Eating more fibre may do more than improve digestion. New research suggests that dietary fibre can also support brain health and protect cognitive function.
Foods rich in fibre include whole grains, fruits, pulses, nuts and seeds. These foods improve overall health and may help slow cognitive decline.
Scientists say fibre strengthens the gut microbiome and supports the gut-brain axis, the communication system between the digestive system and the brain.
Most People Do Not Eat Enough Fibre
Despite its benefits, many people consume far less fibre than recommended.
Studies show that about 97% of men and 90% of women in the United States do not meet daily fibre guidelines. Similar trends appear in the United Kingdom and other countries.
According to Karen Scott from the Rowett Institute at the University of Aberdeen, increasing fibre intake is one of the most effective dietary changes for improving brain health.
Low fibre intake also increases the risk of chronic illness.
How Fibre Works in the Body
Fibre is a carbohydrate that the body cannot fully digest. Instead, it moves through the digestive system largely unchanged.
This process provides several benefits:
It increases stool size and improves digestion
It helps people feel full for longer
It slows the rise of blood sugar levels
Research also shows that people who eat more whole grains tend to have lower body weight and less abdominal fat.
According to John Cummings from the University of Dundee, fibre should be considered an essential nutrient for long-term health.
Fibre and Longer Lifespans
A major review study found that people who consume the most fibre have 15–30% lower mortality risk compared with those who eat the least.
Researchers estimate that consuming about 30 grams of fibre daily can reduce the risk of several diseases, including:
Coronary heart disease
Stroke
Type 2 diabetes
Colon cancer
The greatest health benefits appear when people consume 25–29 grams of fibre per day.
Adding fibre to each meal helps reach this target. For example, a baked potato with beans followed by an apple provides about 15 grams of fibre. Nuts and seeds also add significant fibre to snacks.
Fibre Fuels the Gut Microbiome
The key to fibre’s benefits lies in its interaction with the gut microbiome.
When gut bacteria digest fibre, they produce compounds called short-chain fatty acids. These include acetate, propionate and butyrate.
These compounds provide energy for cells and support many body systems.
Among them, butyrate plays a particularly important role in brain health.
How Fibre Protects the Brain
Researchers believe fibre improves cognition by strengthening the gut-brain connection.
Butyrate helps maintain the protective lining of the gut. This barrier prevents harmful substances from entering the bloodstream and affecting the brain.
According to Scott, higher fibre intake increases butyrate production. This may help preserve memory and cognitive ability.
Research Links Fibre With Lower Dementia Risk
Several studies now link higher fibre intake with improved brain health.
A 2022 study of more than 3,700 adults found that individuals who consumed the most fibre had a lower risk of developing dementia.
Another study involving adults over 60 also showed that higher fibre diets were associated with better cognitive performance.
New Research Shows Possible Causal Effects
Recent research suggests that fibre may directly influence cognition.
A clinical study led by Mary Ni Lochlainn at King’s College London examined twins who took daily prebiotic fibre supplements.
After three months, participants taking fibre performed better on cognitive tests than those who received a placebo.
Researchers also observed changes in the participants’ gut microbiome. The fibre supplements increased levels of beneficial bacteria such as Bifidobacterium.
Fibre May Support Mental Health Too
Emerging research shows that butyrate-producing bacteria may also support emotional wellbeing.
Higher levels of these bacteria have been linked to:
Reduced depression
Better sleep quality
Improved mental health
Studies also show that people with Alzheimer’s disease often have lower levels of butyrate-producing bacteria in their gut.
These findings strengthen the growing evidence connecting gut health and brain health.
A Simple Dietary Change With Big Benefits
Scientists say the gut microbiome remains an underexplored area of health research. However, diet clearly plays a major role.
Increasing fibre intake through whole foods can improve gut bacteria, support brain health and reduce disease risk.
Adding more fruits, vegetables, whole grains, nuts and seeds to daily meals may therefore help protect both the body and the brain over time.
