Fasting is something I advocate – well, widening the time left between meals. So, the last meal of the day would be 7pm and the first meal of the next day would be 1pm.
We’re discovering this narrowing of the eating window has many benefits, and now Cambridge scientists have added a new one – it can reduce inflammation – a potentially damaging side effect of the body’s immune system that underlies a number of chronic diseases.
Wonder of wonders, fasting raises levels of a chemical in the blood known as arachidonic acid, a lipid (a fat) which inhibits inflammation. We know our high-calorie Western diet is linked to obesity, type 2 diabetes and heart disease, all involving chronic inflammation in the body.
Inflammation is our body’s innate response to injury or infection, but it can also be set off by the so-called inflammasome, which acts like an alarm in our body’s cells, and triggers inflammation to help protect our body when it senses damage.
But the inflammasome can trigger inflammation in unwanted ways – it can destroy redundant cells and so release the cell’s contents into the body where they trigger inflammation.
Professor Clare Bryant of Cambridge University says: “What’s become apparent over recent years is that one inflammasome in particular – the NLRP3 – is important in a number of major diseases such as obesity and atherosclerosis, but also in diseases like Alzheimer’s and Parkinson’s which affect older people, particularly in the Western world.”
The way fasting helps reduce inflammations was proven in a study by Prof Bryant’s Cambridge team, collaborating with colleagues at the National Institutes of Health in the US. They studied blood samples from 21 volunteers who ate a 500-calorie meal then fasted for 24 hours before consuming a second 500-calorie meal. The team found that restricting calorie intake increased levels of arachidonic acid. As soon as the individuals ate a meal again, levels of this acid dropped.
Lab studies of arachidonic acid reveal it turns down the activity of the NLRP3 inflammasome. Prof Bryant believes this explains why fasting protects us from inflammation and diseases related to a Western diet. Fasting long term could lower chronic inflammation and thereby prevent such diseases.
“There could be a yin and yang effect going on, whereby too much of the wrong thing is increasing inflammasome activity and too little is decreasing it,” adds Prof Bryant. "Arachidonic acid could be one way in which this is happening.” Aspirin and NSAIDs increase levels of arachidonic acid too, which in turn lower inflammasome activity and hence inflammation.