Salmon vs Tuna - Health impact and Nutrition Comparison

Summary

Salmon and tuna contain similar amounts of calories. However, tuna is higher in protein, while salmon is richer in fats, particularly omega-3 fatty polyunsaturated fats. Salmon is also higher in cholesterol.

Salmon has a more favorable vitamin profile, being richer in vitamins B2, B5, B6, and folate. Then again, tuna is a preferable source of minerals, such as magnesium, phosphorus, iron, and selenium.

Tuna and salmon can both have various beneficial effects on health when consumed in moderation.

Introduction

Salmon and tuna are two of the most widely consumed fishes in the world. Growing in similar conditions, the nutritional composition of these fishes can be very alike. However, in this article, we will also talk about the dissimilarities between salmon and tuna and what impacts these differences have on health.  

Classification

The term salmon includes multiple species of fish that belong to the Salmonidae family. Other types of fish in this family include trout and whitefish.

Salmon is classified as part of the oily fish species; therefore, they are high in omega-3 fatty acids and fat-soluble vitamins.

Tuna, also known as tunny, is part of the Thunnini tribe of the Scombridae family. Tuna shares this family with mackerels and kingfishes.

Appearance

Raw tuna tends to be darker in color when compared to raw salmon due to the higher level of myoglobin and iron. Raw salmon has a light red or orange hue. 

Salmon and tuna, when cooked, lose coloring, becoming different shades of light pink or white.

Raw meat often has visible wavy white lines, called marbling. These are lines of intramuscular fat. Salmon is often richer in fat, having more marbling. Farm-raised salmon tend to be similar to tuna in lack of marbling.

Taste and Use

Tuna and salmon are not too dissimilar in taste. Salmon is often described to have a more robust flavor than tuna. The taste of these fish mostly depends on how they’re cooked.

Depending on availability, salmon and tuna can be used fresh or canned. Fresh fish is often served raw, smoked, or cooked.

Varieties

The six major species included in the term salmon are the Atlantic, King (Chinook), Sockeye (Red), Coho (Silver), Pink (Humpback), and Chum (Dog, Silverbrite). These species can differ in their nutritional values. The king salmon, being the largest one, contains the most fat. Chum, on the other hand, has the lowest percentage of fat. All of these species are similarly rich in protein.

Fifteen species make up the tuna tribe, of which the four most commonly consumed types are the Atlantic bluefin, the albacore or longfin, the skipjack, and the yellowfin or Ahi. Canned tuna is often of the albacore variety, while bluefin is used fresh. 

Tuna and salmon can also be wild-caught or farm-raised. While farm-raised fish can contain antibiotics, wild-caught fish are at a higher risk of contamination with toxins such as mercury and dioxin-like compounds (1).

Nutrition

The nutritional values below are presented for wild, raw Atlantic salmon and fresh, raw bluefin tuna (2).

Macronutrients and Calories

Overall, salmon and tuna have very similar nutritional densities. Salmon consists of 69% water, while tuna contains 68% water.

Salmon and tuna also have the same average serving size of three ounces, equal to 85 grams.

Calories

Tuna is higher by only 2 calories per every 100g serving. A 100g serving of salmon contains 142 calories.

Protein

While both of these fishes are a great source of proteins, tuna is richer in these. One hundred gram serving of salmon contains nearly 20g of protein. At the same time, an equal amount of tuna has 23.3g of protein.

The quality of protein found in salmon and tuna is excellent, as they both contain high amounts of all essential amino acids.

Fats

When looking at the fat compositions of these two, salmon is not only richer in fats but also has a more favorable quality of fats. The predominant fats found in salmon are polyunsaturated and monounsaturated fatty acids. Tuna is higher in saturated fats.

Salmon contains more cholesterol. One hundred gram serving of salmon contains 55mg of cholesterol, while the same amount of tuna has 38mg of cholesterol.

Carbohydrates

Both tuna and salmon do not contain a notable amount of carbohydrates.

Vitamins

Salmon and tuna are both rich in various vitamins. Overall, salmon may be more favorable in its vitamin composition, being higher in vitamins B2, B5, and B6, folate, as well as vitamin D and vitamin E (3). Salmon also contains a small amount of vitamin K, which tuna lacks completely (3).

On the other hand, tuna contains significantly higher vitamin B12, vitamin A, and vitamin B3 levels. 

Salmon and tuna contain a similar level of vitamin B1.

Vitamin Comparison

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

Salmon

4

:

4

Tuna

Contains more Vitamin B2 +24.2%

Contains more Vitamin B5 +21.5%

Contains more Vitamin B6 +55.8%

Contains more Folate +1150%

Contains more Vitamin A +6200%

Contains more Vitamin B1 +23%

Contains more Vitamin B3 +34.1%

Contains more Vitamin B12 +242.1%

Salmon

Tuna

Contains more Vitamin B2 +24.2%

Contains more Vitamin B5 +21.5%

Contains more Vitamin B6 +55.8%

Contains more Folate +1150%

Contains more Vitamin A +6200%

Contains more Vitamin B1 +23%

Contains more Vitamin B3 +34.1%

Contains more Vitamin B12 +242.1%

Minerals

Tuna is the winner in the category of minerals, containing higher levels of magnesium, phosphorus, iron, selenium, choline, and manganese.

However, salmon is richer in calcium, potassium, and copper. Salmon is also a little higher in sodium.

Tuna and salmon have nearly equal amounts of zinc.

Mineral Comparison

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

Salmon

4

:

4

Tuna

Contains more Calcium +20%

Contains more Potassium +51.7%

Contains less Sodium -12%

Contains more Copper +127.3%

Contains more Iron +63.8%

Contains more Magnesium +120.7%

Contains more Phosphorus +63%

Contains more Zinc +20.3%

Salmon

Tuna

Contains more Calcium +20%

Contains more Potassium +51.7%

Contains less Sodium -12%

Contains more Copper +127.3%

Contains more Iron +63.8%

Contains more Magnesium +120.7%

Contains more Phosphorus +63%

Contains more Zinc +20.3%

Glycemic Index

As salmon and tuna contain no carbohydrates, the glycemic index is considered to be 0. You can find more information about the glycemic index of foods containing no carbohydrates on our website.

Acidity

Fresh tuna is a little more acidic when compared to fresh salmon. The pH value of fresh tuna falls in the range of 5.2 to 6.1, while the pH of fresh salmon falls between 6.1 to 6.3 (4). Both fresh tuna and fresh salmon are slightly acidic. The pH of the fish increases, becoming more alkaline as it starts to spoil.

We can also measure acidity by looking at the potential renal acid load or the PRAL value of the given food. This value demonstrates how much acid or base the food produces inside the organism.

The PRAL values for tuna and salmon are 14.1 and 5.9, respectively. This shows that tuna is significantly more acid-producing than salmon.

Weight Loss & Diets

Salmon and tuna contain a similar amount of calories. One serving of salmon or tuna, while providing a moderate amount of calories, also supplies numerous healthy nutrients.

Salmon containing slightly fewer calories per serving might be the better choice for a low-calorie diet. Tuna, on the other hand, is the preferred option for a low-fat diet. Tuna and salmon both fit well into low-carb and low glycemic index diets.

Studies have shown that incorporating lean or fatty fish into restricted-energy diets results in greater weight loss compared to the same restricted-energy diet without seafood (5).

The supplementation of protein found in salmon, called hydrolysate, has been demonstrated to positively affect body mass index in overweight people (6).

Consumption of boiled tuna has also been shown to have potential anti-obesity effects in mice with obesity (7).

Health Impact

Now that we know what nutritional components these fishes consist of, we will look at how they affect our health.

Health Benefits

Cardiovascular Health

One study concluded that consumption of tuna, as well as other broiled or baked fish, but not fried fish or fish sandwiches, was associated with a lower risk of ischemic heart disease, especially decreasing the risk of death from arrhythmic ischemic heart disease (8). 

Supplementation of fish products rich in omega-3 fatty acids, such as salmon or tuna, along with a weight loss diet, can substantially reduce cardiovascular risk in overweight patients with high blood pressure (9).

Omega-3 fatty acids have also been found to possess anti-triglyceridemic, hemostatic, antiarrhythmic, anti-atherogenic, and antithrombotic qualities, which all improve the heart’s structure and function (10). 

Diabetes

Tuna and salmon, containing no carbohydrates, both cause little to no effect on blood glucose levels after consumption.

Daily consumption of one serving of lean, but not fatty, fish has been studied to have beneficial effects on type 2 diabetes (11). As salmon and tuna are fatty fishes, most studies show their consumption not to have a significant effect on the development of diabetes (12).

Cancer

Limited evidence suggests that fish consumption can decrease the risk of colorectal and liver cancers (13).

Fish high in omega-3 fatty acids may also improve prostate cancer survival rates (14).

Downsides and Risks

Diabetes

A potential correlation has been discovered between an increased risk of diabetes and the consumption of farmed salmon, as it may contain persistent organic pollutants that cause insulin resistance and obesity in laboratory mice (15). Wild salmon does not pose similar risks.

Cancer

While baked fish might have a positive effect on health, a high intake of grilled or broiled and charbroiled or barbecued fish may increase the risk of stomach cancer (13).

Mercury Poisoning

Mercury is a toxic metal that can be found in our environment due to pollution. Consequently, when fish consume mercury, they can be a source of mercury poisoning for humans. Wild fish contain mercury in higher amounts when compared to farmed fish.

One study has found wild bluefin tuna to be significantly higher in mercury than Atlantic and chinook salmon (16).

Most commercial seafood has been studied to contain less than the maximum residue limit of mercury (17) and to be a safe source of omega-3 fatty acids (18). However, pregnant women are still advised to stay away from fish high in mercury, as high levels of this toxin are hazardous for developing brains (19).

Sources.

1. https://www.researchgate.net/publication/7514503
2. https://fdc.nal.usda.gov/fdc-app.html#/food-details/173706/nutrients
3. https://fdc.nal.usda.gov/fdc-app.html#/food-details/175167/nutrients
4. https://www.researchgate.net/publication/343396902
5. https://www.nature.com/articles/0803643
6. https://www.researchgate.net/publication/297727596
7. https://pubmed.ncbi.nlm.nih.gov/27498820/
8. https://www.ahajournals.org/doi/full/10.1161/01.CIR.0000055315.79177.16
9. https://academic.oup.com/ajcn/article/70/5/817/4729086
10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3712371/
11. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0089845
12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2768220/
13. https://www.wcrf.org/dietandcancer/exposures/meat-fish-dairy
14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2843087/
15. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0025170
16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3556626/
17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5985176/
18. https://www.researchgate.net/publication/5640885
19. Make smart seafood choices to minimize mercury intake