Research

Hormonal

High-dose long-chain omega-3 supplementation (>4.4 g/day) may worsen glucose metabolism, including increasing the risk of diabetes diagnosis and raising HbA1c and fasting glucose.

If you are taking very high doses of omega-3 (more than 4.4 grams per day), be aware that this might negatively impact your blood sugar levels. While the evidence is not definitive, it suggests a potential risk of worsening glucose control at these high doses. Consult your doctor before maintaining such high doses.

ModerateQualifiesMEDIUM confidence
A suggestion of negative outcomes was observed when dose of supplemental long chain omega-3 was above 4.4 g/d.
Tracey Brown et al. · BMJ · 2019

Why this rating

Based on fewer trials at high doses, with wide confidence intervals, suggesting a 'suggestion' rather than definitive proof.

Source

Omega-3, omega-6, and total dietary polyunsaturated fat for prevention and treatment of type 2 diabetes mellitus: systematic review and meta-analysis of randomised controlled trials

Tracey Brown et al. · BMJ · 2019

DOI 10.1136/bmj.l4697

Meta-analysis · 83 studiesCited 315×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →