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CLA vs. Fish Oil - Which One is Better?

Isaac Robertson
Published by Isaac Robertson | Co-Founder & Chief Editor
Last updated: August 7, 2023
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CLA and fish oil are two of the most popular sources of healthy fats on the supplement market.

But is one really better than the other?

To see how they stack up, we reviewed medical journals and articles tackling their respective benefits, risks, and side effects.

Here’s what we discovered.

Quick Summary

  • Fish oil offers a broader range of scientifically-backed health benefits compared to CLA, making it the better choice overall.
  • Fish oil supplements provide omega-3 fatty acids that support heart health, reduce inflammation, improve mental health, and offer numerous other benefits.
  • CLA may aid in weight loss and muscle preservation, but its effectiveness is still largely unproven, and it has limited research supporting other health claims.

Is CLA And Fish Oil The Same Thing?

supplement yellow pill in a white background

CLA and fish oil aren't the same thing, although they offer essential fatty acids that your body can’t make, which means you must get them from food or supplements.

These long-chain, polyunsaturated fatty acids are both beneficial, but the question of which one you should use will ultimately depend on your specific health goals.

CLA is an excellent choice if you intend to lose weight. Since it prevents fat cells from growing larger, it can also aid weight loss while preserving lean body mass [1].

However, bear in mind that these claims are still largely unproven. Also, CLA has a bit higher price than fish oil.

If your purpose is to boost overall health, a fish oil supplement will make a fantastic addition to your diet. It offers a myriad of health benefits, and the good news is that these claims are supported by years’ worth of scientific data.

And unless you’re eating fatty fish at least three times a week, you probably need to consume fish oil supplements.

Conjugated Linoleic Acid

Conjugated linoleic acid (CLA) is an omega-6 fatty acid commonly found in meat, vegetable oils, dairy products, and the milk of sheep, goats, and cows.

Omega-6 is one of the two types of essential fatty acids that play a role in increasing metabolism, keeping cholesterol levels in check, and boosting your immune system, among other benefits.

CLA is primarily known as a weight-loss supplement, but the study on its effectiveness is varied.

Some research says that CLA has the ability to reduce body fat, improve muscle tone, enhance muscular performance, and build more lean muscle mass. However, other studies have found that it had no impact on body weight [2].

Benefits Of CLA

close up image of a measuring tape used on a woman's waist

Although research on the actual effects of CLA on humans is mixed, there are two key areas where this essential fatty acid might be helpful—fat oxidation and muscle-sparing.

Fat oxidation refers to the process where your body breaks down fatty acids to use as energy.

CLA works to promote the use of fats when you burn calories instead of other nutrients when working out, which can help you lose weight in the long term.

"Studies in animals show CLA may decrease energy intake, increase energy expenditure, and inhibit the production of formation of fat cells, aiding in weight loss. Human studies have had mixed results.”

- Serena Poon, Nutritionist

Muscle-sparing, on the other hand, means that you will lose less muscle when you're dieting. CLA will ensure that you burn fat instead of muscle when you're restricting calories.

Here's the bottom line on CLA: it won't help you lose fat, but it might just improve your diet results with these two mechanisms.

Taking a CLA supplement also offers several potential health benefits, including:

  • Lower risk of heart disease due to its anti-inflammatory properties
  • Reduce the risk of certain types of cancer
  • Reduced diabetes risk
  • Improve body composition

However, the scientific research on these claims is extremely limited.

In controlled experiments involving mice, CLA produced up to 60% better results in weight loss than the control group [3]. Although this is promising evidence, it's unknown whether it will have the same effects on humans.

Downsides Of CLA

woman holding a sheet of pills with her thumbs down

The main drawback of CLA is the lack of research on its effectiveness.

It has a lot of hype, and exaggerated marketing tactics by various brands have overtaken the real science behind the product.

Manufacturers often make big claims about CLA supplements related to fat loss even though there's little scientific evidence to support it.

Companies claim that CLA can help you in the following areas of your health and well-being, but they're simply not true.

Research has proven that CLA supplements don't benefit:

  • fat mass
  • cholesterol
  • insulin sensitivity
  • blood sugar
  • body weight
  • metabolic rate
  • inflammation

CLA may also increase inflammation, cause fatty liver, and result in insulin resistance when taken in high doses for a prolonged period.

Considering these potential side effects, it's better just to get CLA from natural sources in your diet. You also get to save some money because CLA supplements can be pretty expensive.

Fish Oil

fish oil capsules in stack

Fish oil supplements are extracted from fatty fish like cod, salmon, tuna, sardines, and mackerel. They're also an excellent source of omega-3 fatty acids.

The three common types of omega-3 fats are alpha linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

When consumed, omega-3s are broken down into EPA and DHA, responsible for several bodily functions and provide many benefits to your physical and mental health.

Cod liver oil remains the best source of EPA and DHA from fish oil, and it also contains vitamins A and D.

Additionally, omega-3s are "essential," meaning your body doesn't produce them. As most people don’t get enough of these from food sources, supplementation becomes necessary.

Benefits Of Fish Oil Supplements

The high concentrations of omega-3 fatty acids in fish oil can reduce the fats in your bloodstream, lower your blood pressure, and balance your cholesterol.

Omega-3s also play crucial roles in mental health and mood disorders [4]. Omega-3 deficiency is linked to the following conditions:

  • Anxiety
  • Aggression
  • ADHD in children
  • Mood disorders
  • Bipolar disorder
  • Degenerative brain diseases (e.g., Alzheimer’s disease and Parkinson’s disease)

Several studies have also shown that the omega-3 fatty acids in fish oil supplements can boost your general health in the following ways:

  • Decreases inflammation: Fish oils are believed to be vital in reducing cancer risk, pain in the joints, and cardiovascular disease.
  • Reduces depression: Fatty acids produce mood-boosting hormones that can help in reducing depression risk/symptoms, prevent stress and anxiety, and elevate your mood.
  • Improves joint health: The anti-inflammatory effects of omega-3 fats found in fish oil supplements may help relieve rheumatoid arthritis pain.
  • Regulates immune function: Omega-3 fatty acids regulate the immune system and reduce inflammation, which may help in lowering the risk of developing autoimmune diseases.
  • Improves heart health: Eating omega-3 fats may help decrease blood pressure, lower triglycerides, and reduce the risk of heart attacks.
  • Helps with weight loss: Fish oil supplements can suppress appetite and increase metabolic rates—two things that can help you shed pounds.
  • Better brain health: Recent studies have shown that fish oil provides the brain with fatty acids that can reduce inflammation in the brain, increase cognitive function, and protect your existing brain cells.

Given its many health benefits, it’s no surprise that fish oil remains one of the most popular supplements in the world today.

Downsides Of Fish Oil Supplements

woman sitting on bed cover her face

Fish oil supplements are considered likely safe by the FDA, as long as you take them in doses of 3 g or less per day.

Taking anything above that poses serious consequences such as: 

  • Depression
  • Diabetes
  • Bipolar disorder
  • Fatty liver


Can we take fish oil and CLA together?

You can take fish oil and CLA together. Consuming these healthy fats is a great way to maximize their positive effects and benefits to boost your overall health. Just make sure to couple it with proper diet and exercise to achieve results.

Is CLA safe to take?

CLA is safe to take in doses of up to 6 g per day. However, keep in mind that the risk of adverse effects rises with the increased dose.

Does CLA interfere with any medications?

CLA can interfere with certain medications, specifically antihypertensive drugs and anticoagulant/antiplatelet drugs. If you’re taking any of these medicines, it’s best to consult your health provider to confirm if they’re safe to combine with a CLA supplement.

CLA vs. Fish Oil - Final Thoughts

Both CLA and fish oil are good fats that can benefit your health.

However, based on our research, the better choice would be fish oil.

Unlike CLA, fish oil is well-researched and established and offers a broad spectrum of science-backed physical and mental health benefits essential to keeping your body in tip-top condition.

Most fish oil supplements are also cheaper than CLA. However, this isn't to say that CLA is totally ineffective. After all, it depends on what you want to achieve.

We hope this CLA vs. fish oil comparison helps you make the best choice for your health.

Which of these products are in your supplement stash? Leave a comment below.


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