1. Dan Wilson

    Dan Wilson Active 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
    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
    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.
    Last edited: Apr 2, 2018
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  2. kasparovitch

    kasparovitch 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...
  3. Z.W. Wolf

    Z.W. Wolf Senior Member

    To make things murkier:


    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.
  4. deirdre

    deirdre Moderator Staff Member

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

  5. Bill Statler

    Bill Statler 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.
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  6. Whitebeard

    Whitebeard Senior Member

    Like all the cancer scare stories the Daily Mail has run over the years...

    here's a non-exhaustive list
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  7. kasparovitch

    kasparovitch Member

    From Homo Deus by Yuval Noah Harari:
    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.
  8. Rory

    Rory Senior Member

    I stopped drinking coffee 20 years ago and I don't have cancer. That's proof.
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  9. Dan Wilson

    Dan Wilson Active Member

    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.
  10. deirdre

    deirdre Moderator Staff Member

    I doubt that. But what will likely happen is that people will stop listening to ALL warning labels that say Prop 65.
  11. Dan Wilson

    Dan Wilson Active Member

    We've already seen seen people liken cigarettes to red and processed meat. I could see many vocal activists making the comparison although I think most people would not go that far.
  12. deirdre

    deirdre Moderator Staff Member

    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.
  13. qed

    qed Senior Member

    Red meat. Now @deirdre's avatar is making me hungry.
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  14. Efftup

    Efftup Senior Member

    a life with no coffee and bacon is not ACTUALLY longer, it just SEEMS wayy longer.
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  15. MikeC

    MikeC Closed Account

    Evidence you don't have cancer?? :)
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