You will also be familiar with the disease caused by lack of insulin – diabetes – and with the conditions caused by too much or too little hormone – dwarfism and gigantism. Growth during the first eight to ten months of life is largely controlled by food intake, but growth hormone then becomes the dominant influence on how children grow. There are also benign balls of cells, tumours, which secrete growth hormone (GH) and this constant production of GH produces as you’d expect, very tall people-seven foot or taller-the condition is known as gigantism. If excess GH is produced after growing has stopped (again because of a tumour), a condition called acromegaly develops, which causes the bones of the hands, feet and jaw to become enlarged.
The First Book of Samuel in the Bible relates the story of David and the giant Goliath, who was said to be six cubits and a span in height. A cubit is an Egyptian measure, roughly the length of the elbow to the tip of the middle finger and reckoned to be eighteen inches. A span is half a cubit, which would make Goliath well over nine foot tall. The tallest man ever recorded was Robert Wadlow, born in Alton, Illinois, in 1918, who was 8′ 11″. He died when he was only twenty-two. Robert Wadlow had a tumour of the pituitary gland in childhood, causing an excess of growth hormone.
Did Goliath have a hormone problem? I doubt it. Too much growth hormone does not make you a muscle-bound superman. Quite the reverse is usually the case, with respiratory problems, diabetes and high blood pressure being the norm and disabling osteoarthritis of load-bearing joints also an early feature. By his teens, Robert Wadlow needed a walking stick.
Another common problem for those subjected to too much growth hormone is carpal tunnel syndrome, which is caused by pressure on the median nerve in the wrists, and results in numbness and loss of power in the hands. This would have made it impossible for Goliath to hold heavy items like his staff, which the Bible tells us ‘was like a weaver’s beam’, let alone his spear, of which the head alone ‘weighed six hundred shekels of iron’.
Although a very rare form of acromegaly is inherited, most cases are caused by malfunctions of the pituitary and so are ‘one offs’. A further hint on Goliath’s physique comes from the Second Book of Samuel in which it is noted that four more giants had been killed in battle by the Israelites. All are said to come from the tribe of Gath. This sounds as if the Gathites were just exceedingly tall and six cubits and a span is a myth.
However, the opposite case has been made persuasively by endocrinologist Shlomo Melmed of the Cedars Sinai Medical Center, Los Angeles. He argues that Goliath’s height was definitely the result of a pituitary tumour arising in childhood. Such tumours often press upon the optic nerve, leading to loss of peripheral vision, which might account for his seeming unawareness of David and his sling. A blow to the head for a person with this condition could have caused a massive haemorrhage, leading to death, even from a seemingly minor head injury.
The point of the story is surely that David was small by comparison and won the fight through applied weapons technology (a well-aimed sling-shot). A rather more likely sufferer from acromegaly was the Egyptian pharaoah Akhenaten, whose portraits show the typical projecting jaw of the condition.