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What is insulin resistance, and how can it affect your mental health?

Updated: Mar 19

Most people think of Diabetes when they hear the word insulin, but insulin, and specifically insulin resistance, can be a contributing factor or cause of poor mental health.

Insulin resistance and mental health

You may already be familiar with terms such as blood sugar balancing, insulin or even insulin resistance. Often these words and terms are commonly discussed in relation to conditions such as Diabetes, obesity and PCOS (Polycystic Ovary Syndrome). But what about when it comes to your mental health? It’s certainly not something your GP is likely to discuss with you.

Firstly though, let us explain what insulin is, and what it does in the body before we dive into insulin resistance.

Insulin and blood sugars

Insulin is a hormone that is made by the pancreas. When we eat food, it is broken down by the digestive system (specifically the small intestine) into glucose, which is a type of sugar. The glucose is then absorbed into the blood stream, which then signals to the pancreas to release insulin. Insulin then attaches itself to the glucose molecule in order to take it into the cells of your body and use it for energy.

Any leftover glucose is then stored in the liver as glycogen, which gets released when the body needs more energy, for example, when you go long periods without eating, or perhaps when you are exercising.

This is what is meant when you hear the term ‘blood sugar balancing’ - insulin works to ensure that the glucose from food is used and is not left ‘roaming’ around the body.

The more glucose is released from food the more insulin is needed to ‘mop it up’.

It is also a key part of our metabolism. Most of us think of metabolism as ‘burning calories, but actually it’s a lot more complicated than that. Metabolism actually involves converting food not just into energy but also the building blocks of proteins, membranes and other cell part in order to keep us alive!

Problems in this metabolism is what leads to problems in the ways our cells function, like in insulin resistance.

What is insulin resistance?

When the body has too much glucose (e.g. we eat too much), over time it can’t produce enough insulin to keep up with the demand, and so your body can become resistant to insulin. Your body keeps trying to produce more and more insulin in a bid to keep blood sugars stable, but over time, the insulin-producing cells of the pancreas ‘burn out’.

This lack of insulin in relation to high levels of glucose in the bloodstream is what leads to weight gain, increased inflammation (as there is too much ‘sugar’ in the body) and it increases the risk of not just Type 2 Diabetes, but also high blood pressure, high cholesterol, and heart disease.

As for PCOS, this is a complex hormone and metabolic condition that often comes with increased inflammation and insulin resistance. It varies person-to-person, but often genetics or weight gain as a result of the hormone imbalance, being the main drivers.

So what does this have to do with your mental health?

Insulin resistance and mental health

Have you every experienced being ‘hangry’ (bad-tempered or irritable as a result of being hungry) or been around someone who is?

Being 'hangry' is a sign that your blood sugars have fallen too low and it can result in a change in mood. Many people, and my clients, can experience increased anxiety and even depression, without realising that this is linked to their blood sugars. Why?

Glucose is the brain’s main source of fuel

Without enough glucose, or imbalanced blood sugars, this will directly impact brain function, negatively impacting your mood, because as well as helping to manage energy levels (at a cellular level) insulin also helps regulate cognitive function.

The reverse is also true. Too much sugar in the body or insulin resistance, affects cell function and drives inflammation which over time, leads to impaired cognitive function and it begins to damage the neurons in the brain, not just the body.

In fact, a 2021 study2 found that insulin resistance was linked with an increased risk of depression, but also it can have such a profound effect on the brain that it has been linked to Alzheimer’s Disease, also known as Type 3 Diabetes.

In short, insulin resistance disrupts our metabolism, which is the way in which our cells, and brain cells, function!

Dominoes falling. Insulin resistance and mental health

Earlier we described how insulin helps to take glucose into our cells for energy. Within our cells are structures called mitochondria. The main role of our mitochondria is to use oxygen, glucose and ketones (chemicals the body produces when it breaks down fat) for energy in order that the cell can function.

These mitochondria are also involved in the production and regulation of our brain chemicals (neurotransmitters), our hormones (cortisol and our sex hormones) and they also play a role in inflammation and help to control our genes expression.

To summarise: Insulin is needed to take glucose into our cells for energy, but also so our mitochondria (cell batteries) can use it to produce hormones, brain chemicals, reduce inflammation and control gene expression. Insulin resistance disrupts this whole process!

If you’re looking for deeper reading on this, we can highly recommend Brain Energy by Dr Chris Palmer.

Can you reverse insulin resistance?

Yes you can! (If you have Type 2 Diabetes you can also reverse this too but it can be complex and multi-factorial so I would recommend finding a qualified nutritional therapist or functional medicine practitioner to support you in this.)

Insulin, diet & lifestyle

It won’t come as any surprise that your diet and lifestyle are the modifiable factors to ensure good blood sugar management, but also to help you ward off or reverse insulin resistance.

  1. Cut down on ultra processed foods and refined sugars in your diet

  2. Ensure you have good protein levels at every meal and any snacks, as this helps provide a lower and more stable release of glucose to the body

  3. Add more fibre: whole grains, beans, lentils, fruit and vegetables. Fibre helps to better manage blood sugars at meals, but also provides a host of important nutrients to reduce inflammation and protect cells from damage.

  4. Get moving: movement and exercise helps to improve our body’s response to insulin. Even going for a 2-minute walk after a meal helps to improve your blood sugars.4

  5. Incorporating some strength or resistance exercise into your routine helps to build better muscle which in turn makes the body more metabolically flexible.

  6. Get a good night’s sleep - I talked about this week as one of the important foundations for helping your anxiety (you can read the article here). Poor sleep disrupts our hormone balance and metabolism, and is also more likely to have you reaching for sugar because you are tired

  7. Find ways to manage your stress - stress is inflammatory, like poor sleep, and so becomes a metabolic disruptor. Walking in nature, meditation, journalling, gratitude, prayer, taking time to do a hobby you love, whatever it is, do more of it!

  8. Keep an eye on alcohol - it may feel like it helps you de-stress, but only in that moment. Physiologically, it massively affects blood sugars and can cause hypoglycaemia (low blood sugars) especially if you drink too much or on an empty stomach.

If any of this resonates, or you think your blood sugars or insulin resistance is playing a role in your mental wellbeing, then book a free discovery call to find out more about how we can help you get your brain, and blood sugars, back on track!





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