Can omega-3 fats cause inflammation? New insights challenge conventional wisdom

November 1, 2025 •

3 min read

In mid-2025, a study published in the International Journal of Epidemiology reported that higher omega-3 levels were associated with an increase in certain inflammatory markers. This finding deviates from the conventional understanding that these fats are solely anti-inflammatory and prompts a closer look at whether can omega-3 fats cause inflammation under specific conditions or if the widely accepted view needs refinement.

Quick Summary

The interplay between omega-3 fatty acids and inflammation is more involved than traditionally understood. While often seen as anti-inflammatory, some studies indicate they might increase specific inflammatory biomarkers in certain situations. The critical element influencing the body's inflammatory state is the overall dietary balance of omega-6 to omega-3 fatty acids.

Key Points

A Complex Relationship: Recent research indicates that the connection between omega-3s and inflammation is more intricate than previously thought, with studies linking high levels to increases in certain inflammatory biomarkers.
Balance is Key: The ratio of omega-6 to omega-3 fatty acids is crucial; a high ratio, typical of Western diets, can promote a pro-inflammatory state.
High Intake May Have Risks: Excessive intake of omega-3s, often through supplements, might lead to a dysfunctional immune response or oxidative stress, suggesting that more is not always better.
Quality of Supplements is Paramount: Consuming oxidized or low-quality omega-3 supplements can potentially trigger inflammation, underscoring the importance of fresh, well-sourced products.
Source Smartly for Best Results: Prioritizing omega-3s from whole-food sources like fatty fish is generally superior to relying solely on supplements, offering a better nutrient profile and absorption.
EPA and DHA are Crucial: EPA and DHA, primarily from marine sources, are the most biologically active omega-3s for reducing inflammation and producing anti-inflammatory molecules like resolvins and protectins.

The Traditional View: Omega-3 as an Anti-Inflammatory Powerhouse

Omega-3 fatty acids have long been valued for their anti-inflammatory properties. This is largely due to EPA and DHA, long-chain omega-3s from marine sources. These omega-3s influence inflammation through several mechanisms. They can compete with the pro-inflammatory omega-6 fatty acid AA, reducing inflammatory compounds. Omega-3s also help resolve inflammation by producing specialized mediators. Additionally, they can impact gene pathways involved in inflammation. These actions contribute to the observed benefits of omega-3 supplementation in various inflammatory conditions.

New Research: Unpacking the Complex Link to Inflammation

Despite the established anti-inflammatory benefits, recent studies suggest a more complex relationship. A 2025 study, for instance, indicated that higher levels of both omega-3 and omega-6 were linked to increased GlycA, suggesting the connection is not a simple 'omega-3 good, omega-6 bad' scenario and calls for more extensive research. Furthermore, research from 2013 highlighted that high omega-3 intake might affect immune function.

The Critical Role of the Omega-6 to Omega-3 Ratio

The balance between omega-6 and omega-3 fatty acids is crucial for managing inflammation. A typical Western diet often has a high ratio (15:1 to 20:1) due to the use of omega-6-rich vegetable oils in processed foods, fostering inflammation. A healthier ratio, closer to 1:1 or 4:1, is recommended and can be achieved by increasing omega-3 intake and moderating omega-6.

Potential Triggers: Oxidized Supplements and High Intake

Oxidized omega-3 supplements can potentially promote inflammation rather than reduce it. Selecting quality supplements tested for freshness and purity is vital. While omega-3s are sometimes used therapeutically in higher amounts, excessive intake may lead to oxidative stress or interfere with immune responses. Regulatory bodies may provide guidance on daily intake.

Optimizing Your Fatty Acid Intake

To maximize the benefits of omega-3s and minimize potential drawbacks, prioritize a balanced diet.

How to Get Your Omega-3s

Include fatty fish like salmon about twice a week. Plant-based sources such as flaxseed, chia seeds, and walnuts provide ALA. Algal oil is a direct source of EPA and DHA for vegetarians/vegans. If considering supplements, choose reputable, tested brands.

Tips for Balancing Your Omega-6 Intake

Limit vegetable oils high in omega-6 like corn or sunflower oil. Opt for healthier fats such as olive or avocado oil. Reducing processed and fried foods also helps lower omega-6 intake.

Comparison: Food Sources vs. Supplements


Feature	Food Sources (e.g., Fatty Fish)	Omega-3 Supplements (e.g., Fish Oil)
Form	Natural EPA and DHA with other nutrients.	Concentrated EPA and DHA.
Absorption	Generally effective.	Can be effective, particularly for those with low fish intake.
Potential Contaminants	Risk (managed with recommended amounts).	Risk (mitigated by testing).
Oxidation	Low risk if stored/prepared well.	Risk if not handled properly.
Intake Amount	Variable.	Provides a consistent amount per serving.
Overall Balance	Supports natural balance.	Can lead to high omega-3 without addressing omega-6.

Conclusion: A Balanced Approach is Key

While omega-3s are beneficial, recent studies introduce more complexity. The question of whether can omega-3 fats cause inflammation appears to be linked primarily to factors like oxidized supplements or an unbalanced diet. Focusing on a healthy omega-6 to omega-3 ratio through whole foods like fatty fish and limiting processed fats is the recommended strategy. If using supplements, ensure quality and consider guidance on appropriate intake. The emerging evidence underscores the importance of a nuanced perspective and overall dietary harmony. {Link: NIH Office of Dietary Supplements https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/}

Frequently Asked Questions

Scientific understanding is evolving. While omega-3s' anti-inflammatory properties have been established by older studies, newer research, including a mid-2025 study, suggests a more complex relationship. Some inflammatory markers may increase at higher omega-3 levels, indicating a need for further investigation to fully understand these effects.

While an exact number is debated, a lower ratio is generally considered beneficial. The typical Western diet has a ratio around 15:1 or 20:1, while aiming for a ratio closer to 1:1 or 4:1 is often recommended for managing inflammation.

Yes, excessive intake can be problematic. Regulatory bodies may provide guidance on upper limits for daily intake. Exceeding recommended amounts may lead to issues such as oxidative stress, effects on immune function, or increased bleeding risk, particularly with blood-thinning medications.

Oxidized or rancid fish oil may have an unpleasant fishy taste, cause fishy burps, or stomach upset. To reduce this risk, select supplements from reputable brands that test for purity and freshness, and store them correctly.

Prioritizing whole foods like fatty fish for omega-3 intake is generally recommended due to a more complete nutrient profile and effective absorption. Supplements are a convenient option if dietary intake is insufficient, but choosing quality products is important.

EPA and DHA are long-chain omega-3 fatty acids found mainly in marine sources. Both are recognized for their anti-inflammatory effects and contribute to brain, heart, and immune health.

Good food sources include oily fish such as salmon, mackerel, and sardines, as well as nuts and seeds like walnuts, flaxseed, and chia seeds. Algal oil provides direct EPA and DHA and is suitable for vegetarians and vegans.