Let me just say beforehand that I am, like you and everyone else, someone who needs coffee desperately in my mornings. The bitterness of coffee not only serves as a metaphor for the bitterness that is my traffic filled commute to work, but also is remarkably good at shocking me into a state of alertness. All is well until I walk into my office and realize that the vast majority of my work will be centered around one crucial tenant that has been very well hidden: coffee is a possible carcinogen. In fact, the pumpkin-spice-chai-vanilla-caramel-mocha latte pumping machine known as Starbucks has been on the opposite side of a lawsuit by the Council of Education and Research on Toxics (CERT) for quite some time now. Why? This little law in California called Prop 65 which mandates that companies serving products that are known to cause cancer make it abundantly clear with labeling.
So what exactly is the issue here? I’ll break it down faster than Bruce Jenner can get away with vehicular manslaughter. Actually not really, people already forgot about that. Bruce you sly devil, you.
We all know about caffeine, right? How could you not, it’s the world’s most consumed stimulant at the rate of roughly 2.25 billion cups in the world per day. That’s a lot of coffee. However, let’s shine the spotlight on some of the lesser known compounds present in our morning cup of joe.
First off are the diterpenes. Diterpenes are a class of chemicals that are naturally produced by both flora and fauna alike and are composed of four isoprene units. In coffee there are two main diterpenes that saturate the scientific literature, being cafestol and kahweol. While they both sound like gibberish I transcribed from Indiana Jones and the Temple of Doom, they are an anchor of scientific interest and research despite being only 0.5% and 0.3% of the coffee’s weight respectively.
However, the one compound that will steal the proverbial show today is not diterpenes, but acrylamide. The best way of going about describing this chemical in detail would be to talk about its synthesis, or, how exactly it is produced. Acrylamide is not inherent in coffee, but rather is a product of a chemical reaction called the Maillard Reaction. This reaction is common among most forms of cooking because it is the process that is taking place when your food browns. More specifically, when amino acids meet sugar and heat, they combine into flavorful little molecules. You know that amazing umami, or savory flavor you taste when you bite into a seared steak or roasted corn? You can thank the Maillard reaction for that.
I think at this point it is also common knowledge that coffee beans start off raw and are then roasted to produce that wonderful aroma that makes 6 am alarms slightly more bearable. Turns out coffee has an abundance of the amino acid asparagine, which, when exposed to high temperature (typically you need 250 -300 °F), goes through the Maillard reaction to become acrylamide. This is also very common in starchy foods such as french fries or bread.
Let me start off by saying that coffee has been linked to both sides of physical health, the good and the bad. Some say that it has the potential to limit diseases such as type 2 diabetes, Parkinson’s, and cirrhosis; while others say it can bring about increased hypertension and greater risk of heart disease. I’ll get into why there are such conflicting results later. For now, we will turn our attention to the risks that the chemicals mentioned above are most commonly correlated with.
Research behind cafestol mainly centers around the apoptosis process behind cells. Apoptosis is the programmed death of a cell, which sounds morbid at first but in actuality is our body’s natural defense against cancer. A large facet of cancer research is figuring out if exposure to certain chemicals, foods, or environments affects our body’s ability to induce apoptosis. Isolating cafestol from the rest of liquid coffee is a relatively new discovery and thus the research behind cafestol in itself is typically unsubstantiated. Anything from mesothelioma to head and neck cancer are being associated with presence of cafestol as an anti-cancer agent. Oh, and the newest research suggest that cafestol could help our bones produce more osteoblasts, which are the proteins needed to increase bone density. So, the risks associated with developing negative health effects from cafestol alone are generally weak, but this could also be because they are understudied.
Kahweol on the other hand is like cafestol’s under-appreciated sibling. Cafestol would be the shining example of an older brother or sister hogging the parent’s affection whilst kahweol can do everything cafestol can, but to a much lesser degree of effectiveness. We see the same studies looking into its anti-tumor effects and positive influence on bone density. So if you buy into this science (which I’ll tell you why you shouldn’t just yet) make sure to grab an espresso instead of your vente latte as the espresso contains higher concentrations of these two diterpenes.
We now arrive upon acrylamide; the entree to our diterpene appetizers, the cream of the crop, the political to our political correctness, the … I’m sure you can see where this going. Trust me when I say that there is a mountain of research behind this chemical due to its prevalence in food products and the necessity of food companies to prove to the FDA that their product is safe to consume. It is recognized by our government as a possible human carcinogen, but that basically just means that any company can still make products with acrylamide, shrug their shoulders, and let their legal team handle any consequences. Hence, the importance of Prop 65’s mandatory labeling. This isn’t a new topic either, even news organizations have made fancy infographics tracking acrylamide content in food products such as potato chips.
This chemical is very, extremely, incredibly, preposterously, emphatically, astoundingly political. Here is my google scholar search on acrylamide and cancer in 2015 alone. I can tell you for a fact that unlike most other searches, the first 5 pages are all studies that are very relevant to our search term “acrylamide cancer”. There are numerous carcinogenic, cytotoxic, and neurotoxic effects attributed to acrylamide. Due to it’s large presence in coffee, even greater than cafestol and kahweol combined, the effects of drinking coffee as a whole are muddled by all of the other good stuff that comes with it. Scientists have been trying to answer the question of whether or not the good that comes with coffee outweighs the bad, and the answer could either help coffee industries, or potential bankrupt them. Hence:
Coffee has its own food science politics
This entire problem could have been solved in Nazi Germany because their complete disregard for human testing ethics could have made the clinical testing possible to decipher once and for all whether or not acylamide is bad for us. The ideal study would to be of course, giving test subjects acrylamide and seeing what exact dosage is needed to kill us and how. Of course, we live in a society where this is taboo, and rightly so, thus there have been hundred of different ways science has tried to go about finding the same answer with different questions.
Cancer.org has a webpage that best describes the gravity of the situation at hand. Every major government agency has listed acrylamide as a possible carcinogen even though the evidence of its ability to increase risk in cancer has been little reported. This is because it has been recognized that every one of these studies notes the same limitation as the one I just mentioned above. They are all asking different questions to try to get an answer which could only be solved concretely through an incredibly controversial and inhumane clinical study. In medical research, there is no room for martyrs. Deliberate harming of human life in the short term in unacceptable for the potential good in the discoveries in the long term. It’s a classic trolley paradox where we are asked whether or not sacrificing the lives of a few is worth saving the lives of many.
This issue is further complicated by the inherent biases that are tied into a lot of food science research. The food industries, of course, wish to defend the safety of their products. They will often hire scientists to prove their product’s safety, while sometimes disregarding proper experimental methodology to arrive at this conclusion. On the flip side you could have scientists looking into this issue with the intent of proving once and for all, that coffee and the acrylamide present in it are a sleeping public health epidemic. The result is what I like to call “50 million shades of grey”, and its tough to trust anyone especially when they are producing such conflicting results.
A huge reason why there are so many “shades of grey” is because there are a lot more chemicals than just cafestol, kahweol, and acrylamide present in coffee. A lot of studies have produced data explaining what happens when mice and cell samples are exposed to these chemicals alone, but when it is all bundled in the form of coffee, you can’t exactly say what is causing what. Let’s not forget that maybe somebody who drinks five cups of coffee per day also plows through packets of antioxidant-rich blueberries like shoppers in line at Black Friday, and we’re left incredibly unsure if coffee was the culprit to begin with.
So what now?
One thing that is certain is that there is a degree of risk when it comes to drinking coffee. Cancer itself is a basket case of risk analysis and sometimes has been outright attributed to “bad luck” so it’s difficult to discern what approach to take when it comes to coffee. From what I’ve read as a part of my job, you should stick to 1-2 cups per day if you can, and maybe outsource your caffeine intake to the Chinese. What I mean to say is, drink tea. Try to lower your consumption of fried foods and dark roasted coffees as they contain more acrylamide. Opt for a lighter roast as it not only contains less acrylamide per cup, but also more caffeine.
Above all, please don’t tell any of my friends that I described Nazi Germany as the proper arena for groundbreaking medical research. There is such a thing as “too soon” still, right?