Table 1.

Summary of studies of omega-3 fatty acids considered in this narrative review.

Authors/Title/Year	Type of Study	Oil Integration	Sample	Duration	Results
Smith et al. 2015	Randomized study	n-3 PUFA (1.86 EPA and 1.50 g DHA/die) or corn oil	Sixty healthy 60–85-year-old men and women	Six months	Treatment with fish oil derived n-3 PUFA brought benefits on thigh muscle volume, handgrip strength, and tended to increase the average isokinetic leg muscle power
Yoshino et al. 2016	Ten subjects of Smith study (2015) with best answer to treatment	n-3 PUFA (1.86 EPA and 1.50 gDHA/die) or corn oil	Twenty healthy 60–85-year-old men and women	Six months	Different pathways involved in mitochondrial regulation and in the organization of the cell matrix were increased while the pathways related to calpain- and ubiquitin-mediated proteolysis, mRNA translation, and inhibition of mTOR signaling were decreased
Rodacki et al. 2012	Randomized study	3 groups: Group ST (only strength-training), Group ST90 (2 g/die fish oil for 90 days) and ST150 (2 g/die fish oil for 150 days)	Forty-five women	90 or 150 days	Supplementation with fish oil accompanied by strength training increased the neuromuscular system, enhancing the muscle strength and the functional capacity in elderly women
Boit et al. 2017	Randomized study	3 g of fish oil	Fifty men and women	18 weeks	long-chain n-3 PUFA supplementation enhances the increases in maximal isometric torque and muscle quality after 18 weeks of resistance exercise in older women but not in older men
Smith et al. 2011	Randomized study	n-3 PUFA (1.86 EPA and 1.50 g DHA/die)	Sixteen healthy adults	8 weeks	Omega 3 PUFA enhance muscle protein synthesis in response to stimulated feeding
McGlory et al. 2016	Randomized study	Fish oil group (5 g/day fish oil) and CONTROL GOUP (5 g/day coconut oil) took proteins following resistance exercise.	Twenty healthy males	8 weeks	No changes were found neither at REST, nor after physical activity (FED) nor after physical activity + protein intake (FEDEX)
Pahor et al. 2018	Pilot randomized clinical trial	0.7 of fish contained 400 mg of EPA and 200 mg of DHA	289 participants with reduced mobility	12 months	found no significant changes on IL-6 or walking speed
Kamolrat et al. 2013	Randomized study	Two group: fish oil (EPA 49.6%, DHA 50.4%) and control oil (60% olive and 40 & soy)	32 male Rowett strain Lister Hooded rats	8 weeks	The results also indicate an increase in anabolic signalling pathways particularly in type 2 fibres without effects on inflammation processes
Gingras et al. 2007	Randomized study	Two groups: control group (control oil mixture based on 60% cotton seed and 40% virgin olive oils), group LCn-3PUFA (4% menhaden oil)	Six growing steers	15 weeks	Long-term enteral the supply of LCn-3PUFA gives greater sensitivity to elimination of insulin-regulated amino acids and glucose and that these answers occur, in part, in the skeleton muscle
Kamolrat et al. 2013	In vitro study	Three group of murine C2C12 cells: control, EPA group, and DHA group	Murine C2C12 murine cell	28 h	The cells treated with EPA had greater protein synthesis and a lower protein breakdown than the controls and cells treated with DHA
Siam M, et al. 2008	Retrospective cohort study	No	2983 men and women aged 59 to 73		Each additional portion of fatty fish consumed per week was associated with a gain in grip strength 0.43 kg in men and 0.48 kg in women.