My cookbook, The Plant-Based Anti-Inflammatory Cookbook, provides more information on inflammation, a list of “anti-inflammatory superstars” (foods you can get at the grocery store that help fight inflammation), and dozens of recipes using these superstars. Check out more details about the cookbook, and links to sites where you can buy it, by clicking here.

Previous posts and how this post fits in

In the first post of my “Understanding Chronic Inflammation Series,” I provided an overview of the immune system, which is the source of inflammation in the body. In the second post, I answered the question What is Inflammation? and described different manifestations of inflammation in the body, including low-grade chronic inflammation. This type of constant inflammation in our blood, tissues, and organs can have harmful effects on our health, with swelling, extra bloodflow, and damage to healthy tissue. Chronic inflammation appears to be related to some of the most dangerous diseases affecting humans today, including heart disease, cancer, type 2 diabetes, and Alzheimer’s.

In this post I’ll cover the major causes of chronic inflammation. Once we know the major causes, we can decide what we want to do to minimize their impact. Even if some of these causes are out of our control, we can compensate by practicing as many anti-inflammatory habits as possible.

What causes chronic inflammation?

Unfortunately, many aspects of the modern world and modern lifestyles can trigger the immune response and a constant state of low-level inflammation.

Toxins and pollutants

The immune system tries to fight off toxins and pollutants that enter the body, bringing inflammatory consequences with it. The longer our bodies are exposed to toxins and pollutants, the longer the inflammation lasts. Toxins include mold, heavy metals, and pesticides. Pollutants include, among other things, “particulate matter,” tiny pieces of carbon, sulfate, nitrate, and other substances. Wildfires, smog, refinery emissions, and diesel and coal outputs can directly expose the respiratory system to particulates.

In the lungs and other tissues, particulate matter can cause oxidative damage and activate the immune response, leading to inflammation. Some particulate matter can enter the circulatory system, get into tissues, and accumulate in organs. Particles can even cross the blood-brain barrier and cause inflammation and oxidative tissue damage in the brain. Click here for an in-depth article on air pollution and inflammation.

We are prone to “inflammaging” as we age.

Age

Chronic inflammation almost always rises as we get older. Age-related chronic inflammation even has its own name: “inflammaging.” Inflammaging occurs because, as we age, the immune system becomes less reliable. Sometimes immune-cell receptors degenerate and wrongly sense irregularities, triggering the immune response inappropriately. Even the immune cell population as a whole changes over time, with the proportion of immune cells that secrete pro-inflammatory cytokines becoming larger.

As we age, our immune system also tries to cope with a body that has endured a lifetime of stress. Immune cells try to clear out dying cells and cell debris and fix damaged cells and tissues—all this activity causes inflammation. In addition, the immune system isn’t as well regulated when sex hormones decrease. Finally, the integrity of the gut’s barriers is impaired, allowing bacteria and other toxins to more easily enter the bloodstream. All of these phenomena cause the immune system to be more active, which brings along inflammatory consequences.

Click here and here for excellent articles on inflammaging.

Excess weight

Fatty tissue was once considered chemically inactive, but now we know that it releases many hormones and compounds, some of which stimulate immune responses. Much of the problem stems from the size of fat cells when we put on excess weight. We each have a fairly constant number of fat cells in our bodies throughout our lives, meaning that when we intake more calories than the body needs, our fat cells get bigger rather than multiply. These abnormally large fat cells tend to trigger the immune response in a number of different ways.

First, large fat cells secrete pro-inflammatory chemicals that set off the immune cells. These fat cells also tend to die at a faster rate than normal-size cells—often bursting because of size—and immune cells swarm to clean up the mess, bringing on inflammation. Excessive oxidation often develops in obese individuals as well, caused by sleep disturbances, psychological stress, and the digestion of fatty or processed-food. This oxidative stress contributes to additional immune responses and inflammation.

Click here and here to read helpful articles about fat cells and inflammation.

Smoking

Cigarette smoke contains a host of immune-triggering toxins, including bacterial lipopolysaccharides, a very pro-inflammatory compound. In addition, particulate matter in cigarette smoke, like particulate matter in smog and wildfire smoke, can damage the epithelial cells that line our airways. This damage initiates the immune response. Certain chemicals in cigarette smoke can also generate unstable molecules called free radicals that can damage the lining of the lungs.

Click here to see an article on cigarette smoking and inflammation.

Elevated cortisol levels in the blood leads to increased immune response.

Stress

One of the functions of the hormone cortisol is to suppress immune responses in our bodies. People who experience prolonged stress often have high levels of cortisol in their bloodstream. At constant high levels, ironically, cortisol tends to lose its ability to regulate the immune system. That is, immune cells become insensitive to cortisol's regulatory effect, resulting in an out-of-control immune response, with consequent inflammation. Stress also creates more free radicals in the blood, which damage cells and create a state of oxidative stress, setting off more immune responses.

Diets high in animal products, fats, and refined carbs can increase inflammation.

Click here for a good article on the relationship between stress and inflammation.

Pro-inflammatory diet

The typical “Western” diet increases one’s risk of chronic inflammation compared with plant-based diets. In fact, people who eat an omnivorous diet have higher levels of inflammatory markers in their blood, on average, than pescatarians, vegetarians, and vegans. (Click here for a systematic review and meta-analysis of studies done on diet and inflammation.)

The worst nutritional offenders in typical Western diets are saturated fats, endotoxins, and refined carbohydrates (e.g., white sugar and white flour). We need to minimize foods containing these culprits to lower chronic inflammation.

Saturated fat

Saturated fats increase inflammation in several ways.

They make the wall of the intestine more permeable, allowing toxins into the blood that immune cells react to.
They raise oxidative stress, which activates the immune system.
They feed bad bacteria in the gut microbiome, which can activate the immune response.

The following foods have levels of saturated fats that can add up quickly to have a significantly negative effect on inflammation in the body.

Meat, including beef, pork, chicken
Eggs
Dairy, including cheese, whole milk, cream, ice cream, butter
Most restaurant, takeout, and fast food entrees and fried sides (vegan versions too)
Snack foods made with oil, such as potato chips, tortilla chips, cookies, and crackers
Vegan ice cream and creamy treats
Desserts made with butter and/or cream
Vegetable shortening, vegan butter, margarine, palm oil

Endotoxins

Endotoxins, which contain extremely pro-inflammatory lipopolysaccharides, are released when certain kinds of bacteria (called gram-negative bacteria) die in our bodies. Endotoxins can get into the bloodstream in greater numbers if one’s diet contains significant amounts of saturated fat, which makes the wall of our intestines more permeable.

The following foods contain the most endotoxins (i.e., these foods tend to accumulate bacteria that release endotoxins).

Processed meats like ground meat, sausage, ham, baloney, and bacon
Leftover meat, poultry, fish, and seafood

Refined sugar and grains

After a meal or snack with significant sugar and/or refined flour, our blood sugar level increases, which can lead to a rise in free radicals in the body, causing oxidative stress and an increased immune response.

These foods contain a significant amount of refined sugars and grains.

White bread and other baked goods made with white flour and white sugar
Pizza (vegan versions too)
Desserts (store-bought and homemade)
Candy and chocolate candy
Sugary drinks, including soda and sports drinks
Ice cream (dairy and vegan)

As we can see from these lists, the typical Western diet contains a lot of foods with pro-inflammatory ingredients. Minimizing these foods and increasing plant-based foods is key for controlling inflammation. Even vegans who eat a lot of processed vegan foods risk higher inflammation levels.

Conclusion

The good news is that we can choose to eat a more anti-inflammatory diet, decrease our stress levels, and avoid smoking. We can’t do anything about our age and may not be able to control our exposure to pollution, but we can focus on the things we can control.

A future post will discuss how a plant-based diet helps calm inflammation. In the meantime, check out my plant-based recipes on this site as well as these relevant posts to start or continue your anti-inflammatory journey.

What Causes Chronic Inflammation?