The Study
Omega 3 supplementation reduces C-reactive protein, prostaglandin E2 and the granulocyte/lymphocyte ratio in heavy smokers: An open-label randomized crossover trial
This study gave people who smoked a lot a special fish oil pill and saw that their body’s inflammation markers went down. But it didn’t test if they got less sick or lived longer — just that some blood numbers changed. So we know the pill changed those numbers, but we don’t know if it actually made them healthier in the long run.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if taking big fish oil pills daily for six months could reduce inflammation in people who smoke or used to smoke heavily.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 569 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — a 23% drop in CRP is similar to a powerful drug used to lower cancer risk, suggesting this could be meaningful for health.
- 2After six months, CRP (inflammation marker) dropped by 23%, PGE2 dropped by 20–30%, and immune cells shifted to less inflammatory types.
- 3These changes lasted six months after stopping the pills.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Nutrition
Year
2022
Authors
I. Elisia, Michelle Yeung, Sara Kowalski, J. Wong, Hossein Rafiei, R. Dyer, S. Atkar‐Khattra, Stephen Lam, G. Krystal
Related Content
Claims (6)
Higher consumption of omega-3 fatty acids from food leads to lower levels of prostaglandin E2 in humans.
In heavy smokers with high inflammation, taking 3.6 grams of omega-3 fatty acids daily for six months lowers plasma prostaglandin E2 levels by 20–30%. The degree of reduction is related to the amount of DHA in red blood cell membranes, but not to EPA levels.
Taking 3.6 grams of EPA and DHA daily for six months lowers blood levels of C-reactive protein by about 23% in heavy or former smokers with elevated inflammation, and this reduction remains for six months after stopping the supplement.
Taking 3.6 grams of omega-3 fatty acids daily for six months lowers the granulocyte-to-lymphocyte ratio in people who smoke heavily.
After stopping high-dose omega-3 supplements, DHA stays elevated in red blood cell membranes for six months in heavy smokers, but DHA in the blood returns to normal within one month.
Taking 3.6 grams of omega-3 fatty acids daily does not lower levels of several inflammatory markers in the blood of heavy smokers, but it does reduce two specific markers: CRP and PGE2.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.