Interleukin-1 genotype-selective inhibition of inflammatory mediators by a botanical: a nutrigenetics proof of concept

ObjectiveAlthough observational studies have shown that genotype may influence nutritional effects on target outcomes, there are few reported studies that stratified subjects by genotype before a nutritional intervention. This proof-of-concept trial determined whether specifically formulated botanical mixtures reduced inflammation in individuals with genetic variations that predispose to overexpression of interleukin-1β (IL-1β) and early heart disease.MethodsHealthy adults with elevated C-reactive protein (CRP) were stratified into genetic groups based on being positive (IL1Pos) or negative (IL1Neg) for the at-risk IL-1 gene variations. IL1Pos (n = 39) and IL1Neg (n = 40) subjects were then randomized to the candidate botanical formulation or placebo. The botanical formulation included rose hips, a blueberry and blackberry mixture, and a grapevine extract.ResultsAt 12 wk of dosing with the botanical formulation, IL-1β gene expression by stimulated peripheral blood mononuclear cells was significantly lower than at baseline and significantly lower than placebo in IL1Pos and IL1Neg subjects. Mean IL-1β gene expression treatment effect over the 12-wk period was greater in IL1Pos than in IL1Neg subjects. At 12 wk of dosing the botanical mixture produced no mean change in serum CRP levels. However, in IL1Pos subjects, significantly more subjects achieved a reduction in CRP with the botanical mixture than with placebo. No CRP effect was observed in the IL1Neg subjects.ConclusionThis study represents one of a few prospective clinical trials in which genetic variations were shown to differentially influence nutrient effects on outcomes.