Causes Of Type 1 Diabetes: What To Look Out For

Causes Of Type 1 Diabetes: What To Look Out For

Frustratingly, we don’t know precisely why type 1 diabetes develops. However, scientists are working hard to uncover the causes of type 1 diabetes, and researchers have discovered factors that can increase your risk of developing the condition. 


What is type 1 diabetes?


Type 1 diabetes is a chronic condition in which the immune system destroys the cells in the pancreas that produce the hormone insulin. Insulin regulates the levels of glucose in the blood. Without insulin, the body’s cells can’t get the energy they need to work and live, and glucose builds up in the bloodstream.

A healthy immune system protects you against disease and infections. But sometimes, your immune system can attack your body’s cells. In type 1 diabetes, it attacks the beta cells in the pancreas that make insulin.


What causes type 1 diabetes?


Genetics and type 1 diabetes


A tendency to develop type 1 diabetes can run in families. But the genetics of diabetes is not straightforward. There isn’t a single diabetes gene that is handed down from parent to child. Instead, many genes can increase your individual risk of developing diabetes. 

The more of these genes you have, the more likely you are to develop the disease. However, it’s not simple. Even in two people with exactly the same genetic heritage, one person may develop diabetes, and the other won’t. So your risk of getting type 1 diabetes isn’t just written in your genes.

Type 1 diabetes is becoming more common, with the numbers rising too rapidly to be caused by genetic changes alone. Scientists believe that environmental factors may be causing this increase in type 1 diabetes in people genetically vulnerable to the condition. Diabetes UK is funding research to uncover the environmental triggers, including viral infections and nutrition.


Viral infections


Viral infections can trigger type 1 diabetes. Many viruses have been associated with the condition; however, Human Enteroviruses or HEVs have been investigated the most. 

HEV is a family of viruses that infect the bowel. They are spread from faeces to mouth through poor sanitation, hygiene and food preparation. Polio is an HEV, but there are many other Human Enteroviruses that cause mild flu-like illnesses. 

Researchers have found HEVs in people who have recently developed type 1 diabetes and in those who had the condition for a longer time. We don’t yet know how the viral infection triggers diabetes, but there are a few theories:

  • The body may mistake the beta cells in the pancreas for the HEVs and attack them
  • The infection may affect the function of the beta cells so that the immune system sees them as a threat and attacks them
  • The virus might reveal the beta cells to the immune system in a new and different way, triggering an attack

Type 1 diabetes and COVID-19


During the COVID-19 pandemic, doctors identified increasing new cases of diabetes; There is some evidence that the coronavirus might trigger diabetes in some people or make the condition worse in people living with the disease. One study showed that as many as one in twenty people admitted to hospital with COVID-19 developed diabetes when followed up for seven months. 

Some research suggests that there have been more type 1 diabetes diagnoses in children in 2020 compared to previous years. People who had COVID-19 also developed new type 2 diabetes. However, this could be due to the infection or lifestyle changes caused by the lockdown. 

Scientists have linked viruses, like HEVs, with type 1 diabetes. Experts have postulated that the coronavirus may also act as a trigger. Small research studies have demonstrated that the coronavirus can infect the insulin-producing cells in the pancreas, killing them or affecting their function. 

There is also a theory that the coronavirus could trigger the immune system to destroy beta cells causing type 1 diabetes. Doctors are also querying whether Covid-19 causes a new type of diabetes because of the stress of infection and medical treatment, including steroids.

With a novel virus, research is at an early stage, and we are discovering more about its effects and its link to diabetes every day. 


Bowel microbiome


Your gut houses around five hundred million bacteria. These make up our natural microbiome, a balance of good and bad bacteria that helps you digest your food and affects your health and wellbeing. 

The gut bacteria have an impact beyond the bowel walls; they can affect your immune system and how you break down sugars in your food. A diverse microbiome is important for health. It is believed that children who develop type 1 diabetes have different gut microbiomes than those without diabetes. 

Lots of things alter your gut microbiome, including your birth, childhood diet and antibiotics. Research is still underway to find out more about the links.




Unlike type 2 diabetes, type 1 diabetes is not thought to be linked to diet and obesity. However, some scientists have looked into whether your diet in childhood could affect your risk of developing the disease. Experts have looked into the intake of cows’ milk, breast milk, gluten and cereal intake, omega-3 fatty acids, and vitamin D. So far, the evidence is mixed, with no clear link identified. 

The picture is far from clear- but experts believe that type 1 diabetes develops due to an environmental trigger in combination with one or more of the risky genes. Viral infections and the gut microbiome are thought to be factors, and many more are being investigated. Diabetes UK says

Hygiene, pollutants, vaccines, maternal age, psychological stress and seasonal variation have all been put forward as possible environmental factors involved in Type 1 diabetes. It’s a lot to take in, and we don’t have any definitive answers yet, but there’s no shortage of research going on.


To find out more about effective diabetes medications, or to speak to one of our specialists about prospective treatment options, contact us today.


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Carol Willis - Diabetes Clinic Facilitator

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