Pro-Inflammatory Foods: What to Avoid and Why

Many of the foods in the standard American diet may contribute to chronic inflammation, such as refined sugars, artificial sweeteners, trans fats, refined carbohydrates, processed meats, and alcohol. These foods may trigger an inflammatory response within the body that could lead to various effects, including potential damage to cells and organs, metabolic changes, immune system changes, and various health issues.

There is a strong link between diet and inflammation, and increasing evidence suggests the negative impact of proinflammatory foods on overall health. It is important to understand what foods are pro-inflammatory (and why) to make informed diet and lifestyle choices to support overall health and well-being. 

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What is Inflammation?

Inflammation refers to an immune response triggered within the body as a result of exposure to a foreign substance or a perceived stressor. While acute inflammation is a vital part of the immune response in the short term, sustained inflammation over weeks to months (called chronic inflammation) may have negative effects. Many of the foods in the standard American diet may contribute to chronic inflammation, such as processed foods, trans fats, and refined sugars. However, other foods are considered anti-inflammatory, and their consumption may help manage inflammation. A true anti-inflammatory diet focuses on whole, real foods with antioxidants and micronutrients, while minimizing processed foods and other proinflammatory ingredients. 

When the inflammatory response continues beyond the short-term, chronic inflammation may result. This is marked by chronically elevated levels of stress hormones that may have reduced effects, which necessitates the production of higher levels of stress hormones. As chronic inflammation continues, changes in stress hormones may lead to further metabolic changes and potential organ dysfunctions. This is the inflammation and health connection, as it may contribute to autoimmune conditions, reduced ability to manage illnesses, and metabolic conditions, such as high blood pressure, cardiovascular issues, elevated cholesterol levels, fatty liver, prediabetes and diabetes, and obesity.

How Can Lab Testing Help Determine Chronic Inflammation in The Body?

General markers of inflammation include C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).

Additionally, chronic inflammation may have effects on many stress hormones, including cortisol and other glucocorticoids, insulin, thyroid hormones, reproductive hormones (estrogen, testosterone, and progesterone), dehydroepiandrosterone (DHEA), vitamin D 25-OH, norepinephrine, interleukin-6, tumor necrosis factor-alpha (TNF-ɑ), and others.

The Role of Diet in Inflammation

Inflammation can have a variety of different triggers, one of which is what we eat. The standard American diet is often considered proinflammatory. It includes up to 40% of calories from refined carbohydrates and added sugars. By adding in processed meats and trans fats, this number may increase significantly. Processed foods are a major contributor to a proinflammatory diet. The higher the amount of processed foods in the diet, the higher the potential risk of inflammation-related issues. The human body may not efficiently metabolize the foreign ingredients found in processed foods. As a result, cellular changes, metabolic changes, and chronic inflammation may occur.

On the other hand, some of our best food choices are anti-inflammatory, foods that may help manage current and future inflammation. Fruits and vegetables contain polyphenols, which are potent antioxidants, potentially supporting cell health and helping manage many other effects of inflammation. Omega-3 fatty acids (like those found in fatty fish, chia seeds, and avocados) are both anti-inflammatory and immune-supporting, meaning they may help manage inflammation and support your immune health at the same time. Furthermore, many herbs, spices, and food forms may help manage inflammation too, like turmeric, garlic, fermented foods, and others. By focusing on anti-inflammatory foods, you may help manage, reduce, and even prevent chronic inflammation.

Common Pro-Inflammatory Foods

Many foods are considered proinflammatory, meaning their breakdown and metabolism may trigger an inflammatory response within the body. High amounts and long-term consumption of proinflammatory foods may lead to chronic inflammation and potential negative effects. Common pro-inflammatory foods are refined sugars, high-fructose corn syrup, artificial sweeteners, refined carbohydrates, trans fats, some saturated fats, processed meats, and excessive alcohol.

Refined sugars are often considered pro-inflammatory. High-fructose corn syrup is a common sweetener and texture agent in shelf-stable processed foods and beverages. It is particularly concerning for overall health, as studies suggest it may contribute to inflammation, insulin resistance, and obesity. Refined sugars (including high-fructose corn syrup) may trigger the release of proinflammatory cytokines, thus promoting oxidative stress and chronic inflammation. When refined sugars are consumed in large amounts, it may lead to changes in blood glucose levels, prediabetes, and type 2 diabetes mellitus. Eating excessive refined sugars may also cause dysbiosis, which is a disruption of the balance of gut microbiota. This may lead to further inflammation, digestive issues, lowered immunity, altered metabolism, and more.

Artificial sweeteners may also have significant proinflammatory effects. These include aspartame, sucralose, saccharin, erythritol, acesulfame potassium, and xylitol. Artificial sweeteners may cause dysbiosis, which may lead to inflammation, metabolic changes, immune system changes, and digestive problems. The pro-inflammatory nature of artificial sweeteners is known to cause exaggerated inflammatory responses in some people, so tolerance levels may vary.

Trans fats are unsaturated fats that have a hydrogen atom added (called hydrogenated oils) to make them solid at room temperature for the purposes of extending the shelf-life of foods and enhancing food texture. Trans fats, which are commonly found in fried foods, baked goods, margarine, and shelf-stable processed foods, are well-known for their potential pro-inflammatory properties. Not only do trans fats increase levels of low-density lipoprotein cholesterol but they may also promote inflammation by upregulating the production of inflammatory cytokines and oxidative stress markers. Similarly, certain saturated fats, particularly those from processed and red meats, may also contribute to inflammation and cardiovascular health concerns. Limiting the intake of trans fats and some saturated fats, and instead opting for healthier sources of unsaturated fats like omega-3 fatty acids, may help manage inflammation and support overall health.

Refined carbohydrates take many forms. From bread to crackers to chips to cookies, most processed foods that are found in the middle aisles of the grocery store are high in refined carbohydrates. During the heavy processing that occurs, these refined carbohydrates are not only stripped of their healthful ingredients, like dietary fiber, vitamins, and minerals, but they also have more harmful ingredients added to them, like additives, preservatives, and artificial flavorings. The resulting products may be proinflammatory, potentially inducing an inflammatory response as the body tries to break down synthetic ingredients.

Processed meats belong to another large category of highly processed foods. The act of processing meats exposes them to carcinogens in the smoking and curing process. Furthermore, nitrates and nitrites are usually added for preservation, which can form carcinogenic nitrosamines, which have been linked to multiple types of cancers–esophageal, stomach, colon, and brain cancers.

Alcohol is also known to be pro-inflammatory, and heavy alcohol use may contribute to organ changes, brain volume changes, immune system changes, and metabolic changes. Alcohol is specifically linked to inflammation within the gut. This may cause bacterial translocation, endotoxin release, and cytokine excess, all potentially perpetuating inflammation.

Why Avoid Pro-Inflammatory Foods?

There is growing recognition of the role of diet in the development and progression of chronic conditions. Proinflammatory foods are known to potentially cause inflammation, and evidence suggests they may be significant contributors to various chronic conditions. Proinflammatory foods may trigger the release of proinflammatory cytokines and other immune mediators, leading to a state of chronic inflammation.

The potential effects of proinflammatory foods on cardiovascular health are detailed in numerous peer-reviewed publications. High intake of processed meats and sugary snacks has been associated with an increased risk of coronary heart disease, stroke, and hypertension. These foods may promote endothelial changes, arterial stiffness, and plaque formation, potentially contributing to cardiovascular conditions.

The consumption of proinflammatory foods has been linked to insulin resistance, impaired glucose regulation, and ultimately, type 2 diabetes mellitus. Evidence-based studies suggest diets rich in refined grains, sugary beverages, and fried foods may elevate inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6) and fasting insulin levels, potentially worsening insulin resistance and increasing pancreatic β-cell dysfunction.

Proinflammatory foods may play a significant role in the development of obesity, which is itself a major risk factor for numerous chronic conditions. The excessive consumption of processed foods may disrupt the hormonal regulation of appetite and energy balance, leading to increased caloric intake and adiposity. Adipose tissue itself may be proinflammatory, further contributing to insulin resistance, dyslipidemia, and metabolic syndrome.

Increasing evidence suggests correlations between proinflammatory diets and certain types of cancer. A diet high in processed meats, sugary snacks, and refined carbohydrates is associated with an elevated risk of colorectal, breast, and prostate cancers. Chronic inflammation triggered by these foods may promote oncogenic processes such as DNA changes and abnormal cell proliferation.

A high intake of proinflammatory foods and the resulting chronic inflammation are each implicated in the development of neurodegenerative disorders like Alzheimer's and Parkinson's disease. Proinflammatory diets may worsen neuroinflammation and neuronal changes via increased oxidative stress and the formation of free radicals.

Proinflammatory foods may have a fundamental role in the development of chronic conditions, and understanding the role of diet-induced inflammation in chronic conditions is important. Functional medicine emphasizes the importance of dietary modifications as both a preventive and supportive strategy. Adopting an anti-inflammatory diet, characterized by whole foods, fruits, vegetables, and healthy fats, is a step in supporting overall health and well-being.

Identifying Hidden Sources of Pro-Inflammatory Ingredients

Some pro-inflammatory foods are more obvious, like refined sugars, high fructose corn syrup, and trans fats. However, some proinflammatory ingredients may be hidden in processed foods, making them harder to spot. In general, if a food is heavily processed, it likely has many sources of proinflammatory ingredients. Some of the common proinflammatory ingredients include additives, preservatives, flavor enhancers, colors and dyes, and other food production chemicals, like glyphosate.

Monosodium glutamate (MSG) is a flavor enhancer commonly found in processed foods, some ethnic foods, and restaurant foods. MSG consumption is linked to inflammation and oxidative stress, in turn increasing the risk of inflammatory-based chronic conditions, like insulin resistance, obesity, metabolic syndrome, neurologic disorders, immune changes, and food sensitivities.

Many preservatives are commonly used in processed meats to prevent contamination and enhance color and texture. However, nitrates and nitrites are considered pro-inflammatory and carcinogenic. A high intake of sodium nitrate/nitrite is associated with a higher risk of cardiovascular conditions and certain cancers.

Glyphosate is a widely used herbicide in conventional agriculture, commonly found as a residue on many crops like soy, corn, oats, and wheat. Glyphosate is strongly linked to disruptions in gut microbiota, increased intestinal permeability, and decreased immune function. This dysbiosis may lead to chronic inflammation and other associated organ changes.

Synthetic food dyes are added to many processed foods, beverages, and snacks to enhance both their color and their appeal. However, these dyes, most commonly Red 40 and Yellow 5, may cause allergic reactions and inflammation. They are also known to potentially contribute to hyperactivity in children and bladder issues. In children with attention deficit hyperactivity disorder, these synthetic dyes are known to potentially exacerbate symptoms.

Alternatives to Pro-Inflammatory Foods

Fatty fish is one of the best sources of omega-3 fatty acids, an incredible source of the benefits that omega-3 fatty acids provide. By potentially reducing inflammation, the omega-3 fatty acids found in fatty fish like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may lower your risk of metabolic syndrome, heart conditions, diabetes, and other chronic issues. Other concentrated sources of omega-3 fatty acids outside of fatty fish include flaxseeds, chia seeds, and walnuts.

Extra virgin olive oil contains healthy monounsaturated, potentially anti-inflammatory fats, including omega-3 fatty acids. Olive oil is pressed directly from the olives and includes no other ingredients to make it overly processed. Extra virgin olive oil is even less processed. It is mechanically extracted from olives without using high heat or solvents, which helps preserve its antioxidants and polyphenols.

The potential benefits of regularly eating extra virgin olive oil include reduced risk of heart conditions, certain types of cancers, obesity, metabolic syndrome, and many others. Using extra virgin olive oil as part of an overall anti-inflammatory eating lifestyle provides beneficial fats for healthy cell structure and function and important antioxidants and polyphenols to help manage inflammation. 

Leafy green vegetables, like kale, spinach, Swiss chard, bok choy, and lettuces, are considered anti-inflammatory vegetables. They are full of antioxidants and phytochemicals that may help manage inflammation. They also contain vitamin K, which helps support circulation, vitamin C, which helps support immune function, selenium, which also supports immunity, and beta-carotene, which helps manage free radicals and may decrease the risk of cancer. 

Cruciferous vegetables, like broccoli, cauliflower, and Brussels sprouts, contain isothiocyanates. Derived from the breakdown of sulfur-containing compounds, isothiocyanates are functional foods that are linked to significantly lower rates of certain types of cancers in those who eat higher amounts.

Because whole grains are high in phytochemicals, antioxidants, and fiber, many studies support their potential anti-inflammatory properties, thus potentially reducing the risk of chronic conditions.

Dark chocolate is considered highly anti-inflammatory because of the many antioxidants from the flavanols in cacao. Flavanols are high-protective for the endothelial cells within your arteries. This may help protect against endothelial changes, which is the start of plaque formation and coronary artery disease. If the endothelial lining of the arteries remains intact, plaque may not stick to the arterial walls and instead continues to flow through the blood. Dark cacao may also help to manage blood pressure. Choose dark cocoa without added heavy cream, refined sugars, and other additives and preservatives.

When looking for alternatives to proinflammatory foods, choose organic whenever possible, especially for animal products and the dirtiest types of produce. Include at least one serving of fatty fish per week, and prepare your meals with anti-inflammatory unsaturated fats, like extra virgin olive oil and avocado oil. Utilize herbs and spices with potential anti-inflammatory impacts like turmeric, ginger, garlic, and cinnamon to add flavor and nutrition.

Incorporating Anti-Inflammatory Foods into Your Diet

The foundations of antiinflammatory eating truly are basic. Opt for whole, real foods, as close to their natural states as possible. The challenge is in both our modern lifestyles and our modern food supply, where schedules are busier than ever, and processed foods are the rule and not the exception! This makes incorporating an anti-inflammatory eating lifestyle much more complex. 

Aim for 75% of your plate to be plant-based foods at most meals. Choose organic as much as possible, especially for animal products and the dirtiest types of produce. Include at least one serving of fatty fish per week, and prepare your meals with anti-inflammatory unsaturated fats, like extra virgin olive oil and avocado oil. Utilize herbs and spices with potential anti-inflammatory impacts like turmeric, ginger, garlic, and cinnamon to add flavor and nutrition.

Meal planning is a huge factor in success with anti-inflammatory eating. Knowing what you will eat for each meal enables you to make informed food choices and helps you avoid the drive-thru, takeout lines, or delivery, which often offer less anti-inflammatory food options. Variety is important in anti-inflammatory eating, as it provides a wide array of potential health benefits from different foods. Choose fruits and vegetables of different colors to get different vitamins and minerals. 

Base your diet on fruits, vegetables, lean proteins, healthy fats, and whole grains. 

Other factors for success are adequate water intake and regular exercise. Being properly hydrated is crucial for a healthy lifestyle. Drinking enough water may help optimize your metabolism, manage your appetite, regulate your circulation, and improve your mental clarity. 

Drink at least 64 ounces (8 cups) of water per day. Regular exercise is another crucial component of maintaining optimal metabolic health. A combination of strength training and cardiovascular exercise provides potential fitness benefits. Exercise is a great way to help maintain a healthy weight, support lean body mass, and help prevent bone loss. 

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Pro-Inflammatory Foods: Key Takeaways

Proinflammatory foods are known to potentially cause and perpetuate chronic inflammation. By minimizing foods like refined sugars, artificial sweeteners, trans fats, refined carbohydrates, processed meats, and alcohol, you may help avoid some of the main contributors to chronic inflammation. The functional medicine approach to root-cause medicine focuses on reducing pro-inflammatory foods and incorporating anti-inflammatory foods to support overall health and well-being.