Cuttlefish: lean protein, plenty of selenium, and a mollusc allergy to respect

In a randomized crossover trial, 20 healthy adults who got 60 percent of their protein from lean seafood for 4 weeks had fasting triglycerides 27 mg/dL (0.31 mmol/L) lower than on a diet without seafood. Cuttlefish counts as lean seafood, yet it was not in that trial, and we found no trial of cuttlefish itself on any health outcome. What the tables show is a lean, protein dense food. The UK table lists raw cuttlefish at 71 calories, 16.1 g protein and 0.7 g fat per 3.5 oz (100 g), with 110 mg cholesterol and 370 mg sodium. It gives 65 micrograms of selenium per 3.5 oz (100 g) where the USDA table gives 44.8, so that figure differs by about a third depending on the table. Selenium from seafood is well used. In 35 men given labeled trout, fish selenium was absorbed as well as selenate and retained better, and cooking changed neither.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• The UK food table lists raw cuttlefish at 71 calories, 16.1 g protein, 0.7 g fat, 110 mg cholesterol, 65 micrograms selenium and 3.4 mg iron per 3.5 oz (100 g). — CoFID 2021 food Cuttlefish, raw (code 16-254) (n = 1 record) Evidence E source
  Per 100 g: 71 calories, protein 16.1 g, fat 0.7 g, cholesterol 110 mg, selenium 65 micrograms, iron 3.40 mg, sodium 370 mg

What your body absorbs

• In 35 men given stable-isotope labeled trout, selenium from fish was absorbed as well as selenate and retained better, and cooking did not change absorption or retention. — 35 male volunteers aged 18 to 50 in the UK and the Netherlands, parallel randomized, 4 labeled meals over 2 days (n = 35) Evidence B source
  Fish selenium absorption similar to selenate, retention higher (P < 0.001), no difference between processing methods
• In 12 adults eating 3.5 oz (100 g) of shrimp a day for 6 weeks, 83 percent of shellfish selenium was absorbed, yet plasma selenium rose only from 95.2 to 101.5 micrograms per liter. — 12 healthy young adults, 100 g shrimp daily for 6 weeks with a 5 day balance period (n = 12) Evidence C source
  Apparent selenium absorption 83 percent, plasma selenium 95.2 to 101.5 micrograms/L, glutathione peroxidase unchanged

What cooking and storage change

• By the USDA retention table for fish and shellfish, frying from frozen keeps about 95 percent of vitamin B12 and riboflavin and all of the iron and zinc. — USDA Release 6 group factor, Finfish and Shellfish Products, FINFISH(FROZEN),FRIED (code 2601) (n = 1 factor set) Evidence E source
  Retained: vitamin B12 95 percent, riboflavin 95 percent, thiamin 90 percent, iron, zinc, sodium 100 percent
• In a blinded taste test with 120 rounds per food in Japan, people could not reliably tell once-frozen squid sushi from fresh (odds ratio 1.38, 95 percent CI 0.93 to 2.05). — Japanese adults tasting pairs of frozen and unfrozen mackerel and squid sushi, 120 rounds each (n = 120 rounds per food) Evidence B source
  Squid: unfrozen preferred 48.3 percent, frozen 35.0 percent, same 16.7 percent, OR 1.38, 95 percent CI 0.93 to 2.05, P = 0.11

What it does to your health

• When 18 men ate six kinds of shellfish in place of other animal protein, the squid diet, higher in cholesterol, did not change blood lipids but did raise HDL2 cholesterol. — 18 normolipidemic men fed each of six shellfish diets matched for protein (n = 18) Evidence C source
  Squid and shrimp diets: no change in blood lipids; squid raised HDL2; oyster, clam, crab lowered VLDL and LDL
• In 20 healthy adults getting 60 percent of protein from lean seafood for 4 weeks, fasting triglycerides were 27 mg/dL (0.31 mmol/L) lower than on a non-seafood protein diet. — 20 healthy subjects (7 men, 13 women), randomized crossover, 4 weeks per diet (n = 20) Evidence B source
  Fasting triglycerides -27 mg/dL (-0.31 mmol/L) relative to non-seafood diet, P = 0.03, total to HDL cholesterol ratio rise prevented

Safety, limits and interactions

• In a 29-year-old woman, cuttlefish triggered generalized urticaria only when combined with 1.5 g of aspirin, after 20 g and 3.5 oz (100 g) of cuttlefish alone caused nothing more than mouth itching. — one 29-year-old woman with food-dependent exercise-induced anaphylaxis (n = 1) Evidence D source
  Reaction only after cuttlefish plus 1.5 g aspirin, IgE blood test negative, skin prick positive to raw and cooked cuttlefish
• In Italian seafood tested for heavy metals, cadmium in squid exceeded the EU maximum level, while mercury stayed far below limits in squid compared with predatory fish. — fish and seafood products in Italy including European squid and veined squid Evidence C source
  Cadmium above EU maximum level in squid, red mullet, hake and cod; squid lead at 60 percent of the limit
• Among the 14 most eaten marine species in Catalonia, cuttlefish had the lowest hexachlorobenzene level at 0.02 ng per g, against 1.68 in salmon. — 42 composite samples of 14 marine species, Catalonia, Spain (n = 42 samples) Evidence C source
  HCB 0.02 ng/g wet weight in cuttlefish vs 1.68 in salmon and 0.80 in mackerel
• Pooling European studies, food-challenge-confirmed shellfish allergy affects about 0.1 percent of people, while 0.4 percent report it. — 93 European studies of the eight big food allergens, published to 2021 (n = 93 studies) Evidence C source
  Shellfish: self-reported lifetime prevalence 0.4 percent (0.3 to 0.6), challenge-verified 0.1 percent (0.0 to 0.2)
• The FDA Food Code counts all mollusks as fish and requires raw or partially cooked fish served ready-to-eat to be frozen first, at -20°C (-4°F) for 7 days or at -35°C (-31°F) until solid and then 15 hours. Its exemption for molluscan shellfish covers only oysters, clams, mussels and scallops. — fish, defined to include all mollusks, served raw or partially cooked in US retail and food service Evidence E source
  Before raw ready-to-eat service: -20°C (-4°F) for 7 days, or -35°C (-31°F) until solid plus 15 hours; exemption only for oysters, clams, mussels, scallops

Who this works differently for

• Among 45 Spanish patients with mollusc allergy, 55 percent reacted to cephalopods such as squid and cuttlefish, 69 percent had systemic reactions, and tropomyosin explained cross-reactions with crustaceans and dust mites. — 45 patients with mollusc allergy, multicentre, northern Spain (n = 45) Evidence C source
  Cephalopod allergy 55 percent, bivalves 31 percent, gastropods 24 percent, systemic reactions 69 percent
• A 6-year-old girl with anaphylaxis to crustaceans developed FPIES, a delayed vomiting reaction, to cuttlefish, confirmed by oral challenge, while tolerating clams and mussels. — one 6-year-old girl (n = 1) Evidence D source
  Acute FPIES to cuttlefish confirmed by oral challenge, tolerance of bivalves
• People with ulcerative colitis more often had IgG4 antibodies to cuttlefish than healthy controls in a 72-person study, which signals exposure rather than allergy. — 36 patients with Crohn's disease or ulcerative colitis and 36 matched healthy controls (n = 72) Evidence C source
  Positivity to cuttlefish and kiwi significantly more frequent in ulcerative colitis than controls
• FDA lists raw or smoked fish and other seafood among foods that can carry Listeria, and pregnant women are about 10 times more likely to get listeriosis than other healthy adults. — Pregnant women (n = -) Evidence E source
  Raw or smoked fish and other seafood listed as Listeria sources, pregnant women about 10 times more likely to get listeriosis

The bottom line

The cholesterol number worries people more than the feeding data does. In 18 men who ate six shellfish diets in turn, the squid diet, higher in cholesterol, left blood lipids unchanged and raised HDL2 cholesterol. That was squid, and the abstract does not say the order was randomized. Absorbing selenium well does not mean blood levels jump: in 12 adults eating 3.5 oz (100 g) of shrimp a day for 6 weeks, 83 percent was absorbed and plasma selenium went from 95.2 to 101.5 micrograms per liter. Cooking costs little. The USDA retention factor for frozen fried fish keeps 95 percent of vitamin B12 and all of the iron and zinc, though it is a 1975 finfish factor never measured on cuttlefish. In a Japanese taste test of raw squid sushi, freezing barely changed taste. That test measured taste only, not infection. Across 120 rounds, unfrozen was preferred 48.3 percent of the time and frozen 35.0 percent, a gap that did not reach significance (OR 1.38, 95 percent CI 0.93 to 2.05). For people who eat cuttlefish raw, the relevant rule is about parasites, not taste. The FDA Food Code counts all mollusks as fish. It requires fish served raw or partially cooked to be frozen first, at -20°C (-4°F) for 7 days or at -35°C (-31°F) until solid and then 15 hours, so a night in the freezer is not that step. Its exemption covers only oysters, clams, mussels and scallops. It is a code for restaurants and shops that does not name cuttlefish or Anisakis, and it says nothing about home freezers. On contaminants, an Italian survey found cadmium in squid above the EU maximum level and lead at 60 percent of its limit, in squid rather than cuttlefish. In Catalonia, cuttlefish had the lowest hexachlorobenzene of 14 marine species, 0.02 ng per g against 1.68 in salmon, from one region and one contaminant. Who should be careful. Allergy is the real issue. Across European studies, shellfish allergy confirmed by food challenge affects about 0.1 percent of people and 0.4 percent report it, with cuttlefish not counted separately. Among 45 Spanish allergy clinic patients with mollusc allergy, 55 percent reacted to cephalopods such as squid and cuttlefish and 69 percent had systemic reactions, and the authors trace cross-reactions with crustaceans and dust mites to tropomyosin. Tolerating one mollusc does not clear another: a 6-year-old girl with crustacean anaphylaxis had a challenge-proven delayed vomiting reaction (FPIES) to cuttlefish while eating clams and mussels without trouble. In a single case, a 29-year-old woman got only mouth itching from 20 g or 3.5 oz (100 g) of cuttlefish and generalized hives when it came with 1.5 g of aspirin. A positive IgG4 test to cuttlefish reflects eating it and is not a diagnosis of allergy. FDA lists raw or smoked fish and other seafood among foods that can carry Listeria, and pregnant women are about 10 times more likely to get listeriosis than other healthy adults. We have no medicine interaction data specific to cuttlefish, raw or cooked, and that gap is not a sign of safety.

Compared with other foods

Sources

1. cutf-r1-01 · food composition dataset
   Cuttlefish, raw, CoFID 16-254: Energy (kcal) 71, Protein (g) 16.1, Fat (g) 0.7, Cholesterol (mg) 110.0, Selenium (µg) 65, Iron (mg) 3.40, Sodium (mg) 370 per 100 g
   CoFID 2021 (Public Health England), Cuttlefish, raw, code 16-254 · checked 2026-10-01
2. cutf-r1-04 · randomized controlled trial
   RESULTS: Apparent absorption of selenium from fish was similar to selenate and there was no difference between the two processing methods used. However, retention of fish selenium was significantly higher than selenate (P<0.001). ... CONCLUSION: Fish selenium is a highly bioavailable source of dietary selenium. Cooking did not affect selenium apparent absorption or retention from fish.
   Eur J Clin Nutr, 2004 · checked 2026-10-01
3. cutf-r1-05 · controlled feeding study
   The apparent absorption of selenium from shrimps was 83 +/- 4%. ... Plasma selenium concentrations were 95.2 +/- 9.7 microg/L and 101.5 +/- 9.7 microg/L before and after six weeks of shrimp intake, respectively (p<0.05). Plasma and erythrocyte glutathione peroxidase activities were not influenced by shrimp intake.
   J Trace Elem Med Biol, 2001 · checked 2026-10-01
4. cutf-r1-02 · nutrient retention dataset
   USDA-RETN-R6:2601 FINFISH(FROZEN),FRIED, Finfish and Shellfish Products: vitamin_b12_ug 95%, riboflavin_mg 95%, thiamin_mg 90%, iron_mg 100%, zinc_mg 100%
   USDA Table of Nutrient Retention Factors, Release 6, 2007, code 2601 · checked 2026-10-01
5. cutf-r1-03 · randomized controlled trial
   For squid, unfrozen sushi was believed to be superior 48.3% of the time (58 dishes), and frozen sushi, 35.0% of the time (42 dishes). They were felt to be the same in 16.7% (20 dishes) (odds ratio, 1.38; 95% CI, .93-2.05; P = .11). CONCLUSIONS: Freezing raw fish did not ruin sushi's taste.
   Clin Infect Dis, 2015 · checked 2026-10-01
6. cutf-r1-06 · controlled feeding study
   Squid and shrimp diets, higher in cholesterol and lower in n-3 fatty acids, did not change the blood lipids. The ratio of LDL to HDL cholesterol was decreased on the oyster and mussel diets. Oyster, mussel, and squid diets increased HDL2 cholesterol.
   Am J Clin Nutr, 1990 · checked 2026-10-01
7. cutf-r1-07 · randomized crossover trial
   After 3-wk run-in periods and separated by a 5-wk washout period, 20 healthy subjects (7 men and 13 women) consumed 2 balanced diets that varied in main protein sources (60% of total dietary proteins from lean-seafood or nonseafood sources for 4 wk). ... Relative to the nonseafood intervention, the lean-seafood intervention reduced fasting (relative difference by diets: 0.31 mmol/L; P = 0.03) and postprandial (P = 0.01) serum triacylglycerol concentrations.
   Am J Clin Nutr, 2015 · checked 2026-10-01
8. cutf-r1-10 · case report
   As a result, she developed no symptoms except for slight itching of the oral mucosa after eating 20 g or 100 g of cuttlefish with or without concomitant administration of 0.5 g of aspirin. Finally, generalized urticaria appeared after challenge with cuttlefish and 1.5 g of aspirin.
   Arerugi, 2010 · checked 2026-10-01
9. cutf-r1-11 · contaminant survey
   The found metal concentrations were largely below the maximum levels (MLs) established at the European Union level with the exception of Cd. This metal exceeded the MLs in squid, red mullet, European hake and Atlantic cod. Squid and blue mussel showed the highest Pb concentrations which accounted for 60% and 10% of the MLs, respectively.
   Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2012 · checked 2026-10-01
10. cutf-r1-12 · contaminant survey
    The highest HCB levels were found in salmon and mackerel: 1.68 and 0.80 ng/g of wet weight, respectively, whereas the lowest HCB levels were found in cuttlefish, mussel, and shrimp (0.02, 0.03, and 0.04 ng/g of wet weight, respectively).
    Sci Total Environ, 2008 · checked 2026-10-01
11. cutf-r1-13 · meta-analysis of prevalence studies
    The overall pooled estimates for all age groups of self-reported lifetime prevalence were as follows: cow's milk (5.7%, 95% confidence interval 4.4-6.9), egg (2.4%, 1.8-3.0), wheat (1.6%, 0.9-2.3), soy (0.5%, 0.3-0.7), peanut (1.5%, 1.0-2.1), tree nuts (0.9%, 0.6-1.2), fish (1.4%, 0.8-2.0) and shellfish (0.4%, 0.3-0.6). The point prevalence of food challenge-verified allergy were as follows: cow's milk (0.3%, 0.1-0.5), egg (0.8%, 0.5-1.2), wheat (0.1%, 0.01-0.2), soy (0.3%, 0.1-0.4), peanut (0.1%, 0.0-0.2), tree nuts (0.04%, 0.02-0.1), fish (0.02%, 0.0-0.1) and shellfish (0.1%, 0.0-0.2).
    Allergy, 2023 · checked 2026-10-01
12. sf-cuttle-1 · agency advice
    "Fish" means fresh or saltwater finfish, crustaceans and other forms of aquatic life (including alligator, frog, aquatic turtle, jellyfish, sea cucumber, and sea urchin and the roe of such animals) other than birds or mammals, and all mollusks, if such animal life is intended for human consumption. ... before service or sale in *READY-TO-EAT form, raw, raw-marinated, partially cooked, or marinated-partially cooked *FISH shall be: (1) Frozen and stored at a temperature of -20°C (-4°F) or below for a minimum of 168 hours (7 days) in a freezer; ... (2) Frozen at -35°C (-31°F) or below until solid and stored at -35°C (-31°F) or below for a minimum of 15 hours; ... (B) Paragraph (A) of this section does not apply to: (1) *MOLLUSCAN SHELLFISH; ... "Molluscan shellfish" means any edible species of fresh or frozen oysters, clams, mussels, and scallops, or edible portions thereof, except when the scallop product consists only of the shucked adductor muscle.
    FDA Food Code 2026, 1-201.10(B) Definitions (Fish, Molluscan shellfish) and 3-402.11 Parasite Destruction · checked 2026-10-08
13. cutf-r1-08 · prospective clinical study
    RESULTS: We found that 25 patients (55%) were allergic to cephalopods, 14 (31%) to bivalves, and 11 (24%) to gastropods. ... In 31 patients (69%), the manifestation was systemic; 10 (22%) exhibited oral allergy syndrome, and 7 (15%) experienced contact urticaria. ... Tropomyosin appears to be responsible for the high cross-reactivity found between mollusks, mites, and crustaceans.
    J Investig Allergol Clin Immunol, 2024 · checked 2026-10-01
14. cutf-r1-09 · case report
    This report illustrates a rare case of a 6-year-old girl with challenge-proven acute food protein-induced enterocolitis syndrome (FPIES) to cuttlefish (phylum Mollusca, class Cephalopoda), anaphylaxis to crustaceans (phylum Arthropoda), and tolerance to other mollusks, including clams and mussels (phylum Mollusca, class Bivalvia).
    Iran J Allergy Asthma Immunol, 2023 · checked 2026-10-01
15. cutf-r1-14 · case-control
    Serum titers of IgG4 to cuttlefish and onion in patients with UC tended to be higher than those in the control group. ... The number of subjects with positivity to kiwi and cuttlefish was significantly higher in patients with UC than in controls.
    Turk J Gastroenterol, 2019 · checked 2026-10-01
16. sf-lrs-r3-7 · agency advice
    You can get listeriosis by eating raw, unpasteurized milk ... raw or smoked fish and other seafood. ... Pregnant women are about 10 times more likely to get listeriosis than other healthy adults.
    US FDA, Listeria (Food Safety for Moms-to-Be) · checked 2026-10-08