Philosophical Vegan Forum

So over the course of my life as a vegan, I've been aware that the scientific consensus is that meat is unhealthy. However I've really never known why this is the case and when asked why it is in the case I couldn't present anything. Fortunately the few people I was unable to inform are people close to me, so I can reeducate them. Anyways, why is meat unhealthy?

Science doesn't always deal in why; it likes to, but first and foremost it deals in facts.

Give one person a large dose of cyanide, and that person dies.
Did the cyanide cause it, or was it a coincidence?

Get a group of 200 people, randomly assign them to control and experimental groups. The control get a sugar pill and the experimental group get the large dose of cyanide.
99 people in the experimental group die, and only one in the control group dies.
You now have evidence that there's a causal relationship, and it's probably not just a coincidence.

Repeat with a thousand people each. Similar findings?

Large doses of cyanide kill people.
It doesn't matter why -- science tells you that it does.

Now you can experiment to try to figure out why.

Just knowing that meat is unhealthy doesn't require us to know why -- there are many theories, but we're actually not 100% sure exactly why it's as unhealthy as it is.
We just know there's a causative link between many substance in meat, meat itself (as a whole food), and a number of diseases, from heart disease to cancer to diabetes and arthritis.

"Why?" is a much more complicated question, and a matter of ongoing research.

http://nutritionfacts.org/video/food-as-medicine/

Greger mentions a few of the possible whys, but again, we don't yet know for sure on a lot of these.

What Brimstone said is true. I personally think it has a lot to do with meat being rich in animal protein, saturated fat and carsinogens.

Without knowing why something is unhealthy, you are describing correlation and not causation. A good example of how this can lead to flawed thinking is the debate about a carbohydrate diet verses a diet high in lipids or fats or a diet high in both which is what many from the US eat. Does saturated fat cause heart disease or is it correlated with heart disease because people who eat a diet high in saturated fat often consume something else along with it?

dapto wrote: ↑Wed Aug 05, 2020 7:05 am Without knowing why something is unhealthy, you are describing correlation and not causation.

This is a misconception, that's not at all how science works. You can determine that there exists a causal relationship without knowing its mechanisms.
E.g. even without any knowledge of gravity we can determine that lifting and then dropping an apple causes it to fall.

Having the mechanism of action is even better including things like the equations that describe gravity and whether there's an exchange particle (the Higgs boson) at work there, but causation can easily be established experimentally beyond any reasonable doubt without knowing the mechanism -- indeed, in the case of gravity it still remains poorly understood (arguably more poorly understood than the effects of meat on human health).

Would you assert that because we have not found the Higgs boson that we can only claim correlation between the act of dropping an apple and that apple beginning to fall? If not, then you need to rethink your understanding of correlation vs. causation.

dapto wrote: ↑Wed Aug 05, 2020 7:05 amA good example of how this can lead to flawed thinking is the debate about a carbohydrate diet verses a diet high in lipids or fats or a diet high in both which is what many from the US eat. Does saturated fat cause heart disease or is it correlated with heart disease because people who eat a diet high in saturated fat often consume something else along with it?

You're confusing cofactors with a nullification of causation.
In general, saturated fat consumption raises LDL cholesterol (it depends on the type of saturated fat too, e.g. lauric acid from coconut behaves differently from most animal fats but that's unnecessary nuance here if we're just talking about meat), high LDL causally increases risk of arterial plaque formation -- plaques which are literally made of cholesterol.

We know this is causal for many reasons, but some of the best evidence comes from statins which act to lower blood cholesterol and treat the underlying cause -- with extraordinary evidence of efficacy.

There are things that may make the plaques worse or help to clear them, but you can't form cholesterol plaques without blood cholesterol.

A good example of a correlation that muddies the waters is dietary cholesterol, because dietary cholesterol correlates with saturated fat, it's harder to determine if it's the endogenous production of cholesterol or the dietary cholesterol that's the principal cause of the plaques. Both play a role, but right now it seems to be that endogenous production is much higher than consumption except for in hyper-responders -- that means if the two sources of cholesterol are equally harmful, then it's the saturated fat that should be the main focus of public health messaging. Food like shrimp that are high in cholesterol bot low in saturated fat should not be a big issue for most people.

There is another theory that dietary cholesterol might be absorbed much less, but that it may be oxidized and damaged in a way that endogenous cholesterol is not, thus making it more prone to forming plaques (which are composed largely of oxidized cholesterol). Endogenous cholesterol can be oxidized in the body, but that saved step might make dietary cholesterol worse than it appears based on the numbers alone.

And yeah, it's well known that eating a lot of vegetables (antioxidants) can help prevent plaque formation, yet another variable that needs to be considered.

None of that negates the well established causal link between dietary saturated fat and heart disease. There being other variables at play doesn't cancel out causation.
To extend the cyanide analogy, would you say large doses of cyanide just aren't poisonous and aren't causally associated with death because there's another variable (B-12) that can blunt its effect?
Anything that can kill you, from saturated fat (blunted by vegetables) to a car crash (blunted by a seat-belt) has mitigating factors that can be protective. It doesn't mean that thing doesn't cause death and that it's only a "correlation".

brimstoneSalad wrote: ↑Wed Aug 05, 2020 5:50 pm This is a misconception, that's not at all how science works. You can determine that there exists a causal relationship without knowing its mechanisms.
E.g. even without any knowledge of gravity we can determine that lifting and then dropping an apple causes it to fall.

Thanks for engaging. I think you might have misunderstood me. What I was articulating was that knowing that two variables are correlated does not mean that they imply a cause and effect relationship. To take your example lifting and releasing the apple is correlated with it's falling on many occasions. It would be incorrect to conclude though, that what causes the apple to fall is in fact the lifting and releasing.

On the second point, the mechanism by which arterial sclerosis occurs is now well understood. I chose this as an example because it's not as straightforward as just the consumption of saturated fat. You can see articles emerging in response to the scientific literature from as early as 2008 - see here "How Diabetes Drives Atherosclerosis" from University of Rochester Medical Center.

dapto wrote: ↑Thu Aug 06, 2020 8:32 pm Thanks for engaging. I think you might have misunderstood me. What I was articulating was that knowing that two variables are correlated does not mean that they imply a cause and effect relationship. To take your example lifting and releasing the apple is correlated with it's falling on many occasions. It would be incorrect to conclude though, that what causes the apple to fall is in fact the lifting and releasing.

It would be incorrect to conclude that based only on a simple observation of a few correlated examples, where you'd determine the causal link to a moral certainty is through experimentation.

The mere correlation could mean the *falling* is causing the release rather than the other way around, or that there's a third cause that's causing both.
E.g. if apples randomly experienced a strong downward force that caused a hand to release it, and the hand was not releasing the apple on its own.

When we do an experiment in which we can control the release time and show it doesn't correspond to an alternative random force on the apple causing the release (or other uncontrolled external pressure causing the release and the fall) then we can establish causation.

In this case, lifting and releasing an apple *does* cause it to fall. Lifting provides potential energy, and releasing removes the normal force and changes the balances of forces on the apple resulting in acceleration. That's causation. If you don't agree with that then you're very confused about the nature of causality itself. Causality doesn't mean there aren't other forces involved (it doesn't mean a downward force derives from the hand itself), it refers to the thing that changes in conditions that results in the new state (the gravitational force on the apple was there all along; it was a required condition for falling but not the immediate cause).

dapto wrote: ↑Thu Aug 06, 2020 8:32 pmOn the second point, the mechanism by which arterial sclerosis occurs is now well understood. I chose this as an example because it's not as straightforward as just the consumption of saturated fat.

Nobody is saying atherosclerosis is entirely and exclusively caused by dietary saturated fat with no other required conditions.
Having other factors that also contribute doesn't change the fact of causation.

I guess we'll have agree to disagree about what causes objects to fall on earth. I'm of the opinion that gravity is the cause. When we operate in an environment without gravity items don't fall.

But getting back to saturated fat, a diet high in saturated fat doesn't lead to heart disease at all as shown by the Inuit paradox. So following on from my understanding of causation in the gravity discussion, i.e. when objects experience gravity they fall, in diets high in saturated fats it's not until we introduce refined carbohydrates and simple sugars that we see heart disease. Therefore according to my understanding of causation, it's the simple sugars and refined carbohydrates that cause heart disease since removing them from the diet removes the disease risk. This actually makes a lot of sense when you realise that one of the primary drivers of all disease is inflammation and high blood sugar leads to an inflammatory response.

Why is this an important point for vegans? Some vegans eat a diet high in simple carbohydrates believing this to be healthy. About 50% of humans have a genetic predisposition to having difficulty managing blood glucose on a high carbohydrate diet (see genotype rs1061325 on chr22) .

On another note if you are a vegan looking to eat a low carbohydrate diet then a good source of saturated fat can be found in cacao butter as it's low in trans fats.

dapto wrote: ↑Thu Aug 13, 2020 3:16 am I guess we'll have agree to disagree about what causes objects to fall on earth. I'm of the opinion that gravity is the cause. When we operate in an environment without gravity items don't fall.

Nothing else you say is useful or relevant in a discussion like this if you fail to understand the philosophical concept of causality.

If I shoot you with a gun and you die, I didn't cause your death! Your mortality and vulnerability to bullets caused it! I'm innocent, right? That's what you're saying here.

You do not understand causality, period. If you are unable or unwilling to grapple with your misunderstanding of causality then you don't have a place in this discussion.

E.g.

dapto wrote: ↑Thu Aug 13, 2020 3:16 amSo following on from my understanding of causation in the gravity discussion

If you do not understand causality and gravity vs. removal of normal force, then you are unqualified to engage in any further discussion because that misconception is poisoning your understanding of everything else. You need to engage with the gravity analogy, which is far simpler, before you continue to attempt to discuss this.

dapto wrote: ↑Thu Aug 13, 2020 3:16 amBut getting back to saturated fat, a diet high in saturated fat doesn't lead to heart disease at all as shown by the Inuit paradox.

1. Even if it weren't a myth, you're not Inuit and neither are most people, so their genetic susceptibility or immunity is irrelevant to the general population. We're talking about an isolated group having adapted to a very unusual diet for a long time.

2. It's a myth.
We don't have a lot of population data from when Inuit were eating their traditional diet, but from what we do have heart disease was pretty common among Inuit and reduced in incidence as their diets were westernized:
https://www.ncbi.nlm.nih.gov/pubmed/12535749
There's no evidence Inuit adapted to be immune to heart disease, and no reason they should have because it's a disease of old age and doesn't affect reproductive fitness. The only thing they've adapted to is to not go into ketosis.

That said, the empirical points are irrelevant if you refuse to correctly understand causality -- by which in science and common language we're primarily referring to the "efficient" cause, not merely a pre-existing material prerequisite of contributing factor (like "gravity exists").
Read this and rectify your concept of causality before you respond further: https://en.wikipedia.org/wiki/Causality
Failure to do so will be regarded as a violation of forum rules (see rule #1 here: viewtopic.php?f=5&t=2115 ), because at that point you're deliberately misusing the word causality.

If you have questions about causality and honestly don't understand I'm happy to answer them, but don't continue the pretense of arguing using a bad definition and failing to understand the concept at the root of your contention. You must understand what causality means before trying to engage in a discussion about what causes what.

I think I understand where your coming from. Perhaps a court room is a good metaphor for your understanding of causality. If Bob dropped a ball and it fell to a large body because of gravity and the falling was a crime. The judge could apportion blame, some to gravity and some to Bob. And so pass sentence on each.
You could argue then with respect to the Inuit paradox that when Inuit populations developed heart disease in the 1950s after beginning to eat a western diet high in refined carbohydrates and saturated fat that the cause was any of a number of factors from genetic drift to incorrect records or other factors like alcohol consumption or cigarettes. Science looks for evidence, and mechanisms. We both agree that the science of arterial sclerosis is well understood. High blood sugar produces inflammation and cholesterol then forms protective plaque. If we rely on Occam's razor it seems most likely that recent arterial sclerosis in Inuit populations is as a result of their change in diet to one that is high in carbohydrates as well as saturated fat. If this is true of the general population then we would assume that people on diets low in carbohydrates would have a low coronary calcium score or no hard plaque. This is indeed what we find.