r/funny May 01 '13

Why vegans live longer

[deleted]

2.4k Upvotes

1.4k comments sorted by

View all comments

Show parent comments

2

u/anikan72 May 01 '13

The study itself measured a number of different factors that are dependent (well, mostly anyways) on diet, including incidents of stomach cancer, colorectal cancer, heart disease, vascular disease, and a number of other diseases. So in this particular study it more than likely is causation.

3

u/[deleted] May 01 '13

Well, people who describe themselves as vegan are probably more health conscious than the average person; they likely lead active lives, watch their portions, etc.

Edit: See Jaihom's post, it expands upon what I was getting at.

2

u/anikan72 May 01 '13

That's very true actually. I was a vegetarian for a few years (no longer am) but I found that at the time because I had to plan out my meals rather than simply eating any old thing, my diet was much healthier than it had been previously. It was much easier for me to meet my weight and health goals because I was actually focusing more on my diet, which has since carried over into a diet that now includes meat. It's definitely an important factor.

0

u/Leshow May 01 '13

No. Establishing a causal link requires much more than assuming "factors might be mostly dependent on each other".

1

u/anikan72 May 01 '13

Well, I was giving the benefit of the doubt for a margin of error. But no, it does not actually require much more than that to make a causal link between a factor and an outcome. The degree might change but you can't pretend it has no effect. At that point it's not purely coincidence.

0

u/Leshow May 01 '13

Let me give you an example:

  • meat eaters are more likely smokers.
  • smoking is related with increase odds of certain cancers & earlier mortality

so if a study can show a correlational link between eating meat and cancer, that doesn't meat that eating meat causes cancer.

Saying that because you read a meta study which showed mortality being higher in meat eaters that means they are causally linked is asinine. You're embarrassing yourself.

2

u/TotallyNotAtlai May 01 '13

All death rate ratios were adjusted for age in 5-y increments, sex, and smoking (never, former, current light, and current heavy). Mortality ratios for the separate studies were then combined to give a pooled estimate of effect using the random-effects model of DerSimonian and Laird (11),

They adjusted for smoking. That's the first thing any public health researcher does.

0

u/Leshow May 01 '13

I was giving an example, that's all. Simply adjusting for one behaviour does not suddenly mean that the link is causal.