Dietary Patterns and All-Cause Mortality: A NESR Systematic Review

Abstract

Abstract Objectives To inform the 2020–2025 Dietary Guidelines for Americans, the U.S. Departments of Agriculture (USDA) and Health and Human Services (HHS) identified important public health questions to be examined by the 2020 Dietary Guidelines Advisory Committee. The Committee conducted a systematic review with support from USDA's Nutrition Evidence Systematic Review (NESR) team to answer the following question: What is the relationship between dietary patterns consumed and all-cause mortality? Methods The Committee developed protocols that described how they would use NESR's systematic review methodology to examine the evidence related to dietary patterns and all-cause mortality. NESR librarians conducted a literature search. NESR analysts dual-screened the results using pre-defined inclusion and exclusion criteria to identify articles published between 2000 and 2019 that evaluated dietary patterns and all-cause mortality. NESR analysts extracted data and assessed risk of bias of included studies. The Committee synthesized the evidence, developed conclusion statements, and graded the strength of the evidence underlying the conclusion statements. Results This review included one hundred and fifty-three studies, which were well-designed and conducted using rigorous methods, with low or moderate risks of bias. Precision, directness, and generalizability were demonstrated across the body of evidence. Results across studies were highly consistent in the foods and beverages included in the dietary patterns associated with reduced ACM risk. Robustness of results were confirmed by analyses with confounding factors. Conclusions Strong evidence demonstrates that dietary patterns in adults and older adults characterized by vegetables, fruits, legumes, nuts, whole grains, unsaturated vegetable oils, and fish, lean meat or poultry when meat was included, are associated with decreased risk of all-cause mortality. These patterns were also relatively low in red and processed meat, high-fat dairy, and refined carbohydrates or sweets. Some of these dietary patterns also included alcoholic beverages in moderation. (Grade: Strong) Funding Sources USDA, Food and Nutrition Service, Center for Nutrition Policy and Promotion, Alexandria, VA.