Need vegans insight on this research

[Unknownfromheaven]

http://www.plosone.org/article/fetchObj ... tation=PDF
I am also reading it now.

Thank you!

[brimstoneSalad]

People with poor health or chronic conditions are more likely to seek out dietary change, and adopt healthier diets.

This is expressed in the study:

Our results have shown that vegetarians report chronic
conditions and poorer subjective health more frequently. This
might indicate that the vegetarians in our study consume this form
of diet as a consequence of their disorders, since a vegetarian diet
is often recommended as a method to manage weight [10] and
health [46].

It's a really poor study, because it's a population study (and a small one) which doesn't tell us anything about causation.
There are a wealth of strong clinical studies demonstrating causative effects of animal products for poor cardiovascular health, in addition to other chronic conditions.

Carnists attempting to use poor studies like this is like pointing a study on medication, and saying "medication causes disease, because they asked people on medications and not on medications how much disease they had and the people on medication had more disease!".

That is, of course, complete nonsense.

Vegetarian and vegan diets are associated causatively with improvements in chronic disease; they do not cause them, they make them better, which is why people with chronic disease adopt these diets (they aren't perfect, however, and will not cure you overnight; it's another form of medication).

If you look at clinical studies, you will find nothing but benefits from reducing animal products compared to real controls.

[brimstoneSalad]

It's also important to note that most (54.5%) of the "vegetarians" were not vegetarians:

While 0.2% of the interviewees were pure vegetarians (57.7%
female), 0.8% reported to be vegetarians consuming milk and eggs
(77.3% female), and 1.2% to be vegetarians consuming fish and/
or eggs and milk (76.7% female). 23.6% reported to combine a
carnivorous diet with lots of fruits and vegetables (67.2% female),
48.5% to eat a carnivorous diet less rich in meat (60.8% female),
and 25.7% a carnivorous diet rich in meat (30.1% female). Since
the three vegetarian diet groups included a rather small number of
persons (N = 343), they were analyzed as one dietary habit group.

There were something like 30 vegans, which is not a very significant amount, and they were not studied independently (also, these were self reported, so can't really be well trusted anyway).

And of the actual vegetarians, most (80%) ate dairy and eggs -- many lacto-ovo vegetarians actually eat more dairy to compensate for lack of meat, and may have even greater cardiovascular and cancer risk because of that increase.

The only good populations studies on vegetarian diets I know of have been done with Seventh Day Adventists and traditional Buddhists (controlled populations, where other variables are almost non-existent).

Here's an outline of a few studies: http://nutritionfacts.org/video/plant-b ... -diabetes/

[Unknownfromheaven]

Yes, i already said that the number was really low, and that those are not vegetarians, we came up to agree on that at least.

[brimstoneSalad]

Yes, i already said that the number was really low, and that those are not vegetarians, we came up to agree on that at least.

I edited and posted a link, you might have missed that, Dr. Greger covered some better studies in more controlled populations in that video.

[Unknownfromheaven]

Yes, i already said that the number was really low, and that those are not vegetarians, we came up to agree on that at least.

I edited and posted a link, you might have missed that, Dr. Greger covered some better studies in more controlled populations in that video.

)) I did missed it, thank you, i will check it right away!

[inator]

The main problem is what brimstone pointed out:

You can only establish causation with longitudinal studies (differences over time), not cross-sectional ones (at one moment in time). It's more likely that people choose a vegetarian diet because they have health problems than it is that vegetarians develop more health problems. They acknowledge this themselves:

Potential limitations of our results are due to the fact that the survey was based on cross-sectional data. Therefore, no statements
can be made whether the poorer health in vegetarians in our study is caused by their dietary habit or if they consume this form of diet due to their poorer health status. We cannot state whether a causal relationship exists, but describe ascertained associations. Moreover, we cannot give any information regarding the long-term consequences of consuming a special diet nor concerning mortality rates. Thus, further longitudinal studies will be required to substantiate our results

I didn't have time to go through the whole methodology, I'll just say what else caught my eye.

- There's a major problem with how they conceptualized their independent variable 'diet'. The idea was to generate a variable that would reflect animal fat intake, but vegetarians can easily eat more animal fat (many replace meat with dairy and eggs) than meat eaters who don't consume that much dairy.
It's probably why the differences between 'low', 'medium' and 'high' veggie consumption, excluding vegetarians, did show a linear effect of diet on health - the more veggies they eat, the better off they are.
Also:

[...] the measurement of dietary habits as a self-reported variable and the fact that subjects were asked how they would describe their eating behavior, without giving them a clear definition of the various dietary habit groups.

- They're separating the carnivorous diet into three categories of healthfulness (by vegetable intake), without doing the same for vegetarian diets. But there are big differences in veggie consumption with vegetarians too. Those were not accounted for.
You basically get the unsymmetrical sample sizes of n=330 for vegetarian diets and n=990 for carnivorous diets.

- They chose to use the chi-squared test for a relatively small sample size instead of a more exact test. Chi2 is usually best suited for larger populations - this sample size is pretty borderline, especially considering that they've got 4 categories for diet. The more categories you choose to consider, the higher the sample size must be, so you'll have enough observations for each possible pairing.
They probably did that to enhance the differences between the diet categories, raising the statistical significance.

- The only statistically significant afflictions that vegetarians seem to have a higher risk for are allergies, cancer, and anxiety/depression. Again, there's no way to establish causality. It's more likely that people who already have allergies etc. will choose a vegetarian diet than the other way around.
The values for each of those conditions were self-reported. It's entirely possible that vegetarians are just more concerned with their state of health and more aware of it because they go to the doctor more often.
Which is probably also why 'health care' (how often people go to the doctor) was statistically significant, whereas there were less significant differences in other aspects of 'quality of life'.

- There are many more studies that show the contrary. Each probably has weaknesses in its methodology (though this one is particularly bad). The point is that a meta analysis will give you an overview of available information, which is much better than cherry picking the information that proves your point.

[Unknownfromheaven]

Indeed, thank you inator for the insight.

When i became a vegetarian i did not done it on health issues, but on ethical reasons, i eliminated gradually meats, and i first started not consuming the bacon and beef anymore.
It was not an easy transition since i was grown as a meat eater.