Which omega-3 is best for dry eye disease.

Omega‑3 for Dry Eye: What It Is, How It Works, and Whether Fish Oil or Plant‑Based Oils Work Better

Dry eye disease is one of the most common complaints in eye care, and omega‑3 fatty acids are often recommended as part of treatment. But not all omega‑3s are the same—and not all sources have the same evidence behind them. This post breaks down what omega‑3s are, how they reduce inflammation, the top food sources, and what the research says about fish‑based vs. plant‑based omega‑3s for dry eye relief.

What Are Omega‑3 Fatty Acids?

Omega‑3 fatty acids are essential polyunsaturated fats that the body cannot produce on its own. They must be obtained from food or supplements. There are three main types:

• ALA (alpha‑linolenic acid) – found in plant oils

• EPA (eicosapentaenoic acid) – found in fish and seafood

• DHA (docosahexaenoic acid) – found in fish and seafood

Plant‑based omega‑3s (ALA) must be converted into EPA and DHA, but humans convert only a small percentage. This is why fish‑derived omega‑3s are considered more biologically active.

How Omega‑3s Reduce Inflammation

Omega‑3s reduce inflammation by altering the body’s production of eicosanoids, the signaling molecules that regulate inflammatory responses. EPA and DHA shift the balance toward anti‑inflammatory mediators, helping calm chronic inflammation that contributes to dry eye disease  

This anti‑inflammatory mechanism is one reason omega‑3s have been studied extensively for ocular surface disease.

Top 10 Foods Highest in Omega‑3

Based on current nutrition data from Verywell Health, WebMD, and Real Simple, here are the foods richest in omega‑3 fatty acids:

Rank Food Approximate Omega‑3 Content

1 Salmon (wild Atlantic) ~1.3 g per 3 oz (EPA + DHA)

2 Mackerel Very high in EPA + DHA

3 Sardines High in EPA + DHA

4 Herring High in EPA + DHA

5 Anchovies High in EPA + DHA

6 Chia seeds High in ALA

7 Flaxseed / flax oil High in ALA

8 Walnuts High in ALA

9 Soybeans / tofu Moderate ALA

10 Canola oil Moderate ALA

Fish and seafood dominate the list because they contain EPA and DHA directly, while plant foods contain ALA.

Fish Oil vs. Plant‑Based Omega‑3 for Dry Eye: What the Evidence Shows

Dry eye research overwhelmingly focuses on fish‑derived EPA/DHA, not plant‑based ALA. Here’s what the evidence says:

1. Evidence Supporting Fish‑Derived Omega‑3 (EPA/DHA)

Positive Findings

A 2023 systematic review and meta‑analysis of randomized controlled trials found that omega‑3 supplementation improved dry eye symptoms and some objective measures, though results varied across studies (see references below).

Clinical reviews also note that several trials show improvements in lubrication, tear quality, and inflammation with fish‑oil supplementation Verywell Health.

Neutral/Negative Findings

The largest and most rigorous trial—the NIH‑funded DREAM Trial—found no significant difference between high‑dose fish oil (3 g/day EPA+DHA) and placebo for dry eye symptoms or signs over 12 months. The reason why a lot of eye doctors and surgeons recommend omega-3 is because publications demonstrate a decrease of inflammation in the whole body. So even though a lot of patients might not feel improvement with her omega 3 in their dry eye disease, the decreased inflammation of their body has an overall positive effect on decreasing whole body inflammation. And because the meibomian gland cells and the lacrimal gland cells and the goblet cells are so sensitive to overall body inflammation, anything to decrease systemic inflammation is likely to have a long-term benefit.  (See **below)

Interpretation

• Smaller RCTs: often positive

• Large RCT (DREAM): negative

• Meta‑analysis: modest overall benefit

This means fish oil may help some patients, but it is not universally effective.

2. Evidence for Plant‑Based Omega‑3 (ALA, e.g., flax, chia, Udo’s Oil)

What the research shows

• Plant oils provide ALA, which must be converted to EPA/DHA.

• Human conversion is low, limiting anti‑inflammatory impact WebMD.

• There are no major randomized controlled trials showing that ALA‑dominant oils (including Udo’s Oil) improve dry eye.

• Reviews mention plant omega‑3s only as general dietary sources—not as proven dry eye treatments.

Interpretation

Plant‑based omega‑3s are healthy, but not supported by dry eye–specific clinical evidence.

Comparison Chart: Fish Oil vs. Plant‑Based Omega‑3 for Dry Eye

Feature Fish Oil (EPA/DHA) Plant‑Based Oils (ALA, e.g., Udo’s Oil)

Main omega‑3 type EPA + DHA ALA

Conversion needed? No Yes → low conversion

Dry eye RCTs available? Many Very few / none

Evidence of improvement? Mixed (some positive, DREAM negative) Not demonstrated

Anti‑inflammatory strength Strong Weaker

Best for dry eye? Yes—based on current evidence Not supported by trials

Bottom Line

• Omega‑3s reduce inflammation and may help dry eye, but EPA/DHA from fish oil has the strongest evidence.

• Plant‑based omega‑3s (ALA) are healthy but not proven to improve dry eye.

• Even fish oil is not a guaranteed fix—results vary, and the DREAM trial showed no benefit.

• For patients seeking evidence‑based supplementation, fish‑derived EPA/DHA remains the better‑supported choice.

References

1. Verywell Health. 10 Foods High in Omega‑3 Verywell Health

2. Yahoo Health. Omega‑3‑Rich Foods and Bioactive Forms yahoo.com

3. Biology Insights. The Anti‑Inflammatory Effects of Omega‑3 Fatty Acids biologyinsig...

4. Real Simple. Foods High in Omega‑3s Real Simple

**

Below are the Key PubMed-indexed publications showing omega-3 reduces systemic (whole body) inflammation:

A. C-reactive protein (CRP / hs-CRP)

1. Ahmadi M, Askari VR, Shahri B, et al.

Omega‑3 fatty acids effectively mitigate high‑sensitivity C‑reactive protein (hs‑CRP) biomarker of inflammation in acute myocardial infarction patients: a randomized, double‑blind, placebo‑controlled clinical trial.

Naunyn Schmiedebergs Arch Pharmacol. 2024; Published online July 29, 2024.

doi:10.1007/s00210‑024‑03330‑1 Springer

2. Pan L, Zhou Y, Yin H, et al.

Omega‑3 polyunsaturated fatty acids can reduce C‑reactive protein in patients with cancer: a systematic review and meta‑analysis of randomized controlled trials.

Nutr Cancer. 2021;73(11):2254‑2264.

PMID: 34060403 Europe PMC

3. Amin Amlashi M, Payahoo A, Jafari Maskouni S, et al.

Dose‑dependent effects of omega‑3 polyunsaturated fatty acids on C‑reactive protein concentrations in cardiometabolic disorders: a dose–response meta‑analysis of randomized clinical trials.

Inflammopharmacology. 2025;33:2325‑2339.

doi:10.1007/s10787‑025‑01744‑8 Springer

4. Berlana D, Albertos R, Barquin R, et al.

Impact of omega‑3 fatty acid supplementation in parenteral nutrition on inflammatory markers and clinical outcomes in critically ill COVID‑19 patients: a randomized controlled trial.

Nutrients. 2024;16(18):3046.

doi:10.3390/nu16183046 MDPI

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B. CRP, prostaglandin E2 (PGE2), granulocyte/lymphocyte ratio

1. Elisia I, Yeung M, Kowalski S, et al.

Omega‑3 supplementation reduces C‑reactive protein, prostaglandin E2 and the granulocyte/lymphocyte ratio in heavy smokers: an open‑label randomized crossover trial.

Front Nutr. 2022;9:1051418.

doi:10.3389/fnut.2022.1051418 Frontiers

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2. Summary table by inflammatory molecule

Molecule / marker Evidence of reduction with omega‑3 Key PubMed‑indexed papers

hs‑CRP / CRP Significant reductions in acute MI, cancer, cardiometabolic disorders, and critically ill patients receiving omega‑3 (oral or parenteral) vs. control/placebo Springer +3 Ahmadi et al. 2024; Pan et al. 2021; Berlana et al. 2024; Amin Amlashi et al. 2025

PGE2 Decreased PGE2 levels in heavy smokers after omega‑3 supplementation in a randomized crossover design Frontiers Elisia et al. 2022

Granulocyte/lymphocyte ratio Reduced G/L ratio (a systemic inflammation marker) with omega‑3 in heavy smokers Frontiers Elisia et al. 2022