This randomized phase I/II trial studies the side effects and best way to give lyophilized black raspberries in preventing oral cancer in high-risk patients previously diagnosed with stage I-IV or in situ head and neck cancer. Chemoprevention is the use of certain drugs to keep cancer from forming. The use of lyophilized black raspberries may prevent oral cancer. Studying samples of oral cavity scrapings, blood, urine, and saliva in the laboratory from patients receiving lyophilized black raspberries may help doctors learn more about changes that occur in DNA and the effect of lyophilized back raspberries on biomarkers.