.png)
2 hours ago
2
Review
. 2025 Apr 28;8(2):395-407.
doi: 10.31662/jmaj.2024-0324. Epub 2025 Mar 21.
Affiliations
- PMID: 40416032
- PMCID: PMC12095860
- DOI: 10.31662/jmaj.2024-0324
Review
Satoru Yamada et al. JMA J. 2025.
Abstract
Background: The recommendation to limit dietary saturated fat intake is primarily drawn from observational studies rather than randomized controlled trials of cardiovascular disease prevention. Thus, we aimed to investigate the efficacy of saturated fat reduction in preventing mortality and cardiovascular diseases.
Methods: In this systematic review and meta-analysis of randomized controlled trials, Cochrane CENTRAL, PubMed, and Ichu-shi databases were searched for articles up to April 2023. Randomized controlled trials on saturated fat reduction to prevent cardiovascular diseases were selected. Cardiovascular and all-cause mortality and cardiovascular outcomes were evaluated. Changes in electrocardiography or coronary angiography findings were excluded because they could be evaluated arbitrarily. Two or more reviewers independently extracted and assessed the data. A random-effects meta-analysis was performed.
Results: Nine eligible trials with 13,532 participants were identified (2 were primary and 7 were secondary prevention studies). No significant differences in cardiovascular mortality (relative risk [RR] = 0.94, 95% confidence interval [CI]: 0.75-1.19), all-cause mortality (RR = 1.01, 95% CI: 0.89-1.14), myocardial infarction (RR = 0.85, 95% CI: 0.71-1.02), and coronary artery events (RR = 0.85, 95% CI: 0.65-1.11) were observed between the intervention and control groups. However, owing to limited reported cases, the impact of stroke could not be evaluated.
Conclusions: The findings indicate that a reduction in saturated fats cannot be recommended at present to prevent cardiovascular diseases and mortality. Clinical trials are needed to evaluate the effects of saturated fat reduction under the best possible medical care, including statin administration.
Systematic review registration number: This systematic review and meta-analysis was registered with the International Prospective Register of Systematic Reviews (CRD42023428498).
Keywords: all-cause mortality; cardiovascular mortality; meta-analysis; saturated fatty acid; systematic review.
Copyright © Japan Medical Association.
Conflict of interest statement
Satoru Yamada received honoraria for lectures from Elly Lilly and Eat Fun Health Association and has stock in LOCABO Inc. Tomomi Shirai, Sakiko Inaba, Gaku Inoue, Minami Torigoe, and Naoto Fukuyama declare no conflicts of interest.
Figures
Figure 1.
Results of the systematic search and study selection process. *Indicates the PubMed, Cochrane CENTRAL, and Ichusi databases. A total of 9987 studies were included: 3969 from PubMed, 5919 from Cochrane CENTRAL, and 99 from Ichusi.
Figure 2.
Forest plots of saturated fatty acid reduction trials on cardiovascular mortality. No statistically significant reduction was noted. CI: confidence interval; OR: odds ratio.
Figure 3.
Forest plots of saturated fatty acid reduction trials on all-cause mortality. No statistically significant reduction was noted. CI: confidence interval; OR: odds ratio.
Figure 4.
Forest plots of saturated fatty acid reduction trials on myocardial infarction. No statistically significant reduction was noted. CI: confidence interval; OR: odds ratio.
Figure 5.
Forest plots of saturated fatty acid reduction trials on any coronary artery event. No statistically significant reduction was noted. CI: confidence interval; OR: odds ratio.
Figure 6.
Relationship between the reduction in SFA intake and RRR of each outcome. No association suggesting dose dependency was observed between the differential of SFA (x axis) (%) and RRR of each outcome (y axis). CVD: cardiovascular disease; MI: myocardial infarction; RRR: relative risk reduction; SFA: saturated fatty acid.
Figure 7.
Relationship between the reduction in saturated fatty acid intake and ARR of each outcome. No association suggesting dose dependency was observed between the differential of SFA (x axis) (%) and ARR of each outcome (y axis). ARR: absolute risk reduction; CVD: cardiovascular disease; MI: myocardial infarction.
Figure 8.
Relationship between study duration (x axis) and RRR or ARR of each outcome (y axis). According to Pearson’s product-moment correlation analysis, no association between study duration and RRR [upper 4 panels: a)-d)] or ARR [lower 4 panels: e)-h)] was observed. ARR: absolute risk reduction; CVD: cardiovascular disease; MI: myocardial infarction; RRR: relative risk reduction.
Figure 9.
Funnel plots of saturated fatty acid reduction trials on cardiovascular mortality. No publication bias was noted.
Figure 10.
Funnel plots of saturated fatty acid reduction trials on all-cause mortality. No publication bias was noted.
References
-
- Coronary heart disease in seven countries. XVII. The diet. Circulation. 1970;41(4)(suppl):I162-83. - PubMed
-
- Harcombe Z. Dietary fat guidelines have no evidence base: where next for public health nutritional advice? Br J Sports Med. 2017;51(10):769-74. - PubMed
-
- Mensink RP. Effects of saturated fatty acids on serum lipids and lipoproteins: a systematic review and regression analysis [Internet]. World Health Organization; 2016 [cited 2022 Oct 30]. Available from: https://iris.who.int/bitstream/handle/10665/246104/9789241565349-eng.pdf
