The relationship of dairy intake with incident cardiovascular disease

Background: Ecological studies suggest that a high intake of
dairy products increases the risk of cardiovascular diseases
(CVD), which may be due to its saturated fat content. However,
this result is not confirmed by prospective cohort studies. Few
prospective studies have evaluated the direct relationship of
specific dairy products and CVD.
Objective: The aim of this study is to investigate the
relationship of both total dairy intake, as well as specific dairy
subgroups (high-fat dairy, low-fat dairy, milk and milk products,
cheese and fermented dairy), with coronary heart disease
(CHD), stroke and mortality.
Design: EPIC-NL is a prospective cohort study among 35.151
Dutch men and women with an average follow-up of 15 years.
Dairy intake was measured with a validated food frequency
questionnaire (FFQ). Incidence of CHD, stroke and mortality
was obtained by record linkage to a causes of death registry
and hospital discharge diagnosis registry. Cox regression was
used to estimate the association between intake of dairy
products, modeled continuously per SD, and risk of CHD,
stroke and mortality. These associations were adjusted for
gender, age, total energy intake, physical activity, smoking,
education, BMI and consumption of ethanol, coffee, fruit,
vegetables, fish, meat and bread.
Results: Mean intake of total dairy was 421 g/day (range: 0-
3156 g/day). During approximately 15 years of follow-up, 1535
cases of CHD, 687 cases of stroke and 1880 cases of all
cause mortality were documented. Total dairy intake was not
significantly associated with risk of CHD (hazard ratio per SD
increase: 1.00; 95%-CI: 0.94 - 1.06), stroke (HRSD: 0.94; 95%-
CI: 0.87 - 1.03) or all cause mortality (HRSD: 1.02; 95%-CI:
0.97-1.08) in the multivariate adjusted model. None of the dairy
subgroups were related to CHD as well. A borderline
significant association (p=0.10) of low-fat dairy with a
decreased stroke risk (HRSD: 0.93; 95%-CI: 0.86-1.01) was
observed, but none of the other dairy subgroups were
significantly associated with stroke. High-fat dairy intake was
associated with an increased risk of all cause mortality (HRSD:
1.49; 95%-CI: 1.07-2.10). Consequently, the ratio of high-fat to
low-fat dairy tended to be associated (p=0.10) with an
increased risk of all cause mortality (HRSD: 1.03; 95%-CI: 1.00-
1.06). None of the other dairy subgroups were significantly
associated with all cause mortality. A similar, but not statistically significant, association was observed between
high-fat dairy and CVD mortality (HRSD: 1.50; 95%-CI: 0.77-
3.11).
Conclusion: In this Dutch population with a large variation in
amount and source of dairy, total dairy intake was not
significantly associated with risk of CHD, stroke and all cause
mortality. However, high-fat dairy intake was positively
associated with all cause mortality and low-fat dairy intake
tended to be inversely associated with stroke.