Research scientists from Cambridge University are helping to uncover the ways in which fasting may reduce inflammation. Inflammation in the body is thought to be the mechanism by which many chronic diseases develop.
New research published in the scientific journal Cell Reports tells us that fasting increases the levels of the natural lipid molecule arachidonic acid, which may act as an antiinflammatory substance in a similar manner to the way in which aspirin works.
“There could be a yin and yang effect going on here, whereby too much …. is increasing your inflammasome activity and less is decreasing it,” said researcher Professor Clare Bryant from the Department of Medicine at the U. of Cambridge.
“Arachidonic acid could be one way in which this is happening.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.
Some of the mechanisms that researchers wish to discover may also explain how aspirin works, which has never been completely understood.
Generally speaking arachidonic acid is rapidly broken down by the body. Aspirin stops this process, leading to an increase in the body’s arachidonic acid, which as a result, reduces inflammation by reducing inflammasome activity.
“Inflammasomes” act like an alarm within our body’s cells, triggering inflammation to help protect our body when it senses damage. Although inflammation is a natural response to injury or infection,this process can be triggered by other mechanisms, and then inflammasomes may trigger inflammation in deleterious ways .
Professor Bryant further explains,”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.”
Studies have shown over many years that the typical American (and increasingly the world’s) diet — increases the risk of obesity and a number of related conditions such as type 2 diabetes, heart disease, and cancer which are promoted by chronic inflammation in the body. Studies have shown that a high fat diet increases levels of inflammasome activity.
It has been shown that fasting helps reduce inflammation, but the mechanism for this has not been clearly understood.
The scientific explanation is outlined in the Journal cell Reports
It states that NLRP3 inflammasome activity, elevated interleukin (IL)-1β levels and systemic inflammation underlie chronic metabolic inflammatory syndromes. Research now shows that levels of plasma IL-1β are lower in fasting subjects compared to those who have eaten. At the same time, fasting elevates the lipid arachidonic acid (AA) which becomes suppressed upon refeeding. Taken together this studies data show that AA is an important physiological regulator of the NLRP3 inflammasome. Thus, fasting reduces systemic inflammation.
Their work attempts to show how the Non-steroidal anti-inflammatory medications-“COX inhibitors” have broad anti-inflammatory effects- through AA inhibition of NLRP3 activity. A number of papers have investigated how COX-derived eicosanoids might interface with inflammasomes.
The medications called nonsteroidal anti-inflammatories are used in both prescription and over the counter medications. They are “COX inhibitors” decreasing inflammasome mediated IL-1β and IL-18 production. They conclude that “there is a complex lipid regulatory network that may have a concentration dependency” getting back to the notion that arachidonic acid is needed at the right level, and too much can be deleterious. It would seem that according to the findings related to fasting, that the body produces the “right level” when experiencing fasting which is then ant-inflammatory.
A team of researchers at the University of Cambridge and our National Institute for Health produced a study using as subjects 21 volunteers, who ate a 500 calorie meal then fasted for 24 hours before consuming another 500 calorie meal.
They found that restricting calorie intake over the 24 hour fast increased levels of arachidonic acid which lead to less inflammation. When the study subjects ate the next meal, levels of arachidonic acid dropped again.
What the researchers concluded was that arachidonic acid’s effect was to turn down the activity of the NLRP3 inflammasome. At first this was an unexpected finding, as arachidonic acid had been thought to increase inflammation. The best explanation at this point in time is that if overproduced arachidonic acid is indeed inflammatory but a more controlled naturally produced amount of it, as occurs with fasting, will be anti-inflammatory.
The study authors conclude that their data is evidence that Arachidonic acid is an important physiological inhibitor of the NLRP3 inflammasome. Elevation of AA in plasma from fasting study subjects shows the mechanism which explains the drop in IL-1β production and one way in which fasting seems to be anti-inflammatory. The study authors write, “our data also suggest a mechanism by which NSAIDs are anti-inflammatory and identify that AA may have a previously unappreciated role as a primary signaling lipid.”
Professor Bryant, further says, “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.”
The term intermittent fasting is used to explain a dietary pattern that has become increasingly popular. Briefly, it is the dietary method of eating our daily food in a time restricted window, fasting for between fourteen and 16 hours per day. Many testimonials have supported a number of potential health benefits including weight loss, control of blood pressure and blood sugar and the prevention of diabetes and cardiovascular disease. John’s Hopkins School of Medicine has published a guide to this health promoting practice…
The research published in the Journal Cell Reports was funded by the Medical Research Council and the US National Heart, Lung, and Blood Institute.