Balanced diet more beneficial for brain health, study finds

People can develop preferences for certain foods, which can impact overall dietary patterns over time. Recently, growing evidence has highlighted the profound impact of dietary patterns on health, including chronic medical diseases, such as cardiovascular disease, type 2 diabetes, metabolic syndrome and cancer, as well as mental health and/or cognitive impairments such as major depression disorders and anxiety.

Previous research has confirmed the significant connection between diet and mental health, particularly cognitive functions. For instance, a systematic review found that a higher intake of simple carbohydrates is linked to lower cognitive performance. Saturated fatty acids are associated with impaired memory and learning and protein intake may improve executive function and working memory.

In the study, researchers analyzed UK Biobank data on food preferences across categories like dairy, fruits, alcohol, and vegetables. They studied how these preferences related to various brain-related outcomes, including mental health indicators like anxiety and depression symptoms, cognitive function, blood biochemistry, brain structure via MRI, and genetic risk scores for mental disorders.

The researchers found that the balanced dietary group had the most positive outcomes, with lower scores for mental health issues and higher well-being. They also had better reaction times and cognitive performance compared to other groups. Additionally, they exhibited higher levels of gray matter in certain brain areas. However, the vegetarian group had a higher genetic risk for various mental disorders, while the high-protein, low-fiber group had a higher genetic risk for ischemic stroke.

“This study found that a ‘healthier’ diet with balanced preferences in various food categories — fruit, vegetables, starches, protein, and snack foods, are associated with better mental health status, higher levels of cognitive functions and fewer risks of mental disorders,” said Molly Rapozo, RDN, registered dietician nutritionist, and senior nutrition and health educator at Pacific Neuroscience Institute in Santa Monica, CA

Reference: Ruohan Zhang, Bei Zhang, Chun Shen, Barbara J. Sahakian, Zeyu Li, Wei Zhang, Yujie Zhao, Yuzhu Li, Jianfeng Feng & Wei Cheng; Associations of dietary patterns with brain health from behavioral, neuroimaging, biochemical and genetic analyses; Journal: Nature Mental Health; https://doi.org/10.1038/s44220-024-00226-0