There are many studies that look at the health impacts of drinking coffee, but you’d be forgiven if you weren’t clear about whether it’s good for you.Research has found consuming coffee could potentially prevent heart disease, type-2 diabetes, Parkinson’s disease and liver cancer, but the results are often conflicting. Beyond that, other variables can potentially negate any benefits from drinking a cup of Joe. Whether you like your coffee black or with a bit of cream and sugar, for example, makes a difference for your health. How much you drink and even the kinds of filters you use to make coffee could also have an impact.All the conflicting information is enough to keep non-coffee drinkers from lining up at Starbucks, while those who indulge are left scratching their heads about whether they need to cut back or keep on imbibing.But there’s one area where the science seems certain: Some of us are just more genetically wired to like coffee. A number of studies have identified certain genetic variants associated with caffeine consumption and metabolism, which helps us know why some of us choose coffee, and others don’t.Recently, a new study found some additional genetic variants associated with a tendency toward java enjoyment, including one near NRCAM, a gene implicated in vulnerability to addiction. The study looked at nearly 8,000 Caucasian coffee drinkers and found significant evidence of gene association at the single nucleotide polymorphism (SNP) near NRCAM. Using coffee consumption as a model, this new research may help scientists better understand genetic problems with addiction and how to treat them.The recent study also looked at two SNPs that lie in the region between CYP1A1 and CYP1A2 genes — CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, which are important constituents of coffee, whereas caffeine is primarily metabolized by CYP1A2. The study confirmed previous studies and added a new SNP, , to the list of those associated with consumption of coffee and metabolism of caffeine.23andMe looks at a variant that affects how quickly a person metabolizes caffeine based on preliminary research of the SNP . People with and the slower version of the CYP1A2 enzyme 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 the research, while, according to the study, fast metabolizers could actually reduce their heart attack risk by drinking coffee.Additionally, in a 2011 blog post, 23andMe discussed two studies that found an association between coffee and caffeine consumption and SNP variants near the CYP1A1 and AHR genes, helping us know which genes influence the amount of coffee people consume. One study found the SNP near CYP1A1 had a fairly consistent effect – people with the T version were prone to drink about a quarter cup more of coffee a day — and the other showed that people with two copies of a T at near the AHR gene drank about a third of a cup of coffee more each day than those without any copies.To find out whether genetic variants influence their caffeine consumption, 23andMe customers can look up their data for and using the Browse Raw Data feature.Amick Boone is a freelance writer who’s written about health and life sciences for nearly 10 years. When she’s not at her computer, she’s usually in motion – doing yoga, riding her bike or traveling.
Editor’s note: Pending an FDA decision, 23andMe no longer offers new customers access to health reports referred to in this post. Customers who purchased prior to November 22, 2013 will still be able to see their health reports, but those who purchased after that time will not. Those customers will have access to ancestry information as well as access to their uninterpreted raw data.