The bittersweet story of diabetes

You probably know someone in your life with diabetes – a chronic disease that effects about 422 million people worldwide and each year directly causes 1.5 million deaths. Worryingly, both of these statistics have been rising steadily over the last few decades and diabetes has been recognised as the world’s fastest growing chronic condition. Characterised by elevated levels of blood glucose (sugar), diabetes can also lead to serious damage to the heart, blood vessels, eyes, kidneys, and nerves over time.

Insulin is a hormone which, among other functions, is released into the bloodstream when we eat to help regulate blood glucose levels, which may rise dangerously high or drop too low if we lack insulin.

There are two types of diabetes: type 1 is caused by an autoimmune disorder where the body attacks cells in the pancreas that produce insulin, markedly reducing or shutting down insulin production. Type 2 diabetes – the most common type – usually develops in adults when the body becomes resistant to insulin and gradually loses the ability to produce it.

While people with type 2 diabetes may be able to slow or even stop the progression of the condition through changes to their diet and physical activity, there is currently no cure for type 1.

Bittersweet, a documentary selected for the SCINEMA International Science Film Festival in 2018, follows the personal stories of young people living with diabetes and their daily struggle to manage this lifelong disease.

You can watch Bittersweet in full here.

Read on for some recent diabetes research you may have missed.

Marine snail inspires fast-acting injectable insulin

Insulin is an essential medicine for diabetics, but for some marine predators it’s the ultimate weapon. Some ocean dwelling cone snails have an insulin in their venom that can drop the blood sugar of fish prey so swiftly that they’re paralysed and defenseless. This fast-acting venom inspired scientists to design new fast-acting human insulins based on its structure.

Human insulin is normally produced and stored in the pancreas until it’s needed. The individual molecules come together to link first into pairs and then into groups of six, which allows insulin to be stored efficiently.

But this property of insulin isn’t helpful for diabetics who rely on insulin injections. This is because until the clusters separate, the molecules are prevented from making their way from the injection site to the bloodstream. This creates a delay that can make it difficult for people with diabetes to keep their blood glucose within the optimal range, increasing the risk of complications.

But the cone snail’s venomous insulins don’t form these clusters at all, and that’s what makes them so fast acting. Since researchers first discovered this phenomenon in the cone snail species Conus geographus, new insulins that form fewer clusters than natural human insulin have become available to patients. And although they still form pairs, they do separate more easily in the body.

Now, a research team have developed a new hybrid insulin that doesn’t form any of these clusters, using parts of the structure of a new insulin-like molecule found in the cone snail Conus kinoshitai. This new molecule still has the ability to bind to the human insulin receptor (which is key to insulin’s regulation of glucose) and the researchers hope that it, as well as the original Conus geographus-inspired insulin, hold promise as potential diabetes therapeutics.

The study was published in Nature Chemical Biology.

Snail eating fish2 credit baldomero olivera
A fish-hunting cone snail can drop the blood sugar of its prey so precipitously that it quickly becomes paralyzed and defenseless. This phenomenon has inspired scientists to develop insulins that provide people with diabetes better and more immediate control over blood sugar. Credit: Baldomero Olivera

Why yogurt lowers the risk of developing type 2 diabetes

Scientists have known for years that eating yogurt is associated with a reduced risk of type 2 diabetes, but until now the reason why this occurs has been a mystery. Now, new research has found that this protection could come partly from a specific product of metabolism (a metabolite) – called branched chain hydroxy acids (BCHA) – from lactic bacteria in yogurt.

“BCHA are found in fermented dairy products and are particularly abundant in yogurt,” says co-lead author Dr Hana Koutnikova, of Danone Nutricia Research in the Netherlands. “Our body produces BCHA naturally, but weight gain seems to affect the process.”

Researchers studied the effects of eating yogurt on mice that were fed a rich diet in sugars and fats, with one group being given the equivalent of two daily servings of yogurt in humans and the other not. This was carried out over 12 weeks, after which the researchers found the yogurt fed group had better control of blood glucose levels, insulin resistance, and liver function.

By analysing all of the metabolites present in the mice’s blood and livers they measured changes in BCHA levels and found that while levels of BCHA were reduced in obese and insulin-resistant mice, these levels were partially maintained when also consuming yogurt.

They then went on to show that BCHA improves the action of insulin on the metabolism of glucose in liver and muscle cells, increasing their glucose intake.

The researchers suggest that the next step could be to determine whether dietary intake of BCHA can offset the decrease associated with weight gain and help restore normal metabolic function in obese and insulin resistant people.

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