Consumo de laticínios e alimentos ultraprocessados e risco de morte: resultados do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil)

Abstract

INTRODUCTION: Noncommunicable diseases (NCDs) are responsible for more than half of all deaths in Brazil, with cardiovascular disease (CVDs) being the leading cause of death. Diet is the main risk factor for the development of NCDs and plays an essential role in modulating inflammation. Some studies indicate a beneficial effect of dairy products consumption on the risk of cardiovascular death, while consumption of ultra-processed foods has been associated with adverse health effects, including a worse cardiometabolic risk profile and increased risk of death. However, there are still some inconsistent results. In addition, most studies were developed in high-income countries with different dietary patterns. OBJECTIVES: To investigate whether the consumption of dairy products and ultra-processed foods is associated with the risk of death from all causes, CVDs and/or NCDs among participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), after 8 years of follow-up. METHODS: Food consumption was obtained through a semi-quantitative food frequency questionnaire with 114 food items applied at baseline (2008-2010) of ELSA-Brasil. In article 1, we investigated whether the higher consumption of total dairy products and its subgroups (full-fat and low-fat, fermented, and milk), adjusted by total calories according to the residual method and divided into sex-specific quartiles, would be associated with a lower risk of death from CVDs and with reductions in high-sensitivity C-reactive protein (hs-CRP) levels between the first (2008-2010) and second (2012-2014) wave of the study. In article 2, we investigated whether the contribution of ultra-processed foods, in grams/day, on the total dietary consumption would be associated with a higher risk of death from all causes, NCDs and CVDs. In both articles, Cox proportional hazards models were used for mortality analyses and adjustments for baseline confounders were considered. Linear mixed-effect models were used for the analysis of longitudinal changes in hs-CRP levels. Mortality data were obtained through annual follow-up calls and investigations of hospital records and deaths from NCDs and CVDs identified. Deaths in the first year of follow up were not included in the analysis. All participants were followed-up from the first year of the cohort until the date of death, loss to follow-up, or end of the study (12/31/2018), whichever occurred first. RESULTS: Results from article 1 indicated that, after adjustment for confounding factors, individuals in the 3rd (HR: 0.38; 95% CI: 0.15–0.99) and 4th (HR: 0.36; 95% CI: 0.14-0.94) quartiles of total dairy consumption had lower risk of death from CVDs when compared to individuals in the 1st quartile, after 8 years of follow-up. A beneficial effect was also observed for individuals in the 4th quartile (HR: 0.34; 95% CI: 0.14-0.86) of milk consumption and the 2nd quartile (HR: 0.30; 95% CI: 0.10-0.92) of full-fat dairy consumption. However, no association was observed between low-fat or fermented dairy products and cardiovascular mortality. Additionally, total dairy products and their subgroups were not associated with changes in hs-CRP levels after 4 years of follow-up. The results of article 2 showed that, after adjustments, a 10% increase in the proportion of ultra-processed foods in the diet was associated with a 12% higher risk of death from all causes (HR: 1.12; 95% CI: 1.02-1.22) and NCDs (HR: 1.12; 95 CI%: 1.02-1.24). However, no association was observed between consumption of ultra-processed foods and cardiovascular mortality. CONCLUSION: The consumption of total dairy products and milk was associated with a lower risk of death from CVDs, while consumption of ultra-processed foods was associated with an increased risk of death from all causes and NCDs. These findings reinforce the need for stricter public policies that encourage the consumption of fresh and minimally processed foods and discourage the consumption of ultra-processed foods, in an attempt to control NCDs and the risk of death associated with these causes.