This was a gold-standard randomized, placebo-controlled trial. When participants switched out their refined wheat for whole grain wheat, they reduced markers of inflammation and showed higher levels of beneficial phenolic compounds in their blood, urine, and feces:
Whole-Grain Wheat Consumption Reduces Inflammation In A Randomized Controlled Trial On Overweight And Obese Subjects With Unhealthy Dietary And Lifestyle Behaviors: Role Of Polyphenols Bound To Cereal Dietary Fiber, American Journal of Clinical Nutrition, February 2015
Results: [Whole grain wheat] consumption for 4–8 wk determined 4-fold increase in serum dihydroferulic acid (DHFA) and a 2-fold increase in fecal ferulic acid (FA) compared with [refined whaet] consumption (no changes).
Ferulic acid is found in high levels in the cell walls of the hard outer bran layer of grain. Both ferulic acid and dihydroferulic acid are phenolic compounds with antioxidant properties. Ferulic acid has shown antitumor activity against breast and liver cancer in studies.