How we fill our plates plays a significant role in how our brains function, influencing mood and overall mental well-being.

Diet’s Impact on the Brain

Poor-quality food—high in processed and refined sugars and saturated fats, which make up much of the American diet—can detrimentally affect brain health. Even food packaging can contain harmful substances. For example, bisphenol A, a chemical compound primarily used in the manufacturing of plastics, can introduce toxins linked to various diseases.

Kimberly Snodgrass, a registered dietitian nutritionist and spokesperson for the Academy of Nutrition and Dietetics, told The Epoch Times that these foods can lead to significant brain changes linked to depression and anxiety.

“Poor eating habits reduce gray matter and alter neurotransmitter levels in the brain,” she said.

However, a high-quality diet rich in fiber, polyphenols, and antioxidants, such as the Mediterranean diet, can improve outcomes for anxiety and depression.

Research suggests that better diets are associated with increased gray matter and larger brain volume, particularly in areas such as the frontal and temporal lobes, which manage emotions and process information, and the hippocampus, which plays a role in cognition and processing speed.

Rumination, or fixating on negative thoughts, is a chief predictor of depression. There is a clear link between rumination and decreased gray matter volume and increased glutamate concentrations (a neurotransmitter responsible for memory, mood regulation, and cognition). Although research suggests that diet and rumination are both associated with brain structure and function, rumination does not seem to be associated with diet quality. It’s important to note that diet and rumination may still moderate one another via shared pathways, including mental health and cognitive function.

Potential mechanisms in a high-quality diet may include the regulation of oxidative stress, inflammation, gut microbiota, and the body’s stress response, or hypothalamic-pituitary-adrenal axis.

A 2023 review in Ageing Research Reviews indicated that healthy dietary patterns and nutrients are associated with benefits shown in neuroimaging results, demonstrating a protective effect against brain aging and neurodegeneration. Conversely, unhealthy diets are linked to poorer cognitive performance and reductions in brain volume.

Unhealthy nutrient and diet patterns are also associated with increased beta-amyloid peptide, which accumulates as a characteristic of Alzheimer’s disease.

Prolonged adherence to healthy dietary patterns appears particularly neuroprotective. It helps reduce age-related cognitive decline by lowering inflammation, oxidative stress, and metabolic dysfunction while enhancing vascular function.

Antioxidants, protein, fiber, omega-3 fatty acids, polyunsaturated fatty acids, and B vitamins are specific nutrients associated with preserving brain integrity through decreased inflammation.

Cardiovascular diseases and high blood pressure are particularly damaging to brain health and serve as significant risk factors for the development of dementia and mild cognitive impairment.

Dietary patterns low in sodium and rich in magnesium, omega-3 fatty acids, fruits, vegetables, whole grains, and fish help regulate cardiovascular function and maintain healthy blood pressure levels.

In contrast, unhealthy dietary patterns are linked to insulin resistance, which contributes to arterial stiffness, endothelial dysfunction, and increased inflammation—factors that heighten the risk of dementia and cognitive decline.

A meta-analysis published in Clinical Nutrition highlighted the critical role of inflammation in the pathophysiology of mental health disorders, including depression. This comprehensive study, which included over 100,000 participants, established a clear link between pro-inflammatory diets and an increased risk of depression. Consequently, adopting an anti-inflammatory diet may be an effective preventive measure and intervention to alleviate depressive symptoms and reduce associated risks.

Additionally, a 2023 meta-analysis revealed a strong connection between the consumption of ultra-processed foods and a heightened risk of depression.

What to Eat for Brain Health

According to Dr. Sulagna Misra, it’s best to avoid inflammatory foods, such as excessive saturated fats, refined sugars, store-bought sodas and sugary juices, alcohol, and any foods that trigger intolerances or allergies, as these can worsen both physical and mental health symptoms.

“Depriving or overly restricting yourself of joy—unless, of course, it’s really harmful or toxic—can make certain diets unsustainable in the long run,” she added.

To optimize brain health, stick to fresh, perishable foods. Focus on organic, non-GMO fresh produce, unsaturated whole fats, and minimally processed foods. Choose lean meats and fish (depending on your dietary preferences), along with colorful fruits and vegetables that are high in fiber and rich in antioxidants.

“Prioritize ‘farm-to-table’ options whenever possible, and aim for produce free from pesticides,” Misra said.

Snodgrass advised avoiding nutrient-poor foods such as alcohol and simple sugars to support brain and mental health.

“While you don’t need to eliminate these completely, it’s essential to limit them,” she said. “Your brain will thank you for reducing processed foods that are high in saturated fats, trans fats, added salt, and sugar, as the goal is to lower inflammation and oxidative stress.”

Instead, she recommended focusing on nutrient-dense foods such as leafy greens, berries, nuts, fatty fish (opting for low-mercury varieties such as salmon, tilapia, sardines, and pollock), dark chocolate with at least 70 percent cocoa, and unsweetened tea.

When to Expect Results

“Changing your diet can significantly impact your health,” Snodgrass said. “While you shouldn’t expect to see results overnight, consistency will lead to noticeable changes over time. Remember, the better you nourish and care for your body, the more it will reciprocate.”

When making initial dietary changes, it’s common for people to feel unwell, especially if they’re making sudden shifts, Misra said.

“I personally advocate for making small, incremental changes,” she told The Epoch Times. “Practice leads to progress, and we want these adjustments to be sustainable, becoming a lifelong lifestyle.”

She added that improvements may begin to manifest after the first or second week, and will typically become more apparent by the third week.