Population Health Research Institute, McMaster University, Hamilton, ON, Canada.
Population Health Research Institute, McMaster University, Hamilton, ON, Canada; Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.
Lancet. 2018 Nov 24;392(10161):2288-2297. doi: 10.1016/S0140-6736(18)31812-9. Epub 2018 Sep 11.
Dietary guidelines recommend minimising consumption of whole-fat dairy products, as they are a source of saturated fats and presumed to adversely affect blood lipids and increase cardiovascular disease and mortality. Evidence for this contention is sparse and few data for the effects of dairy consumption on health are available from low-income and middle-income countries. Therefore, we aimed to assess the associations between total dairy and specific types of dairy products with mortality and major cardiovascular disease.
The Prospective Urban Rural Epidemiology (PURE) study is a large multinational cohort study of individuals aged 35-70 years enrolled from 21 countries in five continents. Dietary intakes of dairy products for 136 384 individuals were recorded using country-specific validated food frequency questionnaires. Dairy products comprised milk, yoghurt, and cheese. We further grouped these foods into whole-fat and low-fat dairy. The primary outcome was the composite of mortality or major cardiovascular events (defined as death from cardiovascular causes, non-fatal myocardial infarction, stroke, or heart failure). Hazard ratios (HRs) were calculated using multivariable Cox frailty models with random intercepts to account for clustering of participants by centre.
Between Jan 1, 2003, and July 14, 2018, we recorded 10 567 composite events (deaths [n=6796] or major cardiovascular events [n=5855]) during the 9·1 years of follow-up. Higher intake of total dairy (>2 servings per day compared with no intake) was associated with a lower risk of the composite outcome (HR 0·84, 95% CI 0·75-0·94; p=0·0004), total mortality (0·83, 0·72-0·96; p=0·0052), non-cardiovascular mortality (0·86, 0·72-1·02; p=0·046), cardiovascular mortality (0·77, 0·58-1·01; p=0·029), major cardiovascular disease (0·78, 0·67-0·90; p=0·0001), and stroke (0·66, 0·53-0·82; p=0·0003). No significant association with myocardial infarction was observed (HR 0·89, 95% CI 0·71-1·11; p=0·163). Higher intake (>1 serving vs no intake) of milk (HR 0·90, 95% CI 0·82-0·99; p=0·0529) and yogurt (0·86, 0·75-0·99; p=0·0051) was associated with lower risk of the composite outcome, whereas cheese intake was not significantly associated with the composite outcome (0·88, 0·76-1·02; p=0·1399). Butter intake was low and was not significantly associated with clinical outcomes (HR 1·09, 95% CI 0·90-1·33; p=0·4113).
Dairy consumption was associated with lower risk of mortality and major cardiovascular disease events in a diverse multinational cohort.
Full funding sources are listed at the end of the paper (see Acknowledgments).
膳食指南建议尽量减少全脂乳制品的摄入，因为它们是饱和脂肪的来源，据推测会对血液脂质产生不利影响，并增加心血管疾病和死亡率。这一论点的证据很少，而且来自低收入和中等收入国家的关于乳制品消费对健康影响的数据也很少。因此，我们旨在评估总乳制品和特定类型的乳制品与死亡率和主要心血管疾病之间的关联。
前瞻性城市农村流行病学（PURE）研究是一项针对来自五大洲 21 个国家的 35-70 岁个体的大型跨国队列研究。使用特定于国家的经过验证的食物频率问卷记录了 136384 名个体的乳制品摄入量。乳制品包括牛奶、酸奶和奶酪。我们进一步将这些食物分为全脂和低脂乳制品。主要结局是死亡率或主要心血管事件的复合结局（定义为心血管原因死亡、非致命性心肌梗死、中风或心力衰竭）。使用多变量 Cox 脆弱性模型计算危险比（HR），该模型具有随机截距，以考虑参与者按中心的聚类。
在 2003 年 1 月 1 日至 2018 年 7 月 14 日期间，我们在 9.1 年的随访中记录了 10567 例复合事件（死亡[ n=6796]或主要心血管事件[ n=5855]）。与不摄入乳制品相比，总乳制品摄入量较高（>2 份/天）与复合结局（HR 0.84，95%CI 0.75-0.94；p=0.0004）、总死亡率（0.83，0.72-0.96；p=0.0052）、非心血管死亡率（0.86，0.72-1.02；p=0.046）、心血管死亡率（0.77，0.58-1.01；p=0.029）、主要心血管疾病（0.78，0.67-0.90；p=0.0001）和中风（0.66，0.53-0.82；p=0.0003）的风险降低相关。与心肌梗死无显著相关性（HR 0.89，95%CI 0.71-1.11；p=0.163）。较高的牛奶（HR 0.90，95%CI 0.82-0.99；p=0.0529）和酸奶（0.86，0.75-0.99；p=0.0051）摄入量与复合结局的风险降低相关，而奶酪摄入量与复合结局无显著相关性（0.88，0.76-1.02；p=0.1399）。黄油摄入量较低，与临床结局无显著相关性（HR 1.09，95%CI 0.90-1.33；p=0.4113）。
在一个多样化的跨国队列中，乳制品的摄入与死亡率和主要心血管疾病事件的风险降低有关。
文末列出了全部资金来源（见致谢）。
