First, like most businesses, pharmaceutical entities (which chalk up well over $122 billion a year in sales) are interested primarily, if not exclusively, in their own financial health, They do not finance research unless there is a reasonable expectation of recovering those research dollars from sales of patented drugs.

Nature:
Since compounds that already exist in nature - such as vitamins, minerals, amino acids, and herbs - cannot be patented, there is little financial incentive to study them and bring them to market Consequently, the formulary of medicine has become almost exclusively "xenobiotic", that is, brand-new compounds that never before existed in nature.

Dr Julian Whitaker's Health & Healing: Tomorow's Medicine Today March 1998, VoL 8, No.3 Phillips Publishing Inc., USA