Personalized Nutrition Caffeine Intake in Healthy Adults.

Can Including Genotype Information Increase the Effectiveness of Dietary Interventions? Polymorphism of the CYP1A2 Gene and Caffeine Intake in Healthy Adults

Personalized nutrition is one of the most up to date trends in human nutrition and gains much interest of general public and scientists as well. Although we have gained some knowledge on gene-trait associations, the real effectiveness and usefulness of genotype-based nutritional recommendations is unknown. Many personalized nutrition companies are on the market today, some of them use personalized nutrition based on genotype analysis. For this reason, scientific basis of this approach should be clarified. Moreover, the effect of using genotype information in dietary interventions aimed at decreasing caffeine intake has never been tested. Our project can thus increase knowledge which can be applied in dietary counseling practice. Although we focus on caffeine intake, the study is designed as a proof of concept.

Considering current knowledge and recognizing the existing gaps we hypothesize that providing genotype information may increase adherence to dietary recommendations.

The main aim of the project is thus testing the effectiveness of a genotype-based personalized dietary intervention targeted at decreasing caffeine intake.

Specific aims of the study include:

• Implementation of the application for mobile devices which will be designed to assess caffeine intake.
• Testing whether providing information on CYP1A2 polymorphism affects effectiveness of the dietary intervention aimed at decreasing caffeine intake.
• Testing whether changes in dietary behavior can persist over time To accomplish the study goals a group of healthy adults will be enrolled. Participants will complete an informed consent procedure. As we aim at decreasing caffeine intake, we plan to first screen for people drinking at least 2 cups of coffee or with total caffeine intake over 200 mg/day. Then genotype screening will be performed and eligible volunteers will be randomly assigned to one of the study groups which receive either dietary advice or dietary advice and genotype information.

Inclusion criteria:

• age 18-60
• daily coffee intake at a minimum 2 cups (or equivalent total caffeine intake)

Exclusion criteria:

• injuries,
• chronic diseases (e.g. diabetes, metabolic syndrome, cancer, hyperthyroidism),
• recent dieting,
• pregnancy or breastfeeding,
• no caffeine intake,
• taking chronic pain management pills which contain caffeine.