This is the next installment of Snoozical Rambles about Toxicology, which may or may not becomes a weekly theme.  If you are new here, you should go read my disclaimer.  

Today, I’m all jazzed about artificial sweeteners, specifically aspartame.  This is a subject near and dear to my heart, which is to say: don’t fuck with my diet coke, man.  More often than not, when people find out I’m a toxicologist, they give me the side eye and ask me why I’m drinking that diet soda because don’t I know that aspartame will make holes in my brain or give me cancer etc.??

Nope!  No it won’t!  Aspartame is so, so, SO non-toxic.  “But wait! Susie, you said before that the dose makes the poison! And I’ve seen you down a two liter in one evening!”  Yes, you are correct – the dose DOES make the poison – and aspartame doesn’t become a poison unless you are drinking ridiculous volumes.  Here are some numbers: the FDA acceptable daily intake (ADI) for aspartame is 50 mg per kg of body weight.  That equates to over 3 grams of pure aspartame per day for a 135 pound human, on up to 4.5 g for a 200 lb person.  There are about 125 mg of aspartame in a 12 oz can of diet coke, my drink of choice – so that’s about 10.4 mg per ounce.  In order to reach my daily limit of aspartame, I’d need to drink nearly 300 ounces of diet coke.  In a day. I’ve tried, I’ve done some serious focused work, and the most I’ve ever had in a day is two 2 liters.  That’s ~135 ounces. I had to use a bendy straw, and I had several people cheering me on.

Ok, so maybe you’re thinking, wait, that’s not that far from the limit! 135/300, that’s almost halfway there! Right, so that 300? That is equivalent to the 50 mg/kg/day FDA ADI.  That number is health protective, i.e., well below an exposure that could be expected to cause any toxicity in humans – you could ingest that much, every day, for your whole life and experience no health effects.

The ADI is based on a LOT of science: a host of epidemiological studies of humans, as well as long term exposure studies in animal models.  Taking the animal studies first: the National Toxicology Program, an actual reputable research organization, conducted life time exposure studies in rodents  with daily intakes spanning

In acute studies in rodents, no effects were observed at doses exceeding 10,000 mg/kg.  That’s the equivalent of a rat pounding 20 cans (240 oz) of diet coke at once.  Or a human drinking 5600 cans of diet coke. THAT IS A LOT OF DIET COKE, even for me. In chronic, lifetime cancer bioassays in rodents, they fed doses up to 12,000 mg/kg/day for periods up to two years (the lifetime of most rodents), and were unable to detect effects.  NO EFFECTS.  You have to believe me when I say that this INSANE – laboratory rodents LOVE getting tumors, and they just WOULDN’T DO IT.

Epidemiological studies in humans have been similarly boring – no effects, no significance, nothing, nothing.  There was one by Olney et al. (1996) that tried to correlate aspartame with brain tumors, but that study has been roundly dismissed due to wonderful, ethical things like fudging and misrepresenting data. Every other study, and there have been MANY, has found no effects. NO EFFECTS.

Aspartame: the least toxic substance ever, except maybe water.

All the cold hard facts (numbers) in here came from the 2007 Safety Evaluation by B.A. Magnuson et al.  Here is the evaluation summary, and here is the evaluation itself (though you’d have to pay or have journal access to read it).


Oh hey, I’m blind.

So, do you read xkcd? You should, if you don’t. It’s a delightfully nerdy webcomic.  Today’s comic was this infographic about the visual field:

Fascinating, no?  Well, it got me thinking about my visual field.  My eyes are really shitty – they went south around third grade, and haven’t really stopped getting worse since then. So, a 20 year slow deterioration.  No big deal, but they really decided to go for the gold beyond that. I’ve always had deposits of random crap on my optic nerves, which in my case affect my peripheral vision (thus, very clumsy).  So, no peripheral vision – no big deal. BUT THEN, like four years ago, I got optic neuritis.  My optic nerve in my right eye (previously my good eye) got all pissed off for reasons unknown, and parts of it never recovered – the resulting ischemia (lack of circulation) caused parts of the nerve to die, so now it’s like a TV screen with messed up pixels.  This is what my central vision looks like in both eyes:

So, no peripheral in either eye, and yeah my right eye is basically effed.  When this first happened, it was very confusing – I just CAN’T see a lot of what is right in front of my face. It was scary and weird. Now, my brain has largely compensated – it fills in the blanks pretty well most of the time to where I only notice it occasionally.  I can still drive and play sports reasonably well, but I awkwardly miss high fives all the time, and I’m REALLY easy to sneak up on.  Medically, it’s sort of fascinating because idiopathic optic neuritis is a HUGE risk factor for MS – something like 50% of folks who get it end up with MS eventually.  That freaked me out for a long time, but at this point I have no other risk factors and there is nothing I can do about it regardless, so whatever. I haven’t actually thought about that part much in years.

So, that’s today’s interesting factoid.

I have a bit of a dinosaur obsession. Seriously, people send me pictures of dinosaurs all the time, dinosaur figurines are all over my house. Dinosaur clothes, dinosaur costumes. My kid is constantly subjected to dinosaur themed outfits and toys. So, here is a survey of my obsession.

It all began in 2007. Seems like it’s always been that way, but no: on the way to a frisbee tournament in grad school, I purchase some dinosaur figurines, because why not? Well, turns out there is a very natural configuration of t-rex and triceratops:

Boring car ride to Florida? Make friends with a plant eater.

Well, it was love at first sight. Those figurines inspired a jersey for the first co-ed frisbee team I put together:

Everyone's favorite jersey ever.

Which is possibly the thing I am most proud of creating, in my whole life. Including my kid. No, that’s a lie. Or is it? I mean, it’s a heady thing to realize, as you are creating something, that this is it: the peak of your creativity.

The naughty dinosaurs were so emblematic of Kevin and me, that they showed up on his grooms cake (albeit, not in their usual positions) and drawn on the window of our matrimonial carriage. To which my mother referred, “Look! Someone drew the butt-$%#^ing dinosaurs on the car! Hah!” and then I died.

Groom's cake = frisbees made of funfetti cake, obviously.

Since then, the jersey also begat an excellent pair of halloween costumes. We were playing on a food themed frisbee team for a halloween tournament, and all I could think of was dinosaurs. So we went as dinosaur fruit snacks.

Then we decided to have a kid. More opportunities for dinosaurs! First there was a dino-themed baby shower, the highlight of which were the inflatable dinosaurs. (There were also two dino themed cakes, and various stuffed dino presents and dino clothes.)

Needed a quick nap, and they pounced.

And, of course, myriad opportunities to clothe our kid in dino clothes, and also take pictures with awkward dinosaurs in the background.

My mother-in-law snapped this for us.

I figure we have another six to twelve months before she starts picking out her own clothes. She will inevitably hate dinosaurs, so we will force her to love them until our opinions no longer matter. Sucker!

There a lot more dinosaur things in my life, but those are the highlights.

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!


I have lately been getting really RAGEY about certain topics, where the great unwashed masses (i.e., the sector of the general public who disagree with me) take stances that reveal what is, to me, a GROSS MISUNDERSTANDING of biology.  Because I have a LOT of schooling in biology, physiology, etc., I try to remember that what is basic to me may be completely foreign to a layperson, but it’s hard.  Other things, well, I know the underlying biology is not remotely basic, but I wish that there were a way to communicate it to laypeople more effectively.  All of these things make me crazy.  Some examples:

1. Vaccines. I am not sure I can even talk about this without hurting someone.  I will only say two things [today]: first, anecdotal evidence is not the same thing, and does not carry the same [read: any] weight as scientific and  epidemiological evidence. Second, the choice of vaccinating or not affects entire populations, not simply the individual in question.  The amount of restraint I am showing stopping with that is HUGE, let me tell you. 

2. Individual metabolism, weight issues, etc.  It pisses me RIGHT OFF when people assume that every body behaves the same way.  That if only you ate like *I* eat (as in, some asshole, not me (or you) personally), you’d be just as thin and fit!  NO. The amount we understand about diet/exercise/physiology, compared to what we don’t, is like comparing a bottle of water to the fucking OCEAN.  There are some things we know for sure, though: whole foods trump processed, some bodies tend to be heavier than others regardless of diet, exercise AND diet are both important.

3. Mixing frequently used pharmaceuticals and alcohol (e.g., tylenol/acetaminophen, antibiotics, etc.).  Some things, no big deal. Other things, HUGE DEAL.  People joke (I hope it’s a joke) about taking some nyquil and having some wine – NOoOoo.  Alcohol competes with acetaminophen for certain enzymes, forcing the acetaminophen down an alternative metabolic pathway that creates terrible toxins that can lead to liver failure.  As I type this out, I realize it probably isn’t “basic”, so I’ll chalk this up to scientists and doctors failing to communicate effectively.  BUT DAMN, acetaminophen overdose or alcohol-aggravated toxicity is one of the number one causes of liver failure in the US, the top Poison Control call issue, etc., so we should do a better job educating on this!  AND, this failure to communicate is why the dosage on acetaminophen was just reduced: instead of explaining why you shouldn’t take too much, they just reduced the dosage so when people take too much it won’t be as big a deal.  GRR.

4. Alcohol and pregnancy.  I hate this one because of how other people’s opinions end up affecting MY life.  There have been articles circulating about this recently, as a new study (NOT the first one by a long shot) was published showing that drinking MODERATELY while pregnant is not a big deal.  The comments I’ve seen relating to it have been half supportive, half “Oh well, you can hurt YOUR baby, but I won’t drink a DROP because I LOVE mine.”  Well, fuck that tone, first of all, but that aside: the great American hatred of moderation is the issue here.  Things don’t fall cleanly into “healthy” and “toxic” – the dose makes the poison. If you drink too much of ANYTHING, including goddamn WATER, it will do bad things.  But, instead of publicizing the idea of moderation, America decided to take a hard line and say none for anyone.  Like the medical and political establishments basically thought we were all idiots that couldn’t be trusted to understand things like “serving sizes” oh wait shit we can’t.  GAAh.

5.  Artificial sweeteners, slash why I will always drink Diet Coke so help me.  The volume of diet coke you’d have to drink DAILY for your ENTIRE LIFE to cause toxicity?  Well, you’d basically have to become an aquatic mammal that lives in a diet coke ocean.  GALLONS. A day.  When I was pregnant, a co-worker used to come by my office every day and judge me openly about my single DC per day habit. And he was an effing toxicologist, who smokes (see #7).  RAGE.

6.  Bisphenol A.  This isn’t basic, and some of the scientists fall into the unwashed masses camp.  But, as a toxicologist (a reproductive toxicologist at that), let me just say: calm down. “BPA Free!” has become a marketing tool.  BPA is so well-studied at this point, and any potential toxicity is so minor that no one can even come up with anything remotely definitive. The only definitive thing is that a) the levels in human blood are super low, and b) the estrogenicity of BPA is way way less than anything made of soybeans.  So, ya know, freak out about soy.  Also, the shit they are replacing BPA with? Totally un-studied.  So, if you are still freaking out about this, could you at least send me all your old plastic stuff?  Because I will totally use that shit. 

7. When people are totally insane about one of the above, but also smoke.  Like, “Oh, I will NOT use plastic, glass only for me!” as they gesticulate with a cigarette.  Smoking is about the ONLY life choice you, as an individual, can make that will have a measurable impact on your personal health (and the health of others! Awesome!).  The other shit, like BPA, pesticides on your fruit? Incredibly subtle, population level effects – like, you would need MILLIONS of people to possibly see anything, and even then, it’s usually only a weak correlation, not causation

I know that I am missing a lot of things that piss me off (I’m sure you’re super bummed to be missing out on my absurd rage), but #1 clouds my memory of anything else I’ve encountered recently.  Also, I’m kind of sorry if any of this makes you personally angry, but really I’d rather have a rage free educational discussion about all the reasons that I am right.  So, let’s do that instead.


First: thanks for the input on the dress! I’m totally wearing it, and I can’t wait.  

Now, life. I am so damn BUSY, and grah, I kind of hate it. Kind of. No, I do – it’s just a little too far. I like to be medium busy.  But right now, I’m running two concurrent animal studies, both of which involve breeding mice (which is easy but time consuming), I’m very very behind on two three papers, and I’m juggling normal everyday work stuff.  The papers are the thing that I hate – I am a decent writer (we are talking scientific, peer reviewed stuff), but I am SLOW. It is like pulling teeth, or watching paint dry, or perhaps both at once.  I just take forever.  I have at least gotten to a point where I will allow my coauthors and mentors to read my drafts.  I used to be a perfectionist, wouldn’t let anyone near a draft until I felt like it was DONE.  Now, I look forward to the constructive (and usually complimentary) comments, but I’d still rather do just about ANYTHING besides write.  And yet, that is the key to my advancement.  

I have a paper I have to finish by Friday, along with a ton of dissections and several meetings and AHHHH make it stop.  I can’t even look further ahead than Friday without hyperventilating.  On the bright side, there is a HUGE frisbee tournament this weekend and I am so SO excited about it.  Eyes on the prize! 

My wedding dress was one of my favorite things about my wedding. I found it at a thrift store – a new-with-tags J. Crew floor length white cotton sundress, $30, that I bought before I was officially engaged. I took it home and dyed it bright green on my stove.  One of my roommates actually hit me for ruining a perfectly good potential wedding dress, to which I replied “No, I just made it perfect for me.”  And it was PERFECT:


My wedding was also perfect: all our family and favorite people, lots of dancing, and lots of gin. 

So here is my dilemma: can I wear my wedding dress, now a knee-ish length sundress, to my cousin’s wedding in August?  I really REALLY want to, especially because the remnants are currently being made into a dress for Eliza. But, the cousin in question (and a good chunk of the wedding guests) were of course present at my wedding.  I don’t want to seem like I’m trying to upstage the bride or something by wearing my wedding dress to her wedding, but at this point, my dress really just looks like a run of the mill sun dress.  BUT everyone there will know it was my WEDDING dress, so does that trump its actual appearance?  

I never get to wear dresses, and it’s rare to get a non-ridiculous opportunity to wear a matchy matchy dress with my kid (they COMPLIMENT each other, they aren’t like CARBON COPIES so it isn’t totally absurd), so I really want to wear it! But I don’t want to be an asshole.  Verdict?