Compositions and methods for providing a person with an exogenous and therapeutically effective supply of ketones are disclosed. The compositions may consist essentially of (a) purified butyrate (or esters or propionate salts thereof) and (b) purified beta-hydroxybutyrate (or esters or propionate salts thereof). The compositions may further include other pharmacologically active agents, such as acetyl-L carnitine, R- alpha lipoic acid, green tea extract, vitamins, and various combinations of such agents. The methods include providing a person with an exogenous supply of ketones, by orally administering a pharmacologic composition, which is effective to deliver 2000 - 5000 mg of a short chain fatty acid (e.g., butyrate) and 5000 - 10,000 mg of ketone (e.g., beta- hydroxybutyrate) on a daily basis. In addition, methods for increasing nuclear factor erythroid 2 related factor 2 (Nrf2) levels in a group of cells are disclosed, which involve the administration of the compositions described above to the group of cells.