Leafy green insulin

Is biopharmed lettuce the answer to a national diabetes epidemic?

By Andrew Leonard
January 11, 2008 12:12AM (UTC)
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The Salinas Valley of California likes to call itself the "Salad Bowl of the World." According to the Salinas Chamber of Commerce, fully 80 percent of the lettuce consumed in the United States comes from this region. And don't even let us get started on the broccoli and artichokes.

Salinas boosters even claim that the region is responsible for such technological innovations as prepackaged fresh salads and precut vegetables. But such forward thinking is nothing compared to the opportunities proposed at the "Ag Innovation Action Summit" held at Hartnell College in Salinas in November, where various speakers enticed Salinas farmers with dreams of becoming "the Alternate-Oil Fields of the World, the Natural Pharmacy of the World, even the Silicon Valley of the Agricultural World."


The most provocative presentation was made by keynote speaker Henry Daniell, a plant biologist at the University of Central Florida. Daniel's research team at UCF has, he says, successfully implanted the gene for insulin in lettuce. He believes that insulin capsules made from the ground-up lettuce "could someday be used to prevent diabetes before symptoms appear and treat the disease in its later stages," according to reports of research published in Plant Biotechnology Journal last July. The results of tests run on diabetic mice indicate that after eight weeks of treatment with insulin derived from genetically modified tobacco plants, the mice "had normal blood and urine sugar levels, and their cells were producing normal levels of insulin."

Insulin typically is given through shots and not pills so the hormone can go straight into the bloodstream. In Daniell's method, plant cell walls made of cellulose initially prevent insulin from degrading. When the plant cells containing insulin reach the intestine, bacteria living there begin to slowly break down the cell walls and gradually release insulin into the bloodstream.

"Currently, the only relief for diabetes is a momentary relief," Daniell said. "Diabetics still have to monitor their blood and urine sugar levels. They have to inject themselves with insulin several times a day. Having a permanent solution for this, I'm sure, would be pretty exciting."

In Salinas, Daniell suggested that farmers would be able to sell their biotech lettuce for premium prices, and he dismissed fears of gene contamination spreading to non-modified lettuce. Such assertions are typically hotly disputed by anti-GMO activists, and to be sure, the track record for biotech claims on gene containment is not terrific.

Unfortunately for those diabetics who might envision getting their insulin fix while chomping their way through a nice fresh salad, the insulin must be extracted from the lettuce before consumption so doses can be accurately monitored. Which raises an irony alert.


Biopharmed insulin-producing lettuce as an answer to the diabetes epidemic that currently plagues some 20 million Americans -- a number projected to double by 2025 -- could be perceived as addressing the problem in exactly the wrong ass-backwards way. A growing chorus of public health advocates has been arguing for years that the diabetes epidemic in the United States is likely a consequence of our national bad diet. So rather than pour resources into redesigning lettuce, with, at best, uncertain consequences for the ecosystem and our bodies, maybe we should all just eat a lot more lettuce, of the regular old variety.

In that context, the fact that the Salinas valley produces 80 percent of the lettuce consumed in the United States is something to be upset about, not proud. If the country was eating properly, we'd need more than just one Salinas to handle the demand.

Andrew Leonard

Andrew Leonard is a staff writer at Salon. On Twitter, @koxinga21.

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