Cod vs. Perch — Health Impact and Nutrition Comparison

by Elen Khachatrian | Last updated on July 17, 2023

Medically reviewed by Astghik Grigoryan

Summary

Cod and perch contain completeness proteins, which contain all nine essential amino acids that human bodies cannot make on their own. Perch contains a higher concentration of omega-3, monounsaturated, and saturated fats than cod. Both of them are carb-free.

Perch has a higher mineral content than cod; however, cod contains twice the quantity of selenium. Both fishes have an equal amount of Vitamin B1.

Introduction

In this article, you can find the main nutritional differences between perch and cod also their impact on human health.

Habitat

Pacific Ocean perch can be found off the coasts of North America, from California to Alaska's Western Aleutian Islands, compared to cod, which can be found from Greenland to Cape Hatteras, North Carolina, in the Northwest Atlantic. Cod is most frequent in US waters on Georges Bank and in the western Gulf of Maine.

Atlantic cod reside near the seafloor on rocky ledges and slopes. They prefer cold water at depths of 30 to 500 feet. As for the Pacific perch, larvae and immature juveniles reside near the surface, whereas adults and older juveniles inhabit the ocean floor. Adults reproduce and reside in shallow waters in the summer and offshore in the fall and winter.

Appearence

Atlantic cod have a huge head, a blunt snout, and a conspicuous barbel (a whisker-like structure similar to that of a catfish) under the lower jaw. Their colors range from light yellowish-green to red and olive, with darker speckles on the head, fins, tail, and body. Because of their color, brown or grayish with dark patches or patterns on the flanks and a paler belly, Pacific cod are also known as gray cod. As for Pacific perch, their upper backs are pale red with several diffuse olive-green patches. They also have a conspicuous, cone-shaped bump on the bottom of their jaw.

Biology

In comparison to Pacific perch, which grows slowly and can live to be 98 years old, Atlantic cod can live for more than 20 years.

Atlantic cod can grow to be 51 inches long and weigh 77 pounds, whereas Pacific perch can grow to be 20 inches long and weigh 4 pounds.

When compared to Pacific perch, Atlantic cod can breed around 2 to 3 years old, when they are between 12 and 16 inches long, whereas Pacific perch cannot reproduce until they are around 10 years old.

Nutrition

The food types discussed in this article are raw perch and raw cod. You can look at nutrition infographics at the bottom of the page to better understand the difference between these two fishes.

Calories

Both perch and cod are considered moderate-calories foods. The calories per 100g of cod and perch are 105 and 117, respectively.

Proteins

The amounts of protein in perch and cod are almost equal: perch contains 24.86g, and cod has 22.83g of protein per 100g. Both fishes contain high amounts of essential amino acids, such as tryptophan, lysine, histidine, phenylalanine, isoleucine, leucine, valine, methionine, and threonine.

Completeness proteins are those that contain all nine essential amino acids that human bodies cannot make on their own, such as the proteins of cod and perch.

It should be mentioned that the smallest allowed daily protein amount is 55–60g (0.7g per kg of body weight), while the recommended amount is 85–90g, with animal proteins accounting for 55%. Based on the previous information, it follows that consumption of cod and perch may fill this 55%.

Fats

Perch has over 1.4 times the fat content of cod, with 1.18g per 100g vs. 0.86g for the same serving of cod. Perch has twice as much cholesterol as cod, with 115mg per 100g compared to 55mg per 100g for cod. Perch has more omega-3, monounsaturated, and saturated fats than cod.

Carbs

The carb content of cod and perch is zero.

Minerals

Perch has a higher mineral content than cod. When compared to cod, perch is 7 times richer in calcium, nearly twice as rich in iron, 1.8 times richer in phosphorus, 1.4 times richer in potassium, 2.5 times richer in zinc, 5 times richer in copper, and 45 times richer in manganese. When compared to perch, cod has twice the amount of selenium.

Both have nearly identical magnesium and sodium amounts.

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.

Cod

Perch

Contains more SeleniumSelenium

+133.5%

Contains more CalciumCalcium	+628.6%
Contains more PotassiumPotassium	+41%
Contains more IronIron	+136.7%
Contains more CopperCopper	+433.3%
Contains more ZincZinc	+146.6%
Contains more PhosphorusPhosphorus	+86.2%
Contains more ManganeseManganese	+4400%

~equal in Magnesium ~38mg

~equal in Sodium ~79mg

Vitamins

Cod is two times richer in vitamin B6 than perch; it is also high in vitamin B3, B9, and vitamin A. Perch is 1.5 times richer in vitamin B2, 4.8 times richer in vitamin B5, 2 times richer in vitamin B12, and 1.7 times richer in vitamin C compared to cod.

Both fishes have an equal amount 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" charts below show how much of the daily needs can be covered by 300 grams of the food.

Cod

Perch

Contains more Vitamin AVitamin A	+40%
Contains more Vitamin EVitamin E	+∞%
Contains more Vitamin DVitamin D	+∞%
Contains more Vitamin B3Vitamin B3	+32.3%
Contains more Vitamin B6Vitamin B6	+102.1%
Contains more Vitamin KVitamin K	+∞%
Contains more FolateFolate	+33.3%
Contains more CholineCholine	+∞%

Contains more Vitamin CVitamin C	+70%
Contains more Vitamin B2Vitamin B2	+51.9%
Contains more Vitamin B5Vitamin B5	+383.3%
Contains more Vitamin B12Vitamin B12	+109.5%

~equal in Vitamin B1 ~0.08mg

Weight Loss and Diet

The keto diet is appropriate for cod and perch since they contain no carbs.

The Mediterranean diet can also include them. It should be noted that a number of studies and meta-analyses have found that the Mediterranean diet reduces the risk of cardiovascular events and all-cause mortality (2).

Although cod and perch are high in many nutrients, they are medium-calorie foods and should be consumed in moderation when on weight-loss diets.

Health Benefits

Cardiovascular Health

Peptides found in cod may inhibit the angiotensin-converting enzyme (ACE). One of the mechanisms that may lower arterial blood pressure is ACE inhibition. Some antihypertension medications (such as Captopril, Ramipril, Lisinopril, and others) function through the same mechanism (1.2). Unlike cod, there are no studies that show a direct link between the consumption of perch and lowering blood pressure. Still, the omega-3 in it helps lower blood pressure through a variety of mechanisms, including ACE inhibition (3).

According to this cohort study, omega-3 may decrease heart rate, which is important for appropriate cardiac muscle blood supply (3).

Omega-3 fatty acids, protein with vitamins, and even unknown bioactive substances in cod and perch may also play a role in the prevention of cardiovascular disease (such as myocardial infarction and stroke) through a variety of mechanisms, such as lowering circulating levels of total cholesterol, LDL (bad cholesterol), lipoproteins, and triglycerides. (4).

Combining omega-3 fatty acid therapy with baseline statin (such as Atorvastatin, Rosuvastatin, etc.) medication reduces triglycerides by another 29%. As a result, it improves the cardiovascular prognosis of patients with hyperlipidemia (5).

Several epidemiologic and animal studies have demonstrated that omega-3 fatty acids may significantly reduce the risk of atherosclerosis due to their anti-inflammatory characteristics and suppression of endothelial activation (5).

The proliferation of vascular smooth muscle cells is critical in the pathophysiology of atherosclerosis and re-stenosis (the diameter of the coronary artery lumen is lowered after angioplasty). Omega-3 fatty acids have been demonstrated to play a role in the suppression of smooth muscle cell growth (5).

A high omega-3 intake can be obtained by eating fish such as cod and perch twice to three times per week to achieve at least 500 mg/day, or by taking fish oil supplements on a regular basis (3).

Diabetes

Because cod and perch are high in omega-3 fatty acids, they may be useful to diabetics.

According to this rat study, consuming cod liver oil, which is high in omega-3 fatty acids, is associated with a number of biochemical changes that may be beneficial for diabetes, including lower triglyceridemia, increased fatty acid oxidation, higher HDL levels, and lower LDL levels. As a result, not only is hyperlipidemia reduced, but so is insulin resistance (6).

Another study found that omega-3 fatty acids may significantly reduce fasting blood glucose levels (7).

Liver Health

Cod and perch may help prevent fatty liver disease since they contain lipotropic omega-3. The optimal dose has yet to be discovered, but the effects are obvious at 20.83 grams of omega-3 per day. For more optimal statistics, further randomized trials are required (8).

Anemia

Because perch is higher in iron and cod is high in vitamins B9 and B12, both are recommended for anemia and may lower the risk of developing anemia (9).

Nervous system

Several epidemiological studies have found that adequate omega-3 intake or greater serum omega-3 levels are linked to a decreased incidence of depression. Low omega-3 levels have been linked to depressive or anxious moods, poor cognitive function, sleep disturbances, aggressiveness, and impulsive behavior (10). As already mentioned, eating fish such as cod and perch two to three times per week can offer a high omega-3 intake.

Immune system

Omega-3 fatty acids have been demonstrated in studies to reduce the symptoms of a variety of disorders (including sepsis and autoimmune hepatitis) by stimulating the immune system. Obtaining extensive information about the unique direct effect of omega-3 fatty acids on diverse immune system cells would allow future researchers and physicians to optimize and apply omega-3-rich supplements and foods (including cod and perch) for the treatment of a wide range of disorders (11).

Side Effects

Cod, like the majority of fish, contains mercury. Excessive mercury consumption is toxic and can lead to neurological and behavioral problems. It may be especially harmful to children. So, it is better to consume cod in moderation (12).

Perch is high in purines, which can cause kidney stones. A high purine intake causes increased uric acid production, and this concentration promotes the formation of uric acid stones (13).

References

Author name: Elen Khachatrian

Education: Nutrition & Microbiology at YSU

Last updated: July 17, 2023

Medically reviewed by Astghik Grigoryan

Infographic

Infographic link

All nutrients comparison - raw data values

Nutrient			DV% diff.
Vitamin B12	1.05µg	2.2µg	48%
Selenium	37.6µg	16.1µg	39%
Manganese	0.02mg	0.9mg	38%
Cholesterol	55mg	115mg	20%
Copper	0.036mg	0.192mg	17%
Phosphorus	138mg	257mg	17%
Choline	83.7mg		15%
Vitamin B5	0.18mg	0.87mg	14%
Vitamin B6	0.283mg	0.14mg	11%
Calcium	14mg	102mg	9%
Iron	0.49mg	1.16mg	8%
Zinc	0.58mg	1.43mg	8%
Vitamin D	46IU		6%
Vitamin D	1.2µg		6%
Vitamin E	0.81mg		5%
Vitamin B3	2.513mg	1.9mg	4%
Protein	22.83g	24.86g	4%
Potassium	244mg	344mg	3%
Vitamin B2	0.079mg	0.12mg	3%
Folate	8µg	6µg	1%
Polyunsaturated fat	0.292g	0.472g	1%
Calories	105kcal	117kcal	1%
Vitamin B1	0.088mg	0.08mg	1%
Magnesium	42mg	38mg	1%
Vitamin C	1mg	1.7mg	1%
Fats	0.86g	1.18g	0%
Sodium	78mg	79mg	0%
Vitamin A	14µg	10µg	0%
Vitamin K	0.1µg		0%
Saturated fat	0.168g	0.237g	0%
Monounsaturated fat	0.124g	0.195g	0%
Tryptophan	0.256mg	0.278mg	0%
Threonine	1.001mg	1.09mg	0%
Isoleucine	1.052mg	1.145mg	0%
Leucine	1.856mg	2.02mg	0%
Lysine	2.097mg	2.283mg	0%
Methionine	0.676mg	0.736mg	0%
Phenylalanine	0.891mg	0.97mg	0%
Valine	1.176mg	1.281mg	0%
Histidine	0.672mg	0.732mg	0%
Omega-3 - EPA	0.004g	0.101g	N/A
Omega-3 - DHA	0.154g	0.223g	N/A
Omega-3 - DPA	0.013g	0.036g	N/A