Krill Oil vs. Fish Oil: Are They the Same?

These days everyone is taking some kind of “oil” supplement. Whether recommended by a dietitian, another healthcare provider, or taken as a proactive part of one’s health routine, taking omega-3 supplements has become routine for many of us.

Not all omega-3 supplements are the same. Because omega-3 can be found in numerous types of fish, the oils may vary in their composition. Such is the case with krill oil, which is sourced primarily from small crustaceans. 

We’ll discuss the differences between krill and fish oil and whether or not one is better than the other. We’ll also talk about why a newly discovered fatty acid known as C15:0 is making headlines as the better fatty acid supplement. 

Krill Oil vs. Fish Oil: The Sources

Krill oil is derived from Atlantic crustaceans known as Antarctic krill. These tiny, shrimp-like creatures are consumed by whales, birds, and seals. They are rich in two types of omega-3 fatty acids: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). 

Fish oil is derived from fish. Fatty fish like mackerel, sardines, and salmon. Most fish oil supplements contain a blend of these oily fish derivatives. Fish oil supplements also contain the polyunsaturated fatty acids EPA and DHA. 

So far, we have two sources of omega-3 fatty acids. Let’s dig deeper and compare the two.

Which Is Better?

There is limited research surrounding krill oil and its benefits. By contrast, there is a ton of research on omega-3. Interestingly, the vast majority of research proving the cardiovascular health benefits of omega-3 focuses on EPA, specifically without DHA. 

Benefits of Krill Oil

Limited research shows that because the structure of krill oil differs from fish oil, it may be more bioavailable to the body. Krill oil does have more antioxidants, which the body needs to protect against free radical damage. 

There has been at least one study that demonstrated that krill oil might have more heart-protective benefits than fish oil, but this study was small, and more research would be needed to establish this as a principle. 

One benefit of krill oil may be that it does not have as much of the unpleasant side effect, known as “fish burps” as fish oil. Fish burps or a fishy aftertaste are less common (but still present) with krill oil. 

Cons of Krill Oil

The biggest detriment to krill oil is the price. For a daily dietary supplement, krill oil may be too expensive for the average person to afford. 

It may not be worth it to take krill oil supplements since the effects of krill oil are not markedly better than the benefits of taking a fish oil supplement. Additionally, if you are allergic to shellfish, krill oil should be avoided. 

Benefits of Fish Oil Supplements

Fish oil supplements are heavily researched. The benefits that krill oil provides are well-established in fish oil. Fish oil is easily accessible, found in practically every grocery store, pharmacy, and online health and wellness outlet, and reasonably affordable. 

Cons of Fish Oil

Fish oil supplements, like krill oil, consist of polyunsaturated fatty acids, which are liquid at room temperature. This basic structure means that fish oil can become rancid, just like cooking oil that has gone bad in your pantry. 

One study found that more than one in 10 fish oil supplements were rancid on store shelves before they were even purchased. If the fish oil is rancid in the bottle, it will be rancid in your body. 

Additionally, fish oil tastes fishy. Even supposed “burpless” formulas cannot promise you won’t experience a fishy aftertaste while you take your daily dose of omega-3 to support your heart health. 

Finally, there are some side effects of both krill and fish oil that you should know before considering taking a fish oil supplement. Excessive consumption of fish oil and krill oil can lead to:

• Lower blood pressure
• Thinning of blood
• Excessive bleeding if an injury were to occur
• Increased risk of bruising

These side effects may make taking a fish oil or krill oil supplement a less-than-viable option. Thankfully, there is another option. Spoiler alert: It isn’t derived from fish.

A Better Fatty Acid Supplement

Although the newest fatty acid to have been discovered isn’t derived from fish, it does involve sea life. Researchers studying longevity in Navy dolphins discovered that one population of dolphins had fewer cases of age-related illness than another. 

The difference was in their diets. The population living longer, healthier lives ate a diet that included a nutrient known as pentadecanoic acid, or C15:0 for short. This discovery led researchers to take their work further, experimenting with the effects of C15:0 on human cells. As it turns out, the protective benefits of C15:0 are available for humans, too.

What Is C15:0?

C15:0 is an odd-chain, saturated fatty acid that is essential for our bodies and is the first essential fatty acid to be discovered in over 90 years. Essential means our bodies need it to thrive but cannot readily make it on their own. We must get essential nutrients from our diets or from supplements. 

C15:0 works in our bodies on a cellular level by:

• Strengthening cellular membranes. In studies, cell membranes get 80% stronger when C15:0 integrates into them.

• Clearing damaged cells. C15:0 activates AMPK and inhibits mTOR, which help to clear out damaged cells.
  
  
• Regulating inflammatory response. C15:0 significantly calms and lowers proinflammatory cytokines, a key driver of aging.

• Fixing mitochondria. C15:0 repairs mitochondrial function, increasing our cell’s energy output and decreasing damaging reactive oxygen species by 45%. C15:0 has been shown to generate significant cell energy (aka ATP). In one peer-reviewed study, C15:0 was shown to increase ATP levels in cells by 350%.

• Activating AMPK. C15:0 restores cellular and whole-body homeostasis, regulates glucose uptake, and calms our immune systems.

• Activating PPARɑ and PPARẟ receptors. By activating these receptors, C15:0 has been shown in peer-reviewed studies to support metabolic, immune, heart, and liver health in relevant models. These receptors also help to improve mood and deepen sleep.
  
• Improving the gut microbiome.
  

• Targeting 6 out of the 12 hallmarks of aging. 

If you’re attempting to do what you can to improve your heart health, you’ll be happy to know that C15:0 has heart-supportive benefits as well. One study showed that it lowered “bad” LDL cholesterol and regulated triglyceride levels, improving heart health. It’s even been shown to improve liver enzymes and liver health.

Which Is Better? Omega-3 or C15:0?

When studied head-to-head against the purest and most effective form of omega-3 (EPA without DHA), C15:0 was shown to be better, broader, and safer than omega-3. 

• Better. C15:0 had 26 more clinically relevant benefits than omega-3.
• Broader. C15:0 repaired 2.5 times more cell types when compared to omega-3. 
• Safer. C15:0 was safe (at all concentrations tested) for 12 out of 12 cell types tested. Omega-3 was toxic to 4 out of the 12 cell types, including lung and blood vessel cells. 

Combine these benefits with the fact that you’ll never have a fishy aftertaste with a C15:0 supplement (because it is not derived from fish), and the winner is C15:0.

Since the initial publication in Nature’s Scientific Reports in 2020, there are now over 100 peer-reviewed studies to support the essentiality and broad health benefits of C15:0. In fact, C15:0 is so essential for our cells, that not having enough of it places us at risk of developing Cellular Fragility Syndrome.

Cellular Fragility Syndrome

Low levels of C15:0 lead to fragile cells that are associated with accelerated aging and can be a risk factor for developing chronic metabolic, heart, and liver conditions. This nutritional deficiency is thought to affect as many as one in three people globally. 

As published in the scientific journal Metabolites, Cellular Fragility Syndrome is also directly linked to ferroptosis, a type of cell death discovered by Columbia University researchers in 2012, which causes negative health outcomes like NAFLD, heart disease, and diabetes. 

Thankfully, C15:0 nutritional deficiencies and Cellular Fragility Syndrome can be prevented by increasing a person’s circulating levels of C15:0. 

Getting More C15:0

Getting more C15:0 in your diet can be accomplished through dietary changes and/or by taking a supplement. Unfortunately, getting enough C15:0 through food alone may not be the ideal solution. C15:0 is only found in trace amounts in whole-fat dairy products like full-fat butter and whole milk, and many of us gave up whole milk back in the 90s when the war on fat hit full tilt. 

There are a few additional reasons why it may be difficult to get your C15:0 from diet alone:

• Absorption is a problem. In milk (and other foods), C15:0 is attached to branches of lipids called triacylglycerides, aka triglycerides. That means our gut has to use digestive enzymes to break down these triacylglycerides to release C15:0 as a free fatty acid. Once C15:0 is released, it is ready to be absorbed. These multiple steps can make our absorption of C15:0 from foods less efficient. 

• It’s mixed with bad fats. While the good C15:0 fatty acid is present in whole-fat dairy products in trace levels, there are much higher levels of 'bad' even-chain saturated fatty acids that continue to be associated with poorer health. This is one reason why there’s such a huge debate over whether whole dairy is good for us or bad for us. 

• It involves cows and excess calories. Whole-fat dairy products provide a wallop of calories, including sugars (aka lactose), that also require cows. If you’re vegan, you should know that plant-based milks contain no C15:0 whatsoever. 

A solution? Fatty15. 

Fatty15

Fatty15 is the first and only supplement that contains the pure, vegan-friendly version of C15:0. It is sustainably sourced, contains only one calorie, and nothing else. It is already in free fatty acid form to make digestion and absorption a breeze, and it doesn’t contain any bad fats. It is the easiest way to elevate your long-term health and support your longevity without feeling fishy.

Say No to Anchovies

Anchovies on pizza? That’s debatable. But in supplements, stick to fatty15. Avoid the fishy breath and enjoy more cellular benefits than you would with fish oil or krill oil. Your cells (and your friends) will thank you. 

Sources:

Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations--a comparative bioavailability study of fish oil vs. krill oil | PubMed

Evaluation of the effects of Neptune Krill Oil on the clinical course of hyperlipidemia | PubMed

Efficacy of dietary odd-chain saturated fatty acid pentadecanoic acid parallels broad associated health benefits in humans: could it be essential? | Scientific Reports

A review of odd-chain fatty acid metabolism and the role of pentadecanoic Acid (c15:0) and heptadecanoic Acid (c17:0) in health and disease | PubMed

Effect of an Asian-adapted Mediterranean diet and pentadecanoic acid on fatty liver disease: the TANGO randomized controlled trial | ScienceDirect

Hallmarks of aging: An expanding universe | PubMed

Pentadecanoic Acid (C15:0), an Essential Fatty Acid, Shares Clinically Relevant Cell-Based Activities with Leading Longevity-Enhancing Compounds

The Cellular Stability Hypothesis: Evidence of Ferroptosis and Accelerated Aging-Associated Diseases as Newly Identified Nutritional Pentadecanoic Acid (C15:0) Deficiency Syndrome

Broader and safer clinically-relevant activities of pentadecanoic acid compared to omega-3: Evaluation of an emerging essential fatty acid across twelve primary human cell-based disease systems | PLOS One