In the past, moderate coffee consumption has been associated with a reduced risk of developing cardiovascular disease and a reduced risk of early all-cause mortality. Recent discoveries into the gene variations that affect our individual coffee and caffeine metabolism, suggest the possibility that any benefit is genetically determined. A Danish study examined these relationships on three levels. They examined whether there was an association between coffee intake and a reduced risk of cardiovascular disease and all-cause mortality. This was done observationally looking at a large population of over in over 95,000 Danes. Next they examined the relationship between several genetic variants and coffee consumption. They looked at two gene variants near the AHR gene; rs4410790, and rs6968865. They also looked at three variations near the CYP1A1/2 genes; rs2470893, rs2472297, and rs2472299. This was performed in over 112,000 people. Then they looked to see if genetic variations associated with higher coffee consumption conferred greater benefit in a total of over 223,000 individuals.
What they found mirrored some previous findings. There was a U-shaped association between coffee intake and cardiovascular disease and all-cause mortality. In other words those with the lowest risk for developing cardiovascular disease and at the lowest risk for early mortality from any cause drank moderate amounts of coffee. There was also a genetic predisposition towards coffee consumption. Those with the genetic variant rs4410790 near the AHR gene and the genetic variant rs2470893 near the CYP1A1/2 genes consumed 42% more coffee. However, there was no health benefit when assessed by genetic variation.
So what does this tell us?
It tells us that there is a clear association between moderate coffee consumption and reduced risk of cardiovascular disease and a reduced risk of early mortality from any cause. It also confirms that people are genetically predisposed to consume more coffee, those with the gene variant combination of rs4410790 + rs2470893 drink more coffee. However, this gene variation (and others) is not necessarily associated with any health benefit. This means that the benefit associated with coffee consumption holds true (in large populations) and at an individual level may be due to other genetic variations not yet described, non-genetic variables like gut microbiome composition, or while associated with coffee consumption actually be causally due to a distinctly different variable. In other words, while we can say populations that consume moderate cups of Morning Joe have less risk of cardiovascular disease and live longer, like the Fountain of Youth, we have no idea how. So relax, sip it all in, and enjoy those magic beans.
Nordestgaard, A., & Nordestgaard, B. ( 2016). Coffee intake, cardiovascular disease and all-cause mortality: observational and Mendelian randomization analyses in 95 000-223 000 individuals. Int J Epidemiol., doi: 10.1093/ije/dyw325.