Scientists find how fasting may protect against inflammation

Cambridge scientists may have discovered a new way in which fasting helps reduce inflammation-a potentially damaging side-effect of the body's immune system that underlies a number of chronic diseases.

In research published in Cell Reports, the team describes how fasting raises levels of a chemical in the blood known as arachidonic acid, which inhibits inflammation. The researchers say it may also help explain some of the beneficial effects of drugs such as aspirin.

Inflammation is our body’s natural response to injury or infection, but this process can be triggered by other mechanisms, including by the so-called ‘inflammasome’, which acts like an alarm within our body’s cells, triggering inflammation to help protect our body when it senses damage. But the inflammasome can trigger inflammation in unintentional ways – one of its functions is to destroy unwanted cells, which can result in the release of the cell’s contents into the body, where they trigger inflammation.

Professor Clare Bryant from the Department of Medicine at the University of Cambridge said: “We’re very interested in trying to understand the causes of chronic inflammation in the context of many human diseases, and in particular the role of the inflammasome.

“What's become apparent over recent years is that one inflammasome in particular – the NLRP3 inflammasome – is very important in a number of major diseases such as obesity and atherosclerosis, but also in diseases like Alzheimer's and Parkinson's disease, many of the diseases of older age people, particularly in the Western world.”

Fasting can help reduce inflammation, but the reason why has not been clear. To help answer this question, a team led by Professor Bryant and colleagues at the University of Cambridge and National Institute for Health in the USA studied blood samples from a group of 21 volunteers, who ate a 500kcal meal then fasted for 24 hours before consuming a second 500kcal meal.

“It’s too early to say whether fasting protects against diseases like Alzheimer's and Parkinson's disease as the effects of arachidonic acid are only short-lived, but our work adds to a growing amount of scientific literature that points to the health benefits of calorie restriction. It suggests that regular fasting over a long period could help reduce the chronic inflammation we associate with these conditions. It's certainly an attractive idea.”

Reference: Scientists identify how fasting may protect against inflammation; Cell Report; DOI: 10.1016/j.celrep.2024.113700