The Link Between Inflammation, Insulin Resistance, and Metabolic Health

5 minutes read

Inflammation is a vital part of your body’s healing process. Without it, a minor scrape could turn into a serious infection and your body wouldn’t be able to fight off viruses. But when inflammation gets out of control and becomes chronic, its protective mechanisms break down and start to turn on themselves — leading to long-term diseases and metabolic problems that can affect your quality of life.

Some of the most exciting research on inflammation is still underway, and there are a lot of nuances to consider. We’ll walk you through the science behind inflammation and share helpful tools to manage it so it doesn’t become chronic.

What causes inflammation?

Inflammation is your immune system’s response to injury or infection. When you’re exposed to a virus, sprain your ankle, or cut yourself, your body sends its “first responder cells” to the area where there’s a problem. As these first responder cells fight off pathogens, protect healthy tissue from damage, and kickstart the healing process, you may notice redness, swelling, warmth, and other telltale signs of inflammation.

Like cortisol, the stress hormone, inflammation isn’t inherently a bad thing. But when your body thinks it’s constantly under attack and can’t shut off its inflammatory response, that’s when bigger problems arise. When this happens, you become at greater risk for insulin resistance, weight gain, and even long-term illness.

Acute inflammation vs. chronic inflammation

Acute inflammation is a temporary response: your brain gets a 911 call from the part of your body that’s hurt or infected and immediately sends white blood cells — like neutrophils and macrophages — to help destroy invasive organisms (bacteria and viruses) and clear up dying cells [1]. Blood flow increases and blood vessels relax to allow your immune cells and other nutrients to get to the target site quickly — all of which results in swelling and warmth.

Whereas acute inflammation aims to protect healthy cells, chronic inflammation is like an uncontrolled wildfire — and can actually destroy cells and tissues as well as decrease your healthspan. In fact, research suggests that chronic inflammation is linked to a number of diseases like cardiovascular disease, diabetes, chronic kidney disease, and even cancer [2].

Chronic inflammation can be hard to pin down because its symptoms, like fatigue, depression, and weight gain, are associated with many other conditions and illnesses [3]. Plus, it doesn’t just have one cause — there are many, and they can overlap. Our modern lifestyle — featuring a diet high in processed foods, mostly sedentary day-to-day, chronic stress, and dysregulated sleep — can all contribute to low-grade, chronic inflammation [4]. But other causes include:

Autoimmune disorders like Crohn's disease and Alzheimer’s disease
Obesity
Aging (inflammation naturally increases as you get older) [5]
Smoking and excessive drinking
Lingering infections or other cases of untreated acute inflammation

The relationship between inflammation and metabolic health

Chronic inflammation plays a key role in metabolic health disorders like Type 2 diabetes and insulin resistance, though researchers are still trying to understand how all the pieces of the puzzle fit together [6].

What we do know is that inflammation can make your cells insulin resistant — i.e., it interferes with your cells’ ability to take in glucose from the bloodstream [7]. This is triggered by small signaling molecules called proinflammatory cytokines, which are like messengers that your immune cells release to instruct nearby cells to start or stop an inflammatory response.

Research suggests that proinflammatory cytokines induce local insulin resistance because insulin actually has an anti-inflammatory effect [8]. Put another way, insulin works in opposition to proinflammatory cytokines.

This can lead to long-term insulin resistance, which can disrupt your body’s ability to regulate glucose, lead to elevated levels of glucose in the blood, and set you up for prediabetes, Type 2 diabetes, and other metabolic issues.

What makes inflammation so challenging to address is that it perpetuates a cycle of insulin resistance, which can then contribute to even more inflammation — researchers found that insulin resistance is associated with greater activity of a protein that triggers the release of a proinflammatory cytokine [9]. Though there’s a bit of a chicken-and-egg question here as to which comes first, the result is the same — a vicious feedback loop that can be hard to break.

Inflammation and obesity

Since inflammation is so closely tied to insulin resistance, it can have a powerful effect on your weight. We’ve seen that insulin resistance can contribute to weight gain — particularly around the torso — and make it more difficult to reach a healthy weight.

But inflammation also has its own feedback loop with fat tissue in the body. Scientists have found that chronic exposure to proinflammatory cytokines can actually lead to the degradation of muscle mass and change your body composition [10]. This becomes an even more critical issue in elderly folks, where low-grade chronic inflammation and insulin resistance can lead to sarcopenia, a loss of muscle and accumulation of fat mass that can be dangerous.

Excess adipose (fat) tissue also plays a role in amplifying inflammation in the body. You might think that adipose cells are just storage for fat, but recent research has proven otherwise: adipose tissue may in fact actively contribute to inflammation by releasing high levels of proteins that create a pro-inflammatory state [11]. This can even lead to the growth of plaques in your blood vessels that lead to cardiovascular disease, strokes, and even heart attacks [12].

What does this mean for you? Chronic inflammation can trigger both weight gain and insulin resistance, disrupting your body’s ability to regulate blood sugar levels and increasing your risk of developing heart health problems, diabetes, and more.

But how do you know if you have inflammation — and once you find out, how do you manage it?

Do you have chronic inflammation?

Many people often don’t know they have chronic inflammation until they’re diagnosed with a related disease.

Chronic inflammation often goes unnoticed because its symptoms manifest as pain, chronic fatigue, insomnia, mood disorders, digestive issues, or repeated infections [3]. If you’re experiencing any of these symptoms consistently and eat foods high in sugar, avoid exercise, get poor sleep, and experience high stress or anxiety, you may be experiencing chronic inflammation.

Confirming this, however, may be more challenging. One of the better ways to test for inflammation is by testing for levels of high-sensitivity C-reactive protein (hsCRP) test, but this won’t tell you whether it’s acute or chronic inflammation [13]. Fibrinogen is another inflammatory marker you can test for [14]. Talk to your healthcare provider if you think you should be tested for markers of chronic inflammation.

How to manage inflammation for better metabolic health

The good news is that there’s plenty you can do to control inflammation in your body, especially if the causes are related to lifestyle factors. Here are four areas where you can make an impact.

1. Eat anti-inflammatory foods

In addition to spiking your blood glucose levels and leading to a crash, refined sugar and processed foods can also contribute to inflammation [15]. High blood sugar levels can interfere with proper immune function and disrupt your gut microbiome, which plays an important role in regulating inflammation in the body.

Eat lots of colorful, fiber-rich vegetables (which are often packed with anti-inflammatory compounds) and load up your plate with healthy proteins and fats. And ignore the fear-mongering about seed oils — they won’t cause inflammation.

2. Exercise regularly

In addition to improving insulin resistance, regular exercise has been shown to lower inflammatory markers in the body. Multiple studies performed on elderly individuals over the age of 60 generally found that regular moderate-intensity exercise (around 5 hours per week minimum) was linked to reduced inflammation compared to sedentary participants [16].

It’s also been shown that strength and cardio together (1-2 days per week of strength and 3-4 days per week of cardio), rather than aerobic exercise alone, is best for heart and metabolic health. Strength or resistance training also increases muscle mass and reduces fat mass, which can support metabolic health.

3. Manage stress

Over time, high levels of cortisol, the stress hormone, can negatively affect insulin sensitivity, trigger hyperglycemia, and lead to inflammation. While it’s not always easy to avoid stress, you can manage your cortisol levels via breathwork, exercise, time in nature, avoiding processed foods, and community and mitigate the inflammation associated with it.

4. Get regular sleep

Poor sleep hygiene — both an inconsistent sleep-wake routine and not getting enough hours at night — can throw your glucose regulation out of whack and reduce insulin sensitivity. Research also indicates that sleep deprivation plays a role in increasing proinflammatory cytokines, possibly because your body doesn’t have time to properly clear out proteins and waste in the brain that can trigger inflammation [17]. Getting at least 7-8 hours of sleep, sticking to a consistent schedule, eliminating high-carb foods at night, and using a blackout sleep mask can help you improve your sleep quality.

Key Takeaways

Chronic inflammation is an often silent contributor to bigger metabolic health problems, but preventing and managing it often boils down to changes in your lifestyle. Here are some things to remember:

Acute inflammation is your body’s emergency response to infections or injuries — and is healthy.
Chronic inflammation, on the other hand, can lead to insulin resistance, weight gain, and other metabolic issues.
If you’re experiencing pain, chronic fatigue, insomnia, mood disorders, digestive issues, or repeated infections — but aren’t completely sure why — you may be experiencing chronic inflammation. You can get a high-sensitivity C-reactive protein (hsCRP) or fibrinogen test to check, though these won’t necessarily confirm that you have chronic inflammation.
Eat anti-inflammatory vegetables and avoid sugar and processed foods, do a mix of strength and cardio workouts every week, manage your stress, and get good-quality sleep to reduce inflammation.

References:

Written by: James Han

Reviewed by: Emily Johnson, MSc RD

Table of Contents

What causes inflammation?
The relationship between inflammation and metabolic health
Do you have chronic inflammation?
How to manage inflammation for better metabolic health
Key Takeaways