Also, spinach has iron. So excessive spinach consumption at levels that most people couldn't tolerate could also increase colorectal cancer risk? Or no?
Interestingly, Vitamin C increases the rate at which you can get iron from greens such as spinach. So maybe a glass or orange juice and a bowl of salad a day keeps the doctor away.
Edit: Let me offer some USDA data points for those who are curious, but not curious enough to bother Googling for themselves.
Red Bell Peppers: https://fdc.nal.usda.gov/fdc-app.html#/food-details/170108/n...
Green Bell Peppers: https://fdc.nal.usda.gov/fdc-app.html#/food-details/2258588/...
Oranges: https://fdc.nal.usda.gov/fdc-app.html#/food-details/746771/n...
Eating one raw red bell pepper per day is pretty much guaranteed to provide enough vitamin C, even when no other food contains any.
If the red bell peppers are cooked, some of the vitamin C will be lost, but there still should be more than is most kinds of food.
Also explains why I crave red meat and vitamin C after a workout. Can't get enough of the stuff.
Vegetarian resource group 2018 https://www.vrg.org/nutrition/iron.php
> Some might expect that […] vegans might be prone to developing iron deficiency anemia. However, surveys of vegans have found that iron deficiency anemia is no more common among vegetarians than among the general population although vegans tend to have lower iron stores.
> In fact, if the amount of iron in these foods is expressed as milligrams of iron per 100 calories, many foods eaten by vegans are superior to animal-derived foods.[…] you would have to eat more than 1700 calories of sirloin steak to get the same amount of iron as found in 100 calories of spinach.
> Another reason for the satisfactory iron status of vegans is that vegan diets are high in vitamin C
2021 Norway health institute https://pubmed.ncbi.nlm.nih.gov/33803700/
> In conclusion, although the participants were eating a plant-based diet, the majority had sufficient iron status
Nutrients 2021 https://www.mdpi.com/2072-6643/13/9/2964
> We did not find differences in the prevalence of iron deficiency between vegetarians and omnivores among men and women who do not menstruate. Among women who menstruate, vegetarians had a higher prevalence of iron deficiency than omnivores did.
In this last one they’ll mixed non-omnivorous together. Not sure why, and how to calculate it.
A vegan diet can provide enough iron, but this is not automatic. One has to actually take care to ensure this.
While some studies like those quoted by you have found vegans who ate enough iron, studies done in other countries have found vegans with iron deficiencies. I have seen at least 2 or 3 such studies, I think one was about vegans in UK.
While there are many vegetables with a relatively high iron content, their iron content is still rather low so you have to eat greater quantities than many people would want to eat. Moreover, many of those vegetables are not cheap and eating large quantities is likely to make the expenses for the daily food greater than when eating food that includes meat.
So yes, vegans can eat enough iron, but they must be aware of the danger of eating too little iron and they must carefully choose their food to avoid this danger. Similar problems are caused by calcium, which exists in vegetables, but also in much smaller amounts than desirable. It is possible to eat a vegan diet with enough iron and calcium, but in many cases it is much less expensive and also easier to eat less food, but complete it with some iron and calcium supplements.
> One has to actually take care to ensure this.
Yes, but not more complex than eating the perfect omnivorous diet, which nobody does. Do you precisely count your omegas intake? Your daily ratio of carbs/protein/fat…? Some nutrition aficionados do, but the vast majority of the population (rich and poor) does not.
If you find the studies you remember please share them. Iron deficiency is a very common anemia, not only for vegans or poor countries.
On the supplement, it’s interesting to note that most cattle and other farms animals are heavely supplemented so they stay relatively healthy during life and their future flesh has the nutriments expected.
https://historiesofecology.blogspot.com/2015/08/on-spinach-i...
https://www5.in.tum.de/~huckle/Sutton_Spinach_Iron_and_Popey...
It looks like however the absorption of iron in red meat is quite high (15%-35%) compared to spinach (2-5%), so maybe not enough to really be a risk factor.