Ketone bodies are produced from liver cells when carbohydrates are scarce and energy must be obtained from breaking down fatty acids.
When excess ketone bodies accumulate, this abnormal (but not necessarily harmful) state is called ketosis. When large amounts of ketone bodies accumulate such that the body's pH is lowered to dangerously acidic levels, this state is called ketoacidosis. Ketone bodies are transported from the liver to other tissues, where they are reconverted to produce energy. The heart gets much of its energy from ketone bodies, although it also uses a lot of fatty acids. The brain gets its energy from ketone bodies when insufficient glucose is available (during a fast). In the event of low blood glucose, most other tissues have additional energy sources besides ketone bodies (such as fatty acids) but the brain does not. The brain retains some need for glucose, because ketone bodies can be broken down for energy only in the mitochondria, and brain cells' long thin axons are too far from mitochondria. If levels of ketone bodies are too high, the pH of the blood drops, resulting in ketoacidosis. This happens if diabetes is left untreated. A telltale sign of ketoacidosis is a fruity smell on the breath, like an apple.
Certain carbohydrate-restrictive diets induce ketosis for weight loss. Ketosis, again, is not necessarily harmful. However, when enough ketones enter the blood to lower the pH – this condition is ketoacidosis, and it is harmful. It can impair mental sharpness and inflict damaging effects on the body. Sadly and not so uncommon, the phenomenon hits type 1 adolescent girls on a dangerous level. A study found that young women with type 1 diabetes have manipulated their insulin to lose weight through ketoacidosis. In a chronic disease where every number of every reading and every calorie of everything you eat defines the control of your health -- how can diabetes NOT inherently fracture the self-image of young girls and mankind alike?
