Hide this
Cup of Coffee

Story at-a-glance -

  • A World Health Organization International Agency for Research on Cancer (IARC) report has reversed a 25-year-old categorization of coffee from a “possible carcinogen” to “inadequate evidence” that it causes cancer
  • The experts reviewed more than 1,000 studies showing that coffee failed to show detriment to health, and in some cases, lowered cancer risks
  • However, IARC asserted that coffee, South American “mate” and very hot tea can do “thermal damage” and even cause cancer if it exceeds 149 degrees Fahrenheit
  • Multiple studies and reviews report that coffee may provide multiple health benefits, including lowering the risks of several types of cancer, heart disease, type 2 diabetes and neurological disorders

W.H.O. Reverses Position on Coffee Causing Cancer

June 27, 2016 | 34,136 views

By Dr. Mercola

A rare retraction of sorts among a well-respected international scientific body has caused a few raised eyebrows. The World Health Organization (WHO) has now concluded that a regular date with your favorite cup of joe may not cause cancer after all.

This has been met with elation on the part of many coffee drinkers, relief on the part of guilty addicts not really sure if their obsession was necessarily good for them and complete ambivalence on the part of people who don't care; either way, they intend to have their brew, and enjoy it, too.

The International Agency for Research on Cancer (IARC)1 report published in The Lancet Oncology, reads:

"After thoroughly reviewing more than 1,000 studies in humans and animals, the Working Group found that there was inadequate evidence for the carcinogenicity of coffee drinking overall.

Many epidemiological studies showed that coffee drinking had no carcinogenic effects for cancers of the pancreas, female breast and prostate, and reduced risks were seen for cancers of the liver and uterine endometrium. For more than 20 other cancers, the evidence was inconclusive."2

One caveat, however, is that hot coffee or tea can pose a health risk if it exceeds 149 degrees Fahrenheit, and may be culpable in relation to esophageal cancer.

Interestingly, the bulk of the IARC report dealt with the threat of drinking hot coffee as opposed to the apparently nonexistent hazards of the coffee itself. Little mention is ever made of the health problems that are introduced when adding sugar, fake sugar and fake creamer to coffee.

Coffee: Studies Show It to Be Beneficial for Health

There's been a firestorm of rhetoric at intervals over the past century regarding coffee and its supposed dangers, and just as much supposition about its incredible health-boosting advantages. The Atlantic reported:

"In the early 1900s, doctors and health agencies warned that caffeine was essentially 'poison,' and that drinking coffee would cause 'nerve storms,' according to a 1912 issue of The Salt Lake Tribune.

Nervous women, the newspaper cautioned, should abstain from coffee altogether. 'Unsteady nerves are foes of beauty,' it said.

… Over time, the debate about coffee — fueled by a combination of legitimate research, junk science, marketing and the rumor mill — has amounted to what the writer Andrew Revkin has called 'whiplash journalism,' in which sweeping conclusions about what's good or bad for you contribute to a mess of contradictions."3

Many in the scientific community have claimed for decades that coffee actually provides multiple health benefits. In fact, large reviews on the topic have come to the same conclusion that coffee can be erased from the "harmful" list of foods and placed on the "advantageous" list. According to The New York Times:

"Last year, a panel of scientists that shaped the federal government's 2015 dietary guidelines said there was 'strong evidence' that three to five cups of coffee daily was not harmful, and that 'moderate' consumption might reduce chronic disease.

Another group, the World Cancer Research Fund International, reported that coffee protects against multiple types of cancer. And several systematic reviews of studies involving millions of people have found that regular coffee drinkers live longer than others."4

The evidence is fairly convincing that coffee may not only lower your cancer risk, but also your risk of heart disease, type 2 diabetes and neurological disorders.

Reports, Reviews, Evidence and Inconsistencies

It wasn't that long ago — 1991, to be exact — that coffee was termed a "possible carcinogen" linked to bladder cancer. The recent announcement included the acknowledgment that there was simply a lack of evidence that coffee might cause cancer at all.

As a matter of fact, early reports on coffee had compared its hazards with those of lead and diesel fuel.

Those previous studies hadn't taken into account that many of the coffee drinkers under scrutiny were also heavy smokers, according to Dana Loomis, Ph.D., first author of the report and deputy head of the WHO program focused on cancer-causing substance classifications. In addition, more up-to-date studies have become available.

When the group of 23 scientists from 10 countries met in Lyon, France, the issues surrounded the evidence for or against coffee, as well as "mate," a tea-like, high-caffeine drink popular in South America.

The group reviewed more than 1,000 studies, submitted over decades, the upshot of which: coffee failed to show detriment to health in relation to prostate, breast and pancreatic cancers, as had been previously conjectured. In the case of uterine and liver cancers, coffee was linked to a lowered cancer risk.

Twenty other cancer types showed "inadequate" evidential links of coffee being a carcinogen; many showed beneficial associations.

South American 'Mate' Drink Analyzed for Carcinogenic Effect

One of the interesting points made about the above-mentioned mate was that its review was likely based on "single-point-in-time" studies on South Americans with esophageal cancer who probably drank mate.

When the IARC researchers started looking at mate's possible link with cancer, it fell into the "drunk hot" or "very hot" categories. That must have rung a bell, since there's evidence that molten-hot drinks can do thermal damage to the cells in your throat and digestive tract, and possibly trigger cancer.

Further digging into the possibilities netted a bundle of case-control studies (which experts later called "the weakest kind").5 IARC subsequently entered very hot tea and other hot drinks to be a "significant" risk for human esophageal cancer.

As a result, IARC concluded that beverages hotter than 149 degrees Fahrenheit are "probably carcinogenic to humans." According to the Coffee Detective, the best temperature for brewing coffee is between 155 to 175 degrees Fahrenheit.6

Black Bear Coffee Micro Roastery suggests the slightly warmer temperature of 195 and 205 degrees Fahrenheit,7 but study author Loomis said North Americans and Europeans usually prefer to drink theirs at around 136 degrees Fahrenheit.8

Studies and More Studies Not Only Exonerate Coffee but Commend It

As previously noted, 40 studies found either zero connection between coffee consumption and cancer risk or found it actually produced a slightly protective effect. Some of the studies under most scrutiny were those associating coffee consumption with decreasing uterine and liver cancer risks.9

One of the most telling was a report that coffee drinkers exhibit a 15 percent decrease in liver cancer risk for every cup of coffee ingested per day.10 A Harvard T.H. Chan School of Public Health analysis in 2012 reported that drinking coffee was linked to a decreased endometrial cancer risk.11

Another study concluded that drinking at least five cups of coffee a day prevents some brain cancers by as much as 40 percent.12

In 2015, the U.S. Department of Agriculture (USDA) submitted new dietary guidelines concluding that three to five cups of coffee a day 400 milligrams of caffeine was linked to a lowered risk of Parkinson's disease.13

With all this information about coffee, the Mayo Clinic noted on its website that in deciding whether coffee is a positive or negative, it's possible that the health benefits outweigh the risks.

Expert: Coffee Is 'Probably Not Something to Worry About'

It's interesting, however, that even with all the reviews indicating coffee may in fact be a nutritional asset, the WHO experts gave it rather tepid scores. They placed it in the same category as fluoride, low-frequency electric fields and a nail polish solvent called toluene, which they believe showed insufficient potential as a carcinogen.

Not everyone is thrilled with the findings or the halfhearted efforts the agency exerted to get to the bottom of whether coffee drinking is good or bad. Geoffrey Kabat, Ph.D., acancer epidemiologist at the Albert Einstein College of Medicine in New York, noted that the agency seems to diminish positive reports and magnify anything negative. He told The New York Times:

"What the evidence shows overall is that coffee drinking is associated with either reduced risk of several cancers or certainly no clear increase in other cancers … There's a strong signal that this is probably not something that we need to be worrying about."14

The IARC noted, "Since 1971, more than 900 agents have been evaluated, of which more than 400 have been identified as carcinogenic, probably carcinogenic or possibly carcinogenic to humans."15 That list includes substances like asbestos and also processed meats, cigarettes and wood dust. Finding carcinogens in water is pretty sobering to learn. So are reports of the health damage caused by cellphones. One article noted:

"The agency did not go so far as to give coffee its 'probably not carcinogenic' label. In nearly 1,000 carcinogenicity assessments, IARC has exonerated only a single substance — caprolactam, a compound used to make nylon — which has made it the target of vehement criticism."16

The Differences Between Shade-Grown, Organic Versus Conventional Coffee

There are many ways to make sure your coffee is both delicious and good for you, as opposed to not that great and terrible for you. Regarding organic versus conventional coffee, Equal Exchange17 noted:

"Conventional coffee is among the most heavily chemically treated foods in the world. It is steeped in synthetic fertilizers, pesticides, herbicides, fungicides and insecticides … Not only does the environment suffer from this overload, but so do the people who live in it.

Farmers are exposed to a high level of chemicals while spraying the crops and while handling them during harvest. The surrounding communities are also impacted through chemical residues in the air and water. These chemical presences are not just unpleasant; many are highly toxic and detrimental to human health."

In contrast, organic coffee contains no chemicals or synthetic fertilizers. The beans have a richer flavor and come with natural antioxidants. It's healthy for you, more sustainable for the farms that grow it, and vastly better for the planet.

Additionally, coffee is a shade-loving plant, but growers often strip forests to make growing and harvesting easier. This destroys the ecological habitat of many natural pest deterrents, such as birds and lizards, while the pests flourish, resulting in additional pesticide use.

The downward spiral to the environment involves chemical run-off, erosion and potentially contaminated water supplies. Organic, shade-grown coffee is available at numerous retail markets, but you can also order it online. Equal Exchange adds:

"Industries can and do change based on the choices that you make in the grocery store or at your favorite café — so you can vote with your mug! By purchasing organic coffee … you support systems that value healthy ecosystems, sustainable methods and superior coffee."18

Differences Between Light and Dark Roasted Coffee

When choosing your next cup of java, it's helpful to know the differences in the way it's been roasted. If you're looking for a higher boost of caffeine by drinking a darker roast, you're not likely to get it, because the added roasting time to make it darker actually breaks down the caffeine molecules.

Moreover, the roasting process produces a toxic byproduct called acrylamide, linked to an elevated cancer risk. One would think this would necessitate choosing a lighter roast, but strangely enough, at least one study found that the highest amount of acrylamide appears earlier in the roasting process rather than later, after which the acrylamide level begins to degrade.19

Dark roasts also generate more of the chemical N-methylpyridinium than the lighter variety, which helps keep your stomach from producing excess acid. Further, Italian or French dark-roasted coffee or the types used for espresso or Turkish coffee contain more antioxidants such as vitamin E, neuroprotective agents and protein-building glutathione than lighter roasts. The upshot, then, is that dark roasted coffee may have a leg up, so to speak, on lighter roasts, for a couple of different reasons.

The Best Brew: Organic Coffee, Sans Cream and Sugar

Maybe you're one of those people who "cheats" in the coffee category by "indulging" in one of the countless non-dairy creamers at every store and nearly every condiment table. You'll find caramel macchiato, hazelnut or peppermint mocha — you name it. There are liquids and powders and even sugar-free options.

But what's in those products? Well, you'll often find sodium caseinate on the ingredients list, which is a thickener and whitening agent with nutrient-suppressing chemicals. Dipotassium phosphate, used as an anti-coagulant, is also used in fertilizers, and when enough is consumed may cause vomiting and diarrhea.

Those are only two of around a dozen highly questionable substances, and that's without mentioning the high-fructose corn syrup and partially hydrogenated oils, aka trans fats.

It's when you drink your coffee black, with no toxic sugar (which could initiate insulin resistance) or chemical-laced sugar substitutes such as Splenda, aka sucralose, aspartame or saccharine, that you receive the most benefits from the coffee. Even real coffee creamer may keep you from being able to absorb beneficial chlorogenic acids present in black coffee.20

Dear IARC: Concentrate on What You Know Does Damage

Dr. Otis Brawley, chief medical officer of the American Cancer Society (ACS) believes that substances that are known to cause cancer and other diseases may be what entities like IARC should be concentrating on.

"Quitting smoking and reducing alcohol consumption are much more significant for reducing cancer risk than the temperature of what you're drinking … As a heavy coffee drinker, I have always enjoyed my coffee guilt-free, but now there is scientific evidence to justify that."21

Thank you! Your purchases help us support these charities and organizations.