To be honest, we don't need studies on everything to know too much of it will harm you. There are too many of them, always contradicting ones available, which leads to confusion more than anything else.So I kind of surprised myself yesterday with the calculation of the lethal dose of spinach. Maybe someone can go over the numbers and show that I might be off by a factor of 10.
1) Lethal dose of oxalic acid is 15-30 grams:
OXALIC ACID - National Library of Medicine HSDB Database
2) 100 grams of spinach contains 750 mg of oxalic acid, which is among the highest levels for green vegetables:
Oxalates In Spinach - Is Oxalic Acid A Green Smoothie Health Concern? - DavyandTracy.com
So you need roughly ~2 kg or 5 lbs of spinach to get the lethal dose of 15 grams.
3) 100 grams of spinach contains 23 calories:
Spinach, raw Nutrition Facts & Calories
So the lethal dose of spinach corresponds to ~460 calories of spinach, or roughly ~20% of your daily calories, which coincidentally is about the toxic dose of casein protein tested in the rat study cited by the movie Forks Over Knives.
I don't know anybody who eats that much spinach, other than Popeye and his muscles can handle the oxalic acid. However, this does suggest that the "green smoothie" and "green juice" trend might eventually cost some lives, as they do become toxic at high doses. It seems like you would die if you got most of your calories from greens.
Oxalic acid is famous for historically. In world war II, the people in the UK consumed a lot of rhubarb (which is hard to find where I live) as it was available. A lot of them eventually died, as oxalic acid poisoning built up in their body. It's why the rhubarb leaves are typically removed from the stalks in supermarkets, because they're associated with those deaths, though the toxic dose is in fact very high. I didn't know about this until recently. A while back I brought a strawberry-rhubarb pie to a party which included some kids, a mother asked me if I removed "the toxic part of the rhubarb", I had no idea what she meant so I got scared watching the kids running around, and didn't serve the pie. I looked it up after. It turns out that the supermarkets remove that part for you, and it would take a ridiculously high dose regardless.
Apparently some people are also getting kidney stones from eating too much spinach:
Green Smoothie: Toxic Oxalate Crystals (Jan 2015) Townsend Letter, Alternative Medicine Magazine
So that's pretty interesting. We all associate green vegetables with healthy food. They're definitely healthy. But it looks like they're truly, horrifyingly toxic if eaten in large doses.
Though I hope that somebody checks my arithmetic. I was elite at arithmetic growing up, but now I'm old.
It is also counterintuitive, but it does look like the juicing trend popular among vegans and others may in fact be unhealthy if done long-term or done incorrectly. People do great on it so there's probably a way or multiple ways to do it correctly.
You can get water intoxication leading to serious health complications. We are talking about freaking water here. Too much of any food can lead to some issues.
Heck, exercising too much can also lead to serious health complications as well.
That is why I find it remarkably amusing reading or hearing people talk about how they have to cut this or that food.
If you were a meat eater, went vegan, and now you feel just swell, that's actually good. Anybody that feels better is great. Except the problem probably wasn't eating animal protein, it was eating too much of it and likely not getting enough portions of veggies/fruits, which lead to lower micros, and therefore you felt worse.
From an ethical/moral point of view, I totally understand if one wants to cut it out. It is the only intelligent argument for complete elimination of it.
Otherwise, eating your steak with some broccoli at home is totally fine, treating yourself to a chocolate or ice cream, and eating the odd pizza, is entirely fine.
Of course, if you eat pizza 4x per week, with chocolate chip cookies that you dip in a pint of milk as dessert, then no shit it's going to lead to unhealthy findings. Hey, it's animal protein man...That shit will kill ya!
The fact so many vegans and documentaries cannot find it in themselves to seperate or simply acknowledge this is just astonishing to me.
"Eating animal protein will cause cancer"...Ya..."Drinking too much water can kill you"..Also, as you pointed out..."Eating too much spinach will also do serious damage". All statements are correct. All of these statements are also completely stupid if your response is to eliminate all those food, which would lead to a very quick death.
Eliminating any food source is not the answer to superior health.