Tuna vs. Swordfish — Health Impact and Nutrition Comparison

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by Sveta Badalyan | Last updated on May 29, 2023

Medically reviewed by Igor Bussel

Summary

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.

Introduction

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.

Taste

Swordfish is a white-fleshed, mild-flavored fish with a meaty texture, whereas tuna is a tasty fish with an oily, buttery, flaky feel.

Varieties

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.

Nutrition

The nutritional information below is presented for cooked, dry heat swordfish, and cooked, dry heat tuna. This section of the article compares the nutritional value of these foods.

Macronutrients and Calories

Swordfish and tuna are rich in healthy compounds and macronutrients. Swordfish is higher in fats, while tuna is richer in proteins.

Macronutrient Comparison

Macronutrient breakdown side-by-side comparison

Tuna

Swordfish

Contains more Protein +27.5%

Contains more Other +1211.1%

Contains more Fats +26.3%

Contains more Water +15.5%

Tuna

Protein: 29.91 g

Fats: 6.28 g

Carbs: 0 g

Water: 59.09 g

Other: 4.72 g

Swordfish

Protein: 23.45 g

Fats: 7.93 g

Carbs: 0 g

Water: 68.26 g

Other: 0.36 g

Contains more Protein +27.5%

Contains more Other +1211.1%

Contains more Fats +26.3%

Contains more Water +15.5%

Calories

In comparison, tuna is higher in calories. 100g of swordfish has about 172 calories, while tuna has 184 calories.

Protein

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.

Fats

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

Fat type breakdown side-by-side comparison

Tuna

Swordfish

Contains less Saturated Fat -15.6%

Contains more Polyunsaturated fat +34.8%

Contains more Monounsaturated Fat +72.6%

Tuna

Saturated Fat: 1.612 g

Monounsaturated Fat: 2.053 g

Polyunsaturated fat: 1.844 g

Swordfish

Saturated Fat: 1.911 g

Monounsaturated Fat: 3.544 g

Polyunsaturated fat: 1.368 g

Contains less Saturated Fat -15.6%

Contains more Polyunsaturated fat +34.8%

Contains more Monounsaturated Fat +72.6%

Omega-3 fats

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.

Carbohydrates

Swordfish and tuna do not contain carbohydrates.

Carbohydrate type comparison

Carbohydrate type breakdown side-by-side comparison

Cholesterol

Swordfish have more cholesterol levels than tuna. 100g of swordfish contains 78mg of cholesterol, while the same amount of tuna contains 49mg.

Vitamins

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.

Vitamin Comparison

Vitamin comparison score is based on the number of vitamins by which one or the other food is richer. The "coverage" charts below show how much of the daily needs can be covered by 300 grams of the food.

Tuna

Swordfish

Contains more Vitamin A +1853.5%

Contains more Vitamin B1 +212.4%

Contains more Vitamin B2 +385.7%

Contains more Vitamin B3 +13.9%

Contains more Vitamin B5 +228.5%

Contains more Vitamin B12 +571.6%

Contains more Vitamin B6 +17.1%

Equal in Folate - 2

Tuna

Swordfish

Contains more Vitamin A +1853.5%

Contains more Vitamin B1 +212.4%

Contains more Vitamin B2 +385.7%

Contains more Vitamin B3 +13.9%

Contains more Vitamin B5 +228.5%

Contains more Vitamin B12 +571.6%

Contains more Vitamin B6 +17.1%

Equal in Folate - 2

Minerals

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.

Mineral Comparison

Mineral comparison score is based on the number of minerals by which one or the other food is richer. The "coverage" charts below show how much of the daily needs can be covered by 300 grams of the food.

Tuna

Swordfish

Contains more Calcium +66.7%

Contains more Iron +191.1%

Contains more Magnesium +82.9%

Contains less Sodium -48.5%

Contains more Copper +139.1%

Contains more Manganese +53.8%

Contains more Potassium +54.5%

Contains more Selenium +46.4%

Equal in Phosphorus - 304

Equal in Zinc - 0.78

Tuna

Swordfish

Contains more Calcium +66.7%

Contains more Iron +191.1%

Contains more Magnesium +82.9%

Contains less Sodium -48.5%

Contains more Copper +139.1%

Contains more Manganese +53.8%

Contains more Potassium +54.5%

Contains more Selenium +46.4%

Equal in Phosphorus - 304

Equal in Zinc - 0.78

Mercury level

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).

Glycemic Index

Swordfish and tuna are classified as low glycemic index foods because they contain no carbohydrates. The glycemic indexes of both foods are 0.

Insulin Index

The insulin index of swordfish is 59, while tuna has an insulin index of 22.

Acidity

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.

Health Benefits

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.

Cardiovascular Health

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).

Inflammation

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

Pregnancy

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).

References

Author name: Sveta Badalyan

Education: General Medicine at YSMU

Last updated: May 29, 2023

Medically reviewed by Igor Bussel

Infographic

Infographic link

Comparison summary table

Pay attention to the rightmost column. It displays the amounts side by side, giving a clearer understanding of the difference.


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

Nutrient			Opinion
Protein	29.91g	23.45g
Fats	6.28g	7.93g
Calories	184kcal	172kcal
Calcium	10mg	6mg
Iron	1.31mg	0.45mg
Magnesium	64mg	35mg
Phosphorus	326mg	304mg
Potassium	323mg	499mg
Sodium	50mg	97mg
Zinc	0.77mg	0.78mg
Copper	0.11mg	0.046mg
Manganese	0.02mg	0.013mg
Selenium	46.8µg	68.5µg
Vitamin A	2520IU	129IU
Vitamin A RAE	757µg	43µg
Vitamin E		2.41mg
Vitamin D		666IU
Vitamin D		16.6µg
Vitamin B1	0.278mg	0.089mg
Vitamin B2	0.306mg	0.063mg
Vitamin B3	10.54mg	9.254mg
Vitamin B5	1.37mg	0.417mg
Vitamin B6	0.525mg	0.615mg
Folate	2µg	2µg
Vitamin B12	10.88µg	1.62µg
Vitamin K		0.1µg
Tryptophan	0.335mg	0.265mg
Threonine	1.311mg	1.035mg
Isoleucine	1.378mg	1.088mg
Leucine	2.431mg	1.919mg
Lysine	2.747mg	2.168mg
Methionine	0.885mg	0.699mg
Phenylalanine	1.168mg	0.922mg
Valine	1.541mg	1.216mg
Histidine	0.88mg	0.695mg
Cholesterol	49mg	78mg
Trans Fat		0.056g
Saturated Fat	1.612g	1.911g
Omega-3 - DHA	1.141g	0.772g
Omega-3 - EPA	0.363g	0.127g
Omega-3 - DPA	0.16g	0.168g
Monounsaturated Fat	2.053g	3.544g
Polyunsaturated fat	1.844g	1.368g
Omega-6 - Eicosadienoic acid		0.022g

Which food is preferable for your diet?

Low Fats diet

Low Carbs diet

Low Calories diet

Low Glycemic Index diet

is better in case of low 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 summary scores indicate the extent to which this food can fulfill your daily vitamin and mineral requirements if you consume 3 servings, consisting of 100 grams of each (an approximation of 3 serving sizes).

Vitamins Daily Need Coverage Score

171%

95%

Minerals Daily Need Coverage Score

59%

64%

Comparison summary

Which food is lower in Sugar?

Tuna is lower in Sugar (difference - 0g)

Which food contains less Sodium?

Tuna contains less Sodium (difference - 47mg)

Which food is lower in Cholesterol?

Tuna is lower in Cholesterol (difference - 29mg)

Which food is lower in Saturated Fat?

Tuna is lower in Saturated Fat (difference - 0.299g)

Which food is cheaper?

Swordfish is cheaper (difference - $7)

Which food is lower in glycemic index?

The foods have equal glycemic indexes (0)

Which food is richer in minerals?

It cannot be stated which food is richer in vitamins. See the charts below for detailed information. See the charts below for detailed information. See the charts below for detailed information.

Which food is richer in vitamins?

It cannot be stated which food is richer in vitamins. See the charts below for detailed information. See the charts below for detailed information. See the charts below for detailed information.