My bovine aortic valve

[cufflink]

Yesterday I had lunch at a vegan restaurant with a friend I hadn’t seen in years. Naturally we discussed my new diet. We also talked about my artificial aortic valve. My friend has a friend facing the same operation I had, and she asked if I had any advice to share about types of replacement valves.

When I mentioned that my own valve is constructed from cow parts, she asked if that sat well with me as a vegan. I confessed I hadn’t thought about it before, but that it was an interesting question.


Some background

I won’t bore you with the details. Suffice it to say I was born with a fairly common congenital heart defect that results in premature wear and tear on the aortic valve. When the condition was discovered, I learned that the only treatment was replacing the valve. I was followed carefully for 10 years. It was never a question of if the valve would be replaced, but when. By 2005 I had begun experiencing the classic symptoms of angina, and the test results indicated it was time for the operation.

I had to make the choice between a mechanical and a “biologic” valve. Each has its pluses and minuses.

Mechanical valves are very reliable and last a lifetime. The minor drawback is that they’re noisy—they can keep your bedmate up at night. The major drawback is that they tend to promote blood clots, which can result in a stroke, so you need to be on powerful blood thinners—Coumadin, for example, which is also used as rat poison—for the rest of your life. Since precise dosage is crucial and is affected by what you’ve been eating, you need to get your blood tested monthly to determine your “prothrombin time,” a measure of how long it takes your blood to clot.

Biologic or tissue valves are made wholly or partially from animal parts. They don’t promote clots, so there’s no need for blood thinners. Their downside is that unlike mechanical valves, they don’t last forever and will eventually need to be replaced.

I went with a biologic valve, an engineered marvel made partly of a cow’s pericardium. I wasn’t happy with the prospect of being on Coumadin forever, and I took a gamble that by the time the bovine valve wears out, medical science will have progressed to the point that the replacement can be done percutaneously—i.e., through a vein, without my having to undergo open heart surgery again. The gamble seems to have paid off. There’s no sign yet of deterioration, and cardiac surgeons have already begun replacing heart valves through minimally invasive procedures.

The bottom line is that I’m doing great. My heart functions normally and I have no restrictions on my activities. I’m extraordinarily grateful to the pioneering doctors and surgeons who, in the late ‘50s, had the skill, vision, and chutzpah to say, “We can fix this!” Without my new valve, it’s certain I would have died years ago.


The ethical questions

I’m sorry the cow whose parts contributed to my valve had to die. (Of course, many more cows died to support the meat-eating habits I only recently gave up.) But is using an animal in this way ethically justifiable? Or is it tantamount to using an animal for meat or leather?

If you, as a vegan, were in the position I was in, and you had to choose a replacement valve, would it be a no-brainer for you to choose the mechanical valve, with its downsides, as opposed to one that made use of animal parts?

What if there were no mechanical alternative available, and the only choice to keep you alive required the death of an animal. Would you hesitate at all to have the operation? Would that be selfish and speciesist? Or is it just as much of a no-brainer that your own life is of higher value than that of the cow or pig that will “donate” its parts to you?

Thoughts?

[brimstoneSalad]

Great post! I didn't know they were still using bovine parts.

In this case, it's a matter of self preservation. Most vegans consider human life first. Without at least considering your own life first, veganism fails to be a practical philosophy to live by, and dying isn't a good example to set for anybody.

Broadly, the only thing we all agree on is that when it's not necessary,and particularly when it's harmful like the practice of meat eating, then it's wrong. When there's a real trade off, then the disagreement starts- but I don't think you'll meet many vegans who will judge you for this, or call you non-vegan in any sense.

If it's necessary to save a life, then all bets are usually off.
Also, as some consolation, this is a bi-product; nobody killed a cow just for you - they had them left over from killing cows for meat.

Which would I take? I'm not sure.
I suspect that with a good diet, and maybe a lot of garlic and onion, a large dosage of blood thinners might not be necessary. So, the mechanical version certainly has appeal.
Stokes are scary, though. Your bet that they'd be able to replace it more easily paid off. Maybe next time they'll even have superior synthetics they can replace it with, without another open heart surgery?

Either way, it's not something being done out of callousness or apathy- but something necessary for life.
And something unavoidable like this is pretty easy to offset with a little good we do.

[cufflink]

Thanks for your response. I haven't been losing sleep over this question, but I thought it might be worth considering from the perspective of human welfare vs. animal rights. When "human welfare" means the continuation of human life, the answers are fairly clear. But the term often deconstructs to "my own pleasure/comfort/convenience," and then things are not nearly as straightforward.

One related issue we haven't discussed is animal testing. All these artificial valves, whether mechanical or biologic, were almost certainly tested on animals before they were tried on humans, and we can assume the animals died in the process. But maybe that's a discussion for another thread.

[brimstoneSalad]

But the term often deconstructs to "my own pleasure/comfort/convenience," and then things are not nearly as straightforward.

In that case, the best thing to do is look at psychological states. Is the issue subjective, or objective?

People not eating meat aren't less happy, and don't experience less pleasure in life than people eating meat. It's something you just get used to- you stop craving the meat, and eventually it starts to seem quite unappetizing. Additionally, people acting in accordance with their compassion feel more fulfillment, and experience less uncomfortable cognitive dissonance scratching at the backs of their minds- so in that sense it's actually an overall plus (once you get over the hump that is withdrawal from the habit).

Most subjective "deprivations" come down to that- the fact that you get used to them, and they cease to be seen as deprivations.

This is particularly prevalent in the first world.

The same can be said for downsizing living expenses- people who get rid of unnecessary non-functional clutter and move into a smaller place.
After they stop missing the subjective experience of having more room/bigscreen TVs, etc., and/or come to the realization that there's free room outside and a smaller TV closer to you is pretty much the same thing, they find it's less to clean, there's a lower mortgage which means they have to work less and they can do more of other things they enjoy.

It's hard to shake that social programming that stuff=success, that bigger is better, etc. But once you do overcome that notion, the line between need and want, and between real function and subjective aesthetic starts to become sharper.

There's a point where your house becomes so small that you're literally banging into corners every time you turn around, and your kitchen is too small to accommodate your family while cooking (cooking is one of those highly functional uses of elbow room). At that point, it stops being subjective and starts being a more objective problem. As you increase the size of the kitchen, it improves, until it's enough room to get the job done, and beyond that you have rapidly diminishing returns (which weigh against other functional matter, like mortgage).

Most practical matters in life boil down to a calculus that can describe optimal levels for function- commercial kitchen layouts are great examples of this, when speaking of kitchens (which IMO are the most functional room in the average house). Below that optimal level is a matter of need, and above that optimal level is a matter of want.

One related issue we haven't discussed is animal testing. All these artificial valves, whether mechanical or biologic, were almost certainly tested on animals before they were tried on humans, and we can assume the animals died in the process. But maybe that's a discussion for another thread.

I think the biggest problem people have with animal testing is that the vast majority of it is completely unnecessary, or even counterproductive. Companies do it for cosmetics, for example, or lot testing drugs to avoid lawsuits. We need really tort reform to address those matters- as soon as companies don't have to worry about being sued for not testing on animals, then they won't do it (they don't want to waste money on that stuff and generate bad PR).

A small minority of animal testing is actual research. A small minority of that is research on life saving or altering medical practices or drugs. And a small minority of that animal testing is on such research that actually requires or substantially benefits from testing in animal models compared to alternatives.

When it fits all of those qualifications, you'll rarely find anybody to argue against it. But those are very rare experiments.

The first artificial valves may or may not have been tested on non-human animals first: but if they were, they didn't need to be.
In cases like that where people are literally dying from the condition, any number of humans will voluntarily and enthusiastically step forward to be a participant in an untested procedure for the small chance of not dying.

Now, once one basically adequate treatment has been developed, they will stick with that one forever until a new treatment is proven to be equally or more effective in tests. Once people have an option where they are pretty sure they won't die, they're less likely to step forwards for an experimental procedure- even more so because some idiots decided that it's necessary to use an experimental control group for most tests, randomly assigning half of the testees with a placebo and guaranteeing that they will die.
I can't begin to describe how bad of scientific and medical malpractice that is. It's something that needs to be fixed before we can ever hope to use more effective human models to test experimental treatments and actually start saving more lives.

But even that aside, not everybody has that option to not die in the first place- and that's another point where we need both tort reform, and a shift in public consciousness.
There are always volunteers. Always. If not in the first world, then in the second or third world.
There are millions of people who would never have been able to afford the original procedure anyway, and would gladly accept an experimental upgrade for the chance to not die.
The issue with this is mainly two fold:
1. First world people bizarrely see this as 'taking advantage' of those people (despite giving them a better chance of living than they had, and them volunteering for it)
2. Lawsuits.

Due to this, it's just cheaper and more practical to avoid human testing (which is the only true way to confirm results) in favor of other models.


Beyond human models, there are computer models, and in-vitro models that are actually pretty effective for a large percentage of experiments- and the more people use them, the cheaper and more effective they become.

This has become a huge part of advocacy for abolishing animal testing from those in favor in the scientific community.

The reasoning is as such:

1. Non-animal models have the potential to be superior and cheaper than animals models, giving more accurate results, much faster.
2. Our hangup on the currently cheaper, better known, and more readily available animal models prevents substantial investment in these other models
3. If we abolished animal testing, we'd be forced to develop these other models more quickly, and they would receive investment.
Conclusion: In the long run, this would be of great benefit to humanity.
This would result in a few years of stunted development of drugs and other procedures, but as these models matured, they would eventually surpass animal models, and our ability to test would increase exponentially, and we'd be better off in the long run.

It's valid reasoning, most of the argument comes over the premises from people who don't believe in computer or in-vitro models (Harrumph, inconceivable), or people who focus on the immediate future instead of the long-term (people are dying now, not five years from now). Also, from people who don't understand economics (why not use animal models while developing the others?).

EDIT:
I come to realize that was probably TMI
Another thread might be good, if you want to start one to discuss it more.

[thebestofenergy]

It's valid reasoning, most of the argument comes over the premises from people who don't believe in computer or in-vitro models (Harrumph, inconceivable), or people who focus on the immediate future instead of the long-term (people are dying now, not five years from now). Also, from people who don't understand economics (why not use animal models while developing the others?).

Wow, I didn't know about in-vitro and computer models. Very interesting.
By the way, I quickly made this lol http://i.imgur.com/U64znVu.jpg?1

[brimstoneSalad]

Wow, I didn't know about in-vitro and computer models. Very interesting.
By the way, I quickly made this lol http://i.imgur.com/U64znVu.jpg?1

Thanks Energy

As per the subject at hand (heart valves), computer modeling would be the way to go for design, since that deals with fluid dynamics and mechanical simulation, which computers are getting really good at (in part, because of video games, having driven consumer demand for faster and cheaper GPUs which can be used to do certain simulations very quickly).
Things like blood clotting, though, are harder to predict with those kinds of models alone.

In-vitro models are better for things at the cellular level that involve biochemical systems, and less large scale mechanical process. Some of them are pretty amazing (like the "organs on chips")- this is an area where the most progress can be made in the short term.

In the long term (although currently it's in its infancy) we will be able to create computer models of biochemical systems.

PETA's page on the subject is a good read:

http://www.peta.org/issues/animals-used ... l-testing/

Unfortunately, there are still gaps in our ability.
So it's a question of whether we trudge along and hold onto the animal model, waiting for more research and development to be done on the other models until they're already superior (which is what pharmaceutical companies want to do, being risk averse- they'll all switch the moment the non-animal model is cheaper), or apply some pressure to encourage funding of non-animal models, and restrict usage of animal models to force the change faster. It's a political and economic matter.

[cufflink]

People not eating meat aren't less happy, and don't experience less pleasure in life than people eating meat. It's something you just get used to- you stop craving the meat, and eventually it starts to seem quite unappetizing.

I'm glad you brought that up. It's something I've been thinking about.

I strongly suspect that revulsion among vegans towards eating meat is not universal, at least among those of us who became vegan relatively late in life. In my own case, I'll be in a better position to judge in a few years. Right now, though, I can tell you that often when I see non-vegan food—when I look at it purely as an object of consumption, putting its origin out of my mind (an important qualification)—it's still pretty damn appealing. (Admittedly, when I purposely conjure up the image of the animal that was butchered to make this food available, the appeal diminishes considerably.) Will that change in time? I have reason to think it won't. I stopped drinking whole milk decades ago, substituting skim. I've heard and read assurances that when you give up whole milk and drink only non-fat, eventually whole milk becomes unpalatable: it feels as if you're drinking paint. Well, maybe that's true for some people; it certainly wasn't true for me. On the rare occasions that I tried whole milk, it tasted incredibly rich and delicious. Did I therefore go back to drinking it regularly? Not at all, since my reasons for giving it up overcame whatever pleasure I still derived from it.

I think it's a mistake to assure potential vegans they'll all get to the point where they won't miss meat—that veganism is not a sacrifice. In terms of purely sensual pleasure, for some people it is very much a sacrifice. But there's nothing wrong with that! Not all worthwhile things are easy to achieve. Better to acknowledge that for many, veganism is a sacrifice, but one worth making. Otherwise you’re going to get people who’ll think, “How come that sizzling steak is still making my mouth water after all this time? Something must be wrong with me to make me such a failure.”

Additionally, people acting in accordance with their compassion feel more fulfillment, and experience less uncomfortable cognitive dissonance scratching at the backs of their minds- so in that sense it's actually an overall plus . . .

Exactly! That’s what needs to be emphasized—that the peace of mind you achieve when your eating habits align with your compassion, and you lose the cognitive dissonance, more than makes up for what you’re giving up in terms of sensual pleasure. Doing the right thing feels good.

It's hard to shake that social programming that stuff=success, that bigger is better, etc. But once you do overcome that notion, the line between need and want, and between real function and subjective aesthetic starts to become sharper.

There's a point where your house becomes so small that you're literally banging into corners every time you turn around, and your kitchen is too small to accommodate your family while cooking (cooking is one of those highly functional uses of elbow room). At that point, it stops being subjective and starts being a more objective problem. As you increase the size of the kitchen, it improves, until it's enough room to get the job done, and beyond that you have rapidly diminishing returns (which weigh against other functional matter, like mortgage).

Most practical matters in life boil down to a calculus that can describe optimal levels for function . . . Below that optimal level is a matter of need, and above that optimal level is a matter of want.

I’m not convinced there’s an objective border between want and need; the calculus you describe, though appealing in theory, seems quixotic. The problem is that if you try to look objectively at what we really need—what is indispensable for a reasonably decent life—it’s pretty modest. But people being what they are, the vast majority of us don’t want to live ascetic, monkish lives if we can possibly help it. Virtually everyone has wants that go beyond simple need. Marxism, with its idealistic “From each according to his ability, to each according to his needs,” failed because it didn’t take into account this basic fact of human nature. (I realize that’s not the only reason Marxism failed. ) But then the question becomes, how much desire for pleasure/comfort/convenience above pure need is it appropriate for an ethical person to have? And there you’re not going to get agreement.

I have a car. Do I need it? Well, living as I do in a large city with improving but still inadequate public transportation, life without a car is majorly inconvenient. But it’s not impossible. Some people here, generally out of necessity, make do without a car, although it’s not easy. I could sell my car, take the proceeds plus the money I would save on fuel, and donate it to a charity helping kids in Darfur who are dying of malnutrition. It would be inconvenient for me but possibly life-saving for a little kid. Is it unethical for me not to do so—to place my want for an easier life above my genuine need for it? By a purely utilitarian calculus, perhaps. But there’s a long way to go before masses of first-worlders are convinced they should give up whatever crosses the need-want border.

How big a house do I really need? There are developing countries where three medium-sized rooms for a family of eight would be considered a luxury. Few people in the first world would find that even adequate, not to mention luxurious, despite the fact that it’s doable. What’s the appropriate level of want over need?

Can I justify this cup of coffee at Starbucks? It tastes good, but I certainly don’t need it. In fact I don’t need coffee at all. If I took that money . . . etc. etc. Of course if everyone gave up coffee and donated the money they would have spent on it to charity, there would be benefit but also harm, in that coffee growers and workers would lose their jobs. But that seems like a way of starting with the conclusion you want and trying to find rationalizations for it.

On the other hand, there comes a point where want exceeds need to such a degree that virtually all observers see it as wretched excess. If you’re a coffee drinker, you don’t need kopi luwak, which goes for up to $700 a kilo. (I’m not sure I’d drink it if it were free.)

I don’t think people are ever going to agree on where to draw the line—at which point the want-to-need ratio becomes greater than what can be justified ethically. I don’t see the possibility of objectivity here. That said, it’s pretty clear that most of us in the first world could stand to have a lot less “stuff.” At this point in my life, I generally find myself more concerned with de-acquiring excess baggage than with acquiring more of the same.

I think the biggest problem people have with animal testing is that the vast majority of it is completely unnecessary, or even counterproductive. . . .

I come to realize that was probably TMI
Another thread might be good, if you want to start one to discuss it more.

Thanks for the very informative material on animal testing. I agree that such testing is only justified where there are no viable alternatives. As for starting another thread, I might do that later. First I need to read up on it, though, so I can be a more informed discussant.

[cufflink]

By the way, I quickly made this lol http://i.imgur.com/U64znVu.jpg?1

I agree completely!

[brimstoneSalad]

I can tell you that often when I see non-vegan food—when I look at it purely as an object of consumption, putting its origin out of my mind (an important qualification)—it's still pretty damn appealing. (Admittedly, when I purposely conjure up the image of the animal that was butchered to make this food available, the appeal diminishes considerably.) Will that change in time?

The first part of it is the largest part of physiological craving- the out of the blue desire for something without prompting. That fades like cravings for cigarettes or coffee, or anything else.

Actual repulsion isn't necessarily something that's going to come up on its own absent other stimuli (with the exception of the sensation of something being overly rich if eaten- but that's not really the same as repulsion; something being overly rich can still be good unless we have past experiences making us averse to it).

In the example you made regarding milk, the skim milk would have ultimately become as enjoyable as the whole milk used to be, with the whole milk elevated to the status that cream used to enjoy.
Our sense perceptions are all relative like that, which is why I say you're not actually missing out on something once you've gotten used to it.
When you quit eating sweets, carrots and other vegetables (even plain oats) become sweeter to you, as your perceptual standards adjust to the new norm- you haven't really lost out on that, things just get shifted around. Our experiences always normalize as long as we're north of physical deprivation (that's a line we can begin to draw with research).
If you liked drinking cream when you drank whole milk, it stands to reason that you'd still like whole milk after switching to skim. For some people, that's too rich- but other people like the so-rich experience, because they haven't built as strong negative associations with excessive richness with nausea...
And that brings me to the last point:

Admittedly, when I purposely conjure up the image of the animal that was butchered to make this food available, the appeal diminishes considerably

If every time you're exposed to meat, you conjure up those negative associations, eventually it will rub off and you'll start to find the whole thing more and more distasteful without even consciously thinking about it.

Remember Pavlov's dog? It's the same sort of thing, that automatic conditioning works even on subconscious levels within our own minds.

For any person who adopts veganism for moral reasons, this response is almost inevitable given enough time (if they draw up those thoughts and images- some people just avoid seeing meat, and in those cases fewer exposures may rather ironically reduce the effect).

It's not perfect, but it's very widely reported in long term vegans (although sometimes there are odd exceptions which inexplicably pop up).
People who are vegan for health or environmental reasons alone, who don't consider animals moral beings, usually won't experience that because they never create those negative associations that reduce the appeal of the meat.

This is something you probably never did with whole milk. If, for example, you had associated the thickness with the thickness of - let's say puss - every time you saw whole milk before, it might have eventually put you off at sight without having to think about it.

We can train our subconscious impulses remarkably well in some cases, through those associations, even without intending to do so- and I think that's what happens with most vegans who experience that.

It's not that the not eating it causes us to not like it. Not eating it long enough causes cravings to fade, sure, and not eating anything of comparable richness for long enough will cause us to re-calibrate our metrics for what defines richness (thus making it much more rich when next encountered by comparison), but none of those necessarily make it taste bad (just, for some people who don't like "too rich" it might be too much to have all at once).
What makes it smell and/or look revolting is the negative associations that come up when we're exposed to it, subconsciously re-associating those smells and sights with something unpleasant over time and with regular exposure.

Of course, none of that is of any use if you're hungry enough- fellow human being start looking pretty delicious at that point.

I've heard and read assurances that when you give up whole milk and drink only non-fat, eventually whole milk becomes unpalatable: it feels as if you're drinking paint. Well, maybe that's true for some people; it certainly wasn't true for me. On the rare occasions that I tried whole milk, it tasted incredibly rich and delicious.

The same is the case with sweet things- they just taste really really sweet. Some people have built in negative associations with excessive sweetness- perhaps from gorging on sweet things as young children and getting sick- others don't. Because sweetness doesn't have an instinctual "too sweet" gag level, response to those kinds of things is a little subjective.
For somebody who grew up on warhead sour candies, for me there's no such thing as too sour- so even if I don't eat anything sour for months, a lemon won't put me off (although it does taste MUCH more sour if I haven't had one for a while).

Saltiness is a little more objective as far as how somebody will react to "too salty" (or at least it seems to be); there might be an innate reflex against excessive saltiness that's triggered more easily in those who don't eat as much salt, which doesn't exist for other sensations.

Anyway, what did happen, and which I think you describe well, is that your subjective perception of creaminess shifted radically- your whole scale was re-calibrated, which is the whole point about not really missing out from that.

While you were drinking whole milk regularly, cream would have given you that experience of great richness.
Once drinking skim milk, whole milk provided the experiences of great richness, cream would be like an exponentially more rich experience liken unto some kind of religious experience.

But there's nothing wrong with that! Not all worthwhile things are easy to achieve. Better to acknowledge that for many, veganism is a sacrifice, but one worth making. Otherwise you’re going to get people who’ll think, “How come that sizzling steak is still making my mouth water after all this time? Something must be wrong with me to make me such a failure.”

I agree that not all worthwhile things are easy to do. And veganism can definitely be hard in the beginning- cravings can pop up even after a couple years: they just get more and more spaced out and weaker over time.

I'm just not sure how many long term vegans really actively want animal products anymore (aside from things like cheese and ice cream).

I'd love to see more data tracing the recession of cravings for meat; smoking cessation seems to be a very good model, though- both from vegans I know who are ex smokers, and having read the research on its patterns.

I'd also love to do some studies on long term vegans who still find meat appetizing, to find out what their exposure level is like, the context, and how they react to it.
Since overwhelmingly the anecdotal reports seem to be (Both young and old, and it's the same in my case) that the smell of meat became off-putting (including the smell of spices in combinations regularly used to cook meat- I couldn't stand oregano for a long time until I learned to cook with it and disassociate it from meat), I would want to find out what's different about those cases so I could offer advice on how to associate the two things better to help stave off such cravings.

Sure, it doesn't have to be fixed. But why live with uncomfortable cravings when you don't have to? Maybe a test of will power, or character building... but that just doesn't seem right. Ordinary subconscious brain function usually takes care of that within a couple years. If somebody doesn't want to like the smell of meat, and get hungry every time they see a meat ad, I think there's learned behavior that can overcome that.

Exactly! That’s what needs to be emphasized—that the peace of mind you achieve when your eating habits align with your compassion, and you lose the cognitive dissonance, more than makes up for what you’re giving up in terms of sensual pleasure. Doing the right thing feels good.

Yes, and this is the primary thing- just to do the right thing. It wouldn't matter if babies tasted like chocolate- we still wouldn't eat them.
And, often doing the right thing despite it being hard makes it all the more meaningful.

But, at the same time, I don't think veganism has to be hard (at least after the first few months of getting into it, which are the hardest, and then fighting occasional cravings that fade over a couple years).
Why advertise something as harder than it needs to be? After all, I want to encourage more people to try it. And sometimes if you say something is easy, and that they can do it, just the thought alone will make it easier and empower them.

The problem is that if you try to look objectively at what we really need—what is indispensable for a reasonably decent life—it’s pretty modest.

It is modest, but there's no deprivation in that. When you get used to things, they become the norm. Human psychology of happiness doesn't rely on luxury, but on satisfaction with what we have.
People only become unhappy when they become consumed with wants- a modest life can be happier than a luxurious one, because all of the trappings of luxury (where they are above our needs) all normalize back down, and whenever we go without those luxuries for want of them, only then do we become deprived.

It's like any drug addiction. We just reach a new normal- and then when we fall below that high expectation, we experience the suffering of first world problems.

But people being what they are, the vast majority of us don’t want to live ascetic, monkish lives if we can possibly help it. Virtually everyone has wants that go beyond simple need.

Yes, they have wants that go beyond needs, but that's only because other people made them want those things.
We've basically brainwashed each other to covet things that are neither necessary nor useful to improving well being.
The problem is that undoing that mindset is a lot harder than creating it in the first place- like religion, it's an up hill battle.

Marxism, with its idealistic “From each according to his ability, to each according to his needs,” failed because it didn’t take into account this basic fact of human nature. (I realize that’s not the only reason Marxism failed. )

Well, the people who tried to enact Marxism thought they could do it thought force, and they assumed it would be much easier than it actually is.
It takes education, and choice from informed consumers to make it happen- force doesn't do it, that's putting the cart before the horse.

But then the question becomes, how much desire for pleasure/comfort/convenience above pure need is it appropriate for an ethical person to have? And there you’re not going to get agreement.

For a perfect person? None. But those are ideals.

For a good person: just a little less than average.

The important thing is that, as members of society, representing a direction society should strive to move in, we take one tiny step in that direction by being better than the average person.

But there’s a long way to go before masses of first-worlders are convinced they should give up whatever crosses the need-want border.

It takes time. It will take generations. Maybe longer. Maybe we'll never reach that point. But as long as we're moving closer to it, that's OK.

I don’t think people are ever going to agree on where to draw the line—at which point the want-to-need ratio becomes greater than what can be justified ethically. I don’t see the possibility of objectivity here.

There are two stable landings on the path to ethical being.

One is objective, which is the break-even point. Just do more good in the world than harm. You get a lot closer to this by being vegan. By buying a few carbon credits to offset your usage (which is easy enough too), and generally being a good person and occasionally helping others. It's pretty easy to "break even" by doing a little bit of good to make up for the harm we can't help but do.

Once you hit the break-even point, you're an OK person. Donate another penny to charity, and you're technically a good person. Even if you drive a fancy car, live in a big house, and do nothing more for the world. You did your bit, and you did a little more good than harm.

That's an easy thing to do.

The other is society and ability-relative. It's something I tend to call the jerk metric.
If you're Bill Gates, and you're a billionaire, you just have to be a jerk to keep all of that to yourself and not use most of it to make the world a better place- because it's so easy for you to give away a lot of money without affecting you. Bill Gates isn't a total jerk- he started a multi-million dollar foundation with his wife, and gives the vast majority of his fortune away.

Does that make Bill Gates a better person than you or I?
Well, he's probably done more good in the world than you or I could do. But has he done more good in the world than you or I would do if we were in the same position? Maybe not.

The ability-relative metric asks not if you're objectively good, but if you're good relative to your means, and the norms of society- it asks how much you go out of your way or inconvenience yourself to do the right thing. If another person (the average person) were in your shoes, would they do more or less than you?

It's also pretty easy to be better than the average jerk. It means doing the good things that are easy for you to do, and avoiding the bad things that are easy for you to avoid- and then going a bit farther, and doing the good that's a little inconvenient, and avoiding bad things that are a little inconvenient.

If you're better than average, then, for a human in this social context, you're not a jerk.

If you manage to both break even in the world, doing more good than harm, AND not be a jerk, that's about all you can ask for as far as objective metrics of being a decent human being.

Beyond that, it's a slippery slope with no apparent rest stations until you reach sainthood.