What Are Pro-Inflammatory Foods and What Are The Risks?

In case you didn't know, there are foods that are capable of causing inflammation in the digestive tract and the rest of the body. See what they are and how to avoid more problems by changing your habits and avoiding a pro-inflammatory diet.
What Are Pro-Inflammatory Foods and What Are The Risks?
Maria Patricia Pinero Corredor

Written and verified by the nutritionist Maria Patricia Pinero Corredor.

Last update: 26 May, 2022

Diet has a great impact on health. However, there are some types, such as those that consist of pro-inflammatory foods, that contribute to increasing the risk of certain chronic diseases.

There are 2 types of inflammation. Acute inflammation, which occurs in response to injury as a defense mechanism; and chronic inflammation, which occurs when the body tries to eliminate certain harmful substances. Excess abdominal fat can also lead to chronic inflammation.

A pro-inflammatory diet can predispose the body to diseases such as diabetes, cardiac illnesses, and certain intestinal disorders. From this perspective, Dr. David Seaman explains that specific foods (sugars and seed oils) promote inflammation.

How can diet cause inflammation?

Inflammation’s a type of natural defense and a protective signal from the body. However, when it persists or when dietary factors maintain it, it works against us.

There are certain markers in the blood, such as C-reactive protein, interleukin-6, and tumor necrosis factor-alpha that indicate chronic inflammation. As some experts explain, diet influences these markers. For example, the Western diet is associated with high levels of inflammation.
The journal Obesity Reviews tells us that ultra-processed foods and those that are high in calories and very low in vegetables and fruits are associated with higher levels of inflammation. In contrast, a clinical trial showed that the Mediterranean diet, rich in fruits, legumes, olive oil, oily fish, vegetables, and whole grains, has been associated with lower inflammatory markers.

The importance of diets in improving health appeared in a publication by the journal Advances in Nutrition. A tool known as the dietary inflammatory index was used to determine pro- or anti-inflammatory potential.

This index takes into account compounds, nutrients, and foods with pro- or anti-inflammatory properties. Those pro-inflammatory dietary patterns were associated with an increased risk of chronic disease.

Cake, pastries, and candies.
Ultra-processed foods, sugars, and pastries are foods that are considered inflammatory.

What foods are considered pro-inflammatory?

Many foods that we consume on a regular basis can affect inflammation in the body. Below, we’ll review those with pro-inflammatory characteristics.

Trans fats

Trans fats are among the least healthy fats available. They’re formed by the addition of hydrogen to unsaturated fats to make them more stable in storage. We know a good part of them as partially hydrogenated oils.

In this regard, a group of experts clarified that hydrogenated soybean oil causes more inflammation than palm and sunflower oil.

Trans fats are also formed during the margarine manufacturing process. One study mentions the inflammatory effects and the risk of chronic disease of these fats. Experts affirm that they increase inflammatory markers, such as C-reactive protein.

Research showed that trans fats can affect the function of endothelial cells lining the arteries, which is a risk factor for heart disease. Consumption of these fats has also proven to increase inflammatory markers in healthy men with high cholesterol levels.

Other foods high in trans fats include fried fast foods, popcorn, potato chips, vegetable shortenings, pastries, and processed foods, as well as cakes and cookies.

Table sugar and corn syrup

The Western diet uses table sugar and high-fructose corn syrup as its main sweetener. The difference between the two is that sugar contains equal parts glucose and fructose, but in corn syrup more than half is fructose.

As a study reveals, sugar is a pro-inflammatory dietary product. In this regard, studies have shown that mice that consumed diets high in sucrose developed breast cancer.
A randomized clinical trial on groups of people consuming regular and diet soft drinks, milk, or water showed that those who ingested regular soft drinks had increased levels of uric acid, which leads to inflammation and insulin resistance.

The Journal of Nutrition has published information to show that consuming a lot of fructose is linked to obesity, insulin resistance, diabetes, fatty liver, chronic kidney disease, and cancer. One review mentions that fructose is also considered a risk factor for heart disease and increases several inflammatory markers in mice and humans.

We should also consider that sugar’s also used as an added ingredient in candies, chocolates, cakes, donuts, and breakfast cereals.

Read also: 9 Foods with a Surprisingly High Sugar Content

Refined carbohydrates

Research reports that refined carbohydrates can produce inflammation, stimulating the growth of intestinal bacteria that increase the risk of obesity and inflammatory bowel disease.

This type of carbohydrate has a very high glycemic index. In other words, it increases blood sugar very quickly. In older adults, studies have found that eating foods with a high glycemic index can increase the chance of dying from inflammatory disease by almost 3 times.

Another trial in young men supports this finding. When people in the study ate 50 grams (2 oz) of white bread, they had higher blood sugar and inflammatory markers.

Sweets, bread, pastries, cakes, sugary soft drinks, cookies, pasta, refined flour, and processed foods with sugar are sources of refined carbohydrates.

Vegetable oils

Some studies have suggested that oils with omega-6 fatty acids are pro-inflammatory and this type of fat is characteristic of the Western diet. Certain seed oils, such as soybean oil, can activate inflammation.

This is one of the reasons for recommending the consumption of omega-3 fats, such as those found in fatty fish. Omega-3s have significant anti-inflammatory power.

In this regard, a study in rats that ate 20 times more omega 6 than omega 3 showed that they had much higher levels of inflammatory markers than those that ate equal or 5 times higher proportions of omega 6 to omega 3. However, in humans, there’s not yet sufficient evidence of the effect.

Processed meat

Experts have long affirmed the relationship between the consumption of processed meats (bacon, sausages, ham, jerky and smoked meats) and an increased risk of chronic diseases such as diabetes, stomach, and colon cancer.

The presence of advanced glycation end products (AGEs) in these products can cause inflammation, according to some studies. In particular, there’s a strong relationship between colon cancer and the consumption of processed meats, as an inflammatory response.

Excessive alcohol

A clinical trial showed that the inflammatory marker C-reactive protein increases in people who drink a lot of alcohol. In addition, problems can develop with certain bacterial toxins that the colon produces, which get into the blood.

The journal Lancet revealed that excessive alcohol can lead to leaky gut, a condition that causes widespread inflammation in the body and damages different organs. In this regard, experts recommend a maximum of 2 standard drinks per day for men and 1 for women.

Processed meats.
Processed meats have already proven to have an influence as risk factors for certain neoplastic types, such as colon cancer.

The risks of a diet rich in pro-inflammatory foods

Consistently consuming a pro-inflammatory diet can lead to chronic inflammation related to coronary heart disease, depression, and obesity, among others.

Increases the risk of cardiovascular disease

Long-term studies have shown that people who consume pro-inflammatory foods have a 38% higher risk of developing chronic cardiovascular disease. Another study also found the harmful effect of pro-inflammatory foods on cholesterol levels, as opposed to the anti-inflammatory diet.

It may have to do with depression

Although the relationship isn’t yet clear, studies have shown that depressed people who consumed more sugars, trans fats, and refined carbohydrates had increased inflammatory markers in the blood. The results also associate the pro-inflammatory diet with worse symptom status.

It increases the risk of mortality from chronic disease

A group of experts has expressed that chronic inflammation is a causal factor in disability and mortality worldwide. According to the journal Nutrients, pro-inflammatory foods such as ultra-processed foods and trans fats promote chronic systemic inflammation.

Tips for a healthy diet

To avoid inflammation problems, focus on improving your diet, rather than focusing on just one food or nutrient. Many of them interact with each other.

It’s always advisable to increase the variety of plant foods (fruits, vegetables, legumes, whole grains, and olive oil). These contain fiber and phytochemicals, such as polyphenols, with antioxidant effects.

Herbs, spices, tea, and coffee are also excellent sources of polyphenols. So, you can use them on a regular basis. Also, oily fish is a source of omega 3.

To maintain health and increase life expectancy in the face of chronic diseases, you should stop eating pro-inflammatory foods and switch to a healthier diet.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

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This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.