Cutting back on carbohydrates could help stave off depression, scientists suggested today.
The high fat low carb Keto diet has long been touted by celebs promising that it helps you effortlessly slim down simply by cutting out foods like potatoes, pasta and bread.
Since the 1920s, the plan has also been used in mainstream medicine to help treat a major neurological condition — drug-resistant epilepsy.
But Canadian researchers, who tracked the health records of over 40,000 adults, have now discovered the Keto diet could ‘significantly’ lower depressive symptoms.
Scientists could not say exactly why this was the case.
But they suggested that the diet may offers an alternative source of energy for brain cells — which is where it may play a role in treating mental illness.
A keto diet aims, by almost eliminating energy dense carbohydrates, for people to achieve a state called ketosis.
This means no bread, pasta, rice, and no starchy veg such as corn, beans and squash and almost no fruit.
A keto diet aims, by almost eliminating energy dense carbohydrates, for people to achieve a state called ketosis
Without carbohydrates, the body starts to burn stored fat for energy instead, helping people lose weight.
In the study, the researchers from the University of Toronto, assessed the findings of 50 studies involving 41,718 adults across 15 countries.
They were all published between 1965 and 2025 and investigated the link between keto diets and depression and anxiety symptoms.
The scientists found a mean difference of -0.48 overall, meaning there was a ‘moderate’ difference in the reduction of symptoms when a keto diet was implemented compared to control diets.
Ten studies ‘showed a significant association’ between the keto diet and depressive symptoms, with ‘stronger associations’ found in studies using ketone monitoring, they said.
Writing in the journal JAMA Psychiatry, they added that ‘greater improvements in depressive symptoms’ were also observed in ‘very low carbohydrate interventions’ in non-obese participants.
‘These results suggest that keto diets may benefit depression across diverse populations, including major depressive disorder’ they said.
Hypothesising why the keto diet may help, they suggested this was because depression has been linked to a problem with the mitochondria, the ‘batteries’ in all our cells.
Jennifer Aniston has been a fan of cutting out carbs in the past though has since said she does eat them in moderation. Pictured in 2024
A number of celebrities such as Gwyneth Paltrow have spoken about being on the low-carb diet in the past
In some people, the mitochondria can’t handle glucose properly. This is the body’s main fuel source, so the cells don’t work efficiently.
In the brain this can affect the communication between cells, in turn affecting brain function and mental health, the theory goes.
With the keto diet the body uses an alternative source of fuel, ketones — which the liver produces when it breaks down fats, a process called ketosis —, that may effectively stabilise brain function.
But the researchers also acknowledged that their research had ‘important limitations’, including the fact that the studies they analysed ‘varied in design quality, sample size, and intervention length’.
Future work should ‘prioritise’ large studies with ‘standardized keto diet protocols and rigorous ketone monitoring’, they noted.
A keto diet often consists of 75 per cent fat, 20 per cent protein and only 5 per cent carbohydrates.
By contrast, the NHS’s healthy balanced diet advice advocates for 30 per cent fat, 15 per cent protein and 55 per cent carbohydrates.
The typical person on a keto diet is advised to only eat between 20g to 50g of carbohydrates per day.
With a slice of wholemeal bread containing 14g of carbohydrate and a banana 20g, this means people on a keto diet need careful plan their meals.
Despite multiple studies pointing to the potential dangers of a keto diet, including high cholesterol levels and fatty liver disease, it has become increasingly popular.
A number of celebrities such as Gwyneth Paltrow, Jennifer Aniston, Halle Berry and Kourtney Kardashian have spoken about being on the low-carb diet in the past.
Evidence has also suggested other diets, including the Mediterranean diet, and in particular, a diet rich in fish — specifically, fish oil, which has anti-inflammatory effects — in helping treat depression.
In one landmark trial in 2017 at Deakin University in Australia, a third of patients with moderate to severe depression put on a modified Mediterranean diet were able to come off their medication after just 12 weeks.