Exercise vs Junk Food: How Running Can Fight Depression Symptoms

Researchers at University College Cork in Ireland identified specific metabolic pathways through which exercise counteracts the negative behavioural effects of consuming a Western-style diet.

The research demonstrated that voluntary running exercise can mitigate depression-like behaviours induced by high-fat, high-sugar diets associated with both circulating hormones and gut-derived metabolites.

"The findings provide crucial insights into how lifestyle interventions might be optimised to support mental health in an era of widespread ultra-processed food consumption," said Professor Yvonne Nolan from the varsity.

In the study, published in the peer-reviewed journal Brain Medicine, the team exposed adult male rats to either standard chow or a rotating cafeteria diet consisting of various high-fat and high-sugar foods for seven and a half weeks, with half of each dietary group having access to running wheels.

The study revealed that voluntary wheel running exerted an antidepressant-like behavioural effect in poor diet quality, suggesting that physical activity may benefit individuals consuming Western-style diets.

Professor Nolan and team found that the diet dramatically altered the gut metabolome, affecting 100 out of 175 measured metabolites in sedentary animals.

"Exercise showed more selective effects, modulating only a subset of these changes. Three metabolites previously linked to mood regulation stood out for their response pattern: anserine, indole-3-carboxylate, and deoxyinosine were all decreased by the cafeteria diet but partially restored by exercise," Nolan said.

Further, the research utilised comprehensive behavioural testing batteries to assess multiple domains of brain function.

While the junk food alone did not significantly impair spatial learning or recognition memory in these adult rats, exercise produced modest improvements in spatial navigation.

The team also examined anxiety-like behaviours, finding subtle anxiolytic effects of exercise independent of dietary composition.

The findings suggest that while exercise can provide mood benefits regardless of diet quality, achieving full neuroplastic benefits may require attention to nutritional status. This has implications for designing interventions that maximise both feasibility and biological impact, the researchers said.

- IANS