Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was reviewed?
This systematic review and meta-analysis examined fish intake cardiovascular risk relationships in prospective cohorts to produce policy-relevant quantitative estimates for fatal and non-fatal cardiovascular disease (CVD). Following PRISMA methods and PECO(ST) framing, the authors synthesized multivariable-adjusted relative risks for high versus low fish consumption, performed non-linear dose–response meta-regression, and explored heterogeneity by fish type and cooking method. The discussion explicitly considers whether benefits persist despite potential exposure to heavy metals and other pollutants in fish, a salient consideration for HTMC.
Who was reviewed?
The evidence base comprised 20 independent prospective cohort estimates drawn from Europe, the Asia-Pacific region, the USA, and multinational studies, totaling 1,442,407 adults with 18,926,486 person-years and 78,805 CVD events. Median participant age was 56.3 years with balanced sex representation across cohorts; follow-up ranged up to 24.6 years. Quality was appraised via the Newcastle–Ottawa Scale (median score 7/9), and analyses adjusted for major confounders such as age, smoking, physical activity, diet, and energy intake.
Most important findings
| Critical point | Details |
|---|---|
| Overall association | High vs. low fish intake was associated with an ~8% lower combined fatal and non-fatal CVD risk (RR 0.93, 95% CI 0.88–0.98), with non-fatal CVD ~5% lower (RR 0.95) and fatal CVD ~10% lower (RR 0.91). Figure 2 (p. 9) and Figure 3 (p. 10) visualize these pooled estimates; substantial heterogeneity decreased when restricting to higher-quality, energy-adjusted studies. |
| Dose–response pattern | The non-linear analysis (Figure 4, p. 11) shows a monotonic S-shaped decrease. 50 g/day corresponds to ~9% lower risk (RR 0.92), and two to three 150 g portions/week correspond to ~8% lower risk (RR 0.93). Intake of 100–150 g/day links to ~16–28% lower risk. |
| Fish type matters | Across studies reporting species categories, fatty fish intake related to a 12% lower CVD risk (RR 0.89); lean fish showed no reduction (RR 1.05). This supports a mechanistic role for EPA/DHA. |
| Cooking method matters | Fried fish intake was associated with a small but significant increase in CVD risk (~3%, RR 1.03), whereas non-fried fish did not show a clear association when pooled across limited studies. |
| Outcome-specific signals | Pooled risks for myocardial infarction and stroke were not statistically significant overall; however, stroke risk dropped ~9% after excluding one outlier cohort, suggesting potential sensitivity to study design. |
| Quality and heterogeneity | Excluding two lower-quality or discordant studies (with higher CVD at higher fish intake) strengthened the protective association to ~11% and reduced heterogeneity, indicating methodological drivers of between-study variance. |
| Relevance to contaminants | The discussion notes that observed cardiovascular benefits from fish likely outweigh potential adverse effects of heavy metals, toxic compounds, and microplastics commonly found in seafood, though other disease endpoints were not assessed here. |
Key implications
For HTMC, the fish intake cardiovascular risk evidence supports regulatory messaging that moderate fish consumption reduces CVD risk while emphasizing contaminant controls. Primary regulatory impacts include aligning serving guidance to two portions per week and prioritizing fatty fish with verified low heavy metals. Certification requirements should codify mercury and heavy metal limits, validated cooking guidance discouraging frequent deep-frying, and transparent labeling. Industry applications span sourcing protocols and product claims substantiated by dose–response data. Research gaps include contaminant–benefit trade-offs beyond CVD and preparation-specific risks. Practical recommendations favor verified low-metal fatty fish and non-fried preparation.
Citation
Ricci H, Gaeta M, Franchi C, Poli A, Battino M, Dolci A, Schmid D, Ricci C. Fish Intake in Relation to Fatal and Non-Fatal Cardiovascular Risk: A Systematic Review and Meta-Analysis of Cohort Studies. Nutrients. 2023;15(21):4539. doi:10.3390/nu15214539
