I read a fascinating article in the Times the other day – according to new research, bottlenosed dolphins are the only animals apart from humans to develop a natural form of type 2 diabetes. The discovery offers important insights into a disease that affects an estimated 2.75 million adults in Britain.
The difference to humans is that the dolphins can turn their insulin resistant state on and off when appropriate, so it is not normally harmful. Dolphins, therefore, could provide a valuable animal model for investigating type 2 diabetes – if researchers can learn how the animals switch off their insulin resistance before it becomes damaging, it could be possible to develop a cure.
The researchers studies more than 1,000 blood samples collected from 52 dolphins. When the animals had fasted overnight, their blood sugar remained high and their blood chemistry changed in ways similar to diabetic patients. Unlike people with diabetes, the dolphins’ blood reverted to normal once they had been fed. Dr Venn-Watson, from the US National Marine Mammal Foundation who led the study, said that such controlled diabetes might be beneficial to dolphins. Their fish diet is high in protein and low in sugar, and they often go long periods without eating, yet they have large brains with high energy demands. By making their bodies resistant to insulin while fasting, they may be able to keep their brains well supplied with sugar. Once they have eaten, the insulin resistance stops to prevent damage to their health.
The American researchers emphasised that the research did not mean that dolphins should be used as laboratory animals, as their large brains and high intelligence would make this unethical. But studies of their genetic code and physiology, revealed by blood and urine samples, could provide important clues to the biology of diabetes.
We hope you found that useful. Please let us know of any other diabetes research developments that you have heard….We will keep you posted on any further developments of this story.