Diabetes type 3: Alzheimer’s disease

Alzheimer's disease - comic

We’ve been thinking for a while that Alzheimer’s disease was mainly genetic, and that there isn’t much to do about it. We know know that only 5% of the cases have a genetic origin1. Let’s examine the 95% left.

The risk factors

Excluding age and genetics, here are some of the main risk factors:

  • Lack of exercise
  • Obesity
  • Smoking
  • Uncontrolled type 2 diabetes
  • A lack of fruits and vegetables

It can be quite obvious that all of the factors above are similar to the factors of type 2 diabetes. Research evolves pretty fast and we nowadays understand better and better the mechanisms involved in Alzheimer’s disease. Therefore, the link between type 2 diabetes and Alzheimer’s disease is know revealed.

In order to better understand the following articles, it is better to know:

Neurones, the main victims of the disease

As you probably know, Alzheimer’s disease is a degenerative disease: brain neurons deteriorate abnormally fast, and specially those responsible for thoughts, planning, memory and language.

A neurone is a cell, with a core and long arms. Those long arms will connect to other neurones, which enables the carriage of information messages. Those connections are called synapses, and the carried messages are called neurotransmitters.

Healthy neurone
Healthy neurone

So far, so good.

Hyperactivity of the GSK3 enzyme

Research has been able to determine that the GSK3 enzyme, found in the brain, is directly linked to neurones degradation when it shows hyperactivity2.

You don’t really need to understand, but, in two words, it would trigger:

  • phosphorylation of the tau proteins: which destroy the skeletons of the neurones
  • amyloid plaques development: which clogs the synapses synapses and prevent the neurotransmitters to pass
Neurone damaged by GSK3 over activity, tau protein and amyloid plaques - schema
Damaged neurone

So, you only need to remember one thing so far: we are able to identify the culprits of the degradation of neurones, and therefore of Alzheimer’s disease.

Insulin is also in the brain

The blood of the brain is separated from the rest of the body, by a gate, called the blood brain barrier. This enables the filtering of all the pathogens, hormones and others, that could damage the brain.

Since only recently, we know that insulin can also be found in the brain3! But let’s ignore that last parameter because thoses mechanisms are way too complex and unknown for our simple curiosity.

blood brain barrier and insulin - schema

Insulin prevents neurones degradation

Some recent data has demonstrated that insulin plays a major role inside the brain. Specially, it is able to regulate the activity of the GSK3 enzyme, and therefore prevent neurones degradation4 : we consequently have a clear link between insulin and preventing Alzheimer’s disease.

The results are promising: the simple fact of restore insulin in the brain enable to slow down and even stop the disease. Scientists use insulin injection for their experiments, but the effect is exactly the same with the insulin released by the pancreas, because it’s simply the same molecule.

Insulin resistance is implicated

Like we saw during the article about type 2 diabetes: the mechanism of insulin resistance triggers hyperglycemia and an excess of insulin in the blood. This insulin should consequently benefit the brain! Right?

you shall not pass - comic

Actually, the opposite occurs. The gate brain/body is also undergoing insulin resistance, which makes it disrupted and prevents insulin from passing properly. The body has an excess of insulin (hyper-insulinemia), while the brain has a shortage of insulin (hypo-insulinemia). Wow !

blood brain barrier and insulin resistance - schema

Preventing the disease

So, logically, the progress of the disease can be slowed down, and even stopped by fighting against insulin resistance and type 2 diabetes. This can be accomplished via an appropriate diet (low sugar and carbs) and exercising.

This may sound simple, but sugar is everywhere in our occidental food and the number of people suffering from Alzheimer’s diseases increase everyday. At least, you are now warned and you know what to do!

Ketone bodies

From this point, you may be tempted to think that, if you fast or if you go for a low carbs diet, the low insulin level will damage the brain. Actually, that does not happen. It’s even the opposite!

Ketone bodies are substitutes of glucose, produced when this later is not available. As opposed to glucose, ketone bodies do not need insulin to be used by muscles or organs (like the brain).

Research has been able to demonstrate that ketone bodies have a beneficial effect against neurones degradation and also even foresee their injection as a therapeutic use5. So don’t be scared of removing sugar and carbs from your diet! Ketone bodies are as good, if not better!

Conclusion

Alzheimer - comic

We’ve seen that the brain can be provided with energy in two ways:

  • glucose + insulin
  • ketone bodies

In both of those modes, the disease shouldn’t take place when they work properly. If insulin experiences a shortage in the brain, the first mode gets disrupted and the disease spreads over. This lack of insuline is usually triggered by insulin resistance, itself caused by an excessive intake of carbohydrates.

Even though Alzheimer’s disease keeps touching more and more people every day, we now know how to avoid it. The problem is that no serious campaign has been done about it. The sugar lobby still wins so far…

Et vous, essayez-vous de sensibiliser votre entourage aux dangers du sucre ? Laisser un message dans les commentaires.

  1. Causative and susceptibility genes for Alzheimer’s disease: a review
    A. Rocchia, S. Pellegrinib, G. Sicilianoa, L. Murria
  2. The GSK3 hypothesis of Alzheimer’s disease
  3. Insulin in Central Nervous System: More than Just a Peripheral Hormone
    Ana I. Duarte,1 Paula I. Moreira,1,2 and Catarina R. Oliveira1,3
    [note]
    . Some studies have even been able to demonstrate that the brain (of rats) can synthetise insulin[note]D. W. Clarke, L. Mudd, and F. T. Boyd Jr., “Insulin is released from rat brain neuronal cells in culture”
  4. Insulin Action in Brain Regulates Systemic Metabolism and Brain Function
  5. Ketone bodies as a therapeutic for Alzheimer’s disease.

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