Right, you can’t always RCT in humans. But a causal mechanism + RCTs in animals biologically close to humans is convincing for something like lung cancer where minor differences among mammals shouldn’t matter much (although e.g. bears have evolved some crazy stuff to deal with all that fat they eat before hibernating).
where minor differences among mammals shouldn’t matter much
I think you are entirely optimistic. I recently pointed out that the research indicates that animal studies routinely (probably usually) do not transfer, and as it happens, animal smoking studies are an example of this, according to Hanson. So the differences are often far from minor, and even if there were cancer in the animal studies, we could infer very little from it.
I find much to agree with in Hanson’s writings, but in this case I just don’t find him convincing. One issue is that cancer is a scourge of a long-living animal. One hypothesis is that smoking causes long term cumulative damage, and you might not see effects in mice or dogs because they die too soon regardless. There is also the issue that we have a fair idea of the carcinogenic mechanism now, so if you think smoking does not cause harm, there also needs to be a story how that mechanism is foiled in humans.
I find much to agree with in Hanson’s writings, but in this case I just don’t find him convincing.
His interpretation, or his evidence? I point this out because it looks to me like your position has shifted from “the smoking / lung cancer link is established by RCTs in animals” to “even though RCTs don’t establish the smoking / lung cancer link for animals, we have other reasons to believe in the smoking / lung cancer link for humans.”
I find much to agree with in Hanson’s writings, but in this case I just don’t find him convincing...One hypothesis is that smoking causes long term cumulative damage, and you might not see effects in mice or dogs because they die too soon regardless.
So: heads I win, tails you lose? If the studies had found smoking caused cancer in animals, well, that proves it! And if they don’t, well, that just means they didn’t run long enough so we can ignore them and say we “just don’t find them convincing”...
There is also the issue that we have a fair idea of the carcinogenic mechanism now, so if you think smoking does not cause harm, there also needs to be a story how that mechanism is foiled in humans.
You don’t think there were plenty of ‘fair ideas’ of mechanisms floating around in the thousands of animal studies and interventions covered in my animal studies link? Any researcher worth his degree can come up with a plausible ex post explanation.
Right, you can’t always RCT in humans. But a causal mechanism + RCTs in animals biologically close to humans is convincing for something like lung cancer where minor differences among mammals shouldn’t matter much (although e.g. bears have evolved some crazy stuff to deal with all that fat they eat before hibernating).
I think you are entirely optimistic. I recently pointed out that the research indicates that animal studies routinely (probably usually) do not transfer, and as it happens, animal smoking studies are an example of this, according to Hanson. So the differences are often far from minor, and even if there were cancer in the animal studies, we could infer very little from it.
Out of curiosity, do you smoke?
No.
I find much to agree with in Hanson’s writings, but in this case I just don’t find him convincing. One issue is that cancer is a scourge of a long-living animal. One hypothesis is that smoking causes long term cumulative damage, and you might not see effects in mice or dogs because they die too soon regardless. There is also the issue that we have a fair idea of the carcinogenic mechanism now, so if you think smoking does not cause harm, there also needs to be a story how that mechanism is foiled in humans.
His interpretation, or his evidence? I point this out because it looks to me like your position has shifted from “the smoking / lung cancer link is established by RCTs in animals” to “even though RCTs don’t establish the smoking / lung cancer link for animals, we have other reasons to believe in the smoking / lung cancer link for humans.”
So: heads I win, tails you lose? If the studies had found smoking caused cancer in animals, well, that proves it! And if they don’t, well, that just means they didn’t run long enough so we can ignore them and say we “just don’t find them convincing”...
You don’t think there were plenty of ‘fair ideas’ of mechanisms floating around in the thousands of animal studies and interventions covered in my animal studies link? Any researcher worth his degree can come up with a plausible ex post explanation.