Dairy consumption and CVD: a systematic review and meta-analysis

Area of Science:

• Nutritional Epidemiology
• Cardiovascular Disease Research
• Dietary Science

Background:

• Previous epidemiological studies suggest an inverse relationship between dairy consumption and cardiovascular disease (CVD).
• The specific impact of different dairy products and calcium from dairy on CVD risk requires further investigation.
• Understanding these associations is crucial for public health nutrition guidelines.

Purpose of the Study:

• To conduct a meta-analysis of prospective cohort studies examining the association between dairy intake and CVD.
• To evaluate the risk of CVD, coronary heart disease (CHD), and stroke in relation to total dairy, specific dairy products, fat content, and calcium from dairy.
• To explore dose-response relationships and heterogeneity in the observed associations.

Main Methods:

• A comprehensive literature search identified 31 prospective cohort studies for meta-analysis.
• Random-effects meta-analyses were employed to calculate summary relative risk estimates (SRRE) for high versus low dairy intake.
• Stratified and dose-response analyses were performed, with heterogeneity assessed through sub-group and sensitivity analyses.

Main Results:

• Significant inverse associations were found for total dairy intake and stroke (SRRE=0.91), cheese intake and CHD (SRRE=0.82) and stroke (SRRE=0.87), and calcium from dairy and stroke (SRRE=0.69).
• Despite these inverse associations, evidence for clear inverse dose-response relationships between dairy variables and CHD/stroke was limited after adjusting for within-study covariance.
• Heterogeneity was explored, indicating variability in findings across studies.

Conclusions:

• Dairy consumption may be associated with a reduced risk of cardiovascular disease, including stroke and CHD.
• The observed inverse associations, particularly for cheese and calcium from dairy, warrant attention.
• Further research with comprehensive dose-response data is necessary to solidify these findings and understand the nuances of dairy's role in cardiovascular health.