Do Certain Foods Cause Inflammation?

The terms “anti-inflammatory diet” and “anti-inflammatory food” are commonly used by health influencers and fitness enthusiasts, but do foods truly cause inflammation? Here are the facts you need to know.

What is inflammation?

Inflammation is the body’s natural response to protect itself against injury, infection, or foreign bodies such as bacteria and viruses ⁽¹⁾. It is the process by which the immune system recognizes and removes harmful stimuli and begins the healing process. Inflammation can be either acute or chronic.

Acute vs. Chronic Inflammation

There are two main types of inflammation: acute and chronic ⁽¹⁾.

Acute inflammation is sudden and temporary. It occurs in response to an illness or injury, such as a broken bone, cut finger, viral infection like the flu, or bacterial infection like strep throat. Symptoms of acute inflammation include pain, redness, swelling, heat, and loss of function ⁽²⁾.

Chronic inflammation is a form of low-grade inflammation that persists long after the trigger to the initial inflammatory response is gone. While not as intense as acute inflammation, chronic inflammation does not tend to resolve itself and is a contributing independent risk factor to many chronic diseases including rheumatoid arthritis, diabetes, cardiovascular disease, heart disease, high blood pressure, and certain cancers ⁽¹⁾. The symptoms of chronic inflammation vary widely and can be difficult to detect, however, may include joint pain, extreme fatigue, skin issues, mood disorders, and digestive issues.

Acute inflammation, also known as localized inflammation, typically lasts a few hours or days, while chronic inflammation, also known as systemic inflammation, can last for months or years if not treated.

Do Foods Cause Inflammation?

While food choices can contribute to chronic inflammation, individual foods do not cause a direct or immediate inflammatory response in the body, except for food allergies.

While many foods have been shown to aid in reducing inflammation, there is no evidence to suggest that consuming a single food will cause an inflammatory response, unless consumed in excess or a calorie surplus ^{(3, 4, 5)}. Although diets rich in processed foods, such as refined carbohydrates, red and processed meats, and fried foods, are correlated with chronic inflammation, the consumption of these individual foods in minimal to moderate doses has not been shown to cause direct or immediate inflammation in the body.

Rather, it is suggested that chronic inflammation is influenced by components of the overall diet, including total calorie, macronutrient, micronutrient, and phytonutrient intake, as well as exercise and lifestyle choices.

Weight Gain vs. Inflammation

Body weight, which is heavily influenced by food choices, is an often overlooked component of inflammation. The current research demonstrates that when an individual loses, weight inflammation markers go down, and when they gain weight, inflammatory markers go up.

The link between weight gain and inflammation is in part due to the increase in body fat, also known as adipose tissue. Adipose tissue is inflammatory because it produces adipokines which themselves are inflammatory, as they increase inflammatory signaling, immune responses, and oxidative stress ^{(6, 7)}.

Between diets (i.e. Mediterranean, paleo, keto, vegan, etc), there is little to no difference in changes in inflammatory markers when weight loss and calories are equated. For instance, inflammation does not differ between plant vs. animal proteins when macronutrients are equated, and inflammation does not differ between healthy diets that vary in macronutrients ^{(8, 4)}.

The current data suggests controlling fat mass is more important than the means of control for inflammation. Meaning, that whether you choose to create a calorie deficit by counting calories or macros, eat animal or plant protein, practice mindful eating, or follow the principles of intuitive eating, maintaining a healthy body weight is integral to reducing inflammation.

Gut Health vs. Inflammation

There is still much to discover about the gut microbiome, but current research suggests that the presence of certain bacteria is associated with inflammatory molecules that may bring about inflammation in various body tissues, and changes in the gut microbial composition can result in chronic inflammation and metabolic dysfunction ^{(9, 10)}.

While many uncontrollable factors can influence gut health, including genetics, the mode of delivery at birth, the method of infant feeding, and the use of antibiotics, food choices are a controllable factor that can support a healthy gut ⁽¹¹⁾.

Gut bacteria are heavily influenced by what you eat and it is important to make healthy food choices to create a balanced gut microbiome. Consuming a healthy diet with high-fiber foods, fermented foods, prebiotic-rich foods, and probiotic-rich foods while minimizing ultra-processed foods is the best way to support gut health.

Ways to Reduce Chronic Inflammation

Here are some diet and lifestyle tips to reduce chronic inflammation:

1. Maintain a Healthy Body Weight

Body fat, also known as adipose tissue, stimulates the release of inflammatory mediators predisposing the body to inflammation and oxidative stress ^{(6, 7)}. Maintaining a healthy body weight, or healthy BMI, regardless of dietary approach, is integral to reducing chronic inflammation.

2. Eat a Balanced Diet of Whole Foods

The overall context of the diet is more impactful on inflammation than individual foods. Consuming a diet rich in healthy whole foods, including fruits, vegetables, whole grains, beans, lentils, nuts, seeds, milk, eggs, poultry, meat, seafood, and shellfish, is the simplest way to mitigate and reduce chronic inflammation. Not only are these foods unprocessed but they are rich in vitamins, minerals, essential fatty acids, and natural antioxidants which are anti-inflammatory.

By eating balanced meals with protein, complex carbohydrates, fiber, and healthy fats you can help to ensure you are eating adequate help promoting macronutrients and micronutrients.

3. Minimize Ultra-Processed Foods

While there is room for everything in a healthy diet, it is important to limit the total consumption of ultra-processed foods. Often referred to as “unhealthy foods”, ultra-processed foods are defined as formulations of ingredients that are typically created by a series of industrial techniques and processes, and make up approximately 60% of the standard American diet ⁽¹²⁾.

Not only are ultra-processed foods filled with refined sugar, refined carbohydrates, sodium, partially hydrogenated oils, trans fats, and saturated fats, but their unique combination of ingredients makes them hyper-palatable. Hyper-palatable foods are incredibly tasty, but they contain very little nutrition and are very easy to overconsume and, therefore, a major contributor to weight gain, another contributing factor to inflammation.

For this reason, it is best to practice moderation with ultra-processed packaged foods, such as soft drinks, candy, cakes, sweetened breakfast cereals, fried foods, and hot dogs, and focus on building meals with unprocessed or minimally processed foods, such as fruits, vegetables, whole grains, beans, lentils, nuts, seeds, milk, eggs, poultry, meat, seafood, and shellfish.

4. Limit or Avoid Alcohol

Excess consumption of alcohol can cause cell damage and disrupt the body’s immune system, which can trigger systemic chronic inflammation ⁽¹³⁾.

The Dietary Guidelines for Americans recommends that adults of legal drinking age should not drink alcohol or drink in moderation if they choose to drink alcohol. Moderate drinking reduces the risk of chronic disease and is defined as two drinks or less per day for men, and one drink or less per day for women ⁽¹⁴⁾.

5. Stay Hydrated

Maintaining optimal hydration levels can help fight inflammation by flushing out toxins. Moreover, drinking enough water can help to reduce joint pain from inflammation due to its lubricating effect, as an estimated 70% of your joint cartilage consists of water ⁽¹⁵⁾.

While hydration needs depend on a host of factors, including weight, age, gender, geography, and exercise type, it is generally recommended to drink 1/2 ounce to 1 ounce of water per pound of (target) body weight per day.

6. Avoid Smoking

Smoking is associated with a broad range of alterations in systemic immune and inflammation markers, especially in long-term smokers ⁽¹⁶⁾. Cigarette smoking is a risk factor for several chronic health conditions, including coronary heart disease, stroke, emphysema, and cancer, while tobacco use is also a leading risk factor for premature death and all-cause mortality ⁽¹⁷⁾.

7. Exercise Regularly

Regular exercise can help to maintain a healthy weight, reduce stress, and improve overall health, which can all help to reduce systemic inflammation. Physical inactivity leads to the accumulation of visceral fat and consequently the activation of a network of inflammatory pathways, which is linked to several chronic diseases ⁽¹⁸⁾.

Observational studies have consistently shown a link between self-reported levels of physical activity and inflammatory biomarkers ⁽¹⁹⁾. The anti-inflammatory effect of exercise may be due to a reduction in visceral fat, with a subsequent decrease of adipokines, and/or by the induction of an anti-inflammatory environment with each bout of exercise.

It is recommended that adults do, at least, 150 minutes of moderate-intensity physical activity a week, or 30 minutes a day 5 days a week, as well as 2 days of muscle-strengthening activity ⁽²⁰⁾. Long-term progressive resistance training is associated with reduced chronic inflammatory markers, and diet and exercise are the best interventions for weight loss.

8. Get Enough Sleep

Poor sleep can negatively affect immune cells and is associated with higher levels of inflammatory biomarkers, which can contribute to many chronic diseases ^{(21, 22)}. While it’s only natural to have a bad night’s rest from time to time, chronic insufficient sleep can have serious help implications and should be addressed.

The daily recommended hours of sleep vary by age, however, it is recommended that adults aim for 7 or more hours of sleep per night ⁽²³⁾. To practice good sleep hygiene, try to go to bed at the same time every night, sleep in a dark and cool room, avoid digital devices at least 1 hour before bed, and avoid caffeine in the afternoon and evening.

9. Reduce Stress

Research shows that stress can cause inflammation in the body. Intense stress over-activates the immune system, which induces inflammation peripherally and centrally, and this imbalance leads to diversified stress-related diseases ^{(24, 25)}.

Work to manage stress daily by making time to unwind, taking breaks from news and social media, journalling, meditating, connecting time with loved ones, and spending time in nature.

List of Anti-Inflammatory Foods

Here is a list of the top anti-inflammatory foods that have been clinically shown to help fight inflammation:

• Fruits, such as berries, cherries, and avocados
• Green vegetables, such as kale, spinach, and broccoli
• Fatty fish, such as salmon and mackerel
• Nuts and seeds, such as walnuts, flax seeds, and chia seeds
• Whole grains, such as oats, quinoa, and brown rice
• Fats, such as olive oil and full-fat dairy products
• Fermented foods, such as yogurt, kefir, sauerkraut, and kimchi
• Herbs and herbal teas, such as green tea
• Spices, such as turmeric, cinnamon, and ginger

The Bottom Line

Inflammation is the body’s defense mechanism to harmful and foreign stimuli and can be acute or chronic. Chronic inflammation is a form of slow, low-grade inflammation that has been linked to many chronic diseases. While certain foods have been shown to reduce inflammation, there are no foods that inherently cause inflammation in the body. To avoid or reduce chronic inflammation, one should maintain a healthy body weight, prioritize whole foods, reduce ultra-processed foods, limit or avoid alcohol, avoid smoking, stay hydrated, exercise regularly, get enough sleep, and reduce stress.