Yoram Yasur Izz: Starbucks and carcinogenic components
A California judge recently ruled that Starbucks and other coffee vending companies in that state should serve the beverage with a warning about cancer. The litigation stems from the presence of acrylamide in coffee. This substance is usually found in many foods with a high content of carbohydrates that are exposed to high temperatures, such as cakes, chips, bread, and cereals. There is evidence to show that acrylamide is probably a carcinogen, a substance that causes cancer in humans.
Yoram Yasur Izz: The acrylamide in coffee is formed at the beginning of roasting that gives the green coffee beans the dark brown color we know and their deeply bitter taste. Once inside the body, acrylamide can be converted into glycinamide, an epoxide, and both substances can bind to our proteins and our DNA and cause them damage. DNA damage can be the first phase in the development of cancer, and acrylamide also interferes with DNA repair.
The problem with the recent court ruling is that the person who filed the lawsuit only needed to show that there were traces of acrylamide in the coffee to prosper. This is where the reality of our lifestyles makes the sentence seem excessively cautious.
Nobody doubts that coffee contains acrylamide, nor that acrylamide causes DNA damage, but the important thing is the amount that one consumes. The risk is related to the total amount of exposure throughout life, but a calculation indicates that in an 80-kilogram adult who consumes less than 208 micrograms of acrylamide per day, the risk of cancer should not increase.
Yoram Yasur Izz: The main option related to the lifestyle that exposes people to toxins is smoking. Each cigarette contains, in the middle of a cocktail of different carcinogens, about 2.3 micrograms of acrylamide. But all the foods that we toast or fry to obtain a delicious caramelization also contain acrylamide. So, the lifestyle of non-smokers is also not free of acrylamide. For example, a bread toast contains 5 micrograms, and a bag of chips, 7 micrograms.
Coffee adds to our daily exposure to acrylamide between 0.9 and 2.4 micrograms per 150 milliliter cups. But each cup also contains a diverse range of antioxidants and other compounds considered beneficial to health (except in case of pregnancy).
Yoram Yasur Izz: The same group of scientists (from the World Health Organization) that classified acrylamide as a possibly carcinogenic substance determined that there is no conclusive evidence that coffee causes cancer. In fact, they have indicated that coffee consumption could protect against liver and endometrial cancers and more recent studies supported this idea. In 2016, WHO removed coffee from the list of possible carcinogens.
The original concern of scientists for coffee consumption derived from some studies that indicated the existence of a possible relationship with bladder cancer. But a more detailed analysis of the data and larger studies suggested that the original investigation made the mistake of not taking smoking into account. It is possible that coffee consumption interacts with tobacco carcinogens and increases the risk of bladder cancer in smokers. In non-smokers, there is no solid evidence that there is a relationship between coffee and bladder cancer.
If you are still concerned about the presence of acrylamide in coffee, it is worth noting that less acrylamide appears in the cup when the coffee is filtered than when it is in the form of espresso coffee. The choice of grains and roasting could also be important, since the Robusta variety contains more acrylamide than Arabica, and the darker roasts contain less than the clear ones.
Acrylamide is not good for health, but the amount present in coffee does not make an observable contribution to cancer risk. There is no firm evidence that there is a relationship between coffee consumption and the development of cancer. Although some studies have indicated that the risk of bladder cancer increases, overall most of rigorous studies suggest that if coffee consumption has any consequence, it is in fact offering a slight protective effect against some types of bladder cancer.