Raw Atlantic mackerel carries 2.3 g of EPA plus DHA, the long-chain omega-3 fats of fish, in every 100 g, and its total omega-3 (2.67 g per 100 g) ranks fifth among 109 foods on this site. For comparison, raw farmed Atlantic salmon has 1.97 g of EPA plus DHA per 100 g. One 112 g fillet has 230 calories, 4 times the daily value of vitamin B12 (406%), 90% of vitamin D and 90% of selenium.
The word mackerel covers fish with very different mercury levels. FDA and EPA list Atlantic mackerel and Pacific chub mackerel as Best Choices, Spanish mackerel as a Good Choice and king mackerel as a Choice to Avoid because of the highest mercury levels. In FDA’s own testing, king mackerel averaged 0.73 ppm of mercury and Atlantic mackerel 0.05 ppm, about 15 times less. The nutrition numbers on this page are for raw Atlantic mackerel.
The fat in mackerel changes with the season: in a study of chub mackerel, 14 g a day of October fish covered the EPA plus DHA need, against 51 g a day of March fish. Atlantic mackerel also lacks a swim bladder, which sets it apart from its close relatives. Few trials have fed people mackerel itself, and most of them are small studies from the 1980s, so the cards below also include omega-3 capsule trials and say so.
Health benefits of mackerel
No mackerel finding reaches strong evidence. The best-supported result is about the omega-3 fats in it: a Cochrane review of 86 trials found that raising long-chain omega-3 intake lowered triglycerides by about 15% and slightly reduced coronary heart disease events, but most of that evidence came from capsules, and the large VITAL capsule trial did not lower major cardiovascular events. Small trials in which people ate mackerel itself found lower triglycerides and blood pressure within 2 weeks, but they are old and tiny. Here is what 21 studies found, strongest evidence first, from blood fats and blood pressure to children’s thinking, brain mercury and allergy, including the trials that found nothing.
Omega-3 fats from capsules, as in most trials, lowered triglycerides by about 15% and slightly reduced coronary heart disease events but did not change overall deaths or cardiovascular events
Meta-analysis of 86 randomized trials (162,796 people) lasting 12 to 88 months. Most trials gave omega-3 capsules, so this is mostly about supplements, not mackerel, and the authors say there is little evidence on eating fish. Overall deaths (risk ratio 0.97) and cardiovascular events (0.96) did not change significantly, and the coronary heart disease result (risk ratio 0.91) was low-certainty.
A 1 g a day marine omega-3 capsule for a median of 5.3 years did not significantly lower major cardiovascular events or cancer compared with placebo
Placebo-controlled trial in 25,871 US men aged 50 or older and women aged 55 or older. Major cardiovascular events occurred in 386 people on omega-3 and 419 on placebo (hazard ratio 0.92), and cancer in 820 and 797 (hazard ratio 1.03). This tested fish oil capsules, not fish. Funded by the National Institutes of Health and others.
EPA and DHA from fish oil and food sources lowered systolic blood pressure by 1.52 mm Hg and diastolic pressure by 0.99 mm Hg
Meta-analysis of 70 randomized trials that included food sources of EPA and DHA as well as capsules. The drop was larger in untreated people with high blood pressure (4.51 mm Hg systolic), and the diastolic drop appeared with 2 g or more a day. Supported by the Global Organization for EPA and DHA Omega-3s (GOED), which the paper says had no role in the design, analysis or writing.
Herring or mackerel lunches 3 times a week for 16 weeks did not improve thinking scores in 4 to 6 year olds compared with meat
Randomized trial in 232 Norwegian preschoolers (218 analyzed). Fish raised red blood cell omega-3 fats, but the total score change was 17.7 on fish and 17.8 on meat. Children who ate more of the fish did better in a compliance-adjusted look (20.4 against 15.2). Funded by the Norwegian Seafood Research Fund, which the paper says, with the fish supplier Pelagia, had no role in the design, analysis or interpretation.
Show 17 more studies
Eating 135 g of mackerel paste a day for 6 weeks reduced the thromboxane that platelets make, a compound that helps platelets clump compared with a meat paste
Two groups of 40 volunteers took the mackerel or a meat paste, and compliance was about 80%. The mackerel gave about 1.3 g of EPA and 2.3 g of DHA a day, and it also changed the balance of related compounds in urine. It measured blood and urine markers, not heart attacks.
A 2-week mackerel diet lowered triglycerides by 28% and LDL cholesterol by 14% in men with mild high blood pressure, and raised HDL by 12%
Crossover trial in 14 men with mild essential hypertension, who ate a mackerel diet and a herring diet for 2 weeks each. Total cholesterol fell 9% and casual systolic blood pressure 8%, only after mackerel, and blood fats returned to starting levels 3 months later. Uric acid rose 24% after both diets, and plasma renin activity rose 64% after mackerel.
2 cans of mackerel a day for 2 weeks, then 3 cans a week for 8 months, kept blood pressure lower in men with mild high blood pressure while the cholesterol effect faded
Twelve men on mackerel were compared with 11 matched men on their usual diet. In the first 2 weeks, triglycerides, total and LDL cholesterol, blood pressure and thromboxane B2 fell, on about 2.2 g of EPA and 2.8 g of DHA a day. During the 8 months of 3 cans a week, blood fats returned to starting levels but blood pressure stayed significantly lower, and rose only after 2 months back on a normal diet.
A 2-week mackerel diet lowered blood pressure, triglycerides and total cholesterol in 15 healthy volunteers, while herring changed little
Crossover trial in which 15 healthy volunteers ate a prescribed mackerel diet and a herring diet for 2 weeks each. LDL and HDL cholesterol did not change, and blood fats returned to baseline 3 months later. Herring gave minor differences and no significant drop in blood pressure.
A 2-week mackerel diet lowered triglycerides and total cholesterol in 8 people with high blood fats, with smaller changes on herring
Crossover trial in 8 patients with type IV and V hyperlipoproteinemia. HDL cholesterol rose slightly after mackerel, systolic blood pressure was lower lying and standing, and diastolic pressure did not change. Free fatty acids and insulin after a glucose drink were lower at the end of the mackerel period.
Herring or mackerel meals 3 times a week for 16 weeks raised omega-3 fats in red blood cells, urinary iodine and hair mercury in preschoolers, but moved few of 86 blood and urine markers
Exploratory analysis of the same Norwegian trial, with 232 children aged 4 to 6 given fatty fish or meat lunches. The effect sizes were 0.61 for red blood cell EPA, 0.43 for DHA and 0.83 for hair mercury, and there were no or limited effects on markers of micronutrient status or inflammation. Funded by the Norwegian Seafood Research Fund, which the paper says was not involved in the design, analysis or writing.
Herring or mackerel lunches for 16 weeks did not change parent-reported mental health or sleep in 232 preschoolers
Another result from the Norwegian preschool trial, using the strengths and difficulties questionnaire and a parent sleep report. There was no significant difference between the fish and meat groups, in the crude analysis or after adjusting for how much children ate. The paper says the funders, the Norwegian Seafood Research Fund and the fish supplier Pelagia, had no role in the analysis or the decision to publish.
Eating herring or mackerel, which hold more of the fatty acid 16:4(n-3) than salmon or tuna, raised blood levels of it, and in mouse models it blunted chemotherapy
Healthy volunteers (30 took fish oils and 20 ate 4 fish species) had blood levels of the fatty acid measured, and mouse experiments showed fish oil made a platinum drug less effective. There are no patient results. The authors suggest that fish and fish oil high in this fatty acid may best be avoided around chemotherapy days until more data exist.
People who ate the most fatty fish had a lower risk of dying from coronary heart disease (risk ratio 0.83), while lean fish showed no link
Meta-analysis of 19 prospective studies comparing the highest with the lowest fish intake. For fatty fish, coronary heart disease incidence was also lower (risk ratio 0.92) and so was total mortality (0.97). Cardiovascular disease incidence and mortality did not differ significantly for either type. These are links, and the abstract does not single out mackerel.
Each extra 20 g of fish a day went with a lower risk of cardiovascular death (relative risk 0.96)
Dose-response meta-analysis of 14 prospective cohort studies. The link with death from any cause was marginal (relative risk 0.98). It was clear only in Asian studies, while Western studies suggested a nearly U-shaped pattern with the lowest risk near 20 g a day. The authors suggest looking at fish type and cooking method.
Eating seafood at least once a week went with less Alzheimer disease pathology, but only in APOE ε4 carriers, while brain mercury was higher but not linked to damage
Autopsy study of 286 older adults in Chicago, covering seafood in general, not mackerel. Brain mercury rose with the number of seafood meals a week (correlation 0.16), yet higher brain mercury was not significantly linked to brain damage. The design is cross-sectional, so it cannot show cause.
In lab analysis, 14 g a day of October chub mackerel covered EPA plus DHA needs, against 51 g a day of March fish
Chemical analysis and simulated digestion of chub mackerel (Scomber colias) caught in March, June and October, with daily amounts of 51 g, 35 g and 14 g for EPA plus DHA. B12 needs would be met by 15 to 18 g a day, selenium needs by 126 to 133 g. Fatty acids often exceeded 80% bioaccessibility. No people were fed, and this is a different mackerel species.
Parvalbumin is the main allergen of mackerel: 4 of 5 sera from fish-allergic patients reacted to it
Lab study of parvalbumin purified from three mackerel species, including Atlantic mackerel. Antibody reactivity was also shared among the three species. The sample was very small, and the paper does not say how likely a person allergic to one fish is to react to mackerel.
Heating Pacific mackerel extract reduced its reactivity with allergic patients’ antibodies, with a complete loss at 140°C
Lab study of muscle extract heated from 20 to 140°C and tested with patient sera. The parvalbumin protein was not broken down, but it changed shape as heat rose. The authors call it less heat-stable than other fish parvalbumins, but 140°C is far above home cooking, so this is no sign that cooked mackerel is safe for allergic people.
Refined mackerel oil added to a Western diet increased liver fat and worsened blood sugar control in mice, but not on a chow diet
Male mice ate a Western or chow diet with 30 or 60 g of mackerel oil per kg, with a glucose test after 11 weeks. The oil came from processing leftovers, not fillets. The authors link the harm to higher fat digestibility, higher energy intake and lower choline in the liver. Mice are not people.
A mackerel extract rich in the selenium compound selenoneine collected in liver, kidney and spleen but not in plasma in mice
Mice ate the extract, made from mackerel processing leftovers, at 0.07% of their chow for 32 days. In male mice, plasma glucose rose and LDL cholesterol fell. The authors say male mice are sensitive to the extract. This is an animal study of an extract, not of eating the fish.
Peptides from mackerel protein raised liver glycogen by 33 to 35% and lengthened swimming time to exhaustion in mice
Mice were given a purified mackerel protein hydrolysate fraction smaller than 2.5 kDa. Markers of fatigue and oxidative damage fell (blood urea nitrogen 16 to 17%, MDA 16 to 31%). This is an animal study of processed fish protein, with no people involved.
Who should be careful with mackerel
Most people can eat mackerel freely. Take a little care if one of these applies:
- Pregnancy, breastfeeding and young children. Mercury depends on the species. FDA and EPA put Atlantic and Pacific chub mackerel on the Best Choices list (2 to 3 servings of 4 ounces a week in pregnancy), Spanish mackerel on the Good Choices list (1 serving a week) and king mackerel on the Choices to Avoid list. Labels often say only “mackerel”, so ask which kind it is.
- Spoiled fish (histamine). Tuna and mackerel are the fish most often behind scombroid poisoning, which starts within minutes to 2 hours with flushing, a peppery taste, headache or rash and usually lasts 4 to 6 hours. The histamine is not destroyed by freezing, cooking, smoking, curing or canning, so the fish must stay cold from the catch onward.
- Fish allergy. Fish is a major allergen in US law, and an estimated 0.9% of US adults have a convincing fin fish allergy. Parvalbumin, the main mackerel allergen, is shared among mackerel species, so with a diagnosed fish allergy ask an allergist before trying mackerel.
How to choose, store and eat mackerel
- Pick the kind: Atlantic and Pacific chub mackerel suit regular meals, while king mackerel is the one to skip (it averaged 0.73 ppm of mercury in FDA testing against 0.05 ppm for Atlantic).
- Fresh fillet: a raw 112 g fillet (about 4 ounces) has 230 calories and 2.57 g of EPA plus DHA, and cooked, canned or smoked mackerel will differ.
- Weekly amount: the Dietary Guidelines for Americans advise at least 8 ounces of seafood a week, and in an 8-month trial of 3 cans of mackerel a week, blood pressure stayed lower in men with mild hypertension.
Mackerel spoils fast, so keep fresh fish at 40°F (4°C) or below and cook it within 2 days of buying, or freeze it. FDA says most seafood should be cooked to 145°F (63°C), and freezing kills parasites, which matters for raw or cured mackerel.
Sources
- Advice about Eating Fish. US Food and Drug Administration and Environmental Protection Agency. Revised October 2021.
- Mercury Levels in Commercial Fish and Shellfish (1990-2012). US Food and Drug Administration.
- Cladis DP, Kleiner AC, Santerre CR. Mercury content in commercially available finfish in the United States. J Food Prot. 2014.
- Scombrotoxin Poisoning and Decomposition. US Food and Drug Administration.
- Hungerford JM. Scombroid poisoning: a review. Toxicon. 2010.
- Food allergies. US Food and Drug Administration.
- Gupta RS, Warren CM, Smith BM, et al. Prevalence and severity of food allergies among US adults. JAMA Netw Open. 2019.
- Hamada Y, Tanaka H, Ishizaki S, et al. Purification, reactivity with IgE and cDNA cloning of parvalbumin as the major allergen of mackerels. Food Chem Toxicol. 2003.
- Selecting and Serving Fresh and Frozen Seafood Safely. US Food and Drug Administration.
- FoodData Central: Fish, mackerel, Atlantic, raw. US Department of Agriculture. (Nutrition numbers as shown on this site.)
History of mackerel
The English word comes from Old French, where it may have meant either “marked, spotted” or “pimp, procurer”. The first fits the wavy black lines on the back of an Atlantic mackerel, and the link to the second is not clear. In 1758 Carl Linnaeus named the Atlantic mackerel Scomber scomber from the Greek skombros, meaning tunny or mackerel, and the species name was changed to scombrus in 1983.
Romans made garum, a fermented fish sauce, from the innards of fatty fish, mostly anchovies but also sprats, sardines, mackerel and tuna. On most surviving amphora labels that name the fish, it is mackerel. By the time of Augustus the best garum was said to come from Cartagena and Gades (Cadiz) and was called garum sociorum, the garum of the allies. A review of Roman parasites suggests that the enthusiasm for uncooked, fermented fish sauce may have helped spread fish tapeworm.
Before canning and refrigeration, mackerel was preserved mainly by salting and smoking. In England it was usually eaten fresh and often spoiled, and The Cambridge Economic History of Europe remarks that stinking mackerel turns up in English literature more than any other fish. In France it was pickled in heavy salt, and in Japan, where it is called saba, it is cured with salt and vinegar for saba-zushi, which began in Kyoto as a way to carry mackerel inland fresh.
Today the world catches about a million tonnes of Atlantic mackerel a year, with the United Kingdom and Norway landing the most, and the IUCN rated the species Least Concern in 2011. Stocks can still fall: in Canada the fish reached historic lows in 2021, was placed in the “Critical Zone” and was closed to commercial fishing with some exceptions.
Sources
- Mitchell PD. Human parasites in the Roman World: health consequences of conquering an empire. Parasitology. 2017.
- Atlantic mackerel. Wikipedia.
- Mackerel. Wikipedia.
- Mackerel as food. Wikipedia.
- Garum. Wikipedia.
Frequently asked questions about mackerel
Is mackerel good for you?
For most people, yes, if it is a low-mercury kind. Raw Atlantic mackerel has 205 calories, 18.6 g of protein, 2.3 g of EPA plus DHA and 81% of the daily value of vitamin D per 100 g, and a 112 g fillet gives 4 times the daily value of B12. It also has 3.26 g of saturated fat (16% of the daily value) and 70 mg of cholesterol per 100 g. Trials of mackerel itself are small, so the benefit rests mostly on omega-3 research, and king mackerel should be avoided because of mercury.
Is mackerel high in mercury?
It depends on the species. FDA lists average mercury of 0.05 ppm for Atlantic mackerel, 0.088 for Pacific chub, 0.182 for Spanish (South Atlantic), 0.454 for Spanish (Gulf of Mexico) and 0.73 for king mackerel. FDA and EPA rate Atlantic and Pacific chub as Best Choices, Spanish as a Good Choice and king as a Choice to Avoid. A US survey of 77 finfish species found king mackerel up to 1,425 ppb, above FDA’s 1,000 ppb action level.
How often can you eat mackerel?
For Atlantic or Pacific chub mackerel, FDA and EPA advise 2 to 3 servings of 4 ounces a week in pregnancy, and Spanish mackerel counts as 1 serving a week. The Dietary Guidelines for Americans advise at least 8 ounces of seafood a week in general. No trial here defines an ideal amount, though men with mild hypertension ate 3 cans of mackerel a week for 8 months and kept a lower blood pressure.
Is mackerel healthier than salmon?
Mackerel has more EPA plus DHA per 100 g in this site’s USDA data: 2.3 g in raw Atlantic mackerel, against 1.97 g in raw farmed Atlantic salmon and 1.44 g in raw wild salmon. It also has 16.1 µg of vitamin D (81% of the daily value), against 11 µg in farmed salmon (55%). Calories are close at 205 and 208 per 100 g, and no trial here compares the two for health outcomes, so the better fish is the low-mercury one you will eat.
Does mackerel lower blood pressure or cholesterol?
Small trials suggest it can, but they are old and tiny. In 14 men with mild hypertension, 2 weeks of mackerel lowered triglycerides 28%, LDL 14% and casual systolic blood pressure 8%. With 3 cans a week for 8 months the blood fats went back to baseline while blood pressure stayed lower. Across 70 trials of EPA and DHA, mostly capsules, systolic pressure fell 1.52 mm Hg, so do not change blood pressure medicine because of fish.
Can you get food poisoning from mackerel?
Yes, from histamine in fish that was not kept cold. FDA names tunas and mackerels as the fish most often involved in scombroid poisoning, with symptoms starting within minutes to 2 hours and usually lasting 4 to 6 hours. Cooking, freezing, smoking, curing and canning do not destroy the histamine, and a peppery taste is one sign. Seek care if breathing is hard or the tongue swells.
Is mackerel safe during pregnancy?
Atlantic and Pacific chub mackerel are on FDA and EPA’s Best Choices list, with 2 to 3 servings of 4 ounces a week. Spanish mackerel is a Good Choice at 1 serving a week, and king mackerel is on the list to avoid. FDA says fish provide DHA, EPA, iron, iodine and choline that support a child’s brain development.
Can you eat mackerel raw?
Only with care. Freezing kills the parasites that some fish carry, but FDA says freezing does not kill all harmful germs, and most seafood should be cooked to 145°F (63°C). Mackerel also spoils quickly, and histamine from spoilage is not destroyed by freezing or cooking, so freshness matters most.