The plasma proteome of plant-based diets: analyses of 1463 proteins in 50,000 people

Abstract

AbstractBackground and objectivesCirculating proteins are integral to many biological processes. We aimed to assess differences in the plasma proteome between people of different dietary groups defined by degree of animal food consumption.MethodsThe UK Biobank recruited middle-aged adults (mostly 40 to 69 years) throughout the UK between 2006-2010. Relative concentrations of 1463 plasma proteins were quantified using the Olink Proximity Extension Assay on blood samples from 49,326 participants, who were also asked to report their ethnicity and consumption of red and processed meat, poultry, fish, dairy and eggs. We defined six diet groups among the white British participants (23,116 regular meat eaters, 23,323 low meat eaters, 484 poultry eaters, 1074 fish eaters, 722 vegetarians, and 54 vegans), and two diet groups among the British Indians (390 meat eaters and 163 vegetarians). We used multivariable-adjusted linear regressions to assess differences in protein concentrations between diet groups, with correction for multiple testing.ResultsWe observed significant differences in many plasma proteins by diet group (683 proteins in white British participants, 1 in British Indians), in particular many proteins that are majority expressed in the digestive system. Of the biggest differences, compared with regular meat eaters, the non-meat eaters had significantly higher FGF21 (e.g. +0.40 SD in vegetarians), GUCA2A (+0.33), FOLR1 (+0.32), IGFBP2 (+0.31) and DSG2 (+0.30); all groups except the vegans had lower HAVCR1 (−0.38 in vegetarians). The observed differences were generally similar in direction in both ethnicities.DiscussionIn this first comprehensive assessment of plasma proteins by diet group, we identified many differences in proteins between groups defined by animal food consumption; this variation in protein levels suggests differences in various biological activities, including gastrointestinal tract and kidney function, which may relate to differences in future disease risk.