Relations of Variety and Quantity of Dietary Proteins Intake from Different Sources with Mortality Risk: A Nationwide Population-Based Cohort

Objectives: The relations of variety and quantity of dietary proteins intake from different sources with mortality risk were still controversial. We aimed to examine the associations of variety and quantity of different sourced proteins with all-cause mortality risk in adults and older adults.

Materials and methods: 17,310 participants (mean age was 44.0 [SD: 15.9] years and 51.0% were females) with utilizable data from the China Health and Nutrition Survey were included. Dietary intake was collected using three consecutive 24-h dietary recalls combined with a household food inventory. The variety score of protein sources was defined as the number of proteins consumed at the appropriate level, accounting for both types and quantity of proteins. The primary outcome was all-cause mortality.

Results: Over a median follow-up of 9.0 years, 1324 (7.6%) death cases were reported. There were reversed J-shaped relationships of percentages energy from total protein, and protein from legume with all-cause mortality; U-shaped relationships of proteins from unprocessed red meat, processed red meat, poultry and whole grain with all-cause mortality; L-shaped relationships of proteins from egg and fish with all-cause mortality; and a reversed L-shaped relationship of protein from refined grain with all-cause mortality (all P values for nonlinearity < 0.001). Moreover, there was a significant inverse association between the variety score of protein sources with overall mortality risk (per score increment, HR, 0.69; 95%CI, 0.66-0.72).

Conclusions: Greater variety of proteins with appropriate quantity from different food sources was associated with significantly lower risk of mortality in Chinese adults and older adults.