Researchers do not understand why there is a worldwide increase in the incidence of juvenile diabetes, the less common type of the disease
When public health officials express concern over the rising prevalence of diabetes in the US and the rest of the world, they often mean adult diabetes. About 90% of the 350 million diabetics in the world have type 2, a disease whose medical problems usually begin after the age of 40 or 50. Type 2 diabetes is related to the burden that excess weight places on the body's ability to regulate blood sugar. About 25 million people in the US live with type 2 diabetes, and another million with type 1 diabetes (juvenile diabetes), which usually begins in childhood and requires daily doses of insulin.
However, for completely mysterious reasons, the incidence of type 1 diabetes is increasing worldwide at a rate of between 3% and 5% every year. Although this trend does not receive much publicity, it is extremely worrying, because this type of disease can cause disability or death at very young ages.
No one knows clearly why the incidence of type 1 diabetes is increasing. Solving the mystery and slowing the increase, or even reversing the trend, have become extremely pressing issues for public health researchers everywhere. So far they only have one solid clue.
"The reason for the increase in the incidence of the disease in such a short period of time cannot be attributed to genetic changes," says Josephine Imperatore, who heads a group of epidemiologists in the division for the implementation of diabetes research at the American Centers for Disease Control and Prevention. "So environmental factors likely play a major role in the increase."
The counting challenge
The same physical defect underlies both types of diabetes: the inability to utilize insulin and prevent the blood sugar level from rising too high. But in each of the types the defect results from almost opposite processes. Type 1 diabetes, previously called juvenile diabetes, is an autoimmune disease in which the body attacks its own cells, in this case the beta cells in the pancreas, damaging their ability to produce insulin. In type 2 diabetes, formerly known as adult-onset diabetes, insulin resistance develops in the tissues that need it to absorb glucose (such as the liver, muscles and fat tissues). The insulin-producing cells therefore react with overactivity and initially produce a larger than normal amount of the hormone, but then they are no longer able to handle the excess glucose in the blood. Eventually, some people are unable to produce insulin at all.
The first prominent alarm signal that the incidence of type 1 diabetes is on the rise came in 2006, from a World Health Organization project known as DIAMOND (an acronym for words in different languages that mean global diabetes). The survey, which examined 10 years of records from 112 diabetes research centers in 57 countries, revealed that the incidence of type 1 diabetes increased by an average of 5.3% annually in North America, 4% in Asia and 3.2% in Europe.
These findings were confirmed by a statistical analysis of the data from Europe, where the public medical systems responsible for the health of the residents throughout their lives maintain rich databases. In 2009, researchers from the EURODIAB project compared the incidence of diabetes in 17 countries and discovered not only an average increase of 3.9% per year in the incidence of type 1 diabetes, but also that the fastest increase is in children under the age of five. They predict that by 2020 the number of type 1 diabetes cases in these ages in Europe will almost double, from 3,600 to about 7,000 children.
Most estimates of diabetes in the US are partial and more local. Only one comprehensive follow-up survey has been conducted, the SEARCH Childhood Diabetes Surveillance Project, which was funded with federal funds and published its findings in 2007. But it was a preliminary report that did not contain multi-year comparisons. And yet, if you compare his findings with findings from other studies, he points to an upward trend. For example, the 2007 survey found a higher prevalence of type 1 diabetes in the US than the prevalence in the World Health Organization survey conducted a year before. Moreover, the prevalences in the SEARCH study were considerably higher than those of local studies from the 90s in Alabama, Colorado, and Pennsylvania.
competing hypotheses
The challenge facing those trying to explain the trend of the increase in type 1 diabetes is that if the increase is happening all over the world, then the reasons must also be global. Therefore researchers should look for global effects and consider the possibility that different factors will be of greater importance in certain regions.
The list of possible suspects is long. For example, researchers hypothesized that gluten, a protein found in wheat, may play a role because there seems to be an increased risk of type 1 diabetes patients also developing celiac disease, and the amount of gluten most people consume (in processed foods) has increased over the years. Scientists also looked at what age to start feeding babies with root vegetables. Stored tubers may become contaminated with microscopic fungi that apparently contribute to the development of diabetes in mice.
However, none of these research directions produced solid enough results to convince other scientists to gamble and invest an entire career in them. In fact, so far the search for the culprit resembles the penultimate scene in an Agatha Christie mystery, the scene where the detective explains which of the many suspects could not possibly have committed the crime.
Unfortunately, the last scene in the script has not yet been written. These days, the suspects that get the most attention are bacterial, viral or parasitic infections. The presumed cause of the disease is a version of the "hygiene hypothesis" that links the excessively clean modern lifestyle with the development of allergies.
According to the hygiene hypothesis, early exposure to infections or bacteria in the soil teaches the developing immune system how to balance itself and thereby prevents it from reacting in an uncontrolled way later in life when it encounters allergens such as dust or pollen. The hygienic life, so the hypothesis claims, prevents children from this early exposure, and is responsible for the allergy epidemic. The diabetes version of the hygiene hypothesis claims that when the immune system is exposed to infections and learns not to overreact to allergens, it also learns to show tolerance to compounds produced by the body's tissues, thus avoiding the autoimmune attack that destroys the ability to produce insulin.
There is circumstantial evidence to support this hypothesis. Children with brothers and sisters, who may bring home infections from daycare or school, tend to be hospitalized less due to type 1 diabetes (an indirect measure of the prevalence of the disease). The disease is also less common in children who go to kindergarten on their own, and is more common in mice of a special breed that do not face infections because they grow up in a sterile environment.
But these findings are not enough to prove the hypothesis. Christopher Cordwell, a lecturer in medical statistics at Queen's University in Belfast, conducted a meta-analysis of the associations between type 1 diabetes and birth order, maternal age at birth and caesarean section, all indicators that affect the organisms to which young children are exposed. "They are all probably related," he says, "but in my opinion, these are rather weak connections, which are unable to explain the increase in the incidence of diabetes over time."
Back to fat
Recently, the search for a reason for the increase in the incidence of type 1 diabetes took a surprising turn. Some researchers are reconsidering the role of an old enemy: overweight or obesity.
This suspicion may be counter-intuitive because the popular information about diabetes claims that obesity actually causes the body to produce large amounts of insulin (as in type 2 diabetes), and not too small amounts. But some argue that the need to produce so much insulin can wear out the insulin-producing beta cells in the pancreas and cause a child whose beta cells are already weakened to develop type 1 diabetes. According to this idea, known as the acceleration or overload hypothesis, "If you have a chubby child, the fat The excess will challenge the beta cells in his pancreas," says Rebecca Lipton, a retired professor at the University of Chicago. "In a child who has already started the autoimmune process, these beta cells will simply collapse sooner, because they are forced to produce more insulin relative to a thin child."
Obesity is a reasonable suspect. People pile on extra pounds in both rich and poor countries. But the researchers don't just want to explain why there is an increase in the incidence of type 1 diabetes, they obviously want to prevent it. Unfortunately, if excess weight is the main cause of the problem, the task will not be easy. So far, no one has been able to slow the global obesity epidemic (by 2048, according to researchers at Johns Hopkins University, all American adults will be overweight, if current trends continue.) Until society can ensure that most children (and not to mention adults) are Being more physically active, eating healthy foods, and maintaining a healthy weight, diabetes investigators will continue to resemble the detectives who solved the murder, but can do nothing to prevent the next murder.
on the notebook
Marin McKenna is a journalist, blogger and the author of two books about health. She writes about infectious diseases, global health and food policy.
17 תגובות
Too many people use statins
Jonathan,
I did not say that everything is genetics, but only that the ability to be affected by all the factors you mentioned has a genetic basis.
There is no need to wave "despite everything that is known today, people are perceived by genetics and not by the environment" because despite everything you say, the sensitivity to the environment and its effects also have a genetic basis.
Igal,
The sperm, as you know, is created all the time, and the fetus stays in the mother's womb and is influenced by the secretions of hormones in the mother's blood, so there is no situation here of freezing the past.
I understand that it is difficult for you to accept because genetics is a relatively marginal factor, it is less than a 25% effect on morbidity, everything else is environment, lifestyle and more. It is true that the epigenetic properties are reversible and that is the good point, there is a payoff for a healthy life.
But to place the blame on the percentage of patients with genetics is unfounded to say the least.
Genetics is only the potential except for extreme cases of course, the power is in our hands.
It seems to me that you do not understand what is meant by epigenetics, there is no passing of traits here but expression of genes.
You write that "everything related to the secretion of substances in the body, especially hormones, is related to genetics" - hormones are secreted because of mental states, food eaten, and more, and certainly not only because of genetics.
And when you consume hormones from the outside - like milk, or pesticides, you actually disrupt the systems in the body, so why blame everything on genetics and not the environment. It's amazing time and time again that despite everything known today, people are caught by genetics and not by the environment, apparently it's easier - a kind of defense mechanism.
It's like we once claimed that obesity is genetic because fat parents have fat children, it's in the vast majority of cases simply the same spoiled lifestyle.
Jonathan,
First, there is no need to be sorry.
Secondly, there is a connection between diabetes and genetics, and in juvenile diabetes (type 1) it is a connection of about 33%, which still requires a triggering factor for its awakening. However, even those who are affected as a result of a trigger, such as obesity, or for other reasons, are susceptible to diabetes which is derived from genetic reasons. In general, it seems that everything related to the secretion of substances in the body, especially hormones (which are also involved in the issue of diabetes) is apparently influenced by heredity.
Thirdly, it seems to me that caution should be taken when using the concept of epigenetics (perhaps in contrast to researchers dealing with the subject): the ability of genes to be silenced as a result of the activity of other genes or of other substances is also genetic (the ability is inherited)! And if a certain gene is silenced or activated as a result of an "epigenetic" substance, then the process is reversible, the fact that the original (epigenetic) action also occurred after the genes had already been determined. Basically, traits that are transmitted to future generations are transmitted through genes only, because, as I mentioned in the previous sentence, the epigenetic traits are reversible and can pass, or not pass, in some cases in one situation and in some of the cases in another situation. Another thing that bothers me about "epigenetic" traits is the fact that the female's eggs are all formed before she is born, so where is the epigenetics? (Although today there are studies that suggest that it is possible that eggs continue to be formed even after that, although this is questionable).
In conclusion, epigenetics is probably a form of genetics, and obeys the laws of genetics.
Less physical activity, more computer time, more industrialized food and more available sweets = diabetes, what is not clear
It is true that medicine allows the continued existence and spread of weak genes, but as it seems, it has nothing to do with juvenile diabetes. That's why no one does screenings for genetic problems of diabetes. One must first find such a mechanism if it does exist.
I believe that in the future it will be much more common to choose a preferred embryo, one that is more immune to diseases (as shown in the movie What Happened in the Ghetto).
I'm sorry to disappoint you but our quarrels are probably passed on, I know it's frustrating, that our children don't start with a smooth page as we would like. This field was called epigenetics. Here is a short article on epigenetic inheritance:
http://www.eatwell.co.il/?CategoryID=361&ArticleID=2911
As I mentioned earlier, the changes we cause to the genome are not mutations but an effect on the expression of genes. which is different from mutations. Each protein has a genetic code with the information for its replication, but a large part of DNA contains control sites for gene division and many other mechanisms. An effect on the expression of a gene is not a mutation in the gene.
Jonathan,
The damage we cause to ourselves by improper nutrition is not passed on to our children - few changes that the body goes through in its life (only mutations) are inherited and those in the vast majority turn the fetus (if one is created at all) into one that does not survive in most cases. It is true that our lifestyle has an indirect effect on the expression of genes, but if these exist in the population with increasing frequency, their expression also increases. What I offered is a way to understand why the frequency of the problematic genes is increasing in the population (also in percentages) and my answer was that modern medicine increases the survival ability of people who carry problematic genes (and those related to diabetes) and leads to more possibilities for such people to give birth to children who also carry the genes the problematic ones. Don't get me wrong: I think everyone has the right to have children! However, I think that tests for genetic defects that can lead to diabetes and other hereditary diseases should be added to the examinations performed on the fetuses.
Genetics can always be blamed (or not) but in most cases it is the length of life that will affect our health.
We all have the potential to be sick or healthy.
Besides, there is no proof or evidence that juvenile diabetes is a genetic disease.
The only thing that can be shown to have any connection to juvenile diabetes is milk consumption, there are studies that show a connection and there are some that don't, but as a rule this is the most well-founded argument.
It is not clear to me why the writer completely ignored this - I doubt the credibility of writers who present only part of the information.
It may also be that the continued consumption of skimmed milk and cheeses after weaning age and not in the form of formulas is to blame for this, but the studies revolve around the question of breastfeeding (the funding sources refer to the research) and not milk nutrition in general.
In general, to consume food in a non-natural way (milk after weaning age) and to blame genetics seems very puzzling to me.
An article published in a scientific monthly (some say otherwise, but it is stronger than the other arguments in the article):
http://children.webmd.com/news/20080501/new-clue-to-milk-and-diabetes-link
And by the way regarding genes - people use this argument too much without understanding it - with diet and lifestyle we influence the expression of genes, which is no less important than existing genes, and pass this on to our children, who in turn have to invest a lot to repair the damage, or spoil the good.
New studies show an amazing effect on gene expression due to lifestyle:
Moderator,
There are recessive genes, only a double occurrence of which causes actual manifestations, therefore the parents can be carriers and not sick and pass the trait on to their offspring in such a way that it will be expressed. Beyond that, there are problems whose appearance depends on additional genetic factors such as obesity.
מנחם
two things ,
It is accepted by the scientists that the vaccinations and actions of the health system allow non-survivors in the past to survive.
Secondly, if the phenomenon of the disease has increased in modern times, I would not be as quick as you and determine the main culprit. Because the intervention of modern medicine has completely disrupted natural selection. This means more people with diseases, with weak immune systems, with damaged genes, maybe even a tendency to obesity, and their part in the population is growing.
Even if it turns out that there are other influential factors such as food, physical activity and stress, here too without intervention
Medicine would not survive but the weaker ones who get sick from those factors. I hope it is clear to you that it is a mistake on your part to say "your words are unfounded",
Seriously, your words are unfounded, if only for the reason that the parents of the sick children are not necessarily sick!
Perfectly healthy parents can today have a diabetic child.
It is true that in the past diabetics did not produce offspring, but don't forget - in the past there were almost no diabetics at all.
Until recently, people were not allowed to get fat unless they were the heads of the tribe or kings or high-ranking priests. Most ordinary people ate whatever was available, and suffered hunger from time to time not as a rarity but as a completely normal thing during their lives.
People who got diabetes because of a genetic defect were probably few and far between.
In my opinion, the western way of life should be re-examined - the main culprit. The food, the pollution in the sea, the air, the soil and the everyday products that are used.
An article was published a few days ago about autistics here in the science and there is also an inexplicable increase in the number of autistics
Click here to
Let's say that half a percent of those gene carriers survived on average in the past, but when medicine succeeded in reducing mortality
Babies, including those who carry the same genes that without the medicine would not survive, after all, the half percent grows and that's how those gene carriers who carry the same disease multiply
And what about all those babies who got juvenile diabetes, even before they had time to gain weight? Still an inadequate explanation.
Yigal, certainly an interesting hypothesis.
Yigal
It makes sense, after all the health care system upset the entire balance, so the weak did not survive and the genes that caused that weakness
"The reason for the increase in the incidence of the disease in such a short period of time cannot be attributed to genetic changes,"
Sounds completely absurd to me! The reason that seems most logical to me for the increase in the incidence of the disease is that, since modern medicine allows people with the disease to live with the disease, they pass the genes that carry the disease to their offspring and increase the frequency of the disease's appearance in the population. In the past, such children did not survive or at least did not reach the age where they produced offspring, so the said genes did not spread in the population. Admittedly, these are not genetic changes, but the causes are genetic. The situation is similar with regard to many genetic phenomena and for this reason even diseases of the third age were "discovered" and characterized only in the last decades: in the past people did not reach an age where such phenomena could be manifested.
What about the relationship between the length of time the baby naturally breastfeeds and the resistance to diseases such as diabetes?
It seems that in the modern world the baby is breastfed for too short a time and after a few months he switches to consuming milk substitutes.
Does it not affect?