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I study medical and nutritional research for fun. Papers like these are always interesting to me. Oxalates are a mixed bag, and are considered an "anti-nutrien

I study medical and nutritional research for fun. Papers like these are always interesting to me. Oxalates are a mixed bag, and are considered an "anti-nutrient", by binding nutrients and preventing absorption during digestion. Ex: Spinach has loads of calcium, but raw, is a poor source of calcium due to oxalate content. However, cooking foods with oxalates in them breaks down the oxalates and frees up the nutrients and partially prevents the anti-nutrient effect. Excessively high Vitamin C diets (don't supplement to ridiculous amounts, some people do), possibly in combination with low calcium diets (calcium in the body is used to flush oxalates out), can lead to increased risk of kidney stones in diets with high oxalate content. Having a genetic mutation that leads to increased risk of kidney stones can add to this. Please note, there is a lot of ifs in that statement I just said, each one of them independently increases risk, but generally do not reach problematic levels unless you do (or have) more than one. You shouldn't really worry about oxalates, just don't consume oxalate containing foods in absurd amounts, unless you already are at risk of forming the kind of kidney stones effected by oxalates, then you probably should switch to a low oxalate diet. As usual, talk to your doctor if you think you might be at risk.

newbamboo 5y ago
Drinking iced (black) tea is potentially deadly in quantities that some southerners might not see as absurd. https://healthcare.utah.edu/healthfeed/postings/2015/04/042315_cvarticle-iced-tea-kidney.php https://healthcare.utah.edu/healthfeed/postings/2015/04/0423...
- nate_meurer 5y ago
  This is a great example of a myth in the making due to poor reporting and science-by-case-report. The report in question is just that-- a case report. It is not scientific in any sense. There's no way to establish causality here. All we can tell is this guy had oxalate kidney stones, and he also drank a lot of tea. That's it. Controlled studies have found lower rates of kidney stones in tea drinkers: - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412450/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412450/ - Daily Green Tea Infusions in Hypercalciuric Renal Stone Patients: No Evidence for Increased Stone Risk Factors or Oxalate-Dependent Stones - https://www.acpjournals.org/doi/10.7326/0003-4819-128-7-199804010-00003 https://www.acpjournals.org/doi/10.7326/0003-4819-128-7-1998... - Beverage Use and Risk for Kidney Stones in Women - https://academic.oup.com/aje/article/143/3/240/77956 https://academic.oup.com/aje/article/143/3/240/77956 - Prospective Study of Beverage Use and the Risk of Kidney Stones - https://pubmed.ncbi.nlm.nih.gov/23676355/ https://pubmed.ncbi.nlm.nih.gov/23676355/ - Soda and other beverages and the risk of kidney stones And why iced tea in particular? That idea seems to have come from one single doctor, who said in an interview once that cold tea encourages people to drink more of it, versus hot tea. Again, no evidence, just cuz he thinks so: https://www.medicalnewstoday.com/articles/248633#2 https://www.medicalnewstoday.com/articles/248633#2 EDIT: The authors of that case report somehow miscalculated the oxlate content of tea by a factor of ten. They claim that tea contains 50-100mg of oxalate per 100 ml. The actual content is about a tenth of that. Much less than a host of other common foods. And of course their report makes attempt to ascertain the rest of his diet. This is essentially fake health news.
  - deleted 5y ago
    [deleted]
- djmips 5y ago
  Is that reversible, that is did that man recover his kidney function after treatment?
  - nate_meurer 5y ago
    Their letter claims that he underwent dialysis. But it doesn't matter; as I said in my other comment, this is fake health news.
qwt 5y ago
> However, cooking foods with oxalates in them breaks down the oxalates and frees up the nutrients and partially prevents the anti-nutrient effect. This advice should be taken very carefully. The amount of oxalate removed is highly dependent on the cooking method and the food in question. Furthermore, some foods like spinach remain very high in oxalates in comparison to other foods even after preparation. Finally, cooking is not effective at reducing insoluble oxalates. It's probable that insoluble oxalates are less problematic, but I don't know of any good data showing they are harmless.

newbamboo 5y ago

Drinking iced (black) tea is potentially deadly in quantities that some southerners might not see as absurd. https://healthcare.utah.edu/healthfeed/postings/2015/04/042315_cvarticle-iced-tea-kidney.php https://healthcare.utah.edu/healthfeed/postings/2015/04/0423...

nate_meurer 5y ago
This is a great example of a myth in the making due to poor reporting and science-by-case-report. The report in question is just that-- a case report. It is not scientific in any sense. There's no way to establish causality here. All we can tell is this guy had oxalate kidney stones, and he also drank a lot of tea. That's it. Controlled studies have found lower rates of kidney stones in tea drinkers: - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412450/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412450/ - Daily Green Tea Infusions in Hypercalciuric Renal Stone Patients: No Evidence for Increased Stone Risk Factors or Oxalate-Dependent Stones - https://www.acpjournals.org/doi/10.7326/0003-4819-128-7-199804010-00003 https://www.acpjournals.org/doi/10.7326/0003-4819-128-7-1998... - Beverage Use and Risk for Kidney Stones in Women - https://academic.oup.com/aje/article/143/3/240/77956 https://academic.oup.com/aje/article/143/3/240/77956 - Prospective Study of Beverage Use and the Risk of Kidney Stones - https://pubmed.ncbi.nlm.nih.gov/23676355/ https://pubmed.ncbi.nlm.nih.gov/23676355/ - Soda and other beverages and the risk of kidney stones And why iced tea in particular? That idea seems to have come from one single doctor, who said in an interview once that cold tea encourages people to drink more of it, versus hot tea. Again, no evidence, just cuz he thinks so: https://www.medicalnewstoday.com/articles/248633#2 https://www.medicalnewstoday.com/articles/248633#2 EDIT: The authors of that case report somehow miscalculated the oxlate content of tea by a factor of ten. They claim that tea contains 50-100mg of oxalate per 100 ml. The actual content is about a tenth of that. Much less than a host of other common foods. And of course their report makes attempt to ascertain the rest of his diet. This is essentially fake health news.
- deleted 5y ago
  [deleted]
djmips 5y ago
Is that reversible, that is did that man recover his kidney function after treatment?
- nate_meurer 5y ago
  Their letter claims that he underwent dialysis. But it doesn't matter; as I said in my other comment, this is fake health news.

qwt 5y ago

> However, cooking foods with oxalates in them breaks down the oxalates and frees up the nutrients and partially prevents the anti-nutrient effect. This advice should be taken very carefully. The amount of oxalate removed is highly dependent on the cooking method and the food in question. Furthermore, some foods like spinach remain very high in oxalates in comparison to other foods even after preparation. Finally, cooking is not effective at reducing insoluble oxalates. It's probable that insoluble oxalates are less problematic, but I don't know of any good data showing they are harmless.