s ▁to ▁D - am ino ▁ac ids ▁and ▁can ▁be ▁used ▁to ▁detect ▁the ▁amount ▁of ▁D - am ino ▁ac ids ▁in ▁food s ▁to ▁act ▁as ▁a ▁b ios ensor . ▁This ▁is ▁important ▁due ▁to ▁the ▁effects ▁of ▁D - am ino ▁ac ids ▁in ▁the ▁D - is omer ▁or ▁multiple ▁en anti om ers ▁present ▁in ▁food ▁has ▁on ▁the ▁nut r itional ▁value . ▁The ▁more ▁D - is omer ▁or ▁multiple ▁en anti om ers ▁present ▁in ▁food , ▁the ▁lower ▁the ▁nut r itional ▁value ▁of ▁the ▁food ▁is , ▁so ▁using ▁D - am ino ▁acid ▁ox id ase ▁to ▁detect ▁these ▁allows ▁for ▁an ▁increase ▁in ▁selection ▁for ▁nut r itionally ▁valuable ▁food s . ▁There ▁is ▁no ▁evidence ▁to ▁prove ▁that ▁D - am ino ▁ac ids ▁are ▁to xic , ▁but ▁it ▁ra ises ▁many ▁possible ▁concerns ▁whether ▁some ▁food s ▁are ▁to xic . ▁ ▁Medical ▁ ▁Can cer ▁treatment ▁▁ ▁R g D AA O ▁is ▁used ▁in ▁a ▁process ▁called ▁gene - direct ed ▁en zym e ▁prod rug ▁ther apy ▁( G DE PT ) ▁to ▁treat ▁tum ors ▁in ▁cancer ▁patients . ▁This ▁treatment ▁uses ▁R g D AA O ▁as ▁the ▁en zym e ▁and ▁D - al an ine ▁as ▁a ▁substr ate ▁to ▁create ▁a ▁re active ▁o xygen ▁species ▁H 2 O 2 ▁as ▁a ▁product . ▁H 2 O 2 ▁per me ates ▁through ▁tum or ▁cells ▁and ▁dam ages