Bottlenose dolphins could provide vital clues to help Britain’s 2.2 million Type 2 diabetes sufferers.

The mammals have an amazing ability to switch the condition on and off. And if scientists can find out how they do it they could help prevent diabetes in people.

Dolphins and humans share the same glucose blood ­chemistry needed to feed our large brains. Humans have bigger brains relative to their size than dolphins.

But dolphins are able to keep their blood glucose levels high in a diabetic-like state when they have no food to feed the demand from their brains.

The US National Marine Mammal ­Foundation’s Dr Stephanie Venn-Watson said bottlenoses are the first animal model for Type 2 diabetes in humans.

She added: “When dolphins fast overnight they develop diabetes, then when they are fed in the morning they revert back to a non-diabetic state. Effectively they have a switch which can turn diabetes on and off. Discovering how dolphins control this may help humans turn diabetes off.”

Dolphins are thought to have developed their insulin resistance 55 million years ago when they evolved into sea creatures.

Speaking to the American Association for the Advancement of Science meeting in San Diego, Dr Venn-Watson said: “Their large brains need sugar to ­function like us. We can eat carbohydrates but their diet of fish has no sugar in it.

“So it works to have a system which keeps blood sugar high in their bodies. Their liver will go and produce sugar at just the right amount they need.”

And Dr Venn-Watson said dolphins wouldn’t be harmed in any research, adding: “There’s no desire to make a dolphin a lab animal. I don’t think it could ever happen because we all love dolphins too much.”

The number of diabetes sufferers in the UK is predicted to rise to four million in the next 15 years. It can lead to blindness, heart disease and kidney damage.