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.

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 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 studied blood samples from a group of 21 volunteers, who ate a 500 kcal meal then fasted for 24 hours before consuming a second 500 kcal meal.

The team found that restricting calorie intake increased levels of a lipid known as arachidonic acid.

Lipids are molecules that play important roles in our bodies, such as storing energy and transmitting information between cells.

As soon as individuals ate a meal again, levels of arachidonic acid dropped.

When the researchers studied arachidonic acid’s effect in immune cells cultured in the lab, they found that it turns down the activity of the NLRP3 inflammasome.

This surprised the team as arachidonic acid was previously thought to be linked with increased levels of inflammation, not decreased.

Professor Bryant, a Fellow of Queens’ College, Cambridge, added: “This provides a potential explanation for how changing our diet — in particular by fasting — protects us from inflammation, especially the damaging form that underpins many diseases related to a Western high calorie diet.

“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.”


Milton Pereira, Jonathan Liang, Joy Edwards-Hicks, Allison M. Meadows, Christine Hinz, Sonia Liggi, Matthias Hepprich, Jonathan Mudry, Kim Han, Julian L. Griffin, Iain Fraser, Michael N. Sack, Christoph Hess, Clare E. Bryant. Arachidonic acid inhibition of the NLRP3 inflammasome is a mechanism to explain the anti-inflammatory effects of fasting. Cell Reports, 2024; 43 (2): 113700 DOI: 10.1016/j.celrep.2024.113700

Materials provided by University of Cambridge. The original text of this story is licensed under Creative Commons CC BY-SA 4.0. Note: Content may be edited for style and length.

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