Why this matters
Losing muscle with age can mean falls, fractures, and loss of independence. Exercise and protein help—but can nutrition do more? A randomized controlled trial suggests omega-3s might.
Study snapshot
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Design: Double-blind, randomized, placebo-controlled (gold standard)
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Participants: 44 adults, 60–85 years
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Duration: 6 months
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Groups:
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Fish oil: 4 capsules/day delivering ~1.96 g EPA + 1.50 g DHA
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Placebo: 4 capsules/day corn oil
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Exercise: None prescribed (dietary intervention only)
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Citation: Smith GI et al., American Journal of Clinical Nutrition, 2015
What improved with omega-3s
Compared with placebo, the fish-oil group showed meaningful gains in:
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Muscle size: Increased thigh volume
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Strength: Higher handgrip strength and 1-rep max (1RM)
These functional outcomes build on earlier mechanistic work from the same team showing omega-3s can influence muscle-related cellular pathways (Smith GI et al., Clin Sci).
Compliance confirmed: Omega-3 Index jumped
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RBC EPA+DHA (Omega-3 Index) rose 135% in the fish-oil group: ~5.8% → 13.2%
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No change in the placebo group
Using blood levels strengthens confidence that people actually took (and absorbed) the dose. A useful next step would be linking the size of the Index increase to the size of strength gains.
How to interpret this
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This was a well-designed trial showing functional benefits (not just lab markers) in older adults without adding exercise.
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It does not mean fish oil replaces exercise—movement still delivers broad benefits (balance, mobility, cardiovascular health, mood).
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For adults 60+, adding fish (or a quality EPA+DHA supplement) may help preserve muscle mass and strength alongside protein intake and activity.
Practical takeaways
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Food first: Aim for 2–3 servings/week of fatty fish (e.g., salmon, sardines, mackerel).
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Supplements: Trials used ~3.5 g/day combined EPA+DHA. Many people opt for 1–2 g/day for general support—discuss dosing with your clinician.
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Track status: Consider measuring your Omega-3 Index; many benefits are seen as levels approach 8–12%.
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Stay consistent: Benefits accrued over months, not days.
