Editor’s note: Pending an FDA decision, 23andMe no longer offers new customers access to health reports referred to in this post. Customers who received their health information prior to November 22, 2013 will still be able to see their health reports, but those who purchased after that time will only have access to ancestry information as well as access to their uninterpreted raw data. These new customers may receive health reports in the future dependent on FDA marketing authorization.For many of us, everyday is “Coffee Day.” We need no excuse to celebrate a steaming cuppa joe. But someone out there went and made it official several years ago, so in the spirit of International Coffee Day – September 29th – 23andMe broke down the genetics behind why some of us are always jonesing for java.People are simply genetically wired to react differently to their morning coffee. Your genetics affect how you metabolize coffee, and are associated with how much you consume. Genetic differences can explain why some people can chug a Venti without problem, while a few sips is enough to perk up someone else all day long.There are health implications for all this, but those are fairly hotly debated. There are studies that show that coffee can lower risks for type 2 diabetes and some cancers. And it appears that caffeine rather than coffee may help protect against Alzheimer’s and Parkinson’s diseases.23andMe looks at a variant that affects how quickly a person metabolizes caffeine.Slow metabolizers of caffeine who also drank at least two to three cups of coffee per day had a significantly increased risk of a non-fatal heart attack, according to research, while, according to other studies, fast metabolizers could actually reduce their heart attack risk by drinking coffee.Take a look at our “Genetically Wired” infographic and learn a little more about why people respond differently. If you’re a 23andMe customer, find out what your genetics says about whether you’re a fast or slow metablolizer of caffeine.