Eat more mussels.

Mussels deliver all nine essential amino acids with an amino-acid score of 107 — comparable to eggs — making them a complete, high-quality protein.[1] Gram for gram of energy they carry nearly as much protein as lean steak (about 22 g per 600 kJ versus 24 g for beef), while staying lean and low in saturated fat.[1]

Where they pull ahead of most meat is the micronutrients. A 100 g serving carries roughly 6–7 mg of iron — more than beef or spinach, and in the well-absorbed heme form — plus vitamin B12 at around ten times a day's needs, along with selenium, zinc and iodine.[1] Iron, B12 and long-chain omega-3 are exactly the nutrients hardest to get on a plant-only diet, which makes bivalves an unusually good bridge food for anyone cutting back on meat without wanting to supplement everything.

On protein quality, mussels are complete, scoring 107 on the amino-acid scale — a shade above eggs (100); soy and most legumes score lower, limited in one or two amino acids.[1] Here's how it stacks up against other common proteins:

*Amino-acid score is a protein-quality ratio (100 = meets all essential needs in full); lentils are limited in methionine. Plant omega-3 (0*) is ALA, not the long-chain EPA/DHA found in seafood. B12 shown as % of daily need. Other values are typical per 100 g cooked and vary by cut and source.

Salmon is the one common protein that beats mussels on omega-3 — but mussels carry far more iron and B12, at a fraction of salmon's carbon footprint.

Blue mussels grow on suspended ropes and feed themselves by filtering plankton from the surrounding seawater — no feed, no fresh water, no fertiliser, no antibiotics, and no cropland at all.[2] That last point matters more than it sounds: more than three-quarters of the world's farmland is given over to livestock, which returns only a fraction of our calories and protein.[8]

Plant proteins like beans, lentils and tofu are also genuinely low-impact — this isn't “mussels good, plants bad.” But on the raw inputs a food needs, mussels quietly beat almost everything:

A single mussel can filter on the order of 10–25 litres of seawater a day.[3] At farm scale this pulls excess nitrogen and phosphorus — the nutrients that drive algal blooms and dead zones — back out of the sea. Measured over a farm's life, blue mussels come out net-negative on that nutrient pollution.[2]

Because nothing has to be grown, fed or shipped to raise them, farmed mussels sit among the lowest-carbon animal proteins measured. Dedicated life-cycle studies put blue mussels at roughly 0.3–2 kg CO₂e per kg, depending on where you draw the boundary — in the same range as beans and lentils, and dramatically below beef.[4]

Mussels have no brain — only paired cerebral, visceral and pedal ganglia coordinating basic functions like opening and closing the shell.[5] Neurologically they sit far below the animals we're confident can suffer, and a fair bit closer to the plants we already eat without a second thought.

Can we be certain they feel nothing? No — and it's only honest to say so. A 2021 review found no conclusive evidence that bivalves are sentient while stressing the data is thin, and the landmark UK sentience review assessed octopuses and crabs but didn't even include bivalves.[5] But notice the worry cuts both ways: we also can't prove a lettuce isn't sentient, and that uncertainty doesn't stop anyone eating salad. On every measure we have, a mussel is much further from suffering than the chicken or pig on the next plate.

And that's the part worth sitting with. Humans raise and kill on the order of 80 billion land animals a year, the great majority chickens, most in intensive conditions widely judged to be cruel.[10] If their suffering carries even a fraction of the moral weight of ours, the scale is staggering — arguably one of the largest sources of suffering we actively cause. You don't have to accept the strongest version of that to see the asymmetry: swapping a vertebrate that very likely suffers for a bivalve that very likely doesn't is about the lowest-cost ethical upgrade a meat-eater can make.

Frozen, shell-off blue mussel meat is 117.80 kr/kg at Willys — cleaned, cooked and basically all edible. By weight that lands near beef mince; but because it's nearly pure protein with no bone, fat or shell to pay for, per gram of protein it comfortably undercuts steak and holds its own against mince. Bags of in-shell mussels are cheaper still per kilo, and everything keeps for months in the freezer.

Indicative Willys price, early 2026 — varies by store and season.

See where we buy them →

None of the above matters if it isn't a pleasure to eat — and mussels are. Sweet, briny, faster than pasta, and endlessly adaptable: a classic white-wine moules marinière one night, a smoky tomato-and-chorizo broth the next, or just tipped into pasta straight from the freezer. The broth they make is half the point — keep bread nearby.

Start with moules marinière →