Skip to main content

California’s new coffee cancer warning no more than a tempest in a teapot

Europeans have their daily wine, Asians their tea, but it has been estimated that the primary source of dietary antioxidants for the average American is coffee. An impressive lineup of scientific articles attests to coffee’s health benefits, but in March 2018 a California judge ruled that coffee roasters and retailers will have to post a cancer warning label. According to a group called The Council for Education and Research on Toxics, a chemical called acrylamide that forms in trace amounts during roasting is potentially carcinogenic. Citing a law passed in 1986 known as Proposition 65, they sued Starbucks and dozens of other companies. Despite a lack of evidence that acrylamide levels in coffee are enough to cause harm in humans, Los Angeles Superior Court Judge Elihu Berle ruled for the plaintiffs. In so doing, he ran counter to guidance from the World Health Organization, which officially dropped coffee from its list of possible carcinogens in 2016.  The WHO’s determination was based on a review of more than 1,000 studies by its International Agency for Research on Cancer. Even “Dr. Danger” Bob Arnot, who had spent years reporting on the risks of coffee as a medical correspondent for NBC and CBS, reversed course and proclaimed "coffee is the new red wine” and dubbed it “the healthiest new superfood.”

Why coffee is a health food

Studies consistently find that coffee drinkers live longer and have lower rates of mental decline, diabetes, and heart disease.[1] As with wine, there is a J-shaped curve: health benefits up to a certain level of daily consumption, then the opposite. (With coffee the curve is flatter, due to less upside risk of heavy consumption compared to wine.)  One of the larger studies, called the Iowa Women’s Health Study, tracked a cohort of nearly 42,000 postmenopausal women aged 55-69 at enrollment and followed for 15 years. Coffee drinkers who consumed 1-3 cups per day on were on average about 25% less likely to die of cardiovascular disease, with the effect diminishing at 4 cups or greater. Coffee-derived polyphenol antioxidants were credited for the effect. And despite the newly mandated warnings, coffee consumption is associated with lower risk of most types of cancers.[2] Even when evaluating dietary acrylamide consumption specifically, amounts in coffee appear too low to have any measurable impact on cancer risk.[3]
Acrylamide occurs in similar levels in roasted barley and is found in breads, meat, and potato products. It is formed during the roasting process, a result of what is called the Maillard reaction, in which amino acids from proteins combine with sugars to give browned foods their distinctive flavor. But in the case of coffee, the roasting process also increases the antioxidant capacity of the brewed extract.[4] This is reminiscent of wine production, where polyphenols increase and develop along with alcohol during fermentation.
With both coffee and wine however, the benefits are not attributable to the antioxidant polyphenols alone. Alcohol factors in as a net positive in the right amounts with wine, and caffeine is at least part of the reason for java’s rejuvenating effects. For diabetes, there is a benefit with both decaf and regular, but for prevention of Alzheimers and other forms of age-related mental decline it appears that caffeine is involved.[5]
Other than requiring unnecessary expenditure of millions of dollars–money that could be spent on effective cancer prevention strategies–the new law is unlikely to have much effect. I suspect that even the lawyers and plaintiffs in the case haven’t banished their daily brew. But there is a downside to actions like this: they foster consumer cynicism and mistrust of health authorities. Exaggerating a risk too small to measure by invoking new regulations is dismissed as just another buzzkill. We would do well to remember that it was coffee that ushered in the Age of Reason; modern science, enlightened rationality, democracy, and capitalism all came to light in the coffee houses of the 18th century. We could use a bit of enlightenment now! See you at Starbucks . . .

[1] O'Keefe JH1, DiNicolantonio JJ2, Lavie CJ3. Coffee for Cardioprotection and Longevity. Prog Cardiovasc Dis. 2018 Feb 21. pii: S0033-0620(18)30039-2.
[2] Wierzejska R1. Coffee consumption vs. cancer risk - a review of scientific data. Rocz Panstw Zakl Hig. 2015;66(4):293-8.
[3] Kotemori A1, Ishihara J2, Zha L3, Liu R3, Sawada N1, Iwasaki M1, Sobue T3, Tsugane S1; JPHC Study Group. Dietary acrylamide intake and risk of breast cancer: The Japan Public Health Center-based Prospective Study. Cancer Sci. 2018 Mar;109(3):843-853.
[4] Priftis A, Stagos D, Konstantinopoulos K, Tsitsimpikou C, Spandidos DA, Tsatsakis AM, Tzatzarakis MN, Kouretas D.
Comparison of antioxidant activity between green and roasted coffee beans using molecular methods. Mol Med Rep. 2015 Nov;12(5):7293-302.
[5] Panza F1, Solfrizzi V, Barulli MR, Bonfiglio C, Guerra V, Osella A, Seripa D, Sabbà C, Pilotto A, Logroscino G. Coffee, tea, and caffeine consumption and prevention of late-life cognitive decline and dementia: a systematic review. J Nutr Health Aging. 2015 Mar;19(3):313-28.


Popular posts from this blog

How globalization of drinking habits threatens the French paradox

It seems that the more studies we see on the relationship between wine and health, and the larger they are, the more contradictory the results. Headlines summarizing comprehensive international studies declare the French paradox dead, and all alcoholic beverages are equally detrimental. I think there is an overlooked explanation for this: over the past several decades, convergence of drinking patterns around the world has separated wine from its role as a daily part of a meal. Globalization has commoditized our views about drink, toppling it from its role as a culturally specific emblem. Global convergence of drinking There are several recent reports summarizing the trend,[i],[ii],[iii]and it applies for both developed and developing countries. Since the early 1960s, wine’s share of global alcohol consumption has more than halved, declining from 35% to 15%. Beer and spirits have taken up the slack, with beer gaining 42% and spirits adding 43%, both large gains. The bigger story howeve…

Wear red and DRINK red for women’s heart health

This Friday Feb 2nd is the annual “wear red” day in Canada and the U.S. to raise awareness for women’s heart health. Why only a day for the number one threat to women’s health? Women are 5 times more likely to succumb to heart disease than breast cancer, which gets a whole month (October.) Another contradiction is that the advice women hear about prevention of breast cancer is the opposite of what you can do to lower the risk of heart disease: a daily glass of wine. Even one drink a day raises your risk of breast cancer, we are told, ignoring the overriding benefits of wine on heart health. Drink red wine to live longer Here’s why I think women should also “drink red.” For starters, wine helps de-stress and celebrates life. Stress is a factor in heart disease, and if that were the only way wine helped it would be worth considering. But the medical evidence is also strong: a daily glass of red wine helps raise the HDL “good cholesterol” levels, which lowers the risk of cardiovascular p…

Which types of wine are the healthiest?

I am often asked after lecturing on the healthful properties of wine which type is best to drink. Since much of the discussion has to do with the polyphenol antioxidants from the skins and seeds of the grape, red wine is the first criterion since it is fermented with the whole grape rather than the pressed juice. This allows for extraction and concentration of these compounds, familiar ones being resveratrol and tannins. But beyond that, which varietals have the highest concentrations?

According to the Roman philosopher Pliny the Elder, “The best kind of wine is that which is pleasant to him that drinks it” but modern science expects more specifics. (The point of course is that if you have a wine that you enjoy you are more likely to drink regularly and therefore reap the benefits.) But there are several difficulties in singling out certain wines for their healthful properties. Which compounds to measure? Are we talking about heart health or the whole gamut? Is it the varietal of the …