Tomato paste is just a paste made out of tomatoes that have been boiled to reduce the moisture, strained to remove skin and seeds, and boiled again until it forms a thick paste. What you’re left with is essentially concentrated tomatoes, so there’s no reason it can’t be included as part of a healthy Paleo lifestyle.
Tomatoes come loaded with vitamin C and antioxidants, so they not only can be included in a healthy diet, they’re practically essential.
Paleo and Autoimmune Protocol
The only downside is that tomatoes are nightshades, and while that’s not a problem for most people, some people do experience digestive issues and inflammation as a direct result of eating nightshades. If you’re not sure if you’re sensitive, the best way to find out is by eliminating all nightshades from your diet for at least a month, then slowly reintroduce them and note how they make you feel.
Mark Sisson gave his take on nightshades and why we should (or should not) be concerned about them.