Eat & Avoid These Foods to Maximize Brain Health

Lower your risk of cognitive decline for Alzheimer's and other neurodegenerative diseases

Take-Home Message: A proper diet can minimize cognitive decline and the risk of developing neurodegenerative diseases like Alzheimer’s Disease. Focus on consuming anti-inflammatories, antioxidants, monounsaturated fats, polyphenols, and probiotics. Avoid high levels of carbohydrates, sodium, fat, and ultra-processed foods.

By 2050, 5 million more Americans are estimated to be diagnosed with Alzheimer’s Disease. Abiding by researchers’ lifestyle recommendations can drastically reduce your risk of developing a condition like AD.

What we eat has a drastic impact on our health. Diet and brain health are an emerging topic, as scientists begin to recognize patterns between what you put in your body and disease rates. Researchers believe that what you eat can even reduce your risk of brain diseases.

I’ll first provide a summary of these findings for your review, but please read further to gain a deeper understanding of the findings and their underlying mechanisms.

What to Eat

! = Mediterranean Diet, ? = Ketogenic Diet

• (!) Anti-Inflammatories (e.g. Omega 3s): Fish and Nuts - neuroprotection, plasticity, reduce inflammation

• (!) Antioxidants: Fruits, Vegetables, and Whole Grains - neuroprotection, vascular health

• (!) Monounsaturated Fats: Extra Virgin Olive Oil - lower cholesterol, neuroprotection

• (!) Polyphenols: Fruits, Vegetables - antioxidant, anti-inflammatory properties

• (?) Low Carbohydrates: increased cognitive function in the elderly, gut microbiota health,

• Probiotics: Yogurts, Kombucha, and More - alleviate cognitive impairment, reduce Alzheimer’s Disease pathologies (based on mouse model studies)

What to Avoid

• High Sodium Diets: cognitive impairment, tau accumulation

• High Fat Diets: neuroinflammation, cognitive impairment

• Ultra-Processed Foods: neuroinflammation, oxidative stress

Although my blog page aims to identify new studies that focus on the pharmacological aspect of neuroscience research development, I also find many other emerging research areas catch my attention. Specifically, a substantial body of literature demonstrates how lifestyle changes can reduce the risk of disease development and progression.

Last week, I discussed this in the matter of exercise (make sure to check that out if you haven’t). This week, I’ll delve into significant research discoveries related to diet. Changing your diet is a relatively low-cost, low-maintenance method to reduce your risk of ND (neurodegenerative disease) development and progression.

What to Eat:

Mediterranean Diet - Reducing Alzheimer’s Risk & Other Dementias

→Anti-Inflammatories, Antioxidants, Monounsaturated Fats, Polyphenols

Clinical trials show that the Mediterranean diet slows cognitive decline, prevents the reduction of cortical brain region volume, lowers biomarker levels, and more. A recently published meta-analysis, which reviewed 23 studies on this topic, found that adherence to the Mediterranean diet is associated with an 11-30% reduction in the risk of age-related cognitive disorders. This includes an 18% reduction of cognitive impairment, 11% of dementia, and a 30% reduction for Alzheimer’s Disease (AD).

Beyond Alzheimer’s Disease, a study showcased that participants who stuck to a Mediterranean Diet had a lower rate of being diagnosed with Parkinson’s Disease (PD).

Here are the key features of the Mediterranean diet and its benefits:

Anti-inflammatories, like Omega-3 fatty acids, are extremely beneficial for reducing the risk of NDs. Inflammation is a main driver of disease development, especially in nervous tissue.

Antioxidants, including vegetables, fruits, and whole grains, may protect against cardiovascular disease and cognitive decline, as they are rich in potassium, fiber, flavonoids, and carotenoids. Antioxidants also neutralize unstable molecules called free radicals that cause oxidative stress and cellular damage.

Monounsaturated Fats (AKA Extra Virgin Olive Oil) are known to increase “good” cholesterol profiles and decrease “bad” cholesterol profiles. These changes improve vascular health, protecting against microvascular pathologies that contribute to dementia. Further studies have demonstrated olive oil’s protective effects from neurodegeneration and cognitive decline.

Polyphenols, like berries, apples, various vegetables and cocoa, contain resveratrol, a natural compound that offers anti-inflammatory and antioxidant properties. Polyphenols have also been shown to protect against diabetes and cancer.

Combining these nutritional elements maximizes the body’s ability to fight cellular processes correlated with aging, such as mitochondrial dysfunction, oxidative stress, chronic inflammation, and cell death.

Ketogenic Diet - In Moderation

A ketogenic diet is characterized by low-carbohydrate and high-fat consumption. A systematic review covering the ketogenic diet’s impacts on AD (691 participants) suggested that the diet plan can enhance cognitive function in the elderly.

Some small-N (< 100 participants) studies on Parkinson’s Disease showed short-term benefits of a ketogenic diet to alleviate PD symptoms. Larger-scale studies are needed to confirm these findings, so I will not discuss them in detail.

However, the high-fat levels from a ketogenic diet could lead to hyperlipidemia, cardiovascular, and cerebrovascular diseases. So, the ketogenic diet may be optimal in moderation; consider reducing fat and increasing carbohydrate levels in this diet plan.

Other Interesting Neurodegenerative Disease Findings

• Parkinson’s Disease:

  • As previously mentioned, a Mediterranean diet can reduce the rate of PD diagnosis.

  • Greater adherence to a protein-restricted diet resulted in lower levodopa doses and fewer motor symptom fluctuations (read here)

• ALS:

  • A greater intake of Omega-3s resulted in a lower risk of ALS

    • Examples: Fatty fish, walnuts, flax seeds, chia seeds, and more

  • High-calorie fatty acid diets for fast-progressing ALS patients have shown benefits

  • Greater ALS function with higher antioxidant and carotene intake

    • Examples of Carotene: Carrots, sweet potatoes

• Huntington’s Disease: Although there is a clear lack of studies covering diet and HD, check out this review article to learn about HD’s relationship to the vegan, Mediterranean, paleo, carnivore, and ketogenic diets.

What to Avoid Eating

• High-Sodium Diet: Both human and mouse studies have revealed risks associated with consuming high levels of sodium. Each study showed an increased risk of cognitive impairment, and the mouse study even displayed increased tau accumulation, a hallmark biomarker of AD.

• High-Fat Diet: Increasing evidence shows that high-fat diets can induce chronic neuroinflammation, leading to cognitive dysfunction. Mitochondrial damage, neuroinflammation, and insulin resistance form a vicious cycle that reinforces one another. Neuroimaging studies are finding strong correlations between obesity and regional brain atrophy. Fat intake is also linked to hippocampal-dependent learning and memory in both children and adults.

• Ultra-Processed Foods: A systematic review focused on the gut microbiota, which has a strong correlation to the development of NDs, suggests a strong relationship between these foods and dysregulation of the microbiota. This leads to inflammation, oxidative stress, and eventually, cognitive decline.

Final Thoughts

A good reader, researcher, and scientist must have skepticism while forming ideas about these novel findings. Although the previously mentioned studies are properly validated, it is vital to note the biases present. For example, researchers are more likely to get published when producing positive results; there are likely many unpublished studies that do not support these findings. Another consideration is the lack of participant diversity; some diet plans impact different racial and ethnic groups differently.

If you are interested in a deeper understanding or further explanation of any of the above topics, feel free to comment below. I would love to discuss!

Next week I’ll be attending the USC Alzheimer’s Research Day in San Diego. I’ll be reporting on the most fascinating research projects on this blog. Stay tuned!

Sources:

Fekete, M., Varga, P., Ungvari, Z., Fekete, J. T., Buda, A., Szappanos, Á., Lehoczki, A., Mózes, N., Grosso, G., Godos, J., Menyhart, O., Munkácsy, G., Tarantini, S., Yabluchanskiy, A., Ungvari, A., & Győrffy, B. (2025). The role of the Mediterranean diet in reducing the risk of cognitive impairement, dementia, and Alzheimer’s disease: A meta-analysis. GeroScience, 47(3), 3111–3130. https://doi.org/10.1007/s11357-024-01488-3

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