Archive for the ‘science’ Category

Weird things we do to food plants (other than genetic engineering)

Mutant carrot. Photo credit: Joebeone

Here’s an embarrassing confession: when I was eight, the cartoon Attack of the Killer Tomatoes gave me nightmares. Seriously, what could be scarier than giant mutant tomatoes with teeth? (Don’t answer that.)

I’ve been thinking about these killer tomatoes a lot recently in the context of GMOs. Genetically modified organisms probably do seem about as unnatural and just as frightening (if less overt) as these tomatoes. It is scientists playing God. It is taking genes from one organism and sticking them into another. It is definitely unnatural.

But is it significantly more unnatural than other things we do to food plants?

I wanted to talk about some of the other weird s*** humans do to plants in this post, because I think there are a lot of misconceptions about how we develop crops. Unless you survive strictly off foraging, we all eat mutant plants every day. (That is, if you eat fruits and vegetables, which I hope you do.) Virtually all of our food plants are mutants, clones, or freaks, and about as far from their natural state as they can get through intense human meddling. Here are a handful of the ways we grow and eat mutants.

Corn: pretty much unrecognizable from its wild grass ancestor. Photo credit: photofarmer

Cherishing Mutants

Plants don’t evolve to be edible. (Quite the opposite, generally.) Many, in their unmodified state, are toxic, unproductive, hard to get, or just plain unappetizing. If you take a look at the wild ancestors of things like corn or tomatoes, you will almost certainly come to the conclusion that our ancestors must have been damn hungry to eat that. Corn is a great example. It started off as a wild grass with 5-10 extremely hard kernels per spike. Now, we don’t know the whole story, but we guess that when our ancestors found a mutant plant with softer kernels, they saved them to grow more mutant corn plants, maybe bred them with each other. This particular mutation is bad for the plant (soft kernels = seeds are all eaten by predators), but good for humans. Lots of crosses and some more chance mutations later, we have corn. Mutations, which are the raw material of genetic diversity — and which result in novel proteins — still happen. So does cross-breeding. Kevin Folta, a plant geneticist at the University of Florida, estimates that between 10,000 and 300,000 genes are affected when we breed plants the traditional way. We definitely don’t eat what our ancestors ate, and in a lot of ways, that’s a good thing.

Mutagenesis: plant breeding through radiation damage. Photo credit: ssoosay

Making Mutants (MOARRR MUTANTS!)

Right. So mutation is the rough material of genetic diversity, but we can’t control where and what kind of mutations will occur in nature. If we’re trying to get a new a trait into a plant, we can a) damage its DNA through chemicals or radiation and hope that some of the resulting mutants will have good traits; b) insert the gene in through genetic engineering; or c) try to get it through traditional breeding. Believe it or not, we’ve been using the first (mutagenesis) for the past 80 years. Wiki notes that, between 1930-2007, more than 2540 mutagenic plant varieties have been released. These mutants are fairly common in our food supply and include varieties of grapefruit, pear, sweet potato, rice, peppermint, citrus, and yam. No label required. Yay for DNA damage!

A grafted tree. Photo credit: Jbcurio

Attack of the Clones

Not to take down a childhood hero or anything, but Johnny Appleseed probably left behind a lot of apple trees that produced gnarly inedible apples. Apples don’t breed true from seed (since they are not self-pollinated, a Golden Delicious tree will only pass on half its genetic data to its seeds), so in order to get an orchard growing, all the same type of apple, you need clones. Every Honeycrisp apple tree in the world is genetically identical.

One of the really weird things we do in order to clone trees is to take a branch, cut a slice in an existing, related plant, and bind them up until they grow together. This is an age old technique known as grafting. You can end up with at tree that bears several types of fruit! They’re called ‘fruit salad trees.‘ In the photo, you can still see where one tree started and the other left off, yet they’re part of the same tree. Sort of. These guys are the real frankentrees, in my opinion.

Seedless watermelon…nope, definitely not natural. Photo credit: stevendepolo


Would you be insulted if I called you a diploid? I’m one, too. So is your mother. So is my cat. It just means that we have two copies of each of our chromosomes (23 pairs in humans, for a total of 46 — get this, the adder’s tongue fern has 1440!).  Some organisms have just one copy of each chromosome, like bacteria, where others can have four, six, or even more. When something has more than two copies of each chromosome, it’s a polyploid.

Humans have figured out how to induce polyploidy in plants by treating them with a certain chemical (colchicine). We’re not just adding a couple of genes — we’re adding a whole extra genome. (You’ll remember that even one extra copy of one chromosome in humans — 3 copies of chromosome 21 — causes Down syndrome.) And in fact, polyploidy is how we get things like seedless watermelon and seedless bananas. (I know, right? A seeded banana??) First we treat them to get tetraploid plants, which are crossed with regular diploid plants to produce sterile (seedless) offspring. Think about that the next time you eat a banana without spitting out seeds.


Bottom line: humans do lots of weird things to plants, most of which have the potential to result in harmful, toxic, or allergenic foods. We don’t have long term safety tests for most of the foods we eat, including things like hot dogs, goji berries, and root beer (one component, natural sassafras flavor, was found to be carcinogenic fairly recently). Given that almost all of these techniques (except cloning, of course), result in much greater genetic changes than genetic engineering, I think it makes sense to be, if anything, more worried about mutagenesis and polypoidy than genetic engineering.

…Or, if you’re lazy and have a family history of heart disease and cancer anyway, you could be like me and eat lots of fruits and veggies and not worry too much about the other stuff. Just an option.

On a side note, I’m back in school, and my brain is inundated — and I mean polyatomic ions are coming out my ears — with chemistry and biology at the moment. I’m hoping to pursue a graduate degree in botany or plant bio once I’ve beefed up my wussy language arts background. Having this blog has made me realize that it’s time to get out of my house and brain and start doing something about the many problems we face. It’s starting not to be enough for me to sit behind my computer and fret over the miniscule impact of forgetting to bring my reusable bulk bin bags. I want to be doing something. I’m not an activist — I don’t like ideology or emotions — so science it is. I hope you’ll wish me luck and forgive me my erratic postings in the months to come. Peace.

In praise of weeds

Dandelion. Photo credit: David Hepworth

If you can eat, breathe, or exist, thank a plant. Plants often get the short end of the stick when it comes to Things Humans Are Interested In. They’re not all that cute (some might surprise you), they don’t talk (at least not to us), and all in all, compared to your average smart phone or polar bear, seem pretty boring. Yet all the organic carbon on this planet ultimately comes from plants.

From your windowsill miniature rose to the predatory bird of paradise in your backyard, all plants are busy wrenching apart water and carbon dioxide molecules, stripping them of hydrogen and carbon atoms to make organic hydrocarbons (plant sugars). Humans can’t do this. Your Android can’t do this. My fuzzy gray cat can’t do this. Only plants (and algae) do this. Almost every food chain everywhere on the planet starts with plants. 

I’ve taken you on a number of virtual nature walks (woodstreespoisonous plants), but now I’d like to introduce you to the most common and least loved plants of all: weeds.  Weeds are one of the ways I first started to interact with the natural (naturalish?) world. I’ll be fond of them until / unless I start trying to grow things on purpose.

I grew up in my mom’s postage stamp sized garden in northern California. She wasn’t a fastidious gardener (still isn’t), and I was short (and still am), so I paid as much attention to crawling weeds as I did the taller stuff. At that age, I didn’t recognize a distinction between wanted and unwanted plants. Sorry, Mom. I’m responsible for your dandelion explosions. <Poof…>

The names and details came later. Many of them surprised me, since the books that I had first read about these plants led me to expect something…bigger. Grander. Less common. But the more I learned, the more interested I was for their own sake. Here’s a virtual garden of weeds I grew up with. What weeds are in your yard?

Sorrel (genus: oxalis)

Woodsorrel. Photo credit: Pellaea

I thought these were shamrocks for the longest time. One of their alternate names is actually False Shamrock. I wonder if you’re still lucky if you find a four-leafed oxalis? The most common type of sorrel I know has tiny yellow flowers, but among the shade of the redwoods, sorrel has big heart-shaped leaves and tall pink flowers. Oxalic acid gives sorrel a tart flavor. In large doses, oxalic acid causes kidney stones, so if you’re trying to keep yourself alive after the zombie apocalypse, don’t eat too much sorrel. Nice accent on a salad, though. (Note: don’t forage near roads or where plants have been heavily sprayed, like most lawns.)

Clover (genus: Trifolium)

Clover. Photo credit: Public Domain Photos

Clover flowers make nice daisy chains. I cleverly figured this out for myself while sitting in outfield during the softball unit of PE each year. (This should tell you something about my athletic prowess.) It also flavors honey and feeds cows. Red clover increases cows’ milk output, but too much clover can lead to fatal cow bloat. Burr clover has pointy spurred burrs that stick to clothing and fur, so watch out.

Scarlet Pimpernel (genus: Anagallis)

Scarlet Pimpernel. Photo credit: Rictor Norton and David Allen

Instead of crushing on boy band members as a teen, I crushed on well-dressed fictional gentlemen in cravats, including the Scarlet Pimpernel. After reading the book, I hopped online to see what a scarlet pimpernel looked like and was devastated to find that it was neither scarlet (salmon…maybe) nor impressive (flowers are usually smaller than 1/2″). In fact, this was the same unheroic weed that had taken over one corner of my mom’s yard years earlier. My mom was similarly unbelieving when I pointed it out to her on a walk many years later. Despite my disappointment, I still think scarlet pimpernels are pretty. But should anyone be looking for an emblem under which to subvert the French government, may I suggest the star glory instead?

Rattlesnake Weed (genus: Euphorbia)

Rattlesnake Weed. Photo credit: David~O

This one grew in the mortar between bricks, which says something about its tenacity. The stems are filled with a sticky, milky sap that is intensely bitter. Bitterness is often an indication that something has toxic alkaloids. Good thing I never took more than a lick! A tea made from rattlesnake weed was an herbal remedy for snake bites, but you probably don’t want to take a chance on it. Euphorbs are characterized by toxic milky saps that can blister, so although nothing ever happened to me from playing with rattlesnake weed, handle with care. As a rule of thumb, don’t eat a wild plant that has milky sap. And if you taste any plant that is bitter or makes your mouth tingle, put it down at once!

Purslane (genus: Portulaca)

Purslane. Photo credit: Frankenstoen

I recently found out purslane was edible, so this summer, when my mother was ready to weed her garden, I asked her to save the purslane for me. I tried it with scrambled eggs and mushrooms. It wasn’t bad, though a little slimy. The technical term, I believe, is ‘mucilaginous.’ Most importantly: I didn’t die! Purslane is a succulent with a slightly tart edge and interesting texture. If you’re going to eat it, don’t harvest from areas subject to spraying (either from pesticides or dogs).

Pineapple Weed (genus: Matricaria)

Pineapple Weed. Photo credit: ArranET

This small plant with rounded yellow flowers and lacy leaves didn’t grow in my mom’s backyard, but it did grow at my school. When I learned the name, I figured that the flowers look maybe a little (if you turn your head to the side and squint?) like upside down pineapples. But actually, if you pinch a flower open, they have a pleasant, fruity smell that has a hint of pineapple to it. Pineapple weed is related to chamomile, although more bitter, and if you’re in a pinch, rubbing the plant on your skin is supposed to repel insects.


Even recognizing that weeds are a tremendous agricultural problem with no good solution (till and you degrade the soil; no-till and you have to use herbicides), I feel a certain admiration for these hardy, unwanted plants that survive despite the harshest conditions — no water, poor soil, herbicides, insects, fierce competition. They’re continually evolving resistance to our most powerful herbicides and other ways to kill them.

We city dwellers often bemoan the lack of nature in our immediate surroundings, but I dunno…maybe it’s just that we don’t pay enough attention. Do you know what weeds grow around you?

Weed identification resources:

Also, this is what I’ve been up to lately.

Just label it! Supplements, that is.

Let’s talk about a big, billion dollar industry. Lots of hype, little solid data. Basically unregulated. No need to perform safety tests or clinical trials before putting a product on the market. No review or testing by an independent party. Checkered safety record, certain products strongly linked to organ damage, cancer, hepatitis, and death (among other things). Consumed by millions of unsuspecting citizens every year.

GMOs? Nope. I’m talking about the supplement industry.

Image credit: Ano Lobb

Twitter friend @donnzpg recently pointed me to this article on Consumer Reports: 10 Surprising Dangers of Vitamins and Supplements — don’t assume they’re safe because they’re ‘all-natural’. It struck a chord with me because I know people — lots of people — who are intensely skeptical about synthetic cosmetics ingredients and pesticides and GMOs, yet take many supplements and herbals without requiring independent, double-blinded clinical testing results.

I am absolutely guilty of this. I choose cosmetics with very few ingredients (and yep, generally natural ones) and use very few of them, because I fundamentally don’t think the cost/benefit assessment pans out when it comes to something like cosmetics. Yet I haven’t once checked up to see what tests have been done on my daily vitamin. Probably not too many — it came from my well-intentioned mother, who got it at Target. In fact, I feel downright virtuous when I take it even though I’ve read the studies that question the efficacy of vitamins and supplements. (High doses of vitamins can be downright harmful.) I buy fortified orange juice even thoughI just saw a study that suggests that too much calcium and Vitamin D can cause blood and bone issues

Goddammit, brain. If this is the best you can do, I might have to replace you with a more rational model.

As a plant lover and photosynthesis fan, I’m struggling to overcome my naturalistic fallacy and look at plants in a more rational way. Some can heal, many can harm, and a fair number can kill. If you’re not convinced that plants have a dark side, think about this. When the first photosynthesizing organisms arose, they caused a major extinction on earth by flooding the atmosphere with that most unstable, reactive, and poisonous gas — oxygen. But then oxygen became the basis for the ozone layer, which protected life from that other tremendously dangerous, carcinogenic force: UV radiation. If you can eat or breathe or walk under the sun, thank a plant.

At the same time, because plants can’t move, they’ve evolved into incredible chemical factories that protect them from predators. Coffee, bread, chili peppers, and basil are just a few of the things we eat that have naturally occurring carcinogens, and there is nothing that makes these natural chemicals inherently less toxic than synthetic ones. Many of our synthetics are actually based on natural chemicals! As Bruce Ames has said, 99.9% by weight of all pesticides we eat are entirely natural.

What this means is that supplements are chemicals. Essential oils are chemicals. Herbal medicines are chemicals. And the fact that they come from natural sources says exactly nothing about their safety. (It terrifies me when I read about well-meaning green pet owners applying essential oils to their pets. Without clinical testing or dosage information, it’s all one big experiment on a favorite quadruped.)

I’m biased, of course. My aunt died of kidney failure just after turning 40. She had an intense distrust of western medicine and instead relied heavily on traditional Chinese herbal medicine. An autopsy revealed a startling accumulation of heavy metals in her body. These were traced back to the high doses of unregulated herbals she took for 10+ years. She left behind two young children and is much missed.

It’s an anecdote, not a peer reviewed study, but it made an impression on me. And I don’t think it’s altogether an unusual story, either. Supplement makers do not need to test their products or back up their health claims. They do not need to test for or list possible, sometimes extremely serious, drug interactions. They do not need to show allergenicity studies. They have to be proven harmful before the FDA steps in. And they are quite common in processed foods, so it would be fairly easy to overdose on certain vitamins if you drink fortified milk, eat fortified cereal, and pop a daily multivitamin.

I guess my question is: why is the consumer standard of proof so different — and lacking — for supplements? If cosmetic chemicals and GMOs are so alarming, why are we not up in arms demanding that supplement manufacturers prove the safety of their products before peddling them to us?

Just some of the things I’ve been thinking about. Do you take supplements? Have you looked into their safety?

Thoughts on the California GMO labeling initiative

I’m guest blogging over at the Just Farmers blog today about California’s GMO labeling initiative. It’s an issue that I’m solidly on the fence about, and I’ve tried to present both sides fairly. I hope you’ll take a look and let me know what you think! I’ll be featuring farmer Mike Haley’s perspective on the issue next week. Here’s a teaser from the post:


California’s GMO Labeling Initiative – A Consumer’s Perspective

At an Earth Day festival in the San Francisco Bay Area this year, a GMO labeling activist grabbed my arm and told me that labeling GMOs was ‘a matter of life and death.’  A few months and a lot of signatures later, the initiative met the requirements to be voted on this November.

As a Californian and an environmentally concerned citizen, I’ve been following the developing dialogue on GMOs with interest. I’ve seen a growing divide between public’s perception of genetic engineering and the scientific community’s. And while I share concerns over the long term effects of genetic engineering, I really don’t like the reactionary rhetoric being used to promote labeling. In other words, I’m a fence-sitter.  Instead of taking a stance, I’ve been talking to people: scientists, farmers, environmentalists, parents, science teachers. I’m no closer to making a decision, but I’ve been able to look at the major arguments of each side.

As far as I can tell, the argument in favor of labeling is based on:

  • Desire to make and promote transparent, educated choices. As consumers, we want more information about our food so we can make responsible choices for our own health and that of the environment.
  • Concern about the long term effects of GMOs on human and environmental safety.  The safety testing and information on GMOs is not readily accessible to consumers, and the info that is available tends to be from activists who emphasize risks.

Keep reading at Just Farmers

Photo credit: MillionsAgainstMonsanto

The Curious Case of the Transgenic Papaya

I’m on Elephant Journal today, doing a Q&A with the scientist behind the Hawaiian transgenic papaya. I’ve excerpted the beginning of the interview (and it’s a bit lengthy, so be forewarned) and hope you’ll read it with an open mind. And please ask questions! I’ll do my best to get answers for you.


Stop by the farmers’ market in Hilo, Hawaii, and you’ll find knobby cherimoyas, avocadoes the size of eggplants, and mounds of papayas, sunset-fleshed and as smooth and sweet as custard.

That wasn’t always the case. Back in the 90s, Hawaiian papaya farmers were faced with devastation from ringspot virus, a plant virus that reduced papaya production by 50% within six years and just kept spreading. Small farmers faced losing their livelihoods when one plant pathologist developed a virus-resistant variety called the Rainbow and distributed the seeds to struggling farmers – for free. Fourteen years later, Hawaii’s small papaya farmers are flourishing.

There’s  a lot to like about this story –the altruism of the researcher, the success of independent local farmers. But there’s one detail that could change everything about how you see it: the Rainbow papaya is genetically modified. A gene from the ringspot virus was inserted into the papaya, where it acts like a built-in vaccine against the virus. In other words, it’s Frankenfood. Or is it?

I say GMO, you think: Monsanto, Big Ag, lobbyists, corporate interests. But none of these played a major role in the GM Rainbow papaya. And for me, that led to an important realization. Genetic engineering technology is not the same thing as Monsanto/ Big Ag policy. It’s a tool. And like all tools, it can be used for good or bad ends.

I’m a skeptic, so I scoured the web for info – agricultural news sites, activist sites, USDA releases, science journals, and blogs. Then I took my questions to the man who developed the Rainbow, Dr. Dennis Gonsalves, retired Professor Emeritus of Plant Pathology at Cornell and now the director of the USDA’s Pacific Basin Agricultural Center. He’s a straight shooter, detailing the successes and challenges of the project with peer reviewed articles and independently verifiable facts. Halfway through our exchange, it hits me: why shouldn’t we always address our science questions to scientists, not lobbyists or activists?

In that spirit, I’ve included his answers to my questions below.

Q: How did you get started with your work on the transgenic papaya?

I was born and raised on a sugar plantation on Hawaii Island but never aspired to be a scientist until I worked as a technician under Dr. Eduardo Trujillo of the University of Hawaii. He let me loose trying to figure out what was causing a disease of papaya and that experience convinced me that I wanted to be a plant pathologist. Dr. Trujillo was a mentor and an inspiration to me as he would periodically to tell me: “Dennis, don’t just be a test tube scientist, but do things to help people.” […] The feeling of joy was incredible when I first inoculated the transgenic papaya in the greenhouse and it showed resistance to PRSV [papaya ringspot virus]. However, that was nice science but how could we translate it to helping people? Naturally, the challenge came when PRSV invaded the Puna district and within a couple of years the Hawaiian papaya industry was in deep trouble. We had a potential solution, had published some nice papers, but did we have the ‘guts’ to try to help the industry survive? We had never attempted to deregulate a transgenic product, as the common thought was that this was the purview of the big companies. But somebody had to do it, and thus we got out of our ‘comfort zone’ in order to help the farmers.

Q: Did you really give out GE (genetically engineered) papaya seeds for free to farmers?

The seeds were initially distributed free to the growers because I believe the industry (Papaya Administrative Committee) got some grant funds from the state to produce the seeds.  Now, the industry produces the seeds and sells them at cost to the growers.

Q: What non-GE methods were used to attempt to combat ringspot virus on Hawai’i?

People have been trying to do classical breeding to get resistance for a long time.  In Carica papaya, there is no resistance.  Some tolerance is found and people have been trying to incorporate these in some lines.  The tolerance is ‘quantitative’ so it can get diluted.  Bottom line, this has not worked for Hawaiian papaya.

Crops rotation, lower densities, etc. have been tried but they do not work because the virus is rapidly transmitted by aphids.  One way that can work economically is to go into virgin areas where it is far from the nearest virus infected papaya, and continually pull out trees as symptoms develop on the new planting. […] Naturally, the more isolated you are the longer for the virus to ‘find’ the papaya field.  One question is:  Environmentally, is it better to clear virgin forest or land to plant papaya than growing virus resistant GE papaya where papaya growing areas already exist?

Keep reading on Elephant Journal…

Photo credit: leahleaf

Meet the Poisonous Plants In Your Backyard

Lily of the Valley (Convallaria majalis). Pretty, delicate, toxic. Image credit: Leo-seta.

Sadly, the internet tells me that there’s no such thing as a toxophile or toxicophile. If there were, I’d make a blog button for it. (Other suggested blog buttons for my site: Anti-Social Media Expert — thanks, Karen — and Evolutionary Dead End. Alas, I don’t know how to make buttons.) Anyway, what I mean to say is that I kind of have a thing about poisons. And by thing, I mean that people who look too closely at the books on my bookshelf might decline an invitation to dinner.

This is what comes of reading too many Agatha Christie books at a young and impressionable age.

Plant poisons are my favorite. I’m always taken aback by how elegantly and creatively nature addresses the problem of being eaten. Plants can’t run, so instead they wage chemical warfare on their predators. The Indian bean tree, for example, produces a nectar with a compound that only affects cheater species that steal nectar — but not pollinators.

And plenty of plants are well-protected not just against insects, but also bigger animals, like humans. There are lots of them, and they’re all around us. I’ve pulled together some of my favorite common wicked plants, a number of which are probably in either your backyard or a backyard near you. Welcome to my virtual poison garden!

(And for crying out loud, teach your kids to respect plants. I sampled my way through my mom’s garden as a kid and got lucky she didn’t have anything really poisonous. Although I guess that could explain some of my peculiarities.)

Nerium oleander. Image credit: heatheronhertravels

Oleanders are, in a sense, perfect garden shrubs. They’re drought resistant, have nice foliage, and produce lovely symmetrical pinwheel flowers that smell nice. They’re also among the deadliest of common garden plants, possessing a number of cardiac glycosides that affect heart function and can cause death. Even honey made from oleander nectar is toxic. (Most deaths by oleander, however, are intentional. By anecdote, a number of seniors have ended their lives by drinking oleander tea because it was readily available in their nursing home garden. That story makes me sad.) Interestingly, oleanders are also being investigated for therapeutic uses in treating cancer. The dose makes the poison.

Viburnum lantana. Image credit: Bosc d’Anjou

Lantanas have peppy colored flowers and nice leaves, but that’s about where the good news ends. They’re invasive in Australia, Hawaii, South Asia, and Southern Africa because 1) birds like the fruit and spread the seeds; and 2) the leaves are toxic to most species. Lantanas, especially the unripe berries, contain pentacylic triterpenoids that cause liver problems and phototoxicity in grazing animals (including small children).

Digitals spp. Image credit: Salt Spring Community

Foxgloves are an old garden favorite. The name has an odd etymology that doesn’t actually involve small reddish quadrupeds (Wiki can tell you all about it). Another name for this plant is deadman’s bells. Foxgloves contain cardiac glycosides and have actually been used to treat some heart conditions since the 18th century. My grandmother, who has had congestive heart failure, is on a synthesized form of digoxin. However, cross the [narrow] therapeutic threshold and foxgloves can cause nausea, halos, delirium, irregular heart rhythms, and death. All parts of the plant are toxic, not just for humans, but also for dogs and cats. Even drinking the water that cut foxgloves are sitting in can be deadly.

Conium maculatum. Image credit: jkirkhart35

I doubt anyone plants poison hemlock on purpose, but it’s a common weed in fields and pastures. It’s quite a delicate looking plant, a spindly 6′ tall with dainty little white flowers. Purple spots or streaking on the stalks are a dead giveaway, but it resembles plants that are edible or medicinal (Queen Anne’s Lace, wild fennel, parsley. Socrates is probably hemlock’s most famous victim. Hemlock contains a highly toxic compound called coniine, which paralyzes the muscles, including the heart. It doesn’t take much to cause death — 100mg of the leaves, root, or seeds.

There are many, many others: nightshades, sago palms, castor bean, angel’s trumpets, water hemlock (as if one deadly hemlock weren’t enough), buttercups, dieffenbachias…just more proof that nature’s chemicals aren’t necessarily safer than manmade ones. Which poisonous plants do you have in your garden? 

OK, I think I’m done poking my naturalistic fallacy in the eye with a sharp stick now. If you’re interested in the topic, you might enjoy:

Unpacking the idea ‘safe’

Are things either safe or unsafe?

It’s a common demand from the public to scientists: prove to us something is safe before unleashing your monster on the world. And on one hand, it’s a totally fair, reasonable request to not be treated as lab rats. I get that. I hate the idea of having big chemical corporations profiting off their creations that create long term problems for ordinary people and the environment. On the other, whether you’re talking about GMOs or synthetic chemicals, it’s a problematic request for a couple of key reasons:

  • It assumes a binary between safe and unsafe without regard to exposure level or other circumstances. Just about everything can be harmful under the right (or perhaps I should say wrong?) conditions. Take water, for example. Tons of evidence that it’s generally safe to drink. However, it’s still possible to die from drinking too much water. Even small quantities of water, if inhaled, can be deadly. It’s called drowning. Microbes also love water, which is important to know if you’re into DIY personal products.  Does that mean water (and do check out the dihydrogen monoxide website, if you haven’t seen it) is unsafe? Yes — if you define safe to mean that any level of risk from contact with water is unacceptable. Of course, dehydration’s not a lot of fun, either. Water is a simple example, but virtually any substance you can think of has benefits and drawbacks, conditions in which it has no harmful effects, conditions in which it does. That goes for everything from fluoride to Botox.
  • It doesn’t define safe in a way that science can address. Science is good at testing for one thing at a time, under controlled and specific circumstances. Safety is not a trait that can be directly tested for. We can’t run a chemical through a gas spectrometer and have that tell us whether something is safe or not; we infer safety from the absence of observable harmful effects in a fairly wide range of applications, test subjects, and experiments. To get meaningful answers, we need to ask meaningful questions. Instead of asking, “Is BPA safe?” we need to be asking things more like, “Do low doses of endocrine disrupting substances like BPA produce harmful effects on developing human fetuses?” That’s a reasonable request for information, and it’s something scientists could design experiments around to answer.
  • Scientists don’t know what they don’t know. You’ve probably heard of prescription drugs that were withdrawn when they eventually proved to have major, unexpected health impacts. It’s not that tests were necessarily done improperly; it’s that scientists didn’t know enough to ask the right questions before the issues became apparent. It’s impossible to test for lack of harmful effect for everything, at every level, in every remotely plausible circumstance. And although we mostly hear about the failures, when scientists haven’t anticipated and tested for a particular problem, there are many prescription drugs and chemicals that have gone on to establish very solid safety records and saved lives.

Science is limited in the answers it’s able to offer us. Sorry. That’s just the way it is. Sometimes the answers are inconclusive and pending further research. The scientific method can also be a bit clunky with its one variable model when it comes to looking at multiple factors and multiple exposures, which are inevitable in real life scenarios — one of the reasons we’re having such a hard time pinpointing causes for things like cancer and autism. And no, the media totally doesn’t get this. No one’s going to read a headline about inconclusive test results. It doesn’t make for an exciting story.

Instead of asking whether something is safe, I’ve begun to try (try!) to look at things on a spectrum of lower risk to higher risk and think about decisions as risk evaluations.  At the lower risk end, I would include things that have 1) solid, evidence-based records of few or no harmful effects, 2) relatively few/unusual circumstances in which it produces harmful effects, and 3) statistics favoring my likelihood of emerging unscathed.

Here are some things I would consider lower risk  within the parameters of my life:

  • Eating spinach. Yes, spinach contains oxalic acid, which is linked to kidney stones. But as a healthy person, I’d have to eat massive amounts of it all the time to develop significant health issues, and the nutritional benefits associated with eating moderate amounts outweigh the risks.
  • The preservative in my contact lens solution. Used in small quantities, well-tested, and far lower risk than putting something with microbial or fungal growth in my eyes. Definitely less risky than driving in my 10 year old glasses (time to get those replaced!).
  • Cleaning Brie’s litter box. Yes, she’s had toxoplasmosis. That’s why she’s blind. (I sometimes refer to her as Toxokitty. No brownie points for sensitivity there.)  No, she’s not shedding parasite eggs anymore, and no, I’m not pregnant.
  • Sunblock. Something I put on only when I anticipate needing it and can’t avoid peak sun hours or don a hat. In the quantities I use it, it’s not going to have an appreciable effect on my life. The dose makes the poison.
  • Taking allergy medicine. I used to pop an antihistamine daily in the month of May for allergies that otherwise left me a fatigued, sniffly, nosebleedy mess. Now I just go somewhere else on vacation. When I need an antihistamine, I still take it. There are side effects; they make my eyes dry and sometimes affect my energy levels. But I’m willing to accept that risk.
  • Baking in silicone. I bought silicone muffin cup liners a few years ago when I thought they might be greener than the paper I had been using. I’ve wavered in that belief (they take ridiculous amounts of water to clean, won’t biodegrade, and involve fossil fuels), but I still use them every now and then when they make more sense than paper. I’ve read the available studies, and I use them maybe five times a year, at relatively low temperatures.

Higher risk (somewhat likely to result in grievous bodily harm, more proof of harm, or harmful under more circumstances):

  • Driving or riding in a car. Hands down the most statistically dangerous thing I do on a regular basis. Car fatalities are down somewhat in recent years, but there were 32,885 in 2010. That doesn’t include injuries.
  • Drinking alcohol. I seem to be mildly allergic to alcohol and don’t drink, but if you look at the chemical properties of alcohol, it fits many of the criteria we use for calling other substances poisons. There are well-established acute and long term risks associated with drinking, yet we’re much more likely to get excited about the potential toxicity of a synthetic or newer chemical.
  • Eating unidentified wild mushrooms. Most mushrooms are not fatally toxic, but there are a handful that will really do a number on your liver. The chances of randomly picking an amanita to sample may not be that high, but the potential fatality is a deal breaker. For me, anyway. Maybe I’ll do a post later on how to identify an amanita mushroom.
  • Breathing in silica dust. There’s a reason why silicosis is known as ‘potter’s rot.’ Silicosis is not reversible or treatable, and some of the older potters I work with tell me that their lungs, x-rayed, look somewhat like smokers’ lungs. You’d think this would get me to wear a mask, especially when I’m carving clay. Not yet. I’m being stupid like that.
  • Cutting Brie’s claws. Almost inevitably ends in blood loss (mine). ‘Nuff said.

I’m surprised at how reluctant I am to put pottery on that list. A small voice in the back of my brain is protesting, “But I like pottery,” as if that influenced risk level in any way whatsoever. It also wants to add, “But clay is a natural substance,” which it is, and which also doesn’t influence risk level in any way whatsoever. Do you ever want to call your own brain a troglodyte? I do.

I haven’t done the research yet to be able to put other things I do (eat raw cookie dough, for example — I’m pretty sure my current salmonella-schmalmonella attitude is not appropriate) on the spectrum, and frankly, I still fall for naturalistic fallacy all the time. But I still want to point out that headlines don’t present information in perspective with the actual amount of risk something presents. It’s the other, ordinary stuff that’s really likely to get us: poor eating habits, lack of exercise, driving, and I think it’s helpful to keep that in mind when reading alarming headlines or studies. After all, life is one of those things in which no one gets out alive.

Do you classify things as safe or unsafe? What would persuade you that something was safe?

Photo credits:, ell brown

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