Obesity and depression ‘linked due to dietary fats entering brain’

One in four UK adults is obese

Obesity has been linked to depression by scientists for years, but the reasons have always been somewhat unclear until now.

New research led by the University of Glasgow has found that the connection might be down to dietary fats entering the brain through the bloodstream, which can then accumulate and affect neurological signals related to depression.

The study, published in the journal Translational Psychiatry on Friday, was conducted on mice that were fed fat-dense diets.

The researchers said that after close observation, they noted the saturated fatty acids enter into the brains of the mice in their hypothalamus region, which is related to the metabolic system and is known to be linked to depression.

The fatty acids then affected key signalling pathways that are known to be responsible for the development of the mental illness.

Professor George Baillie, lead author of the study at the University of Glasgow, commented: "This is the first time anyone has observed the direct effects a high-fat diet can have on the signalling areas of the brain related to depression.

"This research may begin to explain how and why obesity is linked with depression and how we can potentially better treat patients with these conditions."

Baillie explained that many of us perceive fat-dense foods as comforting and mood-boosting, but that as evidenced in the study, they may have the reverse effect on our psychological wellbeing in the long-term.

"Of course, if you are feeling low, then to make yourself feel better you might treat yourself to more fatty foods, which then would consolidate negative feelings,” he added.

"We all know that a reduction in fatty food intake can lead to many health benefits, but our research suggests that it also promotes a happier disposition.

"Further to that, understanding the types of fats, such as palmitic acid, which are likely to enter the brain and affect key regions and signalling will give people more information about how their diet can potentially affect their mental health."

Obesity rates are under constant scrutiny in the UK given its increasing prevalence, with recent research finding that the numbers might be higher than previously thought given that a large proportion of people in the UK do not have a record of their Body Mass Index (BMI).

The study, which was presented at the European Congress on Obesity (ECO) in Glasgow in April, included data from 77,591 adults from 12 general practices in Scotland.

Experts looked for any recording of BMI and found that one in four patients did not have a record.

The NHS states that one in four UK adults is obese.