Scientists have discovered how intermittent fasting may protect the brain from stress

In the study, animals that had been subjected to prolonged stress but were fed on an intermittent fasting regimen showed fewer signs of depression-like behaviour. They also showed less damage to the myelin – the protective sheath around nerve fibres that helps signals travel more quickly between brain cells.

Important: this is not proof that intermittent fasting treats depression in humans. The study was conducted on adult male mice, which means the findings cannot be directly applied to humans.

Details

Chronic stress has long been linked to an increased risk of depression, anxiety disorders and other mental health problems. One possible consequence of such stress is damage to myelin. Put simply, myelin acts like insulation on wires: it helps nerve signals travel faster and more accurately.

The study authors investigated whether intermittent fasting could mitigate these changes. To do this, adult male mice were subjected to chronic stress for 14 days. Some of the mice were allowed to eat freely, whilst others were only given food during specific time windows – following an intermittent fasting regimen.

The researchers then assessed the mice’s behaviour. In the mice that ate without restriction, stress caused more pronounced depression-like symptoms: they responded less well to a pleasant sweet solution and remained motionless for longer during a stress test.

In mice on an intermittent fasting regimen, these changes were less pronounced. This may suggest that such a feeding regime helped the brain cope better with stress. However, in scientific terms, the focus is specifically on depression-like behaviour in animals, rather than on human depression as a diagnosis.

What was happening in the brain

The researchers also examined myelin in different parts of the brain. Chronic stress damaged it in areas associated with emotions, memory and decision-making: the corpus callosum, the medial prefrontal cortex and the hippocampus.

In mice that were on intermittent fasting, these changes were less pronounced. In other words, the feeding regime was linked not only to behaviour but also to observable changes in brain tissue.

The researchers also studied gut bacteria separately. It turned out that intermittent fasting altered the composition of the microbiota in stressed mice. Certain types of bacteria were associated with improved myelin health and more favourable behaviour, whilst others had the opposite effect.

Why the gut is important here

The connection between the gut and the brain is currently being actively studied. Gut bacteria can influence inflammation, metabolism, immune responses and substances involved in the functioning of the nervous system.

In this study, the authors suggest that intermittent fasting may have protected the brain not directly, but via the so-called ‘gut-brain axis’. In other words, the change in eating pattern may have altered the microbiota, and this in turn affected inflammation, myelin and behaviour.

This is currently a hypothesis based on animal experiments. Clinical trials are needed to understand whether this mechanism works in humans.

Why this is important

This topic is important because chronic stress is one of the most common problems of modern life. If scientists can identify which habits help the brain cope better with prolonged stress, this could lead to new approaches to the prevention and support of mental health.

However, caution is essential here. Intermittent fasting is not suitable for everyone. It can be risky for people with eating disorders, diabetes, pregnancy, certain chronic conditions, and for those taking specific medications.

Therefore, this research should not be interpreted as advice to ‘start fasting to cope with stress’. The correct conclusion is different: in mice, intermittent fasting mitigated the effects of chronic stress on the brain and behaviour, and this mechanism now warrants further investigation.

Background

Intermittent fasting is a regimen in which a person or animal does not eat continuously, but only during specific periods. For example, part of the day is set aside for eating, whilst the rest of the time is spent fasting.

Previously, this approach was studied mainly in relation to metabolism, weight, inflammation and metabolic health. However, the impact of intermittent fasting on mental health and the brain’s resilience to stress remains less clear.

A new study adds a possible mechanism to this discussion: eating on a schedule may alter gut bacteria and, through them, influence the condition of myelin and the brain’s stress responses. However, this is still at an early stage and does not yet constitute a definitive medical recommendation.

Source

Study: Xin Ding et al., “Intermittent fasting protects against stress-induced depression and demyelination via the gut microbiota–brain axis”, *Translational Psychiatry*, 2026.