Proteomic analysis of plasma reveals fat mass influences cancer-related pathways in healthy humans fed controlled diets differing in glycemic load
A partir de l'analyse protéomique du plasma de 80 personnes en bonne santé suivant pendant 28 jours des régimes alimentaires dont la charge glycémique est différente, cette étude montre que le niveau d'adiposité d'un individu influence la réponse physiologique des voies associées à la carcinogenèse
Increased adiposity and diets high in glycemic load (GL) are associated with increased risk of many chronic diseases including cancer. Using plasma from 80 healthy individuals [40 men/40 women, 29 with DXA-derived low-fat mass (FM) and 51 with high FM] in a randomized crossover-controlled feeding trial and arrays populated with 3504 antibodies, we measured plasma proteins collected at baseline and end of each of two 28-day controlled diets: a low GL diet high in whole grains, legumes, fruits, and vegetables (WG) and a high GL diet high in refined grains and added sugars (RG). Following univariate testing for proteins differing by diet, we evaluated pathway-level involvement. Among all 80 participants, 172 proteins were identified as differing between diets. Stratifying participants by high and low FM identified 221 and 266 proteins respectively as differing between diets (unadjusted p<0.05). These candidate proteins were tested for overrepresentation in Reactome pathways, corresponding to 142 (of 291) pathways in the high FM group and 72 (of 274) pathways in the low FM group. We observed that the cancer-related pathways, DNA Repair, DNA Replication, and Cell Cycle, were overrepresented in the high FM participants while pathways involved in post-translational protein modification were overrepresented in participants with either FM. Although high GL diets are associated with increased risk of some cancers, our study further suggests that biology associated with consumption of GL diets is variable depending on an individual's adiposity and dietary recommendations related to cancer prevention be made with the additional consideration of an individual's FM.