Table 2.

The effects of sardine interventions compared to other sources of omega-3 (fish oil supplementation and salmon) on the omega-3 index.

Study	Design	Population	Sample size of the intervention group	Protocol/supplementation	Duration	Omega-3 index (%)
Díaz-Rizzolo et al., 2021 (25)	RCT	Pre-diabetes and ≥ 65 yo	75	200 g of sardine per week plus a T2D-prevention nutritional plan	12 mo	6.64 ± 1.22 → 7.90 ± 1.33 (pre- and post-intervention) *
Balfegó et al., 2016 (26)	RCT	Drug-naïve patients with T2D	17	100 g of sardines 5 days a week plus a standard diet for T2D	6 mo	5.3 ± 0.3 → 8.0 ± 0.4 (pre- and post-intervention)*
Grenon et al., 2015 (94)	RCT	Patients aged 50 and older with lower-extremity Peripheral Artery Disease	40	4.4 g/d of fish oil	1 mo	5.2 → 9.2 (pre- and post-intervention)*
Ramprasath et al. 2013 (93)	RCT	Healthy volunteers	24	600 mg of n-3 PUFA from krill oil	1 mo	4.97 ± 0.69 → 7.20 ± 1.35 (pre- and post-intervention)*
Ramprasath et al. 2013 (93)	RCT	Healthy volunteers	24	600 mg of n-3 PUFA from fish oil	1 mo	4.96 ± 0.59 → 6.51 ± 0.97 (pre- and post-intervention)*
Roos et al., 2020 (92)	RCT	Healthy volunteers	17	2 portions/week of salmon grown on feeds containing mainly fish oil, in which the average portion size was 157.1 g and the EPA + DHA content of fillets was of 2.1 g/100 g	18 w	↑2.3% #
Roos et al., 2020 (92)	RCT	Healthy volunteers	17	2 portions/week of salmon grown on feeds containing mainly rapeseed oil, in which the average portion size was 157.1 g and the EPA + DHA content of fillets was of 0.9 g/100 g	18 w	↑2.0% #

^*p < 0.001 for intragroup comparison.

^#p < 0.01 compared to control group.

DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; PUFA, polyunsaturated fatty acids; RCT, randomised control trial.