If you're eating oats or other grain-based foods, corn or beans that have high amounts of phytic acid, a lot of the minerals in those foods are not going to be absorbed. Phytic acid is something plants use to hold on to chelate means to bite onto minerals. So if you eat oysters with corn like a corn tortilla in the study, you don't absorb much of the zinc at all. You can essentially rob your body of nutrients if you're eating these things together. And then we have something that's just really important and grains and actually overlaps the vegetables.
Have you been led to believe that oatmeal is good for you? This podcast is for you! Paul does a deep dive on why you may want to cut oats (and chocolate, and leafy greens) out for good for reasons like heavy metal accumulation, antinutrients, and defense chemicals.
00:07:30 The problem with grains
00:11:45 Heavy metals in oats, greens, chocolate and fish
00:20:00 How saponins damage the gut
00:31:30 Cadmium and heavy metals in oats, vegetables and chocolate
Effects of saponins and glycoalkaloids on the permeability and viability of mammalian intestinal cells and on the integrity of tissue preparations in vitro: https://pubmed.ncbi.nlm.nih.gov/20650190/