Grumpy toxicologist blathers on

Disclaimer: Before we get into this, you should know that I am a toxicologist, with a bright, shiny, glass encased piece of paper that says as much.  I am not a doctor, or a pharmacist, and while I fancy myself more informed than some doctors and pharmacists, that doesn’t mean you should follow my advice blindly.  These are just my (educated) opinions, the choices I make in my own life – your mileage may vary.

Also worth saying: this is a HUGE can of worms. There is no way for me to succinctly cover these subjects, and also it’s probably impossible for me not to offend someone, or get someone riled up about something I glossed over.  If you are confused about something or want more info, just ask – I love talking about this stuff, and I hope that this obviously a pretty quick rundown.  If you are about to leave a nasty comment about how I don’t know shit, ask yourself if you think I have expressed all the knowledge that came with my fancy PhD and professional experience in this here 1200 word blog post, and then go right ahead and yell at me, because I love a good ridiculous argument.

Ok, moving along. There are a few ideas that are sort of critical to understand before reading the rest of this (or pretty much anything I ever say about tox, drugs, chemicals, etc.):

1.        The dose makes the poison.  Anything, in large enough quantities, can be toxic.  I come back to this idea a LOT – moderation is key. Too much of a good thing is BAD.  A little of a bad thing can be no big deal.  Ultimately, dose is the most important factor when determining if something is safe or unsafe.

2.       Interindividual variability, i.e., my body is nobody’s body but mine.  Unlike most lab animals on which chemicals are tested (and I fully support rigorous animal testing, but I’m betting that’s a conversation for another day), humans vary a LOT.  My personal physiology can be considerably different from yours, and yours, and yours.  Some of these differences are known, some not; some are important, some unimportant.

So, now that that is out of the way. The topics I get asked about most frequently are pesticides, plastics, antibiotics, and sweeteners (artificial, HFCS).  Also a lot about drugs (OTC, RX, and recreational) for a host of reasons (e.g., can I take this with that? Can I take this while pregnant/breastfeeding? etc.).  I’m going to just talk about pesticides right now, as I think this will get lengthy pretty fast (considering I’m already up to like 500 words and I’ve not even gotten to my actual subject yet…)

Right up front, here is my rule of thumb for just about everything: if it isn’t cigarettes [or other tobacco products], it’s not worth worrying about.

First up, pesticides. Ok so I think 99% of organic produce is a waste of money at best, and a marketing scheme at worst. Yeah, I said it. Pesticides, man: it’s better living through chemistry.  Most pesticides have species-specificity. That means that the way they kill whatever pest is harassing your bananas is something that humans don’t have.

So when sensationalist fear mongering jerk wads (like the Environmental Working Group, who puts out the “Dirty Dozen” list) say things like

“Pesticides are toxic by design.  They are created expressly to kill living organisms — insects, plants, and fungi that are considered ‘pests.’”

They are capitalizing on folks not understanding the intricacies of human, animal, insect, plant, and fungal physiology.  Which, duh, most people don’t and shouldn’t! I’m sorry, learning about the life cycles of slime molds and corn smut isn’t really something most people are interested in.  So they read “it kills X, it’s probably bad for Y too” and don’t understand that humans don’t even have the right enzymes or whatever else for it to even matter.  In the quantities these pesticides are actually found on foods, they will not do a damn thing to humans. Now, if you drank a bottle of the pesticide straight up, it would probably do something bad – because even though you don’t have that particular enzyme that makes it toxic to the pest, you probably have some minor pathway that becomes involved when you are exposed to such an enormous dose.  It’s like an overdose of a drug – the normal pathways that get rid of junk for you get overwhelmed, and suddenly there is garbage going where it normally wouldn’t, causing problems.  But the margin between what you are actually being exposed to on that apple, and what would cause toxicity?  Is like a damn dump truck filled with apples, every day, for your whole life.  Saying that the one apple’s worth of pesticide is bad for you is like saying a snowflake could kill you, just because that’s what avalanches are made from.

Leaving aside the toxicity of the pesticides themselves, in many cases, the pesticides are getting rid of something that is terrible for humans.  Sometimes, it’s just something that affects food supply and availability, like certain molds that make something kind of gross or inedible, of bugs that just plain eat it before we get the chance.  But, particularly with a lot of molds, there can be something straight up toxic that grows on the food if pesticides aren’t used.  Example: there is a mold that is endemic to peanuts called Aspergillus.  Some strains of this mold create a byproduct as they grow, called aflatoxin.  It is a primary liver carcinogen.  It is a nasty, terrible compound.  And it’s NATURAL! (Do not EVEN get me started on how just because something is “natural,” it must also be SAFE, oh my sweet hell.)  So, in organic peanut butter, that weird oily concoction much beloved by hippies and hipsters all over this great country, you are eating a side of carcinogen that is simply not present in the non-organic brands (MMmmm JIF!).  That’s just one example – there are a slew of other mycotoxins (toxic mold byproducts) that can occur, most of which are fairly rare in this country (YAY FUNGICIDES), but they are really fascinating.  To me.  Just for peace of mind I will say that the mold on your bread and the mold on your cheese are no big deal, just kind of icky, so be calm and eat your food.

So, I had a few more paragraphs in here about my love of pesticides, but it got a little too sciency and I don’t want to scare y’all away.  I want to make clear that there are definitely drawbacks to some pesticides – they affect some good bugs and organisms and eff with the balance of the environment when they are used too much (just like antibiotics ha ha ha omg).  So, if I were in charge, we’d be all about sustainable farming practices, and no monocultures, and local produce, and la di da.  To minimize their use to what is most sensible and necessary.  BUT – I’m not.  So, I try to support those things when I can, and when I can’t, I buy the plain old produce at the store.  Because when I buy the mass produced organic bullshit, I’m playing into their* hands EVEN MORE.

*The evil marketers and big ag and also probably HITLER.

Updated to add: One important thing that some twitter folks brought up – I have reduced this issue to one of simple toxicity to consumers.  There is a lot more to pesticides – their effects on the folks who apply them (farm workers, and their families), for one – these people get occupational exposures that are quite a lot higher than the end consumers, and this is DEFINITELY an issue worth discussing.  It’s terribly difficult to keep all of these issues in mind, and base your purchasing behaviors off of them consistently – it’s so much to consider!  I end up getting very discouraged about our food supply and farming practices in the US (and many other developed countries).  So, for me – I try to put my money where my mouth is, buy as much as I can from local farmers (meat AND produce). My own opinions are local/sustainable first, organic second.  FOR ME, local meat is more important than local produce.  But this is necessarily a reductionist view – it’s IMPOSSIBLE to keep all the issues in mind (effects of pesticides on consumers, farm workers, ecology; politics of agribusiness; transport and storage issues, agh, my brain hurts).  I might need to just make this stuff another post!  But PLEASE if you have additional thoughts or a different perspective, share it!

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13 Responses to Grumpy toxicologist blathers on

  1. Elsha says:

    Thank you! I love the science-y stuff.

  2. A'Dell says:

    This is awesome. I love everything about it. WRITE MORE!

  3. Diane says:

    Okay, I’m listening about the peanut butter. I never used to eat organic, but I switched to it with all this corn-free eating and you’ve got me freaked. Do they test for that fungus at all? Is this just all up in all the organic peanut butter? WHY IS MY LIVER SO ACHY ALL OF A SUDDEN?

    • snoozical says:

      There is a limit for the amount of aflatoxin that can be in commercially prepared human food (20 ppb) – the FDA does test and regulate the amount. The way aflatoxin causes cancer is through metabolic activation to a reactive epoxide – basically a really unstable compound that binds to whatever is nearby in order to become more stable (sort of like Britney Spears). This epoxide causes a lot of issues to cellular components, one of which – DNA – is kinda important; when it binds to DNA it can cause mutations, and mutations can lead to cancer over time (and with exposure to other bad actors, like the tasty parts of grilled hotdogs). Organic peanuts and organic peanut butter tend to have higher levels of aflatoxin than do non-organic, though if they are commercially prepared, the levels are still under 20 ppb (and unlikely to cause any issues even if you eat peanut butter all the time). So – I would and do sometimes eat organic peanut butter, if it’s around, I just don’t pay for it. And I do keep it refrigerated, as that discourages aflatoxin production. The thing I really won’t eat though, for real – is boiled peanuts or any peanut product purchased from road side stands, which is a big thing in Georgia at least. I also won’t eat peanut anything in countries that don’t regulate aflatoxin.

  4. jonniker says:

    Everything about this is awesome, Susie. Everything. Thank you.

  5. RobinMcDougall says:

    The last two posts are fantastic. Succinct and direct. Refreshing too that you make no bones about it, and are up for a talk.

  6. Lauren says:

    This is awesome. Thanks for your thoughts.

  7. Jennifer says:

    This raises a lot of questions for me that perhaps you can shed some light on.

    First, I had read that the dose does not always make the poison, and largely depends on stage of development and perhaps the individual –

    and is there a cumulative effect of eating an entire diet that is laced with pesticides? (perhaps not a ton of apples all at once, but a diet where everything contains something… and pesticides are in your couches and mattresses and rugs and bedding, as well as your household cleaners and your lawn etc.) And is there any concern of mixing these pesticides with any pharmaceuticals? or other pesticides?

    I look forward to hearing your perspective.


    • snoozical says:

      Sensitive life stages or idiosyncratic individual responses do occur, but even within these scenarios, the dose-response relationship is maintained. That is, regardless of how sensitive an individual may be, the presence and degree of toxicity are still linked to the magnitude of exposure. Life – everything – exists as a bell curve. There are people who are more sensitive, people who are less sensitive to various things. Regulation of exposure limits are geared towards protecting sensitive subpopulations, rather than the average human. Allowable exposures are generally orders of magnitude below levels that cause effects in animals, and known species differences are taken into account.

      As far as the chronic exposure to many pesticides – the cumulative exposure is still very, very low. Chemical mixtures tend to be additive rather than synergistic (i.e., they do not magnify one another to something more than the sum of their parts). Epidemiological studies of broadly occurring, chronic exposures indicate that any possible effects of pesticides are ambiguous, at best: very subtle, population level correlations with a grab bag of biological responses. So, not even enough to establish causation, and this is all very subtle on a population level.

      To distill all of that into something a bit more digestible: in a world where we are constantly surrounded by people blowing smoke in our faces, where we spend hours in cars on highways with tons of exhaust, where many willingly lay in tanning beds or refuse to wear sunscreen, where we fail to follow simple instructions on our pharmaceuticals: don’t worry about it. It won’t even register, on an individual basis. I could make a solid scientific case that worrying about this stuff sends your cortisol levels through the roof and does far more damage than the pesticides.

  8. beanonparade says:

    Yes! I love the science and that you care enough to say these things out loud.

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  10. PinkieBling says:

    This is spectacular. I’ve been buying into the hype, and I mean that literally, as my grocery budget has doubled since I started buying organic. Of course, my doctor told me that pesticides are neurotoxins, so it seemed worth it. Argh.

    What about antibiotics in meat and poultry? I’d love to hear your take.

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