The Race to Zero: A Bean of Plenty
By Joseph F. DeRupo
Everything we see, taste, and feel is an intricate blend of chemicals. Like a primeval alphabet, they’re the fundamental units that define everything in the natural order. Coffee is no exception, crafted from an unassuming green bean. For centuries viewed as a one-dimensional seed with magical properties, coffee has betrayed its rich chemical complexity to the ever-sharper tools of science.
Starting with the basics, the green bean boasts over 300 different chemical compounds, while roasting adds another thousand or so. A litany of multisyllabic, tongue-twisting names, they sort into a shorter list of chemical classes and layperson labels – hydrocarbons, phenols, diterpenes, melanoidins . . . and antioxidants.
Undoubtedly, the most well-known of them is caffeine. However, it’s actually among the smallest of green coffee’s constituent compounds – accounting for only 2% in arabica and 4% in robusta beans by weight.
By volume, chlorogenic acids top the list, comprising up to 12% by dry weight. They are among the many compounds espoused by the popular mantra “antioxidants,” neutralizing errant molecules called “free radicals” in the body, thereby creating direct links to disease prevention. More antioxidants in coffee come from a class of compounds known as polyphenols, which are plant-based micronutrients also found in berries, grapeseed, and pomegranate.
Voluminous scientific evidence has strongly associated chlorogenic acid with both type 2 diabetes risk reduction and liver health. For diabetes, coffee seems to enhance the body’s sugar uptake mechanism. What is clear is a link between consuming coffee, including decaf, and a reduced risk of developing the disease. Evidence is strong and consistent across many scientific studies, revealing a “dose response” effect – that is, the more coffee you consume, the greater the protective effect.
Similarly, numerous studies have linked coffee with protection of the liver. The benefit appears to come from reducing the tissue inflammation that can spawn diseases such as non-alcoholic fatty liver disease, cirrhosis, and cancer. Even among those at higher medical risk, the protection obtains.
Coffee has also been linked to a reduced risk of colon and rectal cancers, postulated to come from methylpyridinium, a strong antioxidant compound. Reduced risk has also been found for cancers of the brain, skin, prostate, mouth, breast, endometrium, and pancreas. The science has become so clear that the International Agency for Research on Cancer (IARC), the cancer research arm of the World Health Organization, gave coffee a clean bill of health. It was the first time the agency has reversed itself – revising its 25-year-old, middling ruling about coffee and cancer, which was based on refuted evidence.
Caffeine, too, offers its own menu of health associations. Among them are protections against early-onset cognitive decline, Alzheimer’s, and Parkinson’s Disease. Scientists also point to caffeine as the source of coffee’s established “ergogenic” properties – that is, boosting physical endurance and athletic performance. Studies also show that caffeine can reduce exercise-related pain, mitigating the effects of lactic acid buildup in the muscles.
The groundswell of positive scientific evidence has been non-stop since around 2000. Scientific study designs had become more refined, stripping away “confounding factors” such as smoking and other lifestyle variables. With that, the old, negative health myths about coffee began falling away, duly pegged to the non-coffee variables. Today, the scales are tipped toward a broad consensus that coffee is a healthful beverage – among scientists, the media, and the consuming public. The shift has been so significant that the current Nutritional Guidelines for Americans has embraced coffee as part of a healthy lifestyle. It’s the first time a beverage–or any consumable–has been mentioned specifically in the guidelines, more popularly known as “MyPlate” and formerly the “Food Pyramid.”
The dark side
However, despite the overwhelming scientific affirmation linking coffee’s remarkable chemistry to good health, there’s a disparate duality of factors that belie a dark side. Taking coffee from bean to cup requires roasting at high temperatures, whereupon the Maillard reaction (what we know as “browning”) creates new compounds from coffee’s natural elements. Second, as scientific tools get increasingly sophisticated, researchers can identify smaller and smaller traces of previously undetectable compounds in just about everything – a progressive “race to zero” for scientific inquiry.
We could say the story begins in 2002. Swedish tunnel builders were getting sick, and scientists traced the source to polyacrylamide, the sealant they were using. But, researchers were surprised to find that the same traces of basic acrylamide molecules also showed up in the bloodstreams of the general population. Sure enough, the scientists found that, by an accident of chemistry, acrylamide molecules are created naturally during cooking in many foods, including bread, cereals, potato chips, crackers, and roasted coffee.
With that, science had begun to look “under the hood” of everyday foods and, as investigative tools have become more sophisticated, deeper and deeper into the chemical engine. Traces of many more compounds in coffee have since been uncovered. While many drive the health benefits linked to coffee, others have spawned some serious legal and regulatory challenges for the industry.
For example, acrylamide and other compounds appear on a list of chemicals declared as carcinogenic by the state of California. Under “Proposition 65,” a law originally passed to protect water supplies, manufacturers must forewarn consumers about any of the roughly 1,000 chemicals on the list. As a result, the coffee industry is in its sixth year of defending itself against a major lawsuit. Other foods have also been the subject of legal action, including breakfast cereals, potato chips, crackers, red wine vinegar, and even baby food. Clearly, Proposition 65 has created a cottage industry for plaintiffs’ lawyers and, as chemical analysis techniques race to zero, it’s anyone’s guess as to how many more compounds will cause legal angst for coffee and other industries. Already, there’s been concern about furfuryl alcohol, furans and 4-methylimidazole, also natural by-products of the browning process found in many foods.
Another by-product of roasting, airborne diacetyl, has presented challenges of a different kind. Previously limited to lawsuits around lung disease associated with exposure to liquid diacetyl added as a flavoring, it’s also been found to arise naturally when unflavored coffee is roasted. Following lurid publicity around exposure to naturally occurring diacetyl, along with an exceptionally low exposure level recommendation by a research arm of the U.S. Centers for Disease Control, coffee manufacturers have been fighting threats by liability insurers to eclipse their policies until more is known about worker exposure. The coffee industry is extensively studying the science to determine healthful exposure levels.
Bottom line, the handful of coffee compounds discussed here are but a fraction of coffee’s chemical cornucopia. Others will undoubtedly be isolated as scientific tools find smaller and smaller traces within nature’s magical mix. Some compounds are likely to explain the strong clinical evidence associating coffee with significant health benefits. Others may attract eager regulators and hungry lawyers to wreak a little havoc for the industry.
Indeed, coffee is a complex little bean. Big picture, coffee has science, history and even culture on its side. But we should temper excitement with vigilance as we continue to learn more.
Joe DeRupo is the former director of external relations and communications with the National Coffee Association.