Dairy consumption and cardiovascular disease risk: a multi-level analysis with inflammatory biomarker mediation

Including dairy products in the diet may help reduce the risk of developing cardiovascular disease (CVD). Nevertheless, how various categories of dairy items influence CVD risk remains insufficiently explored. This study aimed to evaluate the associations between different types of dairy products, their intake frequency, fat content, and the risk of CVD, addressing existing research gaps.

Dairy intake data-including yogurt, cheese, and milk-were obtained from the Global Dietary Database, covering 185 countries between 1990 and 2018. Corresponding CVD burden metrics-including incidence, prevalence, and disability-adjusted life years (DALYs)-were extracted from the Global Burden of Disease study. These data were used to investigate how dairy intake relates to CVD burden globally. Additionally, individual-level data from 30,341 participants in the National Health and Nutrition Examination Survey (NHANES) were analyzed to evaluate the association between dairy product consumption and CVD risk. Finally, directed acyclic graph and causal mediation models were used to confirm whether inflammatory markers partially mediated the association between dairy consumption and CVD risk.

Globally, individuals who consumed greater amounts of milk tended to have a lower risk of CVD. Individually, milk intake was found to be negatively associated with the risk of CVD, coronary heart disease (CHD), and heart attack (HA). Exploratory mediation analysis indicated that systemic inflammatory markers (SIRI), the monocyte-to-lymphocyte ratio (MLR), and the neutrophil-to-lymphocyte ratio (NLR) partially mediated the relationship between milk intake and CVD risk, contributing - 6.09%, -5.02%, and - 4.13% of the total association, respectively. Further analysis showed that individuals who reported drinking milk daily or at least weekly tended to have a lower risk of developing CVD than those who consumed it less than once per week.

Milk intake may offer protective effects against CVD, CHD, and HA, potentially through the mitigation of inflammation. The frequency of milk intake appears to be a key factor influencing CVD risk. These findings highlight the potential public health benefits of promoting regular milk intake as part of a balanced dietary pattern to help reduce the global burden of CVD.