Folic acid, gastric cancer issue. There are concerns with some findings that suggest that folic acid supplementation may increase risk of GI cancers. However, the research is pretty consistent. First, there is a relatively common genetic uniqueness (called a SNP) that causes us to need more folic acid. If you have this uniqueness, folic acid and B12 are a very good idea for a variety of reasons (stroke, cancer, heart dz). If you don’t, it is more likely to create a problem.
Second, overall folic acid may have the potential to make existing tumors worse, but protect them from forming in the first place. So, overall you need to know your genetic status. Then, your lifestyle needs to be “anti-GI cancer;” high fiber, low processed, Vit D, good bacteria, no antibiotics, etc. This will give you the best protection against one of our nastier cancers. If you have the uniqueness and have gastric cancer, folic acid and B12 can massively improve your risk of survival (by 86%!).