Why does type 1 diabetes happen? It’s a question that has racked the brains of researchers and the public for a long, long time. Despite that it is being widely agreed upon, the fact that type 1 diabetes is an autoimmune disease doesn’t guarantee an answer as to how this autoimmunity came about in the first place.
What we are left with are theories and hypotheses, that can only be put through statistical tests to validate its ‘truthfulness’. Whether it is to evaluate the likelihood of how drinking cow milk may raise your risk of getting type 1 diabetes, or if it’s caused by a viral infection, we can only keep on fighting to unravel this disease and hopefully cure it one day.
THE LIKELY CAUSES OF TYPE 1 DIABETES
- ENVIRONMENTAL TRIGGERS – Viruses
When a virus invades the human body, it doesn’t go unnoticed. The immune system starts revving up to prepare itself for the fight.
Antibodies are produced against the viral antigens. Antibodies are like highlighters that mark the viruses as something dangerous, among the sea of other interesting things in your body, to be eliminated by other white blood cells, like the NK (Natural Killer) cells. Yes, the name is exactly what you’d expect, it’s your body’s very own special forces that are like, super-skilled natural killers.
Here, you see the antibodies sticking onto the viral antigens, the more recognisable parts of the virus. The virus here is beginning to look a little worried here.
Recognizing these viral antigens, the antibodies bind and highlights the viruses to the NK cells, which then promptly devours the viruses. That, is the ideal immune response towards viruses.
However, we’re talking about an autoimmune disease today. Where exactly did this all go wrong?This is when something really unfortunate happens. While our body tries to minimise errors, it cannot guarantee anyone the absolute perfect immune response 100% of the time. In fact, to describe it crudely, the main antibodies involved in the immune responses are formed by mutations. Basically it’s like trial and error, but more intense. Say, maybe a genetic lottery that holds much higher chances of you winning. Sometimes, when viral antigens are similar to your own self-antigens, maybe those found on your beta cells, these immune cells mistakenly attack the beta cells that you need for insulin production.
There has been frequent detection of enteroviruses in diabetic patients, suggesting that the viruses has already made themselves welcome in their bodies as homes.¹ This viral persistence is also exhibited by other viral diseases that went on to provoke strong innate immune response, plus immune-mediated tissue damage and local inflammation.
There is reason to pinpoint viruses as one of the culprits behind type 1 diabetes. However, like all effective gangsters, gangsters work better in, well, gangs. This world is riddled with complexities and overlapping of factors, plus, not all people infected with enteroviruses will develop type 1 diabetes. Hence, let’s look at another major area of research in type 1 diabetes – into the world of genetics.
- GENETIC PREDISPOSITIONS
Whether it is their brown eyes, or a cosy house with an ocean view, people inherit a lot of things from their parents. Some people may grow taller than their classmates, but at the same time, still have different heights from their own siblings despite sharing the exact same parents.
Many of the genes that we inherit are like the baseline that our traits start off from. Once that line is established, other environmental factors can come into play to further affect those traits.Similarly, people whom have inherited things like a particular HLA (human leukocyte antigen) complex are also found to have a greater likelihood of developing type 1 diabetes. The function of this complex is to provoke immune responses in the body.³
In fact, many of these HLA complexes associated with type 1 diabetes are all found on chromosome 6.³ Not everyone will inherit every complex that there is, and not everyone will inherit a single one, and not everyone whom don’t inherit a single one will be 100% safe from type 1 diabetes. While genetics help give clues as to why some people have elevated risks of developing type 1 diabetes, it leaves us scratching our heads as to how these genes come into play with other factors to result in the presence or absence of this disease.
For example, having an identical twin with type 1 diabetes gives you a statistically higher risk but it doesn’t necessarily mean you will develop the condition.4
Genetics does not explain either why people will develop type 1 diabetes at different ages. Type 1 diabetes is most commonly diagnosed in 10 to 14 year olds but can be diagnosed at any age.4
With that being said, we can’t lose focus on the bigger, overarching goal of curing type 1 diabetes, once and for all. We hope that you now have an idea of how type 1 diabetes, like all other research topics, have its fair share of controversies and discourse, and the next post will be looking at fresher, new advances that we have made in the war against type 1 diabetes.
- Oikarinen, M., Tauriainen, S., Oikarinen, S., Honkanen, T., Collin, P., Rantala, I., Maki, M., Kaukinen, K. and Hyoty, H. (2012) ‘Type 1 diabetes is associated with Enterovirus infection in gut mucosa’, Diabetes, 61(3), pp. 687–691. doi: 10.2337/db11-1157. [Accessed 17 November 2015]
- GKHam, (2013), A Picture of Asian Twins [ONLINE]. Available at: http://gkhamconsulting.blogspot.com/ [Accessed 17 November 15]
- PharmD, D. S.-M. E. (2014) Type 1 diabetes causes. Available at: http://www.endocrineweb.com/conditions/type-1-diabetes/type-1-diabetes-causes [Accessed 17 November 2015]
- Diabates UK (n.d.) ‘Causes of Type I Diabetes’, Diabetes.co.uk, the global diabetes community, Available at: http://www.diabetes.co.uk/causes-of-type1-diabetes.html [Accessed: 17 November 2015]