Something you said in an article on peppers especially got my attention: "Like eggplants and tomatoes, peppers are a member of the nightshade family."
I'm seeing a Physical Therapist for help recovering from a partially-torn tendon and chronic ankle sprain, plus sporadic episodes of severe foot to calf muscle cramps. For the muscle cramps, doctors have said to try more calcium, D, potassium, and magnesium. The PT recommends avoiding nightshade plants in my diet, and taking curcumin with black pepper extract, thinking that would reduce inflammation. Why would that make sense? I can't see any inflammation. And we just put a dozen tomato plants out in pots!
These sorts of remedies are myth and not really supported by the research.
There have been a few articles that indicate nightshades could be an issue but these are anecdotal and there is little sound science to back up the claims. The theory is that a chemical in nightshades, solanum, leads to inflammation. Some animal studies have supported this but the research has not been well replicated and there is no evidence that this is true in humans.
There is, in fact, recent research that looks at the anti-inflammatory properties of solanum and some indication that it may be a good choice for reducing inflammation:
For now, there just is not enough quality research to support a link between nightshades and arthritis or other inflammatory conditions. The fruit of these plants have lots of antioxidants that should, if anything, reduce inflammation.
There is more evidence surrounding use of various capsicums (peppers) and their potential antioxidant and anti-inflammatory processes. Here are some recent articles as examples of the research that is promising:
Thanks for writing,
Timothy S. Harlan, M.D.
PS: The inflammation your physical therapist is concerned about may be inside the joint or related to the tendon tear and not necessarily visible to you.