Inflammation isn’t always bad – for instance, it can be your body’s natural way of protecting itself when you are sick or injured, and it can also stimulate healing.

However, chronic, sustained inflammation in the body is linked with higher risk of diseases like diabetes, heart disease and obesity.

The foods that you eat can have a major impact on inflammation in your body, and here are 6 foods that can cause inflammation.

1. Sugar and High-Fructose Corn Syrup

High-fructose corn syrup (HFCS) and ordinary table sugar are the two main types of sugar consumed in the Western diet.

Sugars can lead to inflammation, which can put you at higher risk of some diseases. A rodent study showed that mice fed on high-sugar diets developed breast cancer that then spread to their lungs, and this was partly due to the inflammatory response to sugar.

A clinical trial in which people drank regular soda, diet soda, milk or water found that only those who drank regular soda had increased levels of uric acid. This acid drives inflammation and insulin resistance.

Fructose in excess amounts can lead to obesity, insulin resistance, diabetes, fatty liver disease, cancer and chronic kidney disease. High fructose has also been shown to increase some inflammatory markers in both mice and humans.

2. Artificial Trans Fats

Artificial trans fats are created by adding hydrogen to unsaturated fats, which results in a more solid, longer-shelf-life fat.

Most margarines and processed foods contain trans fats, and they are often listed on ingredient lists as “partially hydrogenated” oils.

Artificial trans fats have been shown to cause inflammation and increase risk of disease. They also lower your “good” HDL cholesterol levels, and could impair the function of the endothelial cells that line your arteries.

In a controlled trial of overweight older women, hydrogenated soybean oil increased their inflammation significantly more than palm and sunflower oils.

3. Seed and Vegetable Oils

Vegetable oil consumption in the West increased massively in the last century, and some scientists believe that some vegetable oils, such as soybean oil, cause inflammation due to their high omega-6 fatty acid content.

Omega-6 fatty acids are necessary in small amounts, but people consume far more than they need. Eating omega-3 rich foods like oily fish could improve your omega-6 to omega-3 ratio, and help you gain anti-inflammatory benefits.

However, studies on linoleic acid (the most common dietary omega-6 acid) showed that it had no effects on inflammatory markers.

4. Refined Carbohydrates

Not all carbs are bad for us, but eating refined, processed carbs could contribute to inflammation.

Refined carbs have most of their fiber removed – think white bread, white rice, white flour etc. Research suggests that refined carbs could encourage the growth of inflammatory gut bacteria that can increase the risk of obesity and inflammatory bowel disease.

Refined carbs also raise blood sugar levels more rapidly than lower GI foods. One study of young, healthy men showed higher blood sugar levels and an increase in one inflammatory marker when they were given 50 grams of white bread to eat.

5. Excessive Alcohol

High amounts of alcohol can lead to big problems. The inflammatory marker CRP increased in those who consumed alcohol in one study. The more they drank, the more their CRP increased.

Heavy drinking may also lead to problems with bacterial toxins moving out of the colon and into the body – a condition known as “leaky gut”. This can cause widespread inflammation which leads to organ damage.

Alcohol intake should be limited to two standard drinks per day for men, and one for women.

6. Processed Meat

Common types of processed meat include sausage, bacon, ham, smoked meat and beef jerky. These meats are associated with an increased risk of heart disease, diabetes, stomach cancer and colon cancer.

Advanced glycation end products are formed by cooking meats and some other foods at high temperatures, and they are known to cause inflammation. Processed meats contain more advanced glycation end products than most other meats.

Colon cancer is the disease with the strongest link to processed meat consumption.