There is new evidence indicating that melatonin, a hormone that helps regulate our biological clock, may be linked to type 2 diabetes.
Please look below the main article for some information about diabetes.
It is known that shift workers have a higher risk to develop type 2 diabetes. It is also known that people with type 1 diabetes can sometimes have higher blood glucose levels after taking synthetic melatonin, a product that is used to help with jet lag and sleep problems, although its efficacy for these conditions is far from obvious.
Now, Nature reports that two separate studies, one in Europe and one in the United States, have found that some variants of the gene MTNR1B are related to a higher chance of getting type 2 diabetes. The gene MTNR1B produces a receptor protein that binds to and reacts to melatonin.
The mechanism through which melatonin influences glucose metabolism is unknown as of yet, but we do know that cultured insulin-producing cells of the pancreas produce less insulin when they are exposed to melatonin. Whether this is also true in vivo remains to be seen, but it is certainly a possible explanation for the increase of the risk to develop type 2 diabetes.
The researchers think that this discovery may one day lead to the development of treatments that can block melatonin signalling in the pancreas. This would have to be developed very carefully, however, since the effect of melatonin on the brain should not be impaired. Because many drugs cannot get through the blood-brain barrier, this may well be possible.
What does it all mean for people who take synthetic melatonin? So far, there is no data to indicate that their risk to develop diabetes increases. Most people only take it to ease jet-lag problems, essentially the only use for which there is some evidence. Since they use it only short-term, the risks may be minimal. This risk may increase for people who take melatonin tablets for a longer time. However, there is no evidence for this risk as of yet.
I would like to add to this that synthetic melatonin is often touted as perfectly safe in alternology circles. The truth is that we don't know whether it is or not. Although I do not wish it, I think it would be interesting to see these alternologists' reactions if it were to be shown that the risk is indeed real.
What is diabetes?
Diabetes is not one disease, but several. There is diabetes insipidus and diabetes mellitus.
Diabetes insipidus is so called because the urine of patients with the condition does not taste sweet. Patients with this disease become very thirsty, must drink a lot and then they must urinate very frequently, which can lead to disturbances of the sleep cycle and/or bed-wetting. The condition is usually caused by problems with the kidneys or the pituitary gland.
Diabetes mellitus on the other hand, has to do with insulin problems and high blood glucose (blood sugar). It is called diabetes mellitus because the urine supposedly tastes sweet (no, I didn't try it myself).
These two types of diabetes often produce similar symptoms, but they are unrelated. Tests will show which one the patient has. Diabetes insipidus is the rarest of the two.
To complicate matters, diabetes mellitus is also subdivided into three types:
Type 1, often called juvenile diabetes or insulin-dependent diabetes and which is usually first diagnosed in children, teenagers or young adults. It is an auto-immune disease that destroys the cells in the pancreas that produce the hormone insulin (the islets of Langerhans).
Type 2, often called adult-onset diabetes or non-insulin-dependent diabetes is the most common form of diabetes. In this form, fat, liver and muscle cells can not use insulin properly. Because of that, the pancreas tries to keep up by producing more insulin, but this ability eventually stops. Being inactive and overweight are two of the best-known risk factors.
The third form is gestational diabetes. It is a type of diabetes that develops late in a pregnancy. It usually stops after the child is born, but it does increase the risk to develop type 2 diabetes later in life. It is caused by pregnancy hormones or a shortage of insulin.