Link between protein type, mortality differs by sex, adiposity

Sex, smoking status, and adiposity mediate the associations between dietary animal (AP) and plant proteins (PP) and mortality, reports a study.

Overall, 1,350 adults aged 40‒74 years (50.2 percent female) were included in this longitudinal population-based study. Participants were recruited between 1991 and 1995 and followed for all-cause mortality through the regional mortality registry until 2015.

A food frequency questionnaire was used to collect dietary data. The authors then analysed protein composition within a compositional data analysis framework, modelling the balance of AP and PP within the overall macronutrient composition.

Cox proportional hazards models, adjusted for potential confounders, were used to estimate the associations of protein balances with all-cause mortality. Finally, stratified analyses were conducted to evaluate effect modification.

Four hundred five deaths occurred during follow-up. A greater AP relative to other macronutrients correlated with increased mortality overall (hazard ratio [HR], 1.37, 95 percent confidence interval [CI], 1.00‒1.87) and in males (HR, 1.57, 95 percent CI, 1.05‒2.33).

Stratified analyses revealed associations restricted to ever smokers overall (HR, 2.06, 95 percent CI, 1.32‒3.20), males (HR, 1.90, 95 percent CI, 1.18‒3.06), females (HR, 3.29, 95 percent CI, 1.03‒10.54), and to those with normal weight (HR, 1.91, 95 percent CI, 1.07‒3.41).

No overall association was seen for PP. Furthermore, PP was associated with reduced mortality among females with normal weight.

“The associations between AP and PP and mortality differed by sex, smoking status, and adiposity, supporting more tailored dietary recommendations,” the authors said.