Understanding Insulin Resistance - And Why You Should Care - By Sasha High MD

Let’s talk about insulin resistance. In this blog post, I’m going to tell you why you need to care, and how understanding a little science can help you choose your eating plan.

Let’s jump in with a little physiology. Insulin is a hormone produced by your pancreas in response to a rise in blood sugar. It’s primary job is to direct sugar or glucose from your bloodstream into your cells for fuel. Any additional glucose not needed for fuel is then stored either as glycogen in your liver or muscle, or as fat. In fact, insulin is one of your main fat storage hormones. 

When you develop insulin resistance, your cells essentially stop responding or respond less to the insulin signal - ie they become resistant to the insulin signal. So in an effort to force your cells to listen, your pancreas will produce even more insulin - it’s basically shouting to overcome the resistance. The level of insulin in your blood will be very high (which is called hyperinsulinemia). 

So what causes insulin resistance? Well, like many things in medicine - it’s multifactorial. But here are a few big causes. Number 1) high dietary consumption of sugar and refined carbohydrates (flour products like bread, pasta, muffins). Over many years, if you have a high intake of refined carbs and sugar, you will have chronic hyperinsulinemia and this can lead to insulin resistance. Refined carbs and sugar are like fuel for insulin production. If you decrease them or remove them from your diet, you can reverse the insulin resistance. 2) central belly fat, or visceral adiposity (fat around your internal organs) can cause inflammation in your body which leads to insulin resistance. So excess body fat contributes to insulin resistance, insulin causes more fat storage - it becomes a bit of a cycle. 3) Other health conditions, such as PCOS, chronic kidney disease, fatty liver, and certain medications, like steroids, antipsychotics, can all contribute to insulin resistance.

Now let’s talk about what happens when you develop insulin resistance. Remember that insulin is trying to keep your blood sugar in an appropriate range, by directing the extra sugar into your cells. Well as the cells become more and more resistant to the insulin signal, higher blood levels of insulin are required to keep the blood sugar controlled. This can go on for many years until a point when the cells have so much resistance that even though insulin is super high, the cells no longer respond and that’s when blood sugar starts to rise. We call this: prediabetes or type 2 diabetes. IR has been going on for many years, often silently, before we clue in and diagnose diabetes. 

That’s not all - insulin resistance is also thought to be a major risk factor for metabolic syndrome, fatty liver disease, heart disease, high blood pressure, Parkinson’s disease, possibly Alzeimer’s disease, obesity and even certain cancers. 

Ok - now for the super interesting part. Well, I think it’s super interesting. This is where I love to geek out on the science. Insulin resistance in the brain’s reward center, specifically the dopaminergic neurons of the mesolimbic system, can actually cause your brain to have less reward from food. So your brain in turn seeks more food, more sugary, more rewarding, often high carb foods, in order to get the same effect. And the dopamine effect of insulin resistance is also thought to lead to mood disorders like anxiety and depression.

Ok - so now we’ve covered all the sciency stuff - let’s talk practical. How do you know if you have insulin resistance?

1. You carry your weight around your middle. Insulin causes fat storage, excess fat tissue causes insulin resistance. People who are seeing a lot of weight gain, particularly around the mid-section, that isn’t responding to calorie restriction, likely have underlying insulin resistance as a major contributor. The other important point about this I want to mention is that some people can be “thin on the outside, fat on the inside”. I.e there body size may not be particularly large, but their body fat percentage is high, they have low muscle mass, and there is a lot of extra fat around the internal organs. This is more common in certain ethnic groups. So it’s not body size that leads to health problems, but where the fat is stored on the body and how active that fat is in causing inflammation.

2. Another sign of insulin resistance is a greyish-brown velvety discolouration of the skin (kind of looks dirty) around the neck or in skin folds which is called acanthosis nigricans. It is more common in people with darker skin. 

3. If you have multiple skin tags again around the neck, under arms, under breasts or in the groin area. Neither of these are problems in themselves, but point to a more concerning underlying issue. 

4. Sometimes insulin resistance can make people feel lethargic, groggy, just not mentally sharp, all round blah.

So what can you do? There are some medications you can take, as well as sleep and exercise that will help. But likely the biggest factor that you have control over is the dietary piece. And this is why tonight’s topic relevant to you. Whatever dietary approach you choose as your preferred eating plan - whether it’s keto, paleo, vegan, plant-based, calorie counting, it’s important to minimize refined carbohydrates, starches and sugars. And this doesn’t necessarily come intuitively to people because our food environment very much focuses on low fat, low fat, low fat. But by stripping foods of fat the food industry has pumped them with more sugar. You know, you remove one thing you have to replace it with another. We’ve become so afraid of fat, but totally missed the mark because it’s actually sugar and refined carbohydrates that cause weight gain and the metabolic problems that come along with it. And I’ll caution you that the food industry also does a really good job of making us think that all these processed carb foods are good for us. It spends a lot of time and advertising dollars trying to make flour products seem healthier - by labelling them as whole wheat, multigrain, gluten free, low fat, high fiber - please know it’s all health-washing. In general our North American diet is far too high in refined carbohydrates and sugars and we would all do well by decreasing them.

I get that this may sound scary, even potentially offensive to some people. The idea of rice or bread not being a staple food may be really hard. I get that. And inevitably, when I talk about reducing or minimizing refined sugars, carbs and starches, what people will hear is “carbs are bad”.

But I want you to just watch your thinking on this one. Carbs aren’t “bad” or “good”. They’re just a food group. Food is neutral. But I do think you should have an awareness of what certain foods do for your metabolic health, and how certain foods affect your brain and your eating behaviours, and then decide if your eating plan is working for you or not. And if it’s not, then what do you want to do about that? If you’re struggling with a lot of over-hunger or over-desire, perhaps consider that your food choices may be making life harder for you because of their effect on your brain.