Cod Liver Oil vs Fish Oil: What’s The Difference? We Compare

As a Certified Health Coach many clients ask me about supplements. Since cod liver and fish oil are similar people wonder about their differences. Therefore, let’s answer, what is the difference between cod liver oil and fish oil?

Cod liver oil is extracted from the livers of codfish. Fish oil is extracted from the flesh of fatty fish like salmon, herring, sardines, anchovies, mackerel and tuna. Fish oil contains more omega-3 fatty acids, calories, total fat and cholesterol due to its higher, healthy fat content.

This article will dive deep and compare both of their nutrients, benefits, costs, mercury levels and concerns.

In addition to coaching clients about them, I’ve purchased, researched and consumed both prior to, during and after writing this article.

The Difference Between Cod Liver Oil and Fish Oil

What is Cod Liver Oil?

Cod liver oil is oil extracted from the liver of codfish. It is used as a dietary supplement and provides the omega-3 fatty acids eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), vitamins A and D.

A tablespoon contains 4,080 mcg of vitamin A, 34 mcg (1,360 IU) of vitamin D and 0.84 grams of omega-3 fatty acids¹.

What is Fish Oil?

Fish oil is oil extracted from the flesh of fatty fish like salmon, herring, sardines, anchovies, tuna and mackerel. It is used as a dietary supplement and provides the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

A tablespoon typically provides 1.50 grams to 4.66 grams of omega-3 fatty acids. The amount differs depending on the type. Typical oils include the following:

• Cod liver oil
• Salmon oil
• Herring oil
• Sardine oil
• Menhaden oil

Check the table below to find out how much omega-3s, calories, fat and cholesterol each one provides².

Cod Liver Oil vs. Fish Oil: Nutrition Comparison

The following table compares the nutrients of each one:

Nutrient	Cod Liver Oil (1 Tbsp)	Sardine Oil (1 Tbsp)	Menhaden Oil (1 Tbsp)	Salmon Oil (1 Tbsp)	Herring Oil (1 Tbsp)
Calories	41	123	123	123	123
Omega-3	0.84 g	3.10 g	3.62 g	4.66 g	1.50 g
Total Fat	4.5 g	14 g	14 g	14 g	14 g
Saturated Fat	1.0 g	4.1 g	4.1 g	2.7 g	2.9 g
Cholesterol	25 mg	97 mg	71 mg	66 mg	104 mg

Nutrient sources³⁴⁵⁶

When comparing the nutrients above you’ll notice a large difference between cod liver oil and the other oils. Let’s take a closer look at the nutrients and determine which one is better.

Fish oil is better than cod liver oil due to its higher percentage of omega-3 fatty acids. If your omega-3 fatty acids are provided by another source, then cod liver oil may be better for you due to it providing Vitamins A and D.

Cod liver oil contains less calories, total fat, saturated fat and cholesterol. This is due to the lesser amount of healthy fats and omega-3 fatty acids compared to the healthy fats provided by fish oil. Therefore, if you’re obtaining omega-3s from another source, cod liver oil may be the better choice.

One of the main reasons people takes fish oil is to benefit from its healthy fats, particularly the heart healthy omega -3 fatty acids. Many people know them as DHA, EPA and ALA.

The following is the number of omega-3 fatty acids contained in fish oils:

Type of Fish Oil	Amount of Omega-3 per Tablespoon
*Salmon Oil	4.66 grams
Menhaden Oil	3.62 grams
*Sardine Oil	3.10 grams
Herring Oil	1.50 grams
*Cod Liver Oil	0.84 grams

The Omega-3 Fatty Acids In Cod Liver Oil and Fish Oil

Omega-3 fatty acids are polyunsaturated fats needed for their nutritional value. The fatty acids are not made by the body on its own which is why many medical professionals recommend adding sources of omega-3s to the diet. Sources of omega-3 fatty acids include:

• Seafood
• Seeds
• Fish oil supplements.

The omega-3 fatty acids most nutritionists refer to are:

• Docosahexaenoic acids (DHA)
• Eicosapentaenoic acids (EPA)
• Alpha-linolenic acids (ALA)

DHA and EPA are mainly found in seafood and ALA is found in plant based foods like seeds. ALA converts to DHA and EPA but the conversion rate is very low. Therefore, it’s best to consume DHA and EPA to receive the optimal benefits⁷.

Find out how omega-3 compared in my recent article and find out if it’s better than all the others..

Omega 3 Fatty Acids: How Much To Take Everyday

For EPA and DHA fatty acids, there is no standard daily recommendation for people aged one year or older. The omega-3s adequate intake recommendation from birth to 6 months is 0.5 grams and from 7 to 12 months is 0.5 grams.

The Table below contains the omega-3 recommendations by the National Academy of Medicine.

Age Group	Male	Female	Pregnancy	Lactation
*0-6 months	0.5 grams	0.5 grams
*7-12 months	0.5 grams	0.5 grams
**1-3 years	0.7 grams	0.7 grams
**4-8 years	0.9 grams	0.9 grams
**9-13 years	1.2 grams	1.0 grams
**14-18 years	1.6 grams	1.1 grams	1.4 grams	1.3 grams
**19-50 years	1.6 grams	1.1 grams	1.4 grams	1.3 grams
**51+ years	1.6 grams	1.1 grams

The National Academy of Medicine (IOM), formerly called the Food and Nutrition Board of the Institute of Medicine, established the adequate recommendations for Omega-3 fatty acids ((USDA: What is the Recommended Dietary Allowance (RDA) for omega-3, 6 and 9?)).

They established adequate recommendations for EPA and DHA up to one year old and ALA recommendations from 1 year to adults.

The adequate recommendation for infants to one year old is equivalent to the mean intake of omega-3s in healthy, breastfed infants. They provide this recommendation because human milk provides all three omega-3s, ALA, DHA and EPA.

They only provide recommendations for ALA over one year old because ALA is the only omega-3 essential⁸.

I recently completed an article comparing krill oil. Find out which one is better, costs more or had more mercury.

How To Determine The Correct Amount of Omega-3 Fatty Acids

There’s no official recommendation for how much DHA and EPA to take every day. Therefore, to determine how much DHA and EPA Omega-3 fatty acids to take:

• Confer with a physician first.
• Compare the dosage on a supplement bottle to the amount provided in a serving of whole fish.
• Read the recommendations on the supplement bottle.

Additional tips:

• Determine if the omega-3 fatty acids or Vitamins A and D are more important for you.
• If omega-3 is more important the fish oil provides more.
• If Vitamins A and D are more important, the cod liver oil may be a better choice.
• Don’t take both cod liver oil and fish oil supplements together.
• Take either one with food to aid digestion and absorption of the oil.
• Never discontinue medication for a supplement without conferring with a physician first.

Cod Liver Oil and Fish Oil Costs

Deciding on which oil to consume may involve more than determining whether omega-3s or vitamins are more important. With the rising costs of almost everything in the supermarkets, the cost is a likely factor.

Therefore, let’s examine which one costs more.

Cod liver oil costs more than fish oil. The average cod liver oil price is $22.97 per 200 softgels and fish oil is $9.99 per 180 softgels.

Walmart

• Fish oil – Nature’s Bounty Brand (1,200 mg, 120 softgels)
  • $11.49
• Cod Liver Oil – NOW Brand (1,000 mg, 180 Softgels)
  • $18.37

Costco

• Fish Oil – Kirkland Brand (1,000 mg, 400 Softgels)
  • $12.99
• Cod Liver Oil – NOW Brand (1,000 mg, 180 Softgels)
  • $22.99

Both are easy to locate in the stores. I typically can find more affordable prices and availability on Amazon, Check them out here.

Health Benefits of Fish Oils

Aside from providing energy and making molecules, Omega-3 has many beneficial health benefits worth mentioning⁹.

While both bring polyunsaturated fats to the table¹⁰, combined with the other Omega-3s, fish oil can create healthier hair, skin, brain and vision.

The following are health benefits of cod liver and fish oil:

Heart Health

Heart health may be the most important of all the benefits. Known to lower cholesterol and blood pressure, both oils may help keep your heart healthy and may prevent strokes, heart attacks and heart disease¹¹.

Along with that, it is said to normalize blood flow and heart rate, making things easier on this vital organ. Plus it’s all done through the lowering of triglyceride levels. Triglycerides are the fats cells in the blood.

High levels of triglycerides are what can cause problems in the liver or heart.

Normal levels hover around 150 mg/dL or less, and fish oils supplements (or the other resources of Omega-3) can help in keeping these levels and benefit heart health.

Essentially it helps clear out “bad” cholesterol while keeping or increasing the good cholesterol¹².

Anti-inflammatory and Arthritis

Like other Omega-3 rich foods, both oils have anti-inflammatory abilities. For this reason, taking fish oil supplements has been known to help prevent inflammation-related diseases like arthritis, diabetes and even some cancers¹³.

Improved Circulation

Because Omega-3s are later converted into other helpful molecules, researchers believe the fatty acids help keep a body’s blood vessels strong, capable and flexible. This allows for better blood flow and improved circulation of oxygen ((National Center for Biotechnology: Marine Omega-3 Supplementation and Cardiovascular Disease)).

Brain Capabilities

Anything with the Omega-3 levels found in both oils can help build up and maintain brain cells. Brain cells are constantly being made and repaired by fatty acids. This can decrease the chance of getting cognitive degenerative diseases like Parkinson’s or Alzheimer’s¹⁴.

Eyes and Vision

Due to their omega-3s, fish oil can help prevent retina deterioration. If the intraocular pressure (the fluid pressure in the eye or IOP) is greater than the normal range of 12-22 mm/Hg, glaucoma could occur or will at least be a considerable risk.

With a diet rich in omega-3 fatty acids, eye problems can be less likely. They help keep that IOP at a healthy level. The liver oils also contain vitamin A which provides benefits for the eyes. This is another fantastic reason to take fish oil supplements¹⁵.

Side Effects of Oil Supplements

Both oils are considered safe, but there are some minor side effects. Therefore, a physician should be consulted with prior to taking any supplement.

Cod Liver oil and fish oil possible side effects include the following:

Oil and Bad Breath and Body Odor

The oils in the supplements can linger a while. This can result in bad breath lasting longer than is comfortable.

As for body odor, the supplements are made from pungent oils. Therefore, the fishy “grease” can stay in your system for quite some time and possibly increase the amount you sweat (but this does not happen often).

Digestive Issues

In rare cases, there have been those who suffered stomach cramps and digestive issues. In addition, some people have experienced heartburn and loose stool in response to the upset stomach.

Be cautious when taking supplements and don’t take too much at a time. Following your physician’s recommendation, reading labels and suggested measurements carefully are beneficial with or without side effects.

Oil and Metal and Mercury Contamination

Some fish tend to contain high levels of mercury. Therefore, consequences of taking too much fish oil may exist.

The FDA and EPA established a list of fish to avoid, best fish and good choices based on their mercury levels. Cod, salmon, sardines, herring and menhaden are all listed on the best choice list of fish ((FDA: Advice about Eating Fish)).

Be cautious of where you get your supplements. Though some very good companies sell them but there will always be companies cutting corners and rushing processes.

Definitely do your research and make sure to avoid inferior products. If you don’t choose a reputable company, the fish used to make the tablets may not have been cleaned properly or fished out of safe areas.

Allergies

Allergies exist for many things including shellfish. Although having a shellfish allergy doesn’t automatically disqualify someone from taking fish oils, there may have been cross-contamination in the making and manufacturing process.

Labels and medical professionals could elaborate further on any additional inquiries.

Oil and Bleeding

In rare cases, fish oil supplements have been known to cause nose bleeds and “easy bleeding.” This means if you get a cut, the bleeding might have a hard time stopping. Although this is rare, it can be dangerous.

If this or any other concerns come up, it might be best to stop taking the supplements and speak to a physician.

Unhealthy levels of Vitamin A and D From Oil

More so with cod liver oil, unhealthy levels of both vitamins may exist. This is especially so if taking more than the recommended dosage. Although this is often debated, it’s good to be aware of this and discuss it with a doctor.

In addition, it may cause:

• Nausea
• Rash
• Reduced vitamin E levels
• Negative reactions with certain medications

Read Next Additional Articles!

Salmon Oil vs Fish Oil: Which Is Better?

1. Wikipedia: Cod-liver oil [↩]
2. Wikipedia: Fish oil [↩]
3. Nutrition Value: Fish oil, sardine [↩]
4. Nutrition Value: Fish oil, menhaden [↩]
5. Nutrition Value: Fish oil, cod liver [↩]
6. Nutrition Value: Fish oil, herring [↩]
7. National Institutes of Health: Omega-3 Fatty Acids [↩]
8. National Institutes of Health: Omega-3 Fatty Acids [↩]
9. National Institutes of Health: Omega-3 Fatty Acids [↩]
10. USDA: Fish oil, herring [↩]
11. National Center for Biotechnology Information: Fish oil supplements, longevity and aging [↩]
12. National Center for Biotechnology Information: Role of Cod Liver Oil in Reducing Elevated Lipid Parameters [↩]
13. National Center for Biotechnology Information: Cod liver oil (n-3 fatty acids) as an non-steroidal anti-inflammatory drug sparing agent in rheumatoid arthritis [↩]
14. National Institute of Health: Omega-3 Fatty Acids [↩]
15. National Center for Biotechnology Information: Cod liver oil: a potential protective supplement for human glaucoma [↩]