carbohydrate vs lactose

carbohydrate

noun
  • A sugar, starch, or cellulose that is a food source of energy for an animal or plant. 

  • Any food rich in starch or other carbohydrates. 

lactose

noun
  • The disaccharide sugar of milk and dairy products, C₁₂H₂₂O₁₁, a product of glucose and galactose used as a food and in medicinal compounds. 

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