guarding vs preservative

guarding

noun
  • Tensing of the muscles, especially of the abdomen, in order to minimise the movement and agitation to the internal inflamed organs. 

preservative

noun
  • Any agent, natural or artificial that acts to preserve, especially when added to food. 

adj
  • Tending to preserve. 

How often have the words guarding and preservative occurred in a corpus of books? (source: Google Ngram Viewer )