Some say you should, some say you shouldn’t. I am the first to admit that when it comes to nutrition advice it can get awfully confusing!
Up until recently nutrition recommendations have been fairly standard, based on the premise that everyone has the same nutritional requirements, with the small exception of gender and age group. However, recent research is uncovering that, because we are genetically unique, we may all have different nutritional requirements. Nutrigenomics looks at how individual genetic variation can have an effect on the body’s response to certain foods (1).
These hugely confusing contradictions may actually have some credibility, and this goes back to the fact that we are all individuals. Thereby meaning, depending on your genotype coffee can either be your tonic or your poison (not literally- but you get the idea). Coffee is a major source of caffeine, which is metabolised by your body by the CYP1A2 enzyme. An enzyme usually carries two alleles that contribute to the way it functions (2). Individuals who have two copies of the CYP1A2*1A allele are ‘rapid’ caffeine metabolisers, whereas individuals who carry the CYP1A2*1F allele are ‘slow’ caffeine metabolisers (3). So what significance does all this slow and fast business have on your health?
Quite simply, if you have the gene that makes the fast metabolising version of the enzyme, each time you drink coffee, your body will process and eliminate the caffeine very quickly limiting the negative effects it has on your body, whereas if you have the slow metabolising version of the enzyme the opposite occurs. Therefore if you have the slow metabolising gene, caffeine will have a greater effect on you and caffeine in fact may increase your risk of heart disease. However if you’re a fast metaboliser it may not (oh the injustice of it all!) (3). So it literally is true - in terms of heart disease risk - coffee can either be beneficial or detrimental depending on your genotype. That may help shed a bit of light on all of the conflicting research we see on coffee!
So all very well if you know your genotype, but until genotyping becomes readily available to the average person we are just going to have to make do with what we can. It seems like your best bet is to limit your intake to about 1-3 cups of coffee per day- everything in moderation they say right? But more importantly go with how you feel. If caffeine does not make you feel good, then chances are you probably shouldn’t be drinking it by the gallon. Sometimes listening to your body is all you need to do as it may very well tell you what you need to know.
1. Trujillo, E., Davis, C., & Milner, J. (2006). Nutrigenomics, Proteomics, Metabolomics, and the Practice of Dietetics. Journal of the American Dietetic Association, 106(3), 403-413. doi: http://dx.doi.org/10.1016/j.jada.2005.12.002
2. Yang, A., Palmer, A. A., & de Wit, H. (2010). Genetics of caffeine consumption and responses to caffeine. Psychopharmacology, 211(3), 245-257. doi: 10.1007/s00213-010-1900-1
3. Cornelis, M. C., El-Sohemy, A., Kabagambe, E. K., & Campos, H. (2006). Coffee, CYP1A2 genotype, and risk of myocardial infarction. JAMA, 295(10), 1135-1141. doi: 10.1001/jama.295.10.1135