, observed by an increase in leg extension strength.