The discovery of insulin in 1921 radically transformed diabetes from a fatal disease to a condition that’s chronic and complex but manageable. Today, a hundred years after that discovery, insulin is still the standard treatment. 

Despite huge technological advances such as smart insulin pumps, glucose sensors and control algorithms, the therapeutic principle has remained the same: to replace a hormone the body can no longer produce or use properly. And although insulin saves lives, it’s still a stopgap: it doesn’t cure the disease or prevent the associated long-term complications.

On World Diabetes Day, we explore new lines of research that seek to go one step further: to release patients from their dependence on chronic treatments, improve their quality of life and perhaps one day find a definitive cure.

A 21st-century pandemic

In 2024, 589 million adults were affected by diabetes and, according to the International Diabetes Federation (IDF), the future projections are stark: 643 million by 2030 and 853 million by 2050.  

Of the affected population, more than 90% have type 2 (T2D) and between 5-8% have type 1 (T1D). It’s important to distinguish between these two main types. 

Type 1 is an autoimmune disease caused by a combination of genetic and environmental factors that trigger an abnormal immune response: the immune system attacks the pancreas’s β cells, which are responsible for producing insulin. “As a result, local inflammation occurs and these cells gradually die, ultimately stopping the patient from producing enough insulin” explains Lorenzo Pasquali, a researcher from the “la Caixa” Foundation network in the Department of Medicine and Life Sciences at Pompeu Fabra University (UPF) in Barcelona. 

Lorenzo Pasquali

On the other hand, in type 2 diabetes the body may not produce enough insulin to meet its needs or, even if it does, the body may not be able to use it properly due to a combination of risk factors, including obesity, a sedentary lifestyle and genetic predisposition.

In both cases the result is excess blood sugar, which in the long term can cause ulcers, eyesight problems, kidney damage, strokes and a weakened immune system, seriously affecting the patient’s health.  

The invisible burden of treatment

“For type 1 patients, standard treatment involves multiple daily injections or insulin pumps, as well as the continuous monitoring of glucose levels” explains Pasquali. “It’s a demanding routine that requires constant attention and this has an impact on the mental health and daily lives of those affected”.

In type 2 diabetes, the range of potential treatments is more diverse and depends on the clinical characteristics of each patient. “It usually starts with lifestyle changes such as diet, exercise and weight control, followed by drugs that lower the blood glucose, such as metformin or, more recently, SGLT-2 inhibitors and GLP-1 receptor agonists” notes the researcher. “But when these options fail, insulin once again becomes the last resort”.

Furthermore, despite current advances, insulin can’t replicate the precision with which the pancreas regulates glucose levels. “This can lead to hypoglycaemia or complications which, over time, will affect the patient’s health” explains Pasquali. 

A lifelong solution

“The large pharmaceutical companies develop many more solutions for type 2 diabetes because the market is much bigger” said Esther Latres, Director of the Breakthrough T1D Foundation, in this interview. Since 2024, this organisation has been collaborating with ”la Caixa” Foundation in funding research projects with the following goal: “to improve the lives of people living with T1D but also to promote truly curative therapies”. 

Esther Latres

This is the line of work of Lorenzo Pasquali, who’s researching the use of therapies capable of regenerating the body to restore its ability to produce insulin. These are known as ‘cell replacement therapies’ and they’re based on the transplantation of pancreatic islets or β cells derived from stem cells. The results are preliminary but already point to a possible functional cure for the disease.

“The challenge is ensuring that the new cells survive the immune system’s attack without the need for immunosuppressants” explains Pasquali. His team is studying how inflammation and genetic predisposition influence the destruction of β cells in order to design more resistant versions. “We’ve already identified genes that could reinforce this protection and are testing genetic modifications with promising results” he adds.

The latest advances confirm this potential. In August 2025, two studies published in the New England Journal of Medicine showed that β cells obtained from stem cells can produce insulin for months without the need for immunosuppressive drugs. Although the trials are still small, they represent a milestone. “These are proof-of-concept studies that demonstrate that a functional cure is possible” says Pasquali. “The next challenge will be to ensure their safety, durability and accessibility so they can reach all patients”.

Towards a new era

Diabetes research augurs a future of new therapies capable of restoring the body’s natural insulin production and reducing dependence on external treatments.

“We may still be a long way off from a universal, safe and accessible cure” Pasquali acknowledges. “But we can already envisage a future in which patients with type 1 diabetes can live for long periods of time without insulin and with a better quality of life”.

A century after its discovery, insulin continues to save millions of lives. But science is getting ever closer to offering something even more valuable: the possibility of leaving it behind forever.