Diving into the soy controversies

Part 1 - GMOs .

Cloaked in St. Patrick’s Day green, the marketgoer wobbled his way towards our booth. “You know…” he hollered over. “Soyyyy gives you boobiess!!!”

“Actually, that’s been disproven.” I yelled back, and his face immediately softened, as if thanking God! “My wife makes me eat it…” he confessed, wobbling away.

Soy is controversial, and criticisms surface like whack-a-moles:

• Soy causes deforestation!

• Soy destroys biodiversity!!

• GMOs are poisoning us!!!

• We're all allergic…

The sheer number of claims has created a generation of vague skeptics. We know that soy is bad, but we don’t know why.

On my end, I’m more comfortable playing the “it’s been debunked” card than truly clearing out the dust. I know enough to inform my own actions, but not enough to teach others.

For the next few weeks, let’s dive into the soy food controversies. Let’s understand them, and be that voice of reason the next time our friend tells us they love tofu but don’t love the hormones.

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A thank you to Jacob for submitting a tofu to be identified. If you see an unfamiliar variety at your local market or restaurant and want to learn what it is, you can ask me here.

Jacob, this looks like a soft tofu, fried then braised. You mention the outside skin feels like inari, or Japanese fried tofu puffs. When tofu is fried, water is converted to steam and expands. For very dense tofu, like inari or spongy varieties, steam can’t escape, so the tofu puffs up. This gives the skin that loose texture. You have to fry it slowly, till a skin forms, then bump up the temperature. If you’re curious, check out these videos on how it’s made.

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Week 1: GMOs

For thousands of years, farmers achieved incremental crop improvements through selective breeding. Merging the entire DNA of two cultivars sometimes led to hybrids with higher yields or improved nutrition or rot resistance. In the early 20th century, scientists realized they could incorporate foreign traits by instead mutating genomes with radiation or chemicals. As haphazard as it sounds, mutagen breeding produced thousands of popular crops today, from disease resistant rice strains in China and Vietnam to the American ruby red grapefruit. In the 1990s, farmers took these techniques a step further. Instead of playing round after round of genetic Russian roulette, they learned to throw on the surgical coat. With ribonucleic precision, scientists began splicing individual genes. Enter bioengineered crops.

Genetically engineered (GE) or modified (GM) organisms are controversial. Supporters argue that they increase yields and reduce pesticide usage. Opponents contend that the opposite is true — and that GMOs have created superbugs, destroyed biodiversity, and been mainly a boon to agrochemical monopolies.

Let’s go through these issues one by one, focusing on the soy.

Crop yields.

The evidence suggests that bioengineered soy has led to increases in yield.

One widely-cited study suggests that from its inception to 2014, GE crops have produced 22% increases in yield, largely from improved pest control. Some independent researchers have criticized these findings, arguing that those benefits are overgeneralized and overstated, that the study oversampled the most efficient GE crops (Bt cotton) and undersampled less efficient ones (like herbicide-tolerant soybeans), and drew its conclusions before a recent emergence of superbugs. The criticism is correct in direction, but wrong in conclusion. Looking at studies that focus on US and high income country soybean farming (where there should be the least benefit), we still see a boost of around 7%. Moreover, while superbugs have been emerging, this is not specific to GM crops. In fact, GE crops still use fewer herbicides than conventional. Conventional crops face their own pests too, which is why herbicide-tolerant crops were developed in the first place. (More on pesticide use below.)

Regardless of the specific numbers, it’s clear that American farmers prefer growing GE soybeans, making up a whopping 94% of harvests. This is in spite of the fact that GE soybeans sell for less than conventional, and have higher seed costs. If not for yield or profit benefits, why would farmers choose GMO?

Crop yields have increased because of GMOs, and it’s likely they will continue increasing. One emerging technology, making soybeans adaptable to variable sunlight conditions, has produced a whopping 25% increase in output in field trials, which is basically unprecedented. 

Okay… but why does yield matter?

1. Food security. The UN predicts the world population will reach nearly 10 billion by 2050, and this begs the question: how will we feed everyone? Increasing crop yields, among other things, reduces the need for additional farmland, which reduces the need for deforestation. (Of course, there are other ways to feed more people, like transitioning towards plant-forward diets, reducing biofuel production, and lowering food waste.)

2. Animal farming. 77% of soybeans are fed to livestock. Cheaper feed reduces the cost of meat and increases consumption. According to one listing, GMO commodity soybeans sell for ~15% less than their non-GMO counterparts (granted, livestock don’t eat whole soybeans, but rather soymeal.)

Is cheap, abundant soy good? Depends.

Pesticide use.

Pesticide use and toxicity has likely decreased due to GM crops. Let’s break it down.

Pesticide use volumes have certainly decreased. This is mostly from the introduction of insect resistant (IR) traits. These allow crops, like Bt corn and cotton, to endogenously produce toxins that combat predators, reducing the need for insecticide. (Notably, these toxins are pretty targeted, so are less harmful to other insects, like bees, than broad-range insecticides, and break down quickly in the soil.)

Within the broader category of pesticides, herbicide use volumes have increased. This is due to herbicide tolerance (HT) traits, which make crops like soybeans impervious to broad-spectrum herbicides, like glyphosate. When they were first introduced, HT traits allowed farmers to substitute a larger mix of herbicides for just a couple, lowering overall usage, but as is often the case when particular herbicides are overused, superbugs emerged. To combat these superbugs, overall herbicide use is now increasing. 

This sounds like a strong hit on HT crops, but the truth is more complicated. While glyphosate-resistant superbugs came from a reliance on GMO-specific pesticides, the problem is even bigger for non-HT rice and wheat crops, as well as conventional crops more generally, where herbicide usage is rising the fastest. Glyphosate-resistant superbugs are a small part of a much larger picture of poor pest management.

Beyond pesticide use volume, it’s helpful to think in terms of impact. Some herbicides are more toxic than others. Glyphosate, the active ingredient in Roundup, the most popular herbicide for GE crops and the most widely used herbicide in the world, is regarded by the toxicology community as less toxic and more efficient than other synthetic herbicides (1, 2). Thus, even though herbicide use has gone up due to HT crops, the overall harms of that use has gone down. Human studies haven’t shown harms from acute glyphosate exposure at normally observable levels. Chronic exposure is more uncertain. Rat studies indicate lower chronic toxicity compared to other herbicides, but some recent human studies have shown increasing rates of Non-Hodgkin’s Lymphoma among farm workers. This led the International Agency for Research on Cancers (IARC) in 2015 to classify glyphosate at a Category 2A “probable carcinogen.” Notably, the WHO Joint Food and Agriculture Organization, European Food Safety Authority, European Chemicals Agency, and the US EPA dispute these findings, believing that 1) other factors better explain the higher rates of cancer, 2) many other studies conflict, and 3) there isn’t a clear cancer-causing mechanism. Some researchers point out the difficulty in ascertaining a mechanism, as it would likely involve difficult-to-measure endocrine or microbiome disruptions.

What should we make of this? There is some evidence that glyphosate has contributed to an increase in particular forms of cancer among farm workers who see high chronic exposure. This is worrisome, and there certainly ought to be better farm worker protections. Fortunately, there is no evidence to say that glyphosate has harmed livestock, who eat the majority of our soybeans, or human consumers of soy foods. While it’s possible this lack of evidence is because it’s hard to measure side effects, you could say the same for most foods or additives. Should we not eat any new foods?

To put this issue in context: other diet related conditions like heart disease and diabetes kill 18 million and 2 million people per year, representing nearly 50% of all human deaths. We know how these diseases emerge, as well as how to prevent them. If there are undetected issues with glyphosate, these seem small in comparison to our bigger, avoidable killers.

Gene Flow and Invasiveness.

One concern with GE crops is that they may breed with wild relatives, conferring their adaptive traits and increasing the risk that the hybrid will outcompete and disrupt its ecosystem. These ecological dynamics haven’t been widely studied, but there doesn’t seem to be evidence that this has been a problem. Moreover, emerging research suggests that GE crops can be designed in a way that prevents horizontal gene transfer and interbreeding. This can be done by engineering them to survive on non-standard amino acids, which their offspring would be unable to produce or find in their environment. (This technology doesn’t seem to be widely adopted, so both sides are speculative.)

Biodiversity.

Another popular criticism of GMOs is that they’ve contributed to crop biodiversity loss. Lifted by their efficiency and profitability, and extensive marketing by GMO seed giants, a small number of plants — corn, soy, cotton, canola — have increasingly become monocrops. This trend poses risks to food security, as one exceptionally powerful pest or disease could threaten a large portion of the world’s calories. On the other hand, being able to grow more food on less land can also enhance food security, by creating more calories, without increasing the carbon cost of land use.

Biodiversity loss may be an issue, but avoiding GMOs wouldn’t solve it. Corn and soy were efficient at converting land into calories well before GMOs, and they would continue to be in a post-GMO world. This criticism is of industrial agriculture, which is a separate debate.

Capitalism.

Another popular criticism of GMOs is that the industry behind it is depraved. Most of the GE seed market is controlled by just a few agrochemical giants — Monsanto (Bayer), DuPont Pioneer, etc. — who have historically done some abhorrent things, from promoting agent orange use in Vietnam to miscommunicating about health risks from their products. It’s clear that these corporations aren’t here because of good will. They are ruthless profit-seekers.

Granted, most corporations are ruthless capitalists, and that doesn’t mean we should run from their underlying industries. Like biodiversity loss, capitalism isn’t a criticism of GMO’s — it’s a much bigger debate.

What does this mean for tofu?

To be clear, most American tofu is already non-GMO. Ditto for soy products from China, where GE soy isn’t allowed in human food, oil aside.

So… if you worry about GMOs, one solution is to eat more tofu! Support the conventional soy market.

I myself am a bit concerned about GMOs. Cheaper corn and soy feed makes for cheaper meat. One family farmer suggests it costs ~$750 to raise a pig, with nearly half of that cost from feed. Another farmer estimates that it costs nearly $12.50 to raise a broiler (meat) chicken in your backyard, with about half the cost from feed. (Note: the costs are much lower for CAFOs. Hence, Costco’s $5 rotisserie chicken…)

While I don’t know the exact price elasticities of supply and demand, I pale at the thought of making factory farms even 1% more efficient. There are enough animals suffering in cages.

As for the environment and human health? I think GMOs help us far more than hurt.