What Notto Eat –

Some consensus, much controversy about diet in 3 metabolic diseases

by Margaret Wahl

Mark Tarnopolsky, a professor of pediatrics and medicine at McMaster University in Hamilton, Ontario, remembers clearly a patient he saw more than a decade ago, when he first began specializing in metabolism and nutrition.

The patient was an 8-year-old boy who had rapidly become weak and eventually almost completely paralyzed after exercising. His muscles were breaking down, spilling a protein known as myoglobin into the blood and threatening the survival of the boy’s kidneys, if not of the child himself.

Fortunately, before too much time elapsed, Tarnopolsky was able to come to the right diagnosis. The child had a deficiency of a metabolic enzyme called carnitine palmityl transferase 2 (CPT2), which normally allows fats to be broken down and used for energy.

Specifically, CPT2 escorts molecules known as fatty acids from the main part of a muscle cell into cellular energy “ factories” known as mitochondria.

After intravenous infusions of water and sugar, the child recovered his strength and returned to his normal activities, now armed with a special diet and advice to avoid exercise during periods of stress, such as when he had a cold or the flu.