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I understood the blogger just fine, but I read Heaney's statement differently. I don't find it clear that he's saying that fructose use should be reduced strict

I understood the blogger just fine, but I read Heaney's statement differently. I don't find it clear that he's saying that fructose use should be reduced strictly because of his paper and for no other reason, as the article implies (if it did I would agree with the blogger), especially when he said other bad things about fructose. This is what we really know - in some undetermined context, in conversation, Heaney said "I think this paper has a lot of public health implications. Hopefully, at the federal level there will be some effort to step back on the amount of high fructose corn syrup in our diets," To me it doesn't seem perfectly clear that Heaney intended that the first sentence, by itself, implies the second sentence, though the article sort of makes it look like he did. It's certainly not clear enough to rip him a new asshole, as the blogosphere has done, at least not based solely on the information in this article. If you give me six lines written by the most honest man, I will find something in them to hang him. —Cardinal Richelieu

carbocation 16y ago
"I think this paper has a lot of public health implications." Extrapolating from tissue culture to public health is something that can be rigorously done. This paper doesn't address public health; as such, I don't see how it follows in a scientific fashion that this paper has public health implications. I don't have a problem with the work, or with the author, or with his beliefs about his paper. I simply disagree that his statement, quoted above, is justified by his paper.
- rsheridan6 16y ago
  I haven't read the paper, but the blog post says it cited prospective human studies showing an association between pancreatic cancer and fructose consumption, so it looks like he digressed into something beyond cell cultures to make the case against fructose. He could very well have been overselling his paper (the article certainly is), but it's just possible that the journalist made it look that way to get a sexier story. If the blogger had kept a more objective, factual tone, instead of attacking Heaney, I wouldn't have a problem.
  - carbocation 16y ago
    Let me preface by saying that I don't want to overstate what I think is really a rather modest difference of interpretation that you and I have. I have read the paper, and much of their basic biology seems sound. They show convincingly that pancreatic ductal cancer cell proliferation does not differ between glucose and fructose at a variety of concentrations (figure 1). They then compare pancreatic tumor to hepatic tumor to normal-ish tissues and show a series of metabolic differences when grown in glucose-containing vs fructose-containing media (figure 2). These changes include transketolase activity, ribose synthesis, and release of C13-labeled lactate into the media. Here, I have a bit of an issue. Nobody is claiming that our high-fructose diet causes us to have a glucose-free plasma, so it's totally non-physiologic to compare just glucose vs just fructose (which some of the panels appear to be doing in this figure, while others are comparing glucose vs fructose+glucose, which is a stronger comparison IMHO). There are other figures; they are fine. I like their data. Where they lose me is with the claims that they make from their data. They show in figure 1 that there is no proliferative difference in Panc-1 cells between a glucose vs a fructose "diet" at all concentrations, but then based on data in figure 4 they claim that the TK-inhibitor oxythiamine reduces "fructose-induced Panc-1 cell proliferation." Well, which is it: does fructose induce Panc-1 cell proliferation, or does it not? Your answer will depend upon whether you like figure 1 better or figure 4. While these claims appear to be contradictory to me, it's also possible that I didn't read the paper carefully enough so please correct me if I missed something. At any rate, just because this paper cited other work showing human studies (which it did), that certainly does not mean that this paper itself has policy implications. The human studies that it cited might have policy implications. Especially given figure 1, which shows no difference in proliferation between cancer cells given fructose and those given glucose, I would have a hard time justifying policy claims with this paper.

carbocation 16y ago

"I think this paper has a lot of public health implications." Extrapolating from tissue culture to public health is something that can be rigorously done. This paper doesn't address public health; as such, I don't see how it follows in a scientific fashion that this paper has public health implications. I don't have a problem with the work, or with the author, or with his beliefs about his paper. I simply disagree that his statement, quoted above, is justified by his paper.

rsheridan6 16y ago
I haven't read the paper, but the blog post says it cited prospective human studies showing an association between pancreatic cancer and fructose consumption, so it looks like he digressed into something beyond cell cultures to make the case against fructose. He could very well have been overselling his paper (the article certainly is), but it's just possible that the journalist made it look that way to get a sexier story. If the blogger had kept a more objective, factual tone, instead of attacking Heaney, I wouldn't have a problem.
- carbocation 16y ago
  Let me preface by saying that I don't want to overstate what I think is really a rather modest difference of interpretation that you and I have. I have read the paper, and much of their basic biology seems sound. They show convincingly that pancreatic ductal cancer cell proliferation does not differ between glucose and fructose at a variety of concentrations (figure 1). They then compare pancreatic tumor to hepatic tumor to normal-ish tissues and show a series of metabolic differences when grown in glucose-containing vs fructose-containing media (figure 2). These changes include transketolase activity, ribose synthesis, and release of C13-labeled lactate into the media. Here, I have a bit of an issue. Nobody is claiming that our high-fructose diet causes us to have a glucose-free plasma, so it's totally non-physiologic to compare just glucose vs just fructose (which some of the panels appear to be doing in this figure, while others are comparing glucose vs fructose+glucose, which is a stronger comparison IMHO). There are other figures; they are fine. I like their data. Where they lose me is with the claims that they make from their data. They show in figure 1 that there is no proliferative difference in Panc-1 cells between a glucose vs a fructose "diet" at all concentrations, but then based on data in figure 4 they claim that the TK-inhibitor oxythiamine reduces "fructose-induced Panc-1 cell proliferation." Well, which is it: does fructose induce Panc-1 cell proliferation, or does it not? Your answer will depend upon whether you like figure 1 better or figure 4. While these claims appear to be contradictory to me, it's also possible that I didn't read the paper carefully enough so please correct me if I missed something. At any rate, just because this paper cited other work showing human studies (which it did), that certainly does not mean that this paper itself has policy implications. The human studies that it cited might have policy implications. Especially given figure 1, which shows no difference in proliferation between cancer cells given fructose and those given glucose, I would have a hard time justifying policy claims with this paper.