In one of the world’s smallest countries, the island Nauru in the Southern Pacific, half the population suffers from diabetes. The Nauruans are the fattest people in the world. Cause? The high standard of living enjoyed as a result of the country’s wealth. This wealth was created through selling the country’s indigenous and highly-demanded natural resource – a natural fertiliser originating from the many guano producing birds stopping by.
This example illustrates how eating and drinking can easily become main activities in societies of abundance and gives rise to reflection. It was recently presented by Leif Groop on a science day about the front lines of diabetes research (24th November 2011) at S:t Petri School in Malmö. Groop is one of the world’s leading diabetes researchers and is also professor of endocrinology and head of the Lund university Diabetes Center.
The day was a part of the EU project ComScience. Besides Leif Groop other participating researchers were the biologist Ola Hansson, PhD and specialist on muscle tissue, and the PhD student Wenny Poon whose research focuses on heredity factors. Moderators were Klas-Herman Lundgren from Forskningsnätet’s co-organising association Science & Society (VA) and Jeanette Runol, teacher of biology at the S:t Petri School. Ms Runol and the school nurse Kristina Jönsson were responsible for the majority of the day’s planning. The pupils and teachers representing S:t Petri and the secondary school Österlengymnasiet in Simrishamn totalled slightly more than 60 people. They gave both the arrangement and the researchers high marks at the end of the day.
It is well known that diabetes is connected with the level of blood sugar. Sugar, glucose, comes from food and its main purpose is to provide the cells of the body with fuel. Sugar uptake in the cells needs insulin, a hormone produced in the Islets of Langerhans in the pancreas. In practice, insulin works as a regulator of the glucose level. Hence, if the body produces too little insulin or none at all, the glucose rate will increase to abnormal levels. Even if a person has a normal production of insulin it might not be enough to handle all the sugar that reaches the blood. The cells of the body may also have a reduced sensitivity to insulin, which also causes an abnormal glucose level.
The results of blood sugar irregularities include tiredness, concentration problems, blurred vision and in the worst cases even coma. Typical symptoms are increased thirst and urine formation.
- Diabetes is the world’s most rapidly increasing disease, Leif stated in his description of the complaint. It is common in Europe and USA, and not yet as common but rapidly growing in large parts of Asia and South America.
The fact that diabetes is a widely spread disease was further pointed out by a quick poll among the audience, of which almost a fifth raised their hands to the question whether they had diabetes in their families or circles of acquaintance.
The most well-known types of diabetes are type 1, also known as juvenile diabetes, and type 2, which is commonly developed in older age groups and seems to have a strong connection to lifestyle. However, there are also lesser known types of diabetes, such as the gestational diabetes – occurring in relation to pregnancy and normally disappearing after delivery.
Type 1 is an autoimmune disease, i.e. the body fights and breaks down substances that are produced by itself and necessary for its function, as if they were harmful, foreign matter. In this case, it is the insulin producing cells that are affected. Type 2 is a different case, where the combination of an insufficient capacity for insulin production and decreased insulin sensitivity in the body’s muscle and adipose tissue causes the complaint.
Type 1 is most often easily controlled by injecting insulin while type 2 requires additional treatments that stimulate the insulin producing cells and the glucose uptake of the cells. However, both cases require continuous and lifelong treatments. Finding a permanent cure for diabetes is thus a great challenge, especially when it comes to the rapidly spreading type 2.
The pursuit of a cure is of course one of the driving forces behind diabetes research. One of the ambitions is to develop a diabetes vaccine, another to develop therapies based on stem cells.
- It is however unrealistic that transplantation of the pancreas would be the solution for type 1, Leif Groop says. There would simply not be enough organs.
But of course effective cures require that the cause – or causes – is well defined. We’re not there yet. But some answers to why people develop diabetes type 2 seem well established.
One of them is due to inheritance; i.e. whether others in your family have diabetes. There is an obvious heredity relationship. If a person has relatives with diabetes they themselves are subject to a greater risk.
- But it doesn’t explain why the number of diabetes cases have doubled over the last 30 years, heredity doesn’t change that fast, Leif pointed out.
In that perspective a lack of exercise is a more reasonable explanation.
- Before the days of the remote control we used to move a lot more. With today’s way of living we burn 300-500 kcal less in energy per day than just 50 years ago. But we have not changed our consumption level of food. Therefore, we need 2-3 times more insulin than our ancestors from the savannahs who moved around a lot more.
- The pupils in school should have 90 minutes of physical exercise per day, which they hardly get. Going to a gym a couple of times per week is not enough. Daily, regular exercise is necessary to compensate for all the sitting around.
Ola Hansson is a specialist in what happens within muscles when we exercise. Which genes are activated? How is the aerobic capacity affected?
One the experiments he described aimed to study the opposite situation; what happens when we do not exercise? A group of male test subjects were kept in bed for 21 days. Not unexpectedly, the researchers detected a significant decrease of aerobic capacity in the muscles.
- What’s interesting is that it took them as much time, three weeks, to recover and get back to the initial condition.
Exercising instead of slacking is of course preferable and there is a clear relation between being overweight and exercise. A general health recommendation from the Swedish National Board of Health and Welfare – perhaps not crystal clear – is 30 minutes of semi-intense exercise per day or at least 150 minutes per week. Exercise helps in holding back type 2 diabetes.
- However we can’t say today what kind of exercise gives the best effect. Is high or low intensity the most efficient? Is fitness training better than long walks? Is an even trot preferable to interval training?
- More exact knowledge is needed, as it’s becoming more and more common for doctors to write prescriptions for physical activities, e.g. for treating diabetics.
Perhaps one this that is definite from the research results is after all to exercise on a regular basis, spending enough time on physical training and utilising the opportunities for everyday exercise – taking the stairs, getting off the bus a couple of stops earlier etc.?
The prehistoric Homo sapiens certainly got all the necessary exercise in their everyday life on the savannah or steppe, as did their relative the Neanderthal. A time traveller landing somewhere between 200 000 and 50 000 years ago would probably not meet any type 2 diabetics.
Nevertheless, in order to solve the riddles of type 2 diabetes, extinct human species like the Neanderthal are very interesting for researchers today. Ola Hansson collaborates with Svante Pääbo, working at the Max Planck Institute for Evolutionary Anthropology in Leipzig. Pääbo has discovered that homo sapiens have a some genetic features, around 3%, in common with the genome of the Neanderthal. A similar correspondence can be found with the Denisovan hominin (also named after the finding-place, the Denisova Cave in Russia –the entire finding consists of a finger bone and a tooth). Some of these genes are involved in causing diabetes type 2 for the modern man. The blending between our species and the others may thus be the origin of this disease. It’s an incredibly thrilling track that can give us entirely new perspectives.
Wenny, who just started her postgraduate studies, is also interested in the genetic aspect of diabetes. She wants to map why the risk of diabetes depends on whether the genes come from the father or the mother. During the ComScience day she however shared another perspective. She explained how she, after feeling her way in a number of different research environments, ended up in Leif’s research team at CRC, Clinical Research Center, in Malmö, which is perhaps the biggest diabetes research centre in Europe with its 270 employees.
- I’m a lab rat, I love lab environments and I was incredibly impressed by the fantastic equipment with all the robots performing lots of the lab work, Wenny said. It was something completely different to what I’d seen before. I was totally captivated.
These statements were a perfect culmination to an afternoon that with all desirable clarity demonstrated how incredibly interesting and important a field of research can appear when one gets the opportunity of an in-depth study; listening to the researchers themselves, how they reason and turn the problems and possibilities over in their minds.
This was reflected by all the questions asked; the following are just a couple of examples. The first question was about diet drinks; is a Diet Coke better than a regular Coke?
- Yes, Leif claimed. The sweetener contains zero calories. The injurious effects are overemphasised, at least regarding a reasonable consumption level.
After the break, a question came up about how healthy it is to eat fruit, considering all the sugar it contains. Leif answered that it varies between fruits but from the fruit that happened to be in the room he said that the mandarins had the lowest content of sugar. The pears have a bit more sugar, then bananas and lastly the grapes, which one could just as well stay away from since they contain large amounts of sugar.
ComScience discussions have a particular structure. First, the audience, in this case the pupils, answers a questionnaire that, among other things, aims to show what knowledge they already have of the topic. The programme then opens with a film, in this case about diabetes and obesity among youth. The film was produced by the German management division and, amongst others, Swedish researchers were interviewed. The researchers then present their topics and comment on the film, after which questions are asked. After a coffee and fruit break, the researchers sit down in groups to continue the discussions and answer questions. At S:t Petri, Leif joined one group and Ola and Wenny joined the other. The ComScience discussions were concluded with a new questionnaire for the audience as well as for the organisers and the participating researchers. ComScience is arranged in several places in Europe, for various types of groups – not only for students – and considers many health-related topics other than diabetes, for example asthma and stem cells. The organisation Science & Society is the Swedish node of the ComScience project.
/Text: Forskningsnätet Skåne & VA