Posts Tagged ‘gmos’

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

Polyploidy

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.

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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.

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?

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