Drinking more milk may lower cholesterol levels, risk for CVD (2024)

Drinking more milk is associated with lower cholesterol levels and could reduce the risk for coronary artery disease, according to a study published in the International Journal of Obesity.

“Higher milk intake was associated with greater body fat, but lower cholesterol levels and a lower risk of cardiovascular disease,” Elina Hypponen, PhD, director of the Australian Centre for Precision Health at the University of South Australia, told Healio. “On balance, this suggests that milk can be a part of a balanced heart-healthy diet.”

Hypponen and colleagues conducted a Mendelian randomization study of people with a lactase persistence genotype to examine associations between milk consumption and cardiometabolic parameters. Data were obtained from three large-scale population-based studies. Most of the people included in the study were part of the UK Biobank (n = 404,648), with participants also coming from the Health Retirement Study (n = 8,520) and the 1958 British Birth Cohort (n = 5,672). Anthropometric data and biomarkers were obtained from each of the studies. Milk consumption was measured based on questions in the 1958 British Birth Cohort and the UK Biobank. Researchers used summary statistics from other consortia-based studies to conduct a meta-analysis.

Milk consumption linked to lower cholesterol

Study participants who were T-allele carriers of the lactase persistence gene variant were more likely to consume milk compared with participants with CC hom*ozygotes in both the 1958 British Birth Cohort study (OR = 2.14; 95% CI, 1.57-2.93; P = 1.68 x 10^–6) and the UK Biobank (OR = 1.21; 95% CI, 1.09-1.34; P = 3 x 10^–4).

In the UK Biobank, high milk intake was associated with a higher BMI, systolic blood pressure, diastolic BP, LDL cholesterol, total cholesterol, triglycerides and C-reactive protein and lower levels of HDL cholesterol and HbA1c. No associations between high milk intake and cardiometabolic traits were observed in the 1958 British Birth Cohort. Meta-analysis of data from both studies shows an association between high milk intake and lower HDL cholesterol (P = 2.7 x 10^–6), high triglycerides (P = .001) and higher C-reactive protein (P = 2.6 x 10^–30).

In meta-analysis of the three population-based studies and the consortia-based studies, T-allele carriers of the lactase persistence gene variant who drank more milk had a higher BMI (P = 4.68 x 10^–12), lower LDL-cholesterol (P = 2.08 x 10^–26), HDL cholesterol (P = 9.4 x 10^–13) and total cholesterol (P = 2.38 x 10^–36). Mendelian randomization analysis also confirmed a causal association of high milk intake with higher BMI (P = 3.6 x 10^–5), lower LDL cholesterol (P = 3.6 x 10^–6), lower total cholesterol (P = 1.9 x 10^–6) and lower HDL cholesterol (P = 3 x 10^–5).

“Even if higher milk intake was associated with greater adiposity, it also led to lower cholesterol concentrations and lower CVD risk,” Hypponen said. “This might be explained by milk calcium, which helps to increase lipase activity. Lipases are the enzymes that break down fats within our body and can help to reduce CVD by lowering the levels of cholesterol.”

Drinking more milk may lower CAD odds

In the UK Biobank, drinking more milk was associated with a lower risk for type 2 diabetes (OR = 0.89; 95% CI, 0.82-0.97; P = .007), but no association was observed in the Diabetes Genetics Replication and Meta-analysis (DIAGRAM) consortium. No association between milk consumption and CAD was found in the UK Biobank, but data from the Coronary Artery Disease Genome-wide Replication and Meta-analysis (CARDIOGRAM) consortium showed drinking more milk reduced the odds for CAD (OR = 0.86; 95% CI, 0.75-0.99; P = .03).

“Our studies suggest that milk can be a part of a heart-healthy diet, but large-scale intervention studies would be required before changes in dairy consumption could be recommended for the prevention of CVD,” Hypponen said.

For more information:

Elina Hypponen, PhD, can be reached at elina.hypponen@unisa.edu.au.