Want to live longer? Want a stronger immune system? Sharper brain? Less pain? A more balanced gut?
While the low-fat craze may have been a thing several years back, research is shedding light on the benefits of healthy fats, especially omega-3 fatty acids.
Omega 3s are essential nutrients and a critical part of any healthy diet, playing an essential role in cognition, immunity, heart health, and the gut. But if there’s one thing that can be a deterrent for taking omega-3s, it’s that sometimes their side effects aren’t so pleasant.
Although the side effects aren't a shoo-in for everyone who takes them, some people can experience digestive issues like diarrhea or constipation after taking them, though the reason remains somewhat of a mystery.
So, we’re diving into the issue: do omega-3s in supplement form come with a side of constipation, or can omega-3s alleviate constipation? Most research is diced, but we’re breaking down the truth behind the question. Keep reading to find out!
Key Takeaways
- Omega-3s typically don’t cause constipation; some people even notice smoother stools.
- If you do feel GI changes, check dose, form, oxidation, and what you’re taking it with.
- Hydration, fiber, magnesium, and timing often resolve minor tolerance issues.
- Choose fresh, high-quality omega-3—algal sources avoid fishy aftertaste.
What Are Omega-3s and Fish Oil?
Omega-3s have been the talk of the town for a while now, and there’s a good reason for it. They’re a class of essential fatty acids associated with a lengthy list of potential health benefits.
However, unlike certain compounds, your body can’t create omega-3 fatty acids on its own, so you must obtain them from diet or supplementation to ensure you’re meeting your needs.
And for people on a plant-based diet, meeting the requirements can be tough, as plant-based omega-3s aren’t readily converted into EPA and DHA, the two primary omega-3s.
The three main types of omega-3s we hear about are EPA, DHA, and ALA:
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Eicosapentaenoic Acid (EPA): EPA is a 20-carbon fatty acid found in cold-water oily fish, cod liver, algae oil, and krill oil. Your body can synthesize EPA in its original form. EPA and DHA offer the most health benefits of all omega-3s.
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Docosahexaenoic Acid (DHA): A 22-carbon fatty acid in oily fish, krill oil, algae oil, and fish oil supplements. DHA can be converted back to EPA to maintain balance if too much DHA is consumed.
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Alpha-linolenic Acid (ALA): A plant-based short-chain omega-3 that can be converted into longer-chained EPA and DHA. However, the process is relatively inefficient; less than 10% is converted into EPA/DHA.(1).
Although you’ll find several forms of omega-3s, EPA and DHA are the two active forms and are the most readily absorbed and utilized by the body.
While readily found in many plant foods, ALA can be converted to EPA and DHA, but the conversion process is inefficient and yields only small amounts.
Omega-3s are essential to many physiological functions and are incorporated in many body parts, with high concentrations in cell membranes, where they play a structural role in regulating viscosity and inflammation. (2).
They’re also a key component of fetal development, healthy aging, and the retina. And if that’s not enough, EPA and DHA are precursors to several metabolites that are potent lipid mediators that may be beneficial in preventing or treating several diseases. (3).
Omega 6 vs Omega 3
It’s important to realize that most people don’t get enough omega-3s in their diet. Most modern diets contain anywhere from a 20:1 or 30:1 ratio of omega-6 to omega-3 fatty acids. (4).
Omega-3s are anti-inflammatory, while omega-6s are pro-inflammatory, so a diet high in pro-inflammatory fats could be a problematic breeding ground for disease. Ideally, we want to aim for a 1:1 or 2:1 ratio of omega-6 to omega-3.
Does Fish Oil Cause Constipation: Fact Or Myth?
If you’ve ever taken an omega-3 supplement only to be hit with horrendous digestive issues, you can relate to this one. Although most often, omega-3s will cause diarrhea as opposed to constipation, backups aren’t unheard of.
Diarrhea is more common for people ingesting large amounts of omega-3s, as are other digestive symptoms like flatulence (5), while bloating or indigestion can also happen but tend to be less common than loose stools or smoother bowel movements.
Heartburn and gas may show up too, especially if taking fish oil supplements with food. Constipation is still possible in some people if gas and bloating contribute to a backup. But the frequency and severity of diarrhea may depend on the type of omega-3 you’re talking about.
Flax oil, for example, is a plant-based omega-3 that may have laxative effects at high doses and increase bowel movement frequency. (6).
If you experience diarrhea after taking an omega-3 fatty acid supplement, you may want to reconsider the type of supplement you’re taking and consider if you're taking too much fish oil. Reduce your dosage to see if it persists.
However, experiencing constipation from omega-3 supplements is often more related to a sudden change in diet, low fiber intake, or not drinking enough water than to the supplement itself, though other supplements or foods taken alongside it can also play a role.
Summary
Consuming fish oil tends to support smoother bowel movements and has been linked with a lower risk of constipation thanks to marine omega-3s such as DHA and EPA.
So, if you’re getting backed up after knocking back your supplements, consider what else could be causing them.
How They help: Omega-3s and Constipation
While omega-3s may not cause constipation, they can help to relieve it if you’re left dealing with a backup.
Because fats and oils are natural lubricants, they can help to get the ball rolling in the bathroom, but where constipation and bowel movements are concerned, omega-3s have a few clear advantages.
Intestinal alkaline phosphatase
Omega-3 fatty acids have been shown to increase the production of intestinal alkaline phosphatase (IAP). (7, 8).
IAP is essential for maintaining gut homeostasis and reducing inflammation in the intestines. Researchers have also found links between reduced IAP concentrations and digestive tract conditions like IBS. (9).
Antimicrobial properties
Omega-3s have inherent antimicrobial properties that may help prevent certain endotoxin-producing bacteria species from causing damage to the gut. (7).
Because endotoxins promote inflammation, blocking their build-up can help to mitigate intestinal inflammation and prevent effects like constipation.
Healthier gut flora
The health of your body starts with the health of your gut, and research shows that omega-3s can help balance gut health and promote a healthier gut composition. (10).
Clinical studies of people with IBS found that omega-3 supplementation resulted in a higher population of beneficial bacterial species and lower levels of harmful bacterial groups, promoting a more balanced and favorable microbiome. (7).
Other Health Benefits Of Omega-3s
On top of promoting better bowel movements, omega-3s also offer many health benefits for cardiovascular health, bone and joint health, eye health, brain function and more. Such as:
Decreases Inflammation
While there’s a long list of benefits for omega-3s, this one usually tops the charts. Their ability to reduce inflammation is a big one behind their popularity.
Although some degree of inflammation benefits the body by strengthening immune responses, chronic inflammation carries an increased risk for various diseases, such as rheumatoid arthritis, ulcerative colitis, and Crohn’s. (11).
Studies find that supplementing with omega-3s can decrease levels of C-reactive protein (CRP), IL-6, and TNF-a, which are all inflammatory markers. (12).
While omega-3s may help to relieve some symptoms of inflammatory conditions, curbing inflammation is also protective against chronic health conditions like heart disease, diabetes, and cancer. (13).
Boosts Mood
Research finds that boosting your intake of omega-3s may also bring big benefits when it comes to boosting mood and mental health. They find that people with a higher intake of omega-3 fatty acids have a lower risk of depression than people with a lower intake. (14).
One study even found that taking omega-3s decreased symptoms of anxiety by a whopping 20%. Omega-3s are also being researched for potential benefits for bipolar disorder and schizophrenia. (15-17).
Supports better brain health
Omega-3s, especially DHA, are critical for brain health, and thanks to their powerful anti-inflammatory properties, they may be beneficial for slowing cognitive decline. (18).
Some research suggests they may also improve blood flow to the brain, which is associated with better performance for cognitive tasks, a sharper memory, and a decreased risk of developing dementia. (19).
Promotes Heart Health and Blood Pressure
Heart disease is one of the leading causes of death worldwide - could something as simple as omega-3s help reduce your risk?
Studies show that increasing your intake of omega-3 fatty acids may help reduce several risk factors for heart disease and optimize heart health. It’s been shown to reduce inflammation, decrease triglycerides, and increase blood levels of 'good' HDL cholesterol. (20.)
Additionally, consuming omega-3-rich fatty fish three times a week may reduce diastolic blood pressure, another major risk factor for heart disease. (21).
Omega-3 fatty acids from fish oil may help lower triglyceride levels, which is important for heart health. In the United States, several prescription omega-3 products are FDA-approved to help lower very high triglyceride levels, according to the National Center for Complementary and Integrative Health. (27)
Maintains healthy bones and joints
Aging comes with some unwelcome side effects like arthritis, joint pain, and osteoporosis, but boosting your intake of omega-3s could offer protection against them.
Studies find that supplementing with omega-3 fatty acids can boost calcium absorption to increase bone strength and integrity and protect against bone loss and the risk of osteoporosis. (22).
Omega-3s also reduce inflammation, which may benefit people with arthritis and joint pain. (23).
Recommended Dosage of Fish Oil Daily
Although there is no official recommended daily intake for EPA and DHA individually, many health authorities suggest that around 250 mg per day of combined EPA and DHA is sufficient for healthy adults, primarily to support normal heart function. (24)
Recommended daily intakes have been set for ALA, the third Omega-3 fatty acid. They are 1,100 mg for women and 1,600 mg for men. (25)
Even if you consume EPA and DHA from oily fish or supplements, it's still important to include sources of ALA in your diet. ALA is an essential omega-3 fatty acid with its own recommended intake, while EPA and DHA have separate roles and recommendations.
Omega-3 supplements are generally well tolerated. The U.S. Food and Drug Administration recommends consuming no more than 5g of DHA and EPA a day combined. (25) Other sources suggest fish oil is likely safe for most people in doses of 3 grams or less daily, but taking more than 3 grams daily may increase the chance of bleeding.
Health Warnings: Low Blood Pressure and More
Fish oil can have some adverse effects and other symptoms. Taking high doses of fish oil may worsen existing conditions, such as bleeding disorders (it may delay blood clotting or cause a bleeding risk), low blood pressure, or liver disease. It may also impact blood sugar.
Certain types of omega 3 fatty acids may also be high in vitamin A, which can cause potential toxicity.
Speak to your healthcare provider before taking any dietary supplements if you're taking blood pressure lowering medications, blood thinners or if this applies to you. (26)
Bleeding Risk Examined...
High intakes of fish oil (EPA and DHA) may have a mild blood-thinning effect, which could increase bleeding risk in people taking anticoagulant or antiplatelet medications. However, evidence in healthy individuals does not show a significant increase in serious bleeding at typical supplement doses. (28)
Tip: Avoid Acid Reflux and Other Side Effects of Fish Oil
Splitting your dose into two, taken early morning and night, may help to reduce potential side effects like acid reflux. Taking it with food may also help to reduce any heart burn or indigestion caused by increased stomach acid.
How To Get Enough Omega-3s In Your Diet
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Meeting the recommended intake values for omega-3s is challenging for many people, especially if you don't like eating fish. And because plant-based omega-3s don’t have a great conversion rate, it can be tough to get on a vegan or vegetarian diet.
So, what’s the solution? Making a concerted effort to include foods high in omega-3s, but also using quality dietary supplements to fill in the gaps.
Performance Lab Omega-3 is the cleanest, purest source of omega-3s sourced directly from their original aquatic source, algae.
It’s free of chemicals, dyes, and contaminants that can come along with conventional fish oil supplements and is safe for people on all diets. Plus, you’re getting the optional 2:1 DHA to EPA ratio to support optimal brain health and balanced immune responses.
References
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- Lazzarin, N., et al. "Low-Dose Aspirin and Omega-3 Fatty Acids Improve Uterine Artery Blood Flow Velocity in Women with Recurrent Miscarriage Due to Impaired Uterine Perfusion." Fertility and Sterility, vol. 92, no. 1, 2009, pp. 296-300.
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- Ramos, C. I., et al. "The Short-Term Effects of Olive Oil and Flaxseed Oil for the Treatment of Constipation in Hemodialysis Patients." Journal of Renal Nutrition, vol. 25, no. 1, 2015, pp. 50-56.
- Costantini, L., et al. "Impact of Omega-3 Fatty Acids on the Gut Microbiota." International Journal of Molecular Sciences, vol. 18, no. 12, 2017, article 2645.
- Habib, T. B. "Useful Effects of Omega-3 Fatty Acids on Serum Alkaline Phosphatase and Gamma-Glutamyl-Transferase Levels in Middle Aged Patients with Diabetes Mellitus." Biomedical Research and Clinical Practice, vol. 6, no. 1, 2020, pp. 806-809.
- Bilski, J., et al. "The Role of Intestinal Alkaline Phosphatase in Inflammatory Disorders of Gastrointestinal Tract." Mediators of Inflammation, vol. 2017, 2017, article 9074601.
- Noriega, B. S., et al. "Understanding the Impact of Omega-3 Rich Diet on the Gut Microbiota." Case Reports in Medicine, vol. 2016, 2016, article 3089303.
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