Rats that eat raw food with enzymes live about 3 years. Those given cooked food without enzymes live only 2 years. Similarly in a famous study with cats, those given raw foods lived long and healthy lives. Those given cooked food succumbed early to cancer and other diseases. Most chronic illnesses show an enzyme deficiency.
Many alternative therapies rely upon fasting or juicing.
Fasting frees enzymes to work on the disease and juicing provides a source of fresh enzymes. Even weight control seems linked to enzymes. Pigs given cooked potatoes by farmers fatten quickly. Those given raw potatoes do not gain weight. Apparently, the lipase in the raw potatoes prevents weight gain.