What is the research behind caffeine sensitivity?

At DNAfit, we have a strict inclusion protocol to evaluate whether a gene will be included in our reports. Each gene must have a minimum of 3-peer reviewed studies in humans demonstrating the effect, there must be a consensus on that effect, and that effect must be modifiable through an environmental and lifestyle change. 

Below is a sample of our evidence base for caffeine sensitivity:

Coffee, CYP1A2 genotype, and risk of myocardial infarction

CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension 

Caffeine intake and CYP1A2 variants associated with high caffeine intake protect non-smokers from hypertension