Abstract
BACKGROUND: Puerto Rican adults residing in the US mainland experience a high prevalence of metabolic syndrome (MetS). A diet containing healthy protein-rich sources may help control risk factors for MetS. OBJECTIVE: This study aimed to evaluate 2-year longitudinal associations between intake of various protein-rich foods and changes in the six MetS components. DESIGN: This is a secondary analysis of a longitudinal cohort study using data from the baseline (2004-2007) and 2-year follow-up visits (2006-2011) in the Boston Puerto Rican Health Study. PARTICIPANTS/SETTING: Participants were self-identified Puerto Ricans, aged 45 to 75 years, residing in Boston, Massachusetts, or the surrounding area (n = 1,126). MAIN OUTCOME MEASURES: MetS components were fasting glucose, high-density lipoprotein (HDL) cholesterol, triglycerides, systolic and diastolic blood pressures, and waist circumference. STATISTICAL ANALYSIS: Baseline intake of foods reported in a semiquantitative food frequency questionnaire were expressed as servings/day, and protein-rich foods were categorized as unprocessed white meat, unprocessed red meat, processed meat, milk and yogurt, cheese, fish and seafood, beans, nuts, and eggs. Associations between each continuous protein food group and continuous 2-year change in MetS components were assessed using linear mixed models adjusted for socioeconomic and behavioral factors, and other dietary sources. RESULTS: The top contributors to total protein intake were unprocessed red meat (13.3%) and unprocessed poultry (13.0%), and the lowest were eggs (2.92%) and nuts (0.91%). Higher intake of processed meats was associated with an increase in waist circumference over 2 years (β = 1.28; standard error [SE] = 0.63), whereas higher intake of fish and seafood was associated with a decrease in waist circumference (β = -3.47; SE = 1.39). Intake of unprocessed poultry was associated with a decrease in triglycerides (β = -24.5; SE = 9.13). No other significant associations were observed between protein sources and 2-year changes in MetS components. CONCLUSIONS: Consuming less processed meat and more fish and seafood and unprocessed poultry was associated with decreases in waist circumference and triglycerides among US mainland Puerto Ricans. Other dietary protein sources were not related to cardiometabolic health.