Keto increases your risk of kidney stones. Not recommended for anybody concerned about that. Not to mention blueberries, chocolate, and spinach are considered very high risk for people who form oxalate kidney stones.
I'm far from a doctor, so I'd say do a lot of research and start a conversation about it with your primary care physician. Being male (especially mid-twenties or older) and having family history increases your risk. I don't know if there's any way to calculate one's specific risk, but you can do things like have a 24-hour urinalysis, ultrasounds, MRIs to see if you have any kidney stones right now. Then, whether or not there's anything you can do about them is another topic to research.
In my research, there doesn't seem to be a solid, universal consensus on much. However, I've seen these points get a lot of support:
- kidney stone formation scales inversely with hydration. Less water, higher risk of stones. More water, less risk. I can't say how much you have to drink or where it tapers off, but my doctor prescribed me "buckets" of water, so that's a starting point.
- there are various kinds of kidney stones. One type is formed by oxalates, which is a chemical only found in plants. There's zero oxalates in meat or animal products, and the highest concentrations around in things like spinach, beets, chocolate, nuts.
- Being a carnivore isn't necessarily a cure. Meat changes your urine composition because of uric acid (iirc), which can increase your risk of kidney stones.
- Depending on the type of stone formed, any protein can increase risk (I forget what kind this one is)
- Calcium can bind with oxalate in the body and prevent the oxalates from binding to themselves and your kidney, which is what forms kidney stones. So ensuring that you get enough calcium daily, and especially eating calcium with high oxalate foods, may reduce risk
- Various other things may help. Citric acid may change your urine composition in a way that helps prevent stone formation. For example, apparently drinking beer and wine reduces stone risk by 33% according to some sources.
Frankly, a lot of this comes down to your comfort. Kidney stones are very likely my absolute worst fear in life for personal reasons, so I've gone to considerable lengths to do whatever I can to feel informed and minimize my perceived risk. A friend of mine has an elderly relative who often gets kidney stones, but apparently would rather deal with that than change their diet/lifestyle. So don't take this info dump as a reason to panic, but instead gauge your concern/interest and if you think it's worth looking into, again, do your own research and talk to your doctor.
If you have a medical or academic source for that, I'd love to read it. I did research and could only find this tea mentioned on no-name websites. The closest I could find was this article about dandelion tea from Livestrong, but even that has no sources and mentions 'purported' benefits rather than giving any evidence