A new study has found that temporarily restricting calorie intake could improve the inflammation associated with gum disease, building on previous research which linked fasting with reduced inflammation.
The team at King’s College London divided periodontitis patients into two groups, one following a five-day restrictive diet and the other continuing as normal.
The patients on the fasting diet ate 1,100 calories for two days, then 750 calories for three days, with their diet returning to normal by day seven. This process was repeated three times within six months.
After this period, blood and gingival crevicular fluid were taken from the patients and analysed. The fasting patients were found to have reduced inflammation markers in both samples than those in the control group. This includes both C-reactive protein – a general marker of bodily inflammation – and specific indicators of gum disease.
How does fasting improve gum disease?
Senior author Professor Luigi Nibali said there could be many reasons why fasting is beneficial for periodontitis patients. ‘Fasting reduces oxidative stress in the body, a common cause of inflammation, which can damage cells and DNA.
‘Intake of high calorific foods and refined carbohydrates, for example in cakes and biscuits, can also cause inflammation – so restricting these foods also reduces oxidative stress in the body.
‘It may also be that fasting has beneficial effects on the microbiome – the body’s community of bacteria that help to keep it healthy. However, further research is needed to confirm this relationship.’
Dr Giuseppe Mainas, first author of the study, said it suggests lifestyle modifications could be important alongside proper tooth brushing for patients with gum disease.
He said: ‘Now we have established this relationship, we would like to do a larger study, before potentially incorporating into gum disease treatment in the future. There may be patients where restricting foods can be dangerous, such as those with diabetes, so the advice will need to be targeted to specific patient groups. We are currently investigating how we could implement these benefits in high-risk groups who may not be able to fast.’
Gum disease and wider health
The study is the latest addition to King’s College London’s growing body of research into the relationship between gum disease and wider health.
In November 2025, King’s researchers found an association between root canal treatment and a reduced risk of heart disease and diabetes. Just two months prior, the college released a study which found that following a Mediterranean diet could improve gum health.
Professor Luigi Nibali said: ‘There is emerging evidence about the role that a balanced diet might have in maintaining a periodontal healthy status. Our research shows the potential effect that a nutrient-dense, plant-rich diet could play in improving the nation’s gum health. Nevertheless, more investigation is needed to develop personalised approaches to help people manage their gum health.’
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