Swordfish vs. Tuna — Health Impact and Nutrition Comparison
Swordfish is higher in selenium, choline, vitamin D, and vitamin E. It is also higher in mercury. On the other hand, tuna is richer in iron, copper, magnesium, phosphorus, Vitamin B12, Vitamin A RAE, and calories.
Tuna is also higher in proteins and omega-3 fatty acids, while swordfish is richer in fats and omega-6.
Table of contents
- Macronutrients and Calories
- Omega-3 fats
- Glycemic Index
- Insulin Index
- Weight Loss & Diets
- Health Benefits
- Downsides and Risks
Swordfish (Xiphias gladius) is a member of the family Xiphiidae (order Perciformes), found in warm and temperate oceans. The swordfish is a scaleless, elongated fish with a large dorsal fin and a long sword. It is silvery below and purplish or bluish on top.
Tuna (genus Thunnus) is a member of the family Scombridae (order Perciformes). Tunas are streamlined, elongated fishes with rounded bodies that taper to a narrow tail base and a forked or crescent-shaped tail.
Tunas are typically dark above and silvery below, with an iridescent gloss.
Swordfish is a white-fleshed, mild-flavored fish with a meaty texture, whereas tuna is a tasty fish with an oily, buttery, flaky feel.
The genus Thunnus contains seven tuna species: northern bluefin, albacore, yellowfin tuna, southern bluefin tuna, bigeye tuna, blackfin tuna, and longtail tuna. Swordfish, unlike tunas, have only one species, Xiphias gladius.
Macronutrients and Calories
Swordfish and tuna are rich in healthy compounds and macronutrients. Swordfish is higher in fats, while tuna is richer in proteins.
In comparison, tuna is higher in calories. 100g of swordfish has about 172 calories, while tuna has 184 calories.
100g of swordfish contains 23.45 g of proteins, while the same amount of tuna contains 29.91 g. Tuna is higher in all essential amino acids, particularly tryptophan, histidine, threonine, and isoleucine. However, both are good sources of protein.
The fat content of swordfish is higher. Swordfish has 7.9g of fats per 100g, while tuna has 6.28g. Swordfish contain more saturated fats. In contrast, tuna has more polyunsaturated fats and less monounsaturated fats.
Fat Type Comparison
Tuna contains 1.66g of omega-3 fatty acids, while swordfish contains only 1.07g. Unlike tuna, swordfish also contains 0.02g of omega-6.
Swordfish and tuna do not contain carbohydrates.
Swordfish have more cholesterol levels than tuna. 100g of swordfish contains 78mg of cholesterol, while the same amount of tuna contains 49mg.
Swordfish contains 16.6 µg of vitamin D, while tuna does not.
Tuna, however, is higher in vitamin A and vitamins B3, B5, B2, B1, and B12.
Tuna contains ten times more vitamin B12 and 19 times more vitamin A. Tuna provides 386% more daily vitamin B12 coverage.
Swordfish provides more choline, potassium, and selenium. Swordfish contains 77.5 mg of choline.
Tuna, on the other hand, has more magnesium. Tuna is also lower in sodium.
The amount of mercury in seafood varies depending on the species and the level of pollution in the environment. Swordfish, for instance, have a higher mercury content than tuna. The mercury concentration mean (PPM) for swordfish is 0.995. In contrast, the PPM for tuna is 0.386 (1).
Swordfish and tuna are classified as low glycemic index foods because they contain no carbohydrates. The glycemic indexes of both foods are 0.
The insulin index of swordfish is 59, while tuna has an insulin index of 22.
Swordfish has a typical pH value of 7.33 to 7.94. Tuna has a pH value of 5,2 to 6,1.
The potential renal acid load (PRAL) is another method for determining the acidity of foods. The PRAL value of swordfish is 11.3. The PRAL value of tuna is 18.1. Both of them are acidic.
Weight Loss & Diets
Swordfish and tuna are excellent for the keto diet because they are carb-free and high in healthy fats.
Both are fantastic sources of protein, vitamins, and minerals that are low in calories and cholesterol. Importantly, they are high in Omega-3 fatty acids, which help decrease cholesterol and lower blood pressure, so swordfish, and tuna are DASH-friendly.
Fresh and canned tuna are acceptable Paleo diet foods as they are all-natural protein. Swordfish is also likely paleo-friendly.
Swordfish and tuna are Dukan diet-safe foods.
Swordfish and tuna are unsuitable for vegans.
Swordfish and tuna are good sources of protein and omega-3 fatty acids. They are essential for you and can be healthy in moderate concentrations.
Consuming fish is linked to a reduced risk of cardiovascular disease. There is compelling evidence that a moderate fish diet decreases cardiovascular risk, particularly cardiac mortality, which is due to the benefits of omega-3 fatty acids.
Anti-inflammatory properties of omega-3 fatty acids may contribute to their protection against atherosclerosis, plaque rupture, and cardiovascular mortality (2).
On the other hand, consumption of tuna, alpha-linolenic acid, and omega-3 fatty acids was not linked with the risk of cardiovascular disease in a cohort of women with no prior history of cardiovascular disease(3).
EPA and DHA produce resolvins, which are anti-inflammatory and inflammation-resolving. Because of their anti-inflammatory properties in swordfish and tuna, omega-3 fatty acids are therapeutic in rheumatoid arthritis. Advantages in other inflammatory illnesses and conditions have not been proven (2).
Downsides and Risks
Seafood can be a regular component of your healthy-eating plan throughout pregnancy as long as you avoid fish that are known to be rich in mercury. However, white (albacore) tuna and tuna steaks should be limited to 170 grams weekly.
Swordfish are considered to be rich in mercury, so avoid eating swordfish to limit your mercury exposure (4).
Mercury poisoning is more severe in fetuses and children. Mothers who consume a mercury-containing diet convey the toxicant to their fetuses and infants through breast milk. Children exposed to seemingly acceptable mercury levels have decreased motor function and memory performance. Mercury has been linked to various illnesses, including neurological, nephrological, immunological, cardiac, muscular, reproductive, and even genetic abnormalities (5).
Mercury's Effects on Health
Mercury's vascular effects include increased oxidative stress and inflammation. The inactivation of paraoxonase is another method through which mercury exerts harmful effects on the cardiovascular system. Indeed, mercury poisoning is closely associated with hypertension, coronary heart disease, myocardial infarction, cardiac arrhythmias, carotid artery blockage, cerebrovascular accidents, and widespread atherosclerosis. In contrast, fish, which are high in omega-3 polyunsaturated fatty acids and selenium, help to reduce mercury damage. However, if you restrict your diet to high-mercury seafood, the health advantages of eating fish may exceed the concerns (6).
Comparison summary table
|Lower in Sugar|
|Lower in Sodium|
|Lower in Cholesterol|
|Lower in Saturated Fat|
|Lower in price|
|Lower in Glycemic Index||Equal|
|Rich in minerals||Equal|
|Rich in vitamins||Equal|
All nutrients comparison - raw data values
|Vitamin A RAE||43µg||757µg|
|Omega-3 - DHA||0.772g||1.141g|
|Omega-3 - EPA||0.127g||0.363g|
|Omega-3 - DPA||0.168g||0.16g|
|Omega-6 - Eicosadienoic acid||0.022g|
Which food is preferable for your diet?
|Low Fats diet|
|Low Carbs diet||Equal|
|Low Calories diet|
|Low Glycemic Index diet||Equal|
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Vitamins & Minerals Daily Need Coverage Score
The source of all the nutrient values on the page (excluding the main article the sources for which are presented separately if present) is the USDA's FoodCentral. The exact links to the foods presented on this page can be found below.
- Swordfish - https://fdc.nal.usda.gov/fdc-app.html#/food-details/173704/nutrients
- Tuna - https://fdc.nal.usda.gov/fdc-app.html#/food-details/173707/nutrients
All the Daily Values are presented for males aged 31-50, for 2000-calorie diets.