# Omega-3 Fatty Acids and Cancer: A 25-Year Map of the Research Landscape (2000–2025)

This study mapped 25 years (2000–2025) of global research on omega-3 fatty acids in cancer, analyzing 2,917 publications from the Web of Science database and 7,380 from Scopus. The researchers found that this field has grown from basic laboratory science into a clinically focused area, with the United States, China, and Italy leading publication output. Major themes include inflammation, breast and colorectal cancer, and how omega-3s may help cancer treatment. The authors conclude that the field is shifting toward "precision nutritional oncology," where omega-3s are tested as targeted, individualized additions to cancer therapy.

# Omega-3 Fatty Acids and Cancer: A 25-Year Map of the Research Landscape (2000–2025)

*This patient-friendly article explains how researchers used bibliometric analysis (a method of counting and mapping scientific publications) to understand the entire field of omega-3 and cancer research.*

## Table of Contents

- Key Points
- Why This Research Matters
- What Are Omega-3 Fatty Acids?
- What This Study Set Out to Do
- Study Methods: How the Research Was Conducted
- Key Finding 1: Publication Trends Over 25 Years
- Key Finding 2: Which Countries and Institutions Led the Field
- Key Finding 3: The Journals That Published This Research
- Key Finding 4: The Most Influential Papers
- Key Finding 5: Main Research Themes and Hotspots
- Key Finding 6: The Clinical Trial Landscape
- Clinical Implications: What This Means for Patients
- Limitations: What This Study Could Not Prove
- Recommendations for the Future
- Frequently Asked Questions
- Source Information

## Key Points

- The review mapped over 2,900 omega-3 and cancer publications from 2000 to 2025, showing growth into a stable clinical research field.
- The United States, China, and Italy led publication output; breast and colorectal cancers were the most studied tumor types.
- Clinical trials mainly test omega-3s as supportive cancer therapy, often combined with chemotherapy, radiation, or surgery.
- Most research explores antitumor mechanisms, inflammation, and whether omega-3 intake or blood levels alter cancer risk.
- The field is moving toward precision nutritional oncology, tailoring omega-3 dose, form, and timing to individual cancer patients.

## Why This Research Matters

Cancer remains one of the world's most serious public health challenges. According to the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC), roughly 19.965 million new cancer cases were diagnosed worldwide in 2022 — that's about 1 in 400 people on Earth that year. The disease caused about 9.737 million deaths, or approximately 1 in 820 people.

The future looks even more daunting. By 2050, researchers project that the number of newly diagnosed cancer cases worldwide will exceed 35 million.

Current treatments include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. Yet these approaches have real limits. Chemotherapy and targeted drugs often stop working because tumors develop drug resistance, which is a major cause of treatment failure and cancer recurrence. Anticancer drugs also frequently cause severe side effects, including fatigue, nausea and vomiting, loss of appetite, nerve damage (neurotoxicity), and blood clots (thrombosis). These reactions can seriously damage a patient's quality of life.

This is why doctors and scientists are urgently looking for **adjunctive strategies** (extra treatments that work alongside standard cancer care) to reduce side effects and improve outcomes. Among these, nutritional interventions with anti-inflammatory and immune-modulating properties have attracted growing attention. Omega-3 polyunsaturated fatty acids sit at the center of this interest.

## What Are Omega-3 Fatty Acids?

Omega-3 polyunsaturated fatty acids (PUFAs) are a family of unsaturated fats. Their name comes from their chemistry: the first double bond in their carbon chain appears at the third carbon atom from the methyl (omega) end of the molecule. That small structural detail changes how these fats behave in the human body.

In nutrition and cancer research, three omega-3s matter most:

-
**Alpha-linolenic acid (ALA)** — an essential fatty acid your body cannot make. You must get it through diet. It comes mainly from nuts and plant oils, including chia seed oil, walnut oil, flaxseed oil, and hemp seed oil.
-
**Eicosapentaenoic acid (EPA)** — a longer-chain omega-3 found mainly in fatty fish, seafood, and algal oils.
-
**Docosahexaenoic acid (DHA)** — also found in fatty fish, seafood, and algal oils; it is especially important for brain and eye tissue.

Your body can convert ALA into EPA and DHA through a series of chemical reactions, but this conversion is inefficient. That's why eating fatty fish directly remains the main way humans get meaningful amounts of EPA and DHA.

Omega-3s have an impressive resume of health effects. In the cardiovascular system, they act as anti-inflammatory, vasodilatory (blood vessel-widening), antiarrhythmic (heart rhythm-stabilizing), antihypertensive (blood pressure-lowering), anticoagulant (clot-preventing), and triglyceride-lowering agents. In the nervous system, they are structural components of nerve cell membranes, where they support membrane fluidity, help regulate oxidative stress, dampen inflammation, and protect neurons. During pregnancy, adequate omega-3 intake supports fetal brain and retinal development and reduces the risk of adverse pregnancy outcomes. Omega-3s have also been studied in chronic inflammatory conditions such as asthma, psoriasis, inflammatory bowel disease, rheumatoid arthritis, and diabetes. Some emerging evidence even links omega-3s to biological aging through effects on inflammation and epigenetic regulation (chemical changes that switch genes on or off).

Why might this matter for cancer? Cancer development is closely tied to chronic inflammation, oxidative stress, metabolic disruption, immune dysfunction, epigenetic changes, and altered cell signaling. Omega-3s speak to nearly all of these processes. Laboratory (preclinical) studies suggest omega-3s may slow tumor growth through several mechanisms — inducing apoptosis (programmed cell death), regulating lipid (fat) metabolism, modifying epigenetic signals, modulating immune responses, and remodeling the tumor microenvironment (the surrounding tissue that supports or suppresses tumor growth). Clinical studies have explored whether omega-3s can improve quality of life in patients with cancer cachexia (severe weight loss and muscle wasting), enhance chemotherapy sensitivity, and reduce treatment-related side effects.

## What This Study Set Out to Do

Despite all this research, the omega-3-and-cancer field is fragmented. Studies span basic mechanisms, population epidemiology, biomarker assessments, nutritional interventions, perioperative immunonutrition (giving immune-supporting nutrition around the time of surgery), and combinations with anticancer drugs.

The researchers wanted to step back and see the whole picture. They used a technique called **bibliometrics** — quantitative analysis of publications, citations, and keyword patterns — to systematically map the field from January 2000 to December 2025. Their goal was to identify research trends, knowledge hotspots, and emerging themes, and ultimately to provide evidence-based direction for future laboratory research, nutritional oncology, and clinical practice.

## Study Methods: How the Research Was Conducted

The research team searched three major scientific databases on December 15, 2025: the Web of Science Core Collection (WoSCC), Scopus, and PubMed.

Their search strategy combined two concept groups. The cancer side included terms like "cancer," "tumor," "oncology," "neoplasm," and "carcinoma." The omega-3 side included "omega-3 PUFA," "omega-3 fatty acid," "n-3 PUFA," and related spellings. They limited results to English-language articles and reviews published between 2000 and 2025. For PubMed, they additionally filtered for clinical trials.

After removing duplicates, the WoSCC database yielded **2,917 publications**. Scopus yielded **7,380 distinct records**. Because WoSCC and Scopus format data differently, the researchers analyzed each database separately to avoid information loss. They treated WoSCC as the primary source for detailed analyses because of its standardized records and compatibility with bibliometric software. Scopus data served as a complement, and its keyword analyses appear in the article's supplementary materials.

For the analysis, they used four main software tools:

-
**R software (version 4.5.2)** with the bibliometrix package (version 4.0) — for general bibliometric calculations
-
**VOSviewer (version 1.6.20)** — for mapping collaboration networks between countries and institutions, and for journal/keyword patterns
-
**CiteSpace (version 6.4.R1)** — for detecting citation bursts (papers that suddenly receive intense attention)
-
**Origin 2018** — for evaluating annual publication trends

Two researchers independently performed the data collection and analysis to confirm accuracy and reliability, with a third consulted to resolve any disagreements. Journal impact factors (which measure how often articles in a journal are cited) came from the 2024 edition of the Journal Citation Reports.

Some thresholds were set to keep the maps readable. Countries had to contribute at least 5 documents, organizations at least 10 papers, journals at least 300 citations, and keywords had to appear at least 28 times (in WoSCC) or 23 times (in Scopus). Generic search terms like "omega-3 PUFAs" and "cancer" were deliberately excluded from keyword maps. The researchers reasoned that these words would appear so often — simply because of the search strategy itself — that they would drown out meaningful thematic signals.

## Key Finding 1: Publication Trends Over 25 Years

Between 2000 and 2025, the annual number of publications on omega-3s and cancer increased steadily over time. The field then reached a plateau and experienced a slight decline in the most recent years. There was a notable peak around **2018**.

Both databases told the same story. The WoSCC data showed 2,917 total publications; the Scopus data showed 7,380. The researchers interpreted this pattern to mean that omega-3 cancer research has received sustained attention and settled into a stable research field — not a passing fad.

## Key Finding 2: Which Countries and Institutions Led the Field

The **United States** emerged as the clear global leader in omega-3 cancer research, contributing 819 publications — about 28.1% of corresponding-author papers. **China** ranked second with 391 publications (13.4%), and **Italy** third with 171 (5.9%). Canada (170), Japan (133), and the United Kingdom (122) followed closely.

The researchers also tracked **multiple country publications (MCPs)** — papers written by authors from more than one country. The United States and China produced similar rates of international collaboration: 18.6% and 17.9% of their papers, respectively. But Denmark, Germany, and Korea, despite publishing fewer papers overall, achieved notably higher collaboration rates of **45.5%, 36.9%, and 31.5%**, respectively.

The table below shows the full country-by-country breakdown from the study:

Country
Articles
Single-Country Papers (SCP)
Multi-Country Papers (MCP)
Frequency (%)
MCP Rate (%)

USA
819
667
152
28.1
18.6

China
391
321
70
13.4
17.9

Italy
171
137
34
5.9
19.9

Canada
170
132
38
5.8
22.4

Japan
133
122
11
4.6
8.3

United Kingdom
122
87
35
4.2
28.7

Korea
92
63
29
3.2
31.5

France
91
68
23
3.1
25.3

Brazil
84
66
18
2.9
21.4

Spain
72
57
15
2.5
20.8

Germany
65
41
24
2.2
36.9

Australia
64
47
17
2.2
26.6

India
63
49
14
2.2
22.2

Iran
60
44
16
2.1
26.7

Norway
45
32
13
1.5
28.9

Denmark
44
24
20
1.5
45.5

Netherlands
40
26
14
1.4
35.0

Poland
40
36
4
1.4
10.0

Egypt
29
22
7
1.0
24.1

Sweden
25
16
9
0.9
36.0

Portugal
20
16
4
0.7
20.0

Greece
17
13
4
0.6
23.5

Mexico
16
11
5
0.5
31.3

Switzerland
16
11
5
0.5
31.3

Turkey
16
12
4
0.5
25.0

The United States also maintained the most extensive international collaboration network — the map showed strong links between US researchers and teams across Europe, Asia, and the Americas.

At the institutional level, core contributing centers emerged. Harvard University led with 88 publications, followed by Brigham and Women's Hospital (61), Texas A&M University (58), Harvard Medical School (57), and the University of Alberta (55). Other active institutions included Massachusetts General Hospital (48), the Harvard T.H. Chan School of Public Health (45), the University of Southampton (38), the University of Illinois (36), and The Ohio State University (34). The study's conclusion was that influence in this field comes not just from publishing many papers but also from being deeply connected in collaborative networks.

## Key Finding 3: The Journals That Published This Research

All 2,917 WoSCC publications appeared across **869 different journals**. That's a highly scattered field — no single journal dominates.

The most productive journals by article count were:

-
**Nutrients**: 98 articles — impact factor (IF) 5.0
-
**Nutrition and Cancer-An International Journal**: 83 articles — IF 2.4
-
**Journal of Nutritional Biochemistry**: 66 articles — IF 4.9

But publication count tells only half the story. Citation counts reveal which journals carry the most weight. By citations received, the leaders were:

-
**American Journal of Clinical Nutrition**: 5,299 citations (IF 6.9, from 50 documents)
-
**Cancer Research**: 3,376 citations (IF 16.9, from 19 documents)
-
**Journal of Nutrition**: 3,177 citations (IF 3.8, from 59 documents)
-
**Journal of Biological Chemistry**: 2,813 citations (IF 3.9, from 7 documents)

A co-citation analysis (which looks at which journals are cited together) identified the American Journal of Clinical Nutrition, Cancer Research, International Journal of Cancer, and Nutrients as the core journals forming the intellectual backbone of this field.

The researchers noted a revealing gap: relatively few papers appeared in the highest-impact journals. They called this a "publication gap in high-impact journals" and framed it as both a weakness and an opportunity. Raising the methodological quality of future studies could help the field earn space in more prestigious venues.

## Key Finding 4: The Most Influential Papers

Citation bursts are periods when a particular paper suddenly gets cited far more often than usual. They act like seismographs for scientific attention. The researchers identified the **25 strongest citation bursts** in omega-3 cancer research.

The three most intense bursts were:

1.
**"Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries"** — burst strength 33.61
1.
**"Dietary Long-Chain Omega-3 PUFAs for the Prevention of Cancer: A Review of Potential Mechanisms"** — burst strength 33.11
1.
**"Effects of Omega-3 Fatty Acids on Cancer Risk: A Systematic Review"** — burst strength 25.24

The most recent papers experiencing rising citation activity point to where the field is heading. These include **"Omega-3 Fatty Acids and Inflammatory Processes: From Molecules to Man,"** **"Protective Effects of Omega-3 Fatty Acids in Cancer-Related Complications,"** and the GLOBOCAN 2020 statistics paper.

Looking across all the burst patterns, the researchers identified three core research directions:

1.
**Multi-target anticancer mechanisms** — how omega-3s work at the molecular level through lipid metabolism, inflammatory signaling pathways, and programmed cell death (apoptosis)
1.
**Epidemiological significance** — how dietary omega-3 intake and blood/tissue levels relate to the risk of cancer and other chronic diseases, with fatty acid balance viewed as a key dietary factor in disease risk
1.
**Translational application in clinical cancer care** — how omega-3s can be used to support patients undergoing cancer treatment

## Key Finding 5: Main Research Themes and Hotspots

Keyword co-occurrence analysis (which counts how often terms appear together in papers) revealed the intellectual terrain of the field. The major research themes were:

- "inflammation"
- "breast cancer"
- "risk"
- "colorectal cancer"
- "expression" (referring to gene or protein expression in laboratory studies)

**Antitumor mechanisms** were the dominant focus. In plain terms, the largest share of research investigated how omega-3s attack cancer at the cellular level.

A second major theme connected **dietary omega-3 intake and biomarker status** (objective measures of omega-3 levels in the body) with cancer risk and cancer progression. These studies ask a practical question: does what you eat — or what's measurable in your blood — change your cancer risk?

A third, rapidly growing theme was the **application of omega-3s in actual clinical antitumor therapy**. The keyword data suggest this translational direction has emerged as a prominent hotspot in recent years.

## Key Finding 6: The Clinical Trial Landscape

The researchers also screened PubMed for clinical trial records published between 2000 and 2025, using the same search logic. Two independent reviewers examined titles, abstracts, and keywords to identify trials genuinely testing omega-3s against cancer.

The clinical trial picture showed two clear patterns. First, trials have **primarily focused on antitumor applications** — meaning most trials ask whether omega-3s can fight cancer itself or support cancer treatment, rather than just prevent the disease. Second, there is a clear **tendency toward combined treatment strategies** — omega-3s tested alongside chemotherapy, radiation, surgery, or other therapies.

## Clinical Implications: What This Means for Patients

This is a mapping study, not a clinical trial, so it does not directly prove that omega-3s help any particular patient. But the patterns it reveals carry practical meaning.

First, the field has clearly moved past the question of whether omega-3s might fight cancer in a petri dish. Funding, publications, and clinical trials are now concentrated on **real-world use**: omega-3s as supportive care, as chemotherapy sensitizers, and as an anti-inflammatory tool in patients living with cancer.

Second, the emphasis on "inflammation," "breast cancer," "colorectal cancer," and "risk" tells patients that the most mature evidence clusters in specific areas. Breast and colorectal cancers are the two tumor types where omega-3 research has accumulated the most depth. For patients with these cancers, discussions about omega-3 supplementation are more likely to be grounded in solid data.

Third, the movement toward "precision nutritional oncology" means the future is not about giving everyone the same fish oil pill. The authors describe a framework that combines molecular mechanisms, objective exposure biomarkers (measuring actual omega-3 levels in blood or tissues rather than relying on dietary memory), and clinical intervention strategies. In this future, a patient's omega-3 dose, form (EPA-dominant vs. DHA-dominant vs. ALA), and timing of treatment would be tailored to their specific cancer type, treatment plan, and nutritional status.

The researchers' conclusions are about the structure of science, but the purpose is ultimately patient care: identify which patients actually benefit, at what dose, for how long, and during which phase of treatment.

## Limitations: What This Study Could Not Prove

Several important limitations apply to this bibliometric study.

**Bibliometric studies describe the literature; they do not test treatments.** The citation counts, keyword maps, and burst analyses show where scientists have focused their attention, not whether omega-3s actually improve cancer outcomes. High research activity can reflect funding trends, scientific fashion, or controversy just as easily as it reflects proven benefit.

**The search was restricted to English-language articles and reviews.** Important work published in Chinese, Spanish, German, or other languages would have been missed. Given that China is the second-largest publishing country in this field, English-only searching could skew the picture.

**The two largest databases could not be merged** because of format differences. The researchers analyzed WoSCC and Scopus separately to avoid losing data, but this means the headline numbers (2,917 and 7,380) come from two parallel universes rather than one integrated dataset.

**The citation burst method lags reality.** The three strongest bursts all related to papers published around 2020 or earlier. Very recent work, however important, has not yet had time to accumulate citations.

**Keyword exclusion rules shaped the results.** The researchers removed generic terms like "omega-3 PUFAs" and "cancer" and set high frequency thresholds. Different thresholds could have produced different thematic maps.

**Journal impact factors measure journals, not individual articles.** A paper in a low-impact journal may be practice-changing, while a paper in a high-impact journal may be ignored.

Finally, affiliation analysis tracks where authors are based, not where the research was conducted or funded. Institutional prestige (like Harvard's eight-affiliation presence in the top 20) can be amplified by well-resourced centers that host many international collaborators.

## Recommendations for the Future

Based on the gaps they identified, the authors recommend that future research focus on five key areas:

1.
**Standardized exposure assessment** — develop and adopt consistent methods for measuring omega-3 intake and tissue levels so studies can be compared directly
1.
**Dose–response modeling** — define how much omega-3 is needed to produce a biological or clinical effect, and whether more is better
1.
**Patient stratification** — identify which subgroups of patients (by cancer type, genetics, treatment regimen, or nutritional status) are most likely to benefit
1.
**Clinically meaningful endpoints** — measure outcomes that matter to patients, like survival, quality of life, and treatment tolerance, not just laboratory markers
1.
**Precision trial design** — define target populations, optimal formulations and dosages, and appropriate intervention windows (for example, before surgery, during chemotherapy, or after treatment concludes)

In their own words: research on omega-3 PUFAs in oncology is "progressively shifting from mechanistic exploration toward clinically oriented and translational applications." The emerging vision is a precision-oriented nutritional oncology, where omega-3s are deployed deliberately — to the right patient, at the right dose, at the right time.

What does this mean for patients reading this today? Speak with your oncology care team before starting any omega-3 supplement. The evidence base is promising but still maturing, and the unanswered questions in this map — dose, timing, and who benefits most — are exactly the questions your doctor needs answered before making a recommendation.

## Frequently Asked Questions

### Does omega-3 really help fight cancer, based on this 25-year research review?

In laboratory studies, omega-3s slowed tumor growth through several mechanisms, including inducing cell death and reducing inflammation. Clinical trials mainly explore omega-3s as supportive care alongside chemotherapy, radiation, or surgery. This mapping study describes research patterns; it does not prove that omega-3s improve outcomes for any specific patient.

### Which cancers had the most omega-3 research, and should patients with other cancers use omega-3s?

The most mature evidence clusters around breast cancer and colorectal cancer. Other cancer types have less published research. This article does not say whether omega-3s help other cancers. Patients should ask their oncology team about evidence for their specific cancer type before considering omega-3 supplements.

### I am having chemotherapy. Is it safe to take omega-3 supplements?

Omega-3s are being tested as chemotherapy sensitizers and to reduce side effects, but optimal dose, timing, and which patients benefit remain unanswered questions. This review did not establish safety or effectiveness. Consult your oncology care team before starting any supplement, especially during active cancer treatment.

### What does 'precision nutritional oncology' mean for patients?

Instead of giving everyone the same fish oil pill, future care would tailor omega-3 dose, form, and timing to a patient's cancer type, treatment plan, and measured blood or tissue omega-3 levels. This approach is still emerging and not yet a standard part of patient care.

### Is omega-3 meant to prevent cancer or treat it?

The review found that clinical trials have primarily focused on antitumor applications, meaning using omega-3s to fight cancer or support cancer treatment, rather than only preventing disease. Many trials test omega-3s combined with chemotherapy, radiation, or surgery. More research is still needed.

### What were the main limitations of this omega-3 cancer research overview?

This was a bibliometric study, meaning it mapped publications and citations; it did not test treatments. The search was English-only, separated two databases, and citation bursts lag behind new work. High research activity can reflect funding trends, not proven benefit. Always interpret findings with your doctor.

### Should I get a second opinion before taking omega-3 supplements during cancer treatment?

No single answer applies to everyone. Because omega-3 research is still maturing, the right dose, form (EPA vs DHA vs ALA), and timing during chemotherapy, radiation, or surgery remain unsettled. The strongest evidence clusters around breast and colorectal cancer, but even there the decision to supplement is not precision-based yet. Before taking omega-3s during cancer treatment, a second opinion can help clarify whether supplementation is appropriate for your specific cancer type, treatment phase, and nutritional status. Diagnostic Detectives Network provides independent expert second opinions.

## Source Information

**Original article:** "Bibliometric and visual analysis of omega-3 polyunsaturated fatty acids in cancer research (2000–2025)"

**Authors:** Gao C, Li Y, Su H, Yu X, Lu X, Liang X, Tao F, Duan X.

**Affiliations:** Department of Clinical Nutrition, Department of Oncology, and Department of Radiation Oncology, Liaocheng People's Hospital, Liaocheng, China

**Journal:** Frontiers in Nutrition, Volume 13, Article 1818038

**Publication date:** July 8, 2026

**DOI:** 10.3389/fnut.2026.1818038

**Article type:** Systematic Review (open access, licensed under CC BY)

*Note: This patient-friendly article is based on peer-reviewed research. It is intended for educational purposes and does not constitute medical advice. Always consult your healthcare provider about diet and supplement decisions, especially during cancer treatment.*


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