Eating a diet high in processed food increases the risk of depression, research suggests.

What is more, people who ate plenty of vegetables, fruit and fish actually had a lower risk of depression, the University College London team found.

Data on diet among 3,500 middle-aged civil servants was compared with depression five years later, the British Journal of Psychiatry reported.

The team said the study was the first to look at the UK diet and depression.

They split the participants into two types of diet – those who ate a diet largely based on whole foods, which includes lots of fruit, vegetables and fish, and those who ate a mainly processed food diet, such as sweetened desserts, fried food, processed meat, refined grains and high-fat dairy products.

After accounting for factors such as gender, age, education, physical activity, smoking habits and chronic diseases, they found a significant difference in future depression risk with the different diets.

Those who ate the most whole foods had a 26% lower risk of future depression than those who at the least whole foods.

By contrast people with a diet high in processed food had a 58% higher risk of depression than those who ate very few processed foods.