Posted by: Footler PJ11 NOV 2009
While writing about World Diabetes Day, I was reminded of the story of the Ossabaw Island pigs. Ossabaw is one of a string of islands off the coast of the US state of Georgia. Its name comes from a word in the Muskogean or Creek language meaning “the place of yaupon holly bushes”.
The Muskogean people used the leaves of the cassine or yaupon holly (Ilex vomitoria) to infuse a tea which induced vomiting in a ritual of cleansing and purification.
The explorers who crossed the oceans in search of new lands often carried livestock such as pigs and goats to provide fresh meat for their crews. Some of these animals were deposited on suitable islands as a larder should supplies of food run short.
In many places the animals devastated the local vegetation and wildlife so causing the extinction of endemic species — but that is another story.
Some time in the early 1500s, Spanish explorers surveying the eastern coast of North America left a small herd of pigs on Ossabaw Island. In order to thrive, the pigs had to adapt to conditions on the island. They became smaller, a process known as “insular dwarfism”, and also had to cope with the food cycle on the island, which provided little to eat during the spring season.
Isolated on their island the Ossabaw Island pigs have remained a distinct population. They developed a unique biochemical method of fat metabolism to allow them to store a larger proportion of fat than other breeds of pig. In conjunction they also have a form of low-grade, non-insulin dependent diabetes. This makes them excellent study animals for research into the condition.
Several institutions, including the University of Georgia, have used them to help us to understand how the “thrifty gene” in sedentary, obese Ossabaw pigs (and humans) leads to metabolic syndrome or pre-diabetes.
Metabolic syndrome is characterised by central obesity, increased blood glucose, high blood cholesterol and triglycerides, and high blood pressure. A genetic predisposition to obesity can lead to Type 2 diabetes and heart disease.
Sadly, the Georgia Department of Natural Resources decided to eradicate the pigs from Ossabaw Island and now Indiana University School of Medicine and Purdue University have the only large scale breeding colony of Ossabaw pigs suitable for this research.