Lower serum cholesterol levels were significantly associated with higher aggression in experimental-control group studies (b = -0.56, p = 0.002), but not in one-group correlational studies.
Meta-Analysis (n=6,285)
Are low serum cholesterol levels associated with increased aggression?
Lower cholesterol levels are associated with increased aggression in case-control studies, particularly in psychiatric populations, but this association is absent in correlational studies.
Effect estimate: b = -0.56
p-value: p=0.002
Background: Previous research has suggested a potential association between low serum cholesterol levels and aggressive or violent behavior; however, findings across studies have been inconsistent, and meta-analytic evidence remains limited. Objectives: To meta-analyze the association between serum cholesterol levels and aggression, and to examine whether study design, population characteristics, and biological sex moderate this relationship. Methods: A meta-analysis of peer-reviewed English-language studies was conducted. Web of Science, APA PsycInfo, APA PsycArticles, PubMed, and Ovid Medline were searched up to September 2025. Eligible studies examined the relationship between serum cholesterol and aggression using either experimental–control group designs or one-group correlational designs. Risk of bias was assessed indirectly through study design characteristics and heterogeneity analyses. Random-effects meta-analyses with restricted maximum likelihood estimation were performed separately for each design type. Results: Twenty-nine studies comprising 6285 participants were included. In experimental–control group studies (15 comparisons; n = 3345), lower cholesterol levels were significantly associated with higher aggression (b = −0.56, SE = 0.15, p = 0.002), although heterogeneity was substantial (I2 = 91.0%). In contrast, one-group correlational studies (17 samples; n = 2940) showed no significant association between cholesterol and aggression (b = 0.07, SE = 0.05, p = 0.160; I2 = 90.8%). Differences in psychiatric status and sex distribution between study designs were pronounced and may partially explain discrepant findings. Limitations: The evidence base was characterized by high heterogeneity, variable operationalizations of aggression, and a predominance of older studies. Risk of bias could not be formally assessed using standardized tools. Conclusions: This meta-analysis indicates that lower cholesterol levels are associated with increased aggression primarily in studies comparing aggressive and non-aggressive groups, particularly within psychiatric populations. The absence of this association in correlational studies suggests that population characteristics, measurement methods, and sex distribution critically influence observed effects. Future research should clarify underlying biological mechanisms and address methodological heterogeneity.
Fritz et al. (Wed,) conducted a meta-analysis in Aggression (n=6,285). Serum cholesterol levels was evaluated on Association between serum cholesterol levels and aggression in experimental-control group studies (b = -0.56, p=0.002). Lower serum cholesterol levels were significantly associated with higher aggression in experimental-control group studies (b = -0.56, p = 0.002), but not in one-group correlational studies.