Cod vs Haddock - Health impact and Nutrition Comparison

INTRODUCTION

The cod and the haddock are both white fish species which differ from oily fish in that they have oil only in their liver. They belong to the family of Gadidae. The cod belongs to the genus Gadus. The stocks are declining due to many reasons, namely overfishing and no recovery afterward (1). The haddock stocks are also facing decline; however, only recently, parts of the stocks have started recovering (2). Haddocks are known for their mild taste compared to stronger tasting fish like salmon. The cod and the haddock are fish of great economic significance (3). The cod is relatively cheaper than the haddock, the difference being around 14.7$. Whitefish are low-fat protein alternatives to high-fat red meat.
Let’s understand how these two items are nutritionally similar or different and the benefits associated with these foods through discussions and visuals.

NUTRITION

We will make use of the visuals to compare the nutritional content of both fish. The cod is lower in calories and therefore is favored over the haddock in a low-calorie diet. Both fish contain no carbohydrates and are therefore suitable for diabetics or people following a low carbohydrate diet. Both fish are very high in protein and are a recommended source of protein. Because they have less fat content than red meat, they can be used as a lower-fat version red meat substitute as a source of protein. The haddock is higher in proteins. Both fish contribute to 3% of the daily fat intake, given 300g of the food is eaten. The haddock is lower in saturated fats. On the other hand, the cod is lower in cholesterol, sodium, and glycemic index. The cod is higher in polyunsaturated and monounsaturated fatty acids.  Both fish don’t contain any fiber.

VITAMIN COMPARISON

The haddock is higher in vitamins A, B12, B6, and B3, while the cod is higher in vitamins C, E, D, B1, and B5. The haddock contains no vitamin C, while the cod does. Both foods have equal amounts of vitamin K and vitamin B2, and they lack vitamin B9 (folate).

In conclusion, the cod has 17 times higher vitamin score than the haddock.

MINERAL COMPARISON

The haddock is higher in phosphorus and choline, while the cod is higher in magnesium and potassium. The haddock is higher in sodium by almost five times. The cod contains more iron, calcium, potassium, magnesium, and zinc, while the haddock has higher phosphorus.
In a nutshell, the two fish have almost equal mineral scores, the haddock score being a bit higher.

AMINO ACID COMPARISON

The haddock is higher in the following amino acids: tryptophan, threonine, isoleucine, leucine, lysine, methionine, phenylalanine, valine, and histidine.

GEOGRAPHICAL DISTRIBUTION 

The haddock (Melanogrammus aeglefinus) is found in the Northern Atlantic (4). Meanwhile, the cod lives in the North Atlantic and Arctic Oceans (5). 

DIFFERENCES IN TASTE AND TEXTURE

The haddock is significantly less sweet, less salty, and has a weaker fish flavor and aftertaste.

DIFFERENCES IN APPEARANCE

The haddock is usually gray in color with a prominent black blotch on the shoulder and a black lateral line, while the cod is usually green or yellow with some dark spots and a white lateral line (6).

HEALTH IMPACT

Studies related to the specific health impact of haddock or the specific health impact of the cod are lacking. This is due to the fact that the impact of the fish group is studied, which includes whitefish as well as fatty and oily fish.

GENERAL

Cods and haddocks are a great source of vitamins B6 and B12. Vitamin B6 plays a role in mental function, mood regulation, and formation of red blood cells. Studies show that vitamin B6 deficiency has been linked to some neural and psychiatric disorders, namely migraines, depression, chronic pain, and seizures (7). Vitamin B6 and B12 are involved in parts of the homocysteine metabolism, and deficiencies in these nutrients will cause elevated blood homocysteine levels. Elevated blood homocysteine levels have been shown to negatively affect mental health (8).  Vitamin B12 plays a role in the metabolism of macronutrients and helps in the formation of the genetic material of the cell. It also aids in red blood cell formation and hence anemia prevention. 

CARDIOVASCULAR DISEASE (CVD)

Different organizations recommend a minimum of 2 servings of fish to promote cardiovascular health. A study showed that fish consumption was linked with a decrease in the occurrence of myocardial infarctions in people with type 2 diabetes. The study also suggests that fish consumption is inversely correlated with the incidence of CVD and overall mortality (9).

Part of the cardioprotective properties of cod and haddock is due to their richness in omega 3 polyunsaturated fatty acids

ALLERGY

As fish consumption has been on the rise for decades, so has been the reports of reactions to fish. In fact, fish allergy is not only mediated through the fish itself but by different toxins and parasites such as ciguatera and Anisakis.  Allergic reactions to fish can be life-threatening. Fish allergy in children usually cannot be outgrown. Exposure to this allergen may be through ingestion, handling, or even inhalation. Fish allergy is dependent on geographical location, eating patterns, type of fish processing, and other factors (10).

A small proportion of the population may be allergic to whitefish such as haddock or cod. According to the American College of Allergy, Asthma and Immunology, a fish allergy may only show during adulthood period (11).

MERCURY POISONING

Like most types of fish, the haddock and the cod contain mercury. Excessive mercury in the body is known to have neurological as well as behavioral implications. Pregnant and breastfeeding women need to pay special attention to mercury consumption.

PROTEIN

The cod and haddock are both around 97% protein and 3% fat. A serving size of 100g of cod provides around 17g of protein. On the other hand, the haddock is higher in proteins as a serving size of 100g of haddock provides around 20g of proteins. The dietary reference intake of protein for a normal person is 0.8g per kilogram of body weight daily. If you are physically active, underweight, or suffering from an illness, the recommendation of protein intake would change. Proteins are needed for growth, maintenance, cell structure, providing energy, transport of substances throughout the body, balance of body fluids, and other functions.

VITAMIN B5

The cod has 300 times more vitamin B5 than the haddock. The RDI of vitamin B5, also called pantothenic acid, is 5 mg for a healthy adult (12). Vitamin B5 is necessary for the formation of certain hormones, the formation of red blood cells, metabolism, and healthy digestive system maintenance.

FISH SELECTION

Always opt for fresh haddock and cod. You can tell by a firm texture. Whole fresh fish should have bright eyes and red gills. Avoid cod and haddock that smell weird.

Make sure the fish is kept frozen or cooled on ice to prevent food poisoning. If you are traveling long distances before reaching a freezer, consider using a cooler.

STORAGE

The haddock and the cod remain in good to reasonable storage conditions for 5 to 10 days on ice. After 15 days on ice, the fish should not be eaten. Gutted haddock that is to be frozen can be kept on ice for a maximum of 2 days. The haddock that has been kept cool for more than 7 days should not be used for the preparation of frozen products. “All smoked haddock products can be quick-frozen and kept satisfactorily in cold storage; a shelf life of at least 7 months in first-class condition is possible at -30°C” (13). Cod stored at -20°C can be in excellent condition for up to 8 months and still edible after 4 years (15).

RECOMMENDATIONS

The 2015-2020 Dietary Guidelines for Americans recommends the consumption of at least 8 ounces of seafood per week for healthy people following a 2000 calorie diet (14). Breastfeeding or pregnant women need to ensure intake of 8-12 ounces of seafood per week, and their fish choices need to be from the low mercury fish group (15). High mercury consumption may harm the fetus. For the reduction of cardiovascular disease risk, The American Heart Association (AHA) recommends having 2 to 3.5 oz cooked portions of fish at least twice per week (16).

CULINARY TIPS

The Haddock and the cod can be baked, broiled, fried, poached, smoked, and sautéed. To prepare a healthy dish, caution should be taken in the preparation method. Try to avoid the use of unhealthy fats and refined carbohydrates when preparing your fish dish.

ENVIRONMENTAL IMPACT

Haddocks and cods are overfished (1,2). We need to establish sustainable fishing to ensure the livelihood of these fish for future generations, and to prevent the loss of these species. Haddocks and cods that are labeled MSC in blue are certified sustainable (17,18).

SUMMARY

The cod and the haddock are nutritious foods. The haddock is richer in vitamins A, B12, B6, and B3, while the cod is higher in vitamins C, E, D, B1, and B5. The haddock is richer in proteins, while the cod is higher in calories. The haddock is higher in 9 essential amino acids. To conclude, the cod and the haddock are relatively sustainable low-fat protein replacement for red meat with many nutritional and health attributes.

1. https://www.sciencedirect.com/science/article/pii/S235198941400050
2. http://www.ices.dk/sites/pub/CM%20Doccuments/CM-2009/C/C0409.pdf 
3. https://www.researchgate.net/publication/287708282
4. https://repository.library.noaa.gov/view/noaa/4036
5. http://www.fao.org/3/x5911e/x5911e01.htm 
6. https://www.sciencedirect.com/science/article/pii/B012227055X0046851.    
7. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858
8. https://synapse.koreamed.org/articles/1059827
9.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5851676/
10.  https://pubmed.ncbi.nlm.nih.gov/23440653
11.  https://acaai.org/allergies/types/food-allergies/types-food-allergy/fish-allergy
12. https://ods.od.nih.gov/factsheets/PantothenicAcid-HealthProfessional/#
13. http://www.fao.org/3/x5939e/x5939e01.htm
14. http://www.fao.org/3/x5911e/x5911e01.htm
15. https://www.fda.gov/food/consumers/advice-about-eating-fish#
16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3705336
17. https://www.msc.org/what-you-can-do/eat-sustainable-seafood/fish-to-eat/haddock  
18. https://www.msc.org/what-you-can-do/eat-sustainable-seafood/fish-to-eat/cod