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What is inflammation and how is it useful?

This article describes what inflammation is, what happens with it, and the role diet plays in sustaining acute inflammation.
Woman having knee pain.

Inflammation is the reaction of living tissue to local injury or damage.

A recent study with over 2,000 participants has shown that adults who had a high intake of antioxidant compounds from foods like apples and pears, strawberries and red wine had much lower levels of inflammatory biomarkers in their blood which would reduce their risk for many chronic diseases.

For example, it is well established that people who have a high intake of fruit and vegetables in their diet have a lower risk of heart disease and stroke.

What happens with inflammation?

The process of inflammation is designed to be helpful to the body in repairing injury. It should be an acute (or very fast) response whereby the immune cells quickly remove damaged tissue and destroy any invading micro-organisms.

Normal tissue structure is restored and the immune signals that amplify the inflammatory response are switched off. The immune cells retreat back into the bloodstream. Order is restored. This type of inflammation occurs with normal processes of healing for example after a slight cut or wound.

The inflammatory response

The inflammatory response in each case is similar. Early response is made by the cells lining the blood vessels local to the site of injury. These are the cells of the vascular endothelium. First, they dilate bringing more blood into the area. Then the cells pull apart slightly allowing fluid and proteins from the blood to move into the surrounding tissues, causing local swelling.

The endothelial cells also respond to the injury by initiating a cascade of signals directed at immune cells circulating in the blood. On receiving these signals, the immune cells immediately cluster in this local area and start to leave the blood, pushing their way across the now leaky endothelium to enter the tissue at the site of injury.

The four cardinal sins of inflammation

Together, these local changes initiate the four cardinal signs of inflammation: redness, heat, swelling (from increased local blood flow, the escape of blood fluid into tissues and the influx of immune cells), plus pain (from damage to local nerve endings).

Dysfunctional inflammation

Dysfunctional inflammation occurs when the immune response becomes chronic and does not resolve or end. Chronic inflammation can occur in many different parts of the body in response to many different diseases.

Examples, where chronic inflammation develops and causes ongoing problems, include rheumatoid arthritis, inflammatory bowel disease, coronary heart disease and type 2 diabetes.

The harm can be caused by many different things: it can be physical (mechanical injury/heat/cold/sun exposure), toxic (corrosive chemical, X-ray), or due to an infectious agent (virus/bacteria/parasite).

What role does diet play?

A healthy diet is very important to sustain the acute inflammation that ends in wound healing. Wound healing is much slower in people who are malnourished. Different elements in the diet can also influence the course of chronic inflammation.

Foods that have pro-inflammatory properties will promote the influx of immune cells into the tissue and increase the risk of further damage and disease.

In contrast, foods with anti-inflammatory properties aid in the resolution of inflammation, promoting healing so that immune cells can return to the blood.

If you’d like to learn more about food as medicine, check out the full online course from Monash University, below.


© Monash University 2021. CRICOS No. 00008C
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Food as Medicine

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