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Type 2 diabetes – an infectious plague of the 21st century

26th July 2023

David Matthews, Professor Emeritus in Diabetic Medicine at the University of Oxford, gave the Paul Cromme Award Lecture at the recent Primary Care Diabetes Europe (PCDE) conference in Barcelona. Professor Matthews took this opportunity to explore a new way of looking at the challenge posed by the growing pandemic of type 2 diabetes. Dr Susan Aldridge reports. 

Professor Matthews opened by reflecting upon the Black Death, which swept through Europe between 1346 and 1353 and became the world’s greatest ever demographic disaster – until COVID-19 came along. With his daughter Philippa, a professor of infectious diseases at Oxford, he wrote a paper back in 2011 with the provocative title ‘Type 2 diabetes as an infectious disease: is this the Black Death of the 21st century?’. “We looked at the fact that we are currently facing a global epidemic of obesity and diabetes,” he said. “In some settings, prevalence is up to 50% and half of those affected will die of complications.”

Professor Matthews’ theme is that there are significant resonances and comparisons between type 2 diabetes and infectious diseases. COVID-19 has undoubtedly been a huge catastrophe – with 80 million infections in 2020 alone – that transformed society with schools and industries closed down, society in lockdown, and daily messaging on mask wearing and social distancing. Meanwhile, the International Diabetes Federation report revealed that prevalence of type 2 diabetes was 537 million in 2021, which is 6.5 times more than the number with COVID-19 the year before. 

“So why did COVID-19 cause massive societal change, but diabetes has not?” asked Professor Matthews. Maybe because COVID-19 was all about headlines, while diabetes is more about trends, which we tend to ignore. In the UK, the trend means that between now and 2030 the number of people with diabetes will go up by one million – a 25% increase.  

What type 2 diabetes, a non-communicable disease, and COVID-19, a communicable disease, have in common is that both are demographic, economic and personal catastrophes. COVID-19 spreads like an epidemic and so does type 2 diabetes, the difference being that COVID-19 can spread in days, while diabetes takes decades and this slow spread tends to get ignored. COVID-19 can kill in a matter of days while diabetes will take 10 years or more. “So you discount the diabetes because it’s in the future,” Professor Matthews said. In 2020/2021, there were 2.5 million COVID-19 deaths, but 6.7 million dying from diabetes.   

Is type 2 diabetes infectious?

For COVID-19, there was a clear pathogen involved and Professor Matthews believes this is also the case for type 2 diabetes – it’s not an infectious agent, that we know of, but rather the toxic environment we live in. “We can think of type 2 diabetes as an infectious plague of the 21st century,” he said.  

People traditionally think of epidemics as involving communicable disease. In 1990, half the deaths and disability in the world were due to communicable disease, but two-thirds of health problems today are related to chronic diseases, also known as non-communicable diseases, and infectious disease is no longer a dominant cause of death in developing countries. So the term epidemic can be applied to communicable and non-communicable diseases.

How does the way COVID-19 was dealt with compare with how we address type 2 diabetes? With COVID-19, the first steps were data collection and assembly of emergency teams. Primary prevention measures were then set up and treatments identified, while the basics of transmission were established with ways of breaking the infectious cycle, including immunisation.  

Now, looking at type 2 diabetes in comparison, data is collected of course, but this is very diffusely spread across countries. There is some primary prevention work and, when it comes to identification of possible therapies, we do know how to treat type 2 diabetes. “So we wait for it to happen and then start to treat it, instead of preventing it,” said Professor Matthews. “It’s all brilliant science, but it’s treating something that’s already happened.” 

In type 2 diabetes, we still haven’t established the basics about what’s going on, especially with insulin resistance. Nor is there real action on breaking the cycle of ‘infection’ or immunising against the toxic environment. 

“What is the causative agent in obesity/type 2 diabetes, if it is an infectious-type disease?” asked Professor Matthews. “Type 2 diabetes is related to the obesogenic environment that surrounds us. It is transmissible by the society that you and I, government and industry – especially the food industry – construct. It’s not related to any moral failings, it’s about a toxic environment where it is hard to make healthy choices.” 

As a simple example, Professor Matthews asked delegates to raise their hands if they’d eaten more breakfast in the conference hotel than they normally would. Several did. It was beautifully laid out, but it still represented a toxic environment because if you expose people to multiple choices then they will consume more, as has been proved in animal experiments. “Stimulus is everywhere and size is everything,” he said. “This is the way society is changing and infecting you, for industry upsizes and supersizes and makes profits from that.”   

Focus on fast food

Obesity is now a pandemic and the causes are obvious. “Government, scientists, health workers and individuals use excuses as to why no action is needed,” Professor Matthews said. “For instance, government says that food is the responsibility of the individual. That is nonsense and we have to call it out.”

Meanwhile, some scientists say that obesity is genetic. There may be some truth in this but what has been going on in our population over the last five years or so cannot be explained by genetic change. People living in poverty will say, ‘the best value meal I can find is fast food’. “I’m afraid that’s completely true,” said Professor Matthews. “So we’ve got a society that is obesogenic where poverty is forcing you to be overweight and that’s a political problem.” 

We are changing what we eat, with an accelerating trend towards a diet high in saturated fat, sugar and refined foods, but low in fibre. And average food consumption per person is due to go up from 2680 calories in 1997-1999 to nearly 3000 calories in 2030. Eating habits are changing too. Eating together as a family is less common, while snacking on the go is on the increase. Portion sizes are up too and more food is eaten outside the home or in the form of ready-meals.  

Intervention is key

Stepping back into history again, Professor Matthews recalled how, in 1854, John Snow removed the handle from the Broad Street pump and stopped a serious outbreak of cholera. “He intervened and that’s what we need to do,” he said. “The Diabetes Prevention Program shows that lifestyle intervention gives you delay and prevention, but at a cost of €11,000 per case of diabetes prevented because this was a medical model involving dietitians and encouragement delivered by healthcare professionals. This cannot be translated to the community. We need societal interventions.”

He cited Community Interventions for Health (CIH), a large, comprehensive multinational study for community interventions – its goal was to create sustainable interventions that prevent and control leading chronic diseases by addressing risk factors. The CIH study has collected data on smoking, physical activity, diet, biometric data and environmental scans, and developed interventions in schools, workplaces, neighbourhoods and health centres. 

These ran for two years with follow-up, involved over 12,000 people and looked at knowledge, attitudes, behaviours and locus of change. Professor Matthews showed many examples of the CIH study’s work, such as healthy meals in workplace canteens, outdoor gyms and even one that could be applied in the PCDE conference venue – namely, ‘decision prompts’ to take the stairs. “If you want a quiet time here, sit on the stairs,” he noted. “No one is going up and down them.”

As mentioned earlier, governments fear interventions might make it look as if they are telling people what to eat, but there are other approaches that could be adopted, such as taxing certain foods or making food labels more prominent by putting them on the front of packets, instead of in small print on the back. Calorie labelling on menus, once fiercely opposed by restaurants but now adopted in some places, could save thousands of lives and billions in healthcare expenditure.  

The CIH study has shown that effective interventions must be culturally sensitive, context specific and involve partnerships between local stakeholders and communities. Their success depends on a range of factors, including sustained commitment, stakeholder engagement and a tailored approach.

Besides taking these learnings on board, Professor Matthews urged delegates to also get involved with the European Diabetes Forum, the World Health Organisation and the Global Alliance against Chronic Disease. Health education, social marketing, community mobilisation and structural change are all needed to engineer societal change at the level of the individual, family, community and society.

As Michelle Obama put it, ‘We, as parents, are our children’s first and best role models and this is particularly true when it comes to their health. We can’t just lie around on the couch eating French fries and candy bars and expect our kids to eat carrot sticks and run around the block’. Healthcare professionals can set an example too. “So do use the stairs and not the lift here,” Professor Matthews urged delegates.  

Non-communicable diseases, including diabetes, kill 36 million people a year, nine million of them before age of 60 when they are in the prime of life as breadwinners. “But we can prevent this, as we know the problems are tobacco, alcohol, unhealthy diet and inactive lifestyle solutions,” said Professor Matthews. “And we can afford it. From just $1 per person per year, even poor countries can turn the tide. It’s a global issue requiring a global response from government, the United Nations, civil society and the private sector, with all countries committing to high level political action to reduce exposure to risk factors, strengthen health systems, improve access to care, set targets and measure results.” 

In conclusion, we can learn from COVID-19 by treating type 2 diabetes as a transmissible disease. “Let’s not have our grandchildren say, ‘between 1980 and 2035, a huge plague of diabetes wrought havoc throughout the world. It was understood, but not prevented. It was the greatest ever demographic disaster’,” concluded Professor Matthews. “We must all play our part in making sure this doesn’t happen.” 

To learn more about promoting lasting behaviour change, enrol on the EASD e-Learning course ‘Lifestyle intervention’.

Any opinions expressed in this article are the responsibility of the EASD e-Learning Programme Director, Dr Eleanor D Kennedy.