2 ms·

Don't those studies accout for such types of influence?

brigadier132 3y ago
They try isolate confounders using statistical methods but these are not intervention studies and they rely on self reported data. There are obvious limitations with such approaches. You could imagine that people who are careful enough with their diet to completely avoid red meat also probably do physical activity of some sort. How many people that avoid red meat in their diet also eat at mcdonalds? They aren't locking people up in a resort and strictly monitoring and controlling what they ingest.
- hombre_fatal 3y ago
  Would you also bite that bullet with regard to the association between cigarettes and lung cancer? We don’t have RCTs. How do we know that it’s not just the fact that people who smoke also don’t exercise? Well, it’s simple: we trivially adjust for exercise. Just like we have prospective cohort research on unprocessed vs processed red meat: we can design studies that measure it. (This is aimed at your sibling comment) If you’re saying there’s a confounder we don’t know about in play: then what is it and what evidence would you bring to the table to justify its inclusion in our inference model? Note: that evidence would have to be at least as good as the evidence you’re rejecting for not having that magical secret confounder. That said, even before getting to cancer outcomes, I would replace red meat with another protein source just to avoid saturated fat. And if I was only moved by cancer outcomes and refused to change my high red meat diet, I would ensure I'm eating lots of veg/fruit to insulate myself against the risks which is what you see in the Tomorrow Alberta Project prospective cohort analysis among the highest red meat eaters who also ate the most fruit/veg.
amanaplanacanal 3y ago
They try to. Unfortunately you can’t account for all of them, because we don’t know all of them. Once it’s published that X is healthy or Y is unhealthy then people change their lifestyle in accordance. You can’t tell if some other thing that people do because they heard it is healthy is the real cause.
mdhen 3y ago
They try, but not successfully. It is called the healthy user effect. If something is already considered unhealthy by conventional wisdom then people trying to be healthy dont do that thing. And it's extremely difficult to account for because the differences between those people and everyone else are very large and difficult to lock down, since they will tend to do lots and lots of things that you are supposed to do for good health, but most people dont.

They try isolate confounders using statistical methods but these are not intervention studies and they rely on self reported data. There are obvious limitations with such approaches. You could imagine that people who are careful enough with their diet to completely avoid red meat also probably do physical activity of some sort. How many people that avoid red meat in their diet also eat at mcdonalds? They aren't locking people up in a resort and strictly monitoring and controlling what they ingest.

hombre_fatal 3y ago
Would you also bite that bullet with regard to the association between cigarettes and lung cancer? We don’t have RCTs. How do we know that it’s not just the fact that people who smoke also don’t exercise? Well, it’s simple: we trivially adjust for exercise. Just like we have prospective cohort research on unprocessed vs processed red meat: we can design studies that measure it. (This is aimed at your sibling comment) If you’re saying there’s a confounder we don’t know about in play: then what is it and what evidence would you bring to the table to justify its inclusion in our inference model? Note: that evidence would have to be at least as good as the evidence you’re rejecting for not having that magical secret confounder. That said, even before getting to cancer outcomes, I would replace red meat with another protein source just to avoid saturated fat. And if I was only moved by cancer outcomes and refused to change my high red meat diet, I would ensure I'm eating lots of veg/fruit to insulate myself against the risks which is what you see in the Tomorrow Alberta Project prospective cohort analysis among the highest red meat eaters who also ate the most fruit/veg.

amanaplanacanal 3y ago

They try to. Unfortunately you can’t account for all of them, because we don’t know all of them. Once it’s published that X is healthy or Y is unhealthy then people change their lifestyle in accordance. You can’t tell if some other thing that people do because they heard it is healthy is the real cause.

mdhen 3y ago

They try, but not successfully. It is called the healthy user effect. If something is already considered unhealthy by conventional wisdom then people trying to be healthy dont do that thing. And it's extremely difficult to account for because the differences between those people and everyone else are very large and difficult to lock down, since they will tend to do lots and lots of things that you are supposed to do for good health, but most people dont.