"Cancer cells slurp up fructose, US study finds"
That's the headline on Reuters, touting recent research published in the journal Cancer Research by scientists at the University of California Los Angeles. The implication—pushed by Reuters, other news agencies and even the head of the research team, Dr. Anthony Heaney—is that this study proves a potentially deadly link between diets high in high fructose corn syrup and pancreatic cancer.
Reality: This is no smoking gun. Far from it. I spoke with Dr. Otis Brawley, chief medical officer of the American Cancer Society, to get some perspective and find out what's really going on.
The researchers took existing* pancreatic cancer cells and grew them in a petri dish, outside of a human body. Some were fed on pure glucose, and some on pure fructose.
Cancer cells eat sugars of all kinds, Dr. Brawley told me. And this study confirmed that. The pancreatic cancer cells slurped up not only the fructose, but also the glucose. And they grew quite well on both. The difference lay in how efficiently the cells were able use the sugary fuel.
"Basically, certain cars prefer high octane gas versus regular. And what this article is saying is that, to these pancreatic cancer cells, fructose was more like high octane gas while sucrose was regular," Brawley said. "Fructose allowed them to grow more efficiently, which is different from faster. They were deriving a little more energy from every molecule of fructose."
The study does provide an interesting jumping-off point for further research, Brawley told me. But, on it's own, it doesn't say anything about high fructose corn syrup (which isn't pure fructose, but rather little-more-than-50/50 mixture of glucose and fructose). In fact, it doesn't even mean that pancreatic cancer cells in a human body would use pure fructose more efficiently than pure glucose.
That's because pancreatic cancer cells behave differently in a body than they do in a test tube, Brawley told me.
"I have treatments that can cure pancreatic cancer in the petri dish," he said. "We've had that for more than 50 years. But they don't work on pancreatic cancer in humans. That tells me there's a difference, biologically, between cancer cells in a petri dish and cancer cells in a person and we have to respect that."
I asked Brawley whether there had been any studies done that correlate diets high in high fructose corn syrup to prevalence of pancreatic cancer in humans. There are two, he said. But both show only a very weak statistical relationship. And there are several other studies, looking at the same thing, which found no connection at all. If there is a link, nobody has proved it.
So here's what we know:
1) Pancreatic cancer cells eat all kinds of sugar and use it to grow and multiply.
2) In a test tube, they can do that process more efficiently with fructose than with glucose.
3) We don't know whether that applies to pancreatic cancer cells in a human body. There's a reasonable chance that it doesn't.
4) These results are not something that can be extrapolated to apply to consumption of high fructose corn syrup in a human diet.
That's it. That's all the evidence tells us. Nothing else. There may well be health problems with high fructose corn syrup—I'm not familiar enough with the broader research to know—but this particular study really shouldn't be pointed to as evidence for that theory.
*I underline that because some people have apparently gotten the idea that the study shows fructose causes pancreatic cancer. The study absolutely did NOT show anything of the sort.