Cancer warning labels on coffee

Dan Wilson

Senior Member.
Proposition 65, otherwise known as The Safe Drinking Water and Toxic Enforcement Act, is making more impacts in California. A judge has recently ordered that coffee companies will be required to put warning labels on their cups declaring that coffee carries risks of cancer. While many coffee shops do already have warning signs in their store, this law would require warning labels in plain sight. This is an example of a scientific question influencing policy and seems to be surrounded by misunderstanding so here I want to address why coffee is considered by some to be dangerous and how well that perspective falls in line with what experiments have been able to demonstrate.

Coffee is getting this attention because the beans, like some other starchy foods, form small amounts of acrylamide after being heated to high temperatures (250F). The amount of acrylamide in any heated food varies depending on how long this chemical reaction goes on. But for coffee, the average numbers are as follows: https://www.ncbi.nlm.nih.gov/pubmed/24325083
The highest mean acrylamide concentrations were found in coffee substitutes (818 pg/kg) followed by instant coffee (358 microg/kg) and then roasted coffee (179 microg/kg). One single cup of coffee (160 ml) delivered on average from 0.45 microg acrylamide in roasted coffee to 3.21 microg in coffee substitutes.
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Since we do not know the minimum dose that can translate to an increased risk of cancer in humans, these numbers are hard to interpret on a practical level. Nevertheless, acrylamide is listed by the International Association on Cancer Research (IARC) as a "probable carcinogen." Since there is always confusion about what this actually means whenever it is reported, let's take the time to clarify this.

Whenever a substance is classified by IARC, both lab and human studies are taken into consideration. In the case of acrylamide, lab studies that involve putting it in rats' drinking water (in amounts equaling 1,000 to 10,000x the amount humans are exposed to) have shown that acrylamide greatly increases risk of certain cancers. Human studies have tried to correlate acrylamide with cancer risk by measuring how often subjects consume foods higher in acrylamide. https://www.cancer.org/cancer/cancer-causes/acrylamide.html
Most of the studies done so far have not found an increased risk of cancer in humans. For some types of cancer, such as kidney, endometrial, and ovarian cancer, the results have been mixed, but there are currently no cancer types for which there is clearly an increased risk related to acrylamide intake.
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While these studies are survey based and thus have limitations, they have not revealed an increased risk in any cancers associated with acrylamide. So while animal studies show that acrylamide can cause cancer, no evidence suggests that it poses a danger at the levels found in cooked foods. These two sets of data lead to the classification of "probably carcinogenic." As I've explained in other threads, this classification does not speak to how carcinogenic the chemical can be, just whether or not it is a carcinogen in the context of normal exposure.

Given this information, we now have the question: should people be warned about this? How worried should people be that probable carcinogens are in their coffee? The reality is that we are exposed to a variety of carcinogens every day just by eating, drinking, and breathing air. Whether or not these exposures pose a risk to our health is determined by lab experiments, human case studies, and looking at trends in human populations. Typically, warning labels are placed if evidence is strong in all of these categories and a reasonable causal link can be established. This was the case with cigarettes.

One can argue that just because we don't yet have the evidence, we can say that people have the right to know that they are consuming something that might be harmful. However, preemptively labeling goods as such can cause a lot of unnecessary confusion and worry. While it is always possible that next week some clever group of researchers might find a causal link between the amounts of acrylamide consumed in coffee and certain cancers, the fact that such a link has not been obvious up until now is a good indication that the link would very likely be weak, if it exists. The evidence to justify a cancer warning label on all coffee cups because of acrylamide is just not there right now.
 
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kasparovitch

Active Member
Nice thread. I had read about this news today and I'm happy Dan brought it here.

The most important part there is the quote from cancer.com

The problem here is that thousands of people will stop drinking coffee by such alarming warning, at least in California, and will keep sunbathing...
 

Z.W. Wolf

Senior Member.
To make things murkier:

https://www.caffeineinformer.com/caffeinated-coffee-the-anti-cancer-wonder-drug

Study after study has been showing the cancer fighting properties of coffee because of the rich antioxidants it contains.
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The article goes on to provide a list of such studies.

But I'm guessing the judge in question simply has to follow a relevant law - which doesn't have any provision for considering the potential health benefits of the same substance.
 

deirdre

Senior Member.
To make things murkier:

https://www.caffeineinformer.com/caffeinated-coffee-the-anti-cancer-wonder-drug

Study after study has been showing the cancer fighting properties of coffee because of the rich antioxidants it contains.
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The article goes on to provide a list of such studies.

But I'm guessing the judge in question simply has to follow a relevant law - which doesn't have any provision for considering the potential health benefits of the same substance.


Quoting from a website called "caffeineinformer" is akin to believing a FB meme without fact checking, so just for the benefit of public health...


And many of the newer studies link coffee drinking to a lowered risk of some types of cancer, including prostate cancer, liver cancer, endometrial cancer, and some cancers of the mouth and throat.

But in some of these studies, the benefit was found in people who drank 4 to 6 cups of coffee a day, which is a lot. Too much caffeine can interfere with sleep, trigger migraines, and cause digestive problems. And if you take your coffee with cream and sugar, the added fat and calories can contribute to weight gain – which increases the risk for many types of cancer. According to Colleen Doyle, MS, RD, American Cancer Society managing director of nutrition and physical activity, the surest steps any of us can take to lower cancer risk are: don’t smoke, eat well, and be physically active.

And if you want to consume more antioxidants, consider adding more vegetables and fruits to your diet.

https://www.cancer.org/latest-news/can-coffee-lower-cancer-risk.html
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Perhaps putting a cancer warning on coffee makes people less safe.

As we get inundated by more and more warnings, the normal human reaction is to start ignoring them. At best, it becomes difficult to find out which warnings are the most serious (tobacco, Tide pods...) when they're lost in a flood of trivial danger alerts.
 

Whitebeard

Senior Member.

kasparovitch

Active Member
From Homo Deus by Yuval Noah Harari:
In truth [future superhumans] will actually be a-mortal, rather than immortal. Unlike God, [they] could still die in some war or accident, and nothing could bring them back from the netherworld. However, unlike us mortals, their life would have no expiry date. So long as no bomb shreds them to pieces or no truck runs them over, they could go on living indefinitely. Which will probably make them the most anxious people in history. We mortals daily take chances with our lives, because we know they are going to end anyhow. So we go on treks in the Himalayas, swim in the sea, and do many other dangerous things like crossing the street or eating out. But if you believe you can live for ever, you would be crazy to gamble on infinity like that.
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That's why I'll keep taking my daily espresso. Trials on mice exposing them to more than a thousand times acrylamide concentrations consumed by humans in coffee isn't enough evidence. Further, if I quit coffee I'll be exposed to acrylamide anyway.

I don't plan to climb the Himalayas, but I'll keep swimming in the sea sometimes, as well as crossing streets and eating out.
 

Dan Wilson

Senior Member.
Perhaps putting a cancer warning on coffee makes people less safe. As we get inundated by more and more warnings, the normal human reaction is to start ignoring them. At best, it becomes difficult to find out which warnings are the most serious (tobacco, Tide pods...) when they're lost in a flood of trivial danger alerts.
That is my worry. Should people also be warned about cyanide in apple seeds? Or all of the foods that naturally contain small amounts of formaldehyde? I think these are comparable situations to warning people about acrylamide in coffee. We know that eating apples and foods that naturally contain formaldehyde (ex: carrots and spinach) aren't going to significantly increase your risk for cancer yet the warnings would likely all be perceived to be on the same level as cigarettes.
 

deirdre

Senior Member.
We've already seen seen people liken cigarettes to red and processed meat
not sure comparing processed meats to coffee is a good comparison. or.. are you saying I'm supposed to cut down on my coffee AND my bacon!!!??? cause.. now I'm totally bummed out. Although.. I would be willing to swap some coffee for bacon. hmmmm.
 
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