Inflammation can be good or bad, depending on the situation.
On one hand, it’s your body’s natural way of protecting itself when you are injured or sick.
It can help your body defend itself from foreign invaders, and can stimulate healing.
On the other hand, chronic, sustained inflammation in the body can be harmful.
It is linked to an increased risk of diseases like diabetes, heart disease, obesity and many others (1, 2, 3).
Interestingly, the foods you eat can have a major effect on inflammation in your body.
Here are 6 foods that can cause inflammation.
1. Sugar and High-Fructose Corn Syrup
Table sugar (sucrose) and high-fructose corn syrup (HFCS) are the two main types of added sugar in the diet.
Sugar is 50% glucose and 50% fructose, while high-fructose corn syrup is about 55% fructose and 45% glucose.
One of the reasons that added sugars are harmful is increased inflammation that can lead to disease (4, 5, 6, 7, 8).
In one study, when mice were fed high-sucrose diets, they developed breast cancer that spread to their lungs, in part due to the inflammatory response to sugar (6).
In another, the anti-inflammatory action of omega-3 fatty acids was impaired in mice that were fed a high-sugar diet (7).
And in a randomized clinical trial where people were assigned to drink regular soda, diet soda, milk or water, only those in the regular soda group had increased levels of uric acid, which drives inflammation and insulin resistance (8).
Sugars can also cause harm because they supply excess amounts of fructose.
While the small amounts of fructose in fruits and vegetables are fine, getting large amounts from added sugars is a bad idea.
Eating a lot of fructose has been linked to obesity, insulin resistance, diabetes, fatty liver disease, cancer and chronic kidney disease (9, 10, 11, 12, 13, 14, 15).
Researchers have also found that fructose causes inflammation within the endothelial cells that line your blood vessels (16).
High fructose intake has also been shown to increase several inflammatory markers in mice and humans (10, 17, 18, 13, 19, 20).
Bottom Line: Consuming a diet high in sugar and high-fructose corn syrup drives inflammation that can lead to disease. It may also counteract the anti-inflammatory effect of omega-3 fatty acids.
2. Artificial Trans Fats
Just about everyone agrees that artificial trans fats are the unhealthiest fats you can eat.
They’re created by adding hydrogen to unsaturated fats, which are liquid, in order to give them the stability of a more solid fat.
Trans fats are often listed as “partially hydrogenated” oils on the ingredients lists on food labels.
Most margarines contain trans fats, and they are often added to processed foods in order to extend shelf life.
Unlike the naturally occurring trans fats found in dairy and meat, artificial trans fats have been shown to cause inflammation and increase disease risk (21, 22, 23, 24,25, 26, 27, 28, 29).
In addition to lowering beneficial HDL cholesterol, trans fats have been shown to impair the function of the endothelial cells lining the arteries (26).
Our ancestors consumed high-fiber, unprocessed carbohydrates for millions of years in the form of grasses, roots and fruits (34).
However, eating refined carbohydrates can drive inflammation, which in turn may lead to disease (34, 35, 36, 37, 38).
Refined carbohydrates have had most of their fiber removed. Fiber promotes fullness, improves blood sugar control and feeds the beneficial bacteria in your gut.
Researchers report that the refined carbohydrates in our modern diet may encourage the growth of inflammatory gut bacteria that can increase risk of obesity and inflammatory bowel disease (34, 36).
Refined carbohydrates have a higher glycemic index (GI) than unprocessed carbohydrates. High-GI foods raise blood sugar more rapidly than low-GI foods do.
In one study, older adults who reported consuming the highest amount of high-GI foods were 2.9 times more likely to die of an inflammatory disease like COPD (37).
In a controlled study, young, healthy men that were fed 50 grams of refined carbohydrate in the form of white bread responded with higher blood sugar levels and an increase in the inflammatory marker Nf-kB (38).
Bottom Line: High-fiber, unprocessed carbohydrates are healthy, but refined carbohydrates raise blood sugar levels and promote inflammatory changes that may lead to disease.
5. Excessive Alcohol
Moderate alcohol consumption has been shown to provide some health benefits.
However, higher amounts can lead to severe problems.
In one study, the inflammatory marker CRP increased in people who consumed alcohol. The more alcohol they consumed, the more their CRP increased (39).
People who drink heavily often develop problems with bacteria moving out of the colon and into the body. This condition, often called “leaky gut,” can drive widespread inflammation that leads to organ damage (40, 41).
To avoid alcohol-related health problems, intake should be limited to two standard drinks a day for men and one standard drink a day for women.
Here is an image showing what is considered a “standard drink” for several types of alcoholic beverages:
Photo Source: National Institute on Alcohol Abuse and Alcoholism.
Bottom Line: Heavy alcohol consumption can increase inflammation and potentially lead to a “leaky gut” that drives inflammation throughout the body.
6. Processed Meat
Consuming processed meat is associated with an increased risk of heart disease, diabetes, stomach cancer and colon cancer (42, 43, 44).
Common types of processed meat include sausage, bacon, ham, smoked meat and beef jerky.