A high-fat, low-carbohydrate diet has been found by Edinburgh researchers to improve the daily mental health and energy levels of people living with bipolar disorder.

Participants who followed a ketogenic diet, which is high in fats and very low in carbohydrates, for six to eight weeks reported improvements in their mood, energy, impulsivity management and anxiety levels.

Study lead and University of Edinburgh Baszucki Research Fellow in Metabolic Psychiatry, Centre for Clinical Brain Sciences, Dr Iain Campbell, said:

“These results add to a small but growing body of evidence suggesting that a ketogenic diet may be a safe and effective intervention for bipolar disorder, alongside existing medications.

“There is an urgent need for larger replication studies and carefully designed randomised clinical trials to build on these findings.

“Poor metabolic health is a significant problem for people with bipolar disorder, so the study of metabolic treatment approaches is very much welcomed by the patient community.”

Reduced carbohydrate intake leads to the body processing fat for fuel, creating chemicals called ketones.

These have been previously linked to neurological and wider health benefits for certain conditions, with a keto diet being used in the treatment of some forms of epilepsy for more than a century.

The benefits of a ketogenic diet are now being studied across a range of conditions.

The Edinburgh researchers say these findings suggest that a keto diet may help mitigate common health risks associated with bipolar disorder, including diabetes and heart disease.

Almost all participants saw improvements in BMI and blood pressure, with 19 losing an average of 9lbs over six-eight weeks.

One third of participants have continued their diet voluntarily following the study.

Brain imaging also revealed that the keto diet can lead to reductions in two key chemical messengers in the brain that are associated with bipolar.

The researchers explain that this presents a potential mechanism behind the diet’s effectiveness for patients, which they hope to probe further in future studies.

Professor Danny Smith, Chair of Psychiatry and Head of Division of Psychiatry at the Centre for Clinical Brain Sciences, said:

“The idea that a severe mental illness such as bipolar disorder may respond to a metabolic treatment such as the keto diet is challenging and exciting.

“We are looking forward to carefully exploring links between metabolism and mental illness over the next few years, as part of the work within the new UKRI Hub for Metabolic Psychiatry in Edinburgh.”

Read more: Health leaders push for action on diet and exercise; Regulation key to reducing obesity; Scheme for GPs to help lost patients extended; Breastfeeding in Glasgow: A collective responsibility; Children's health at risk from food insecurity; ADHD linked to childhood tantrums; Study shows diet can hold diabetes at bay for years