Table 2.

Main foods that can be found in the Mediterranean diet and their mechanisms in each disease.

Components of Mediterranean Diet	Effects on Cognitive Performance in Parkinson’s Disease	Effects on Cognitive Performance in Alzheimer’s Disease	Reference
Legumes	Antioxidants can help neutralize free radicals produced in the brain, consequently also reducing inflammation.	They can reduce oxidative stress and inflammation in the brain.	[43]
Red wine	It contains antioxidant and anti-inflammatory properties. Its constituent resveratrol has been associated with the reduction of oxidative stress, the inhibition of inflammation, and the promotion of neuroplasticity. It appears to affect beta-amyloid plaques.	Some compounds found in red wine, such as resveratrol and quercetin, may act as inhibitors of the enzyme monoamine oxidase B (MAO-B), which has been implicated in the degeneration of brain cells in Parkinson’s disease.	[44,45]
Vegetables	They can help reduce the buildup of beta-amyloid plaques in the brain. Plants are an important source of folic acid, which can help reduce levels of homocysteine, an amino acid associated with Alzheimer’s disease. They contain glucosinolate sulfates, which can promote the production of enzymes that eliminate toxic substances from the brain.	They contain vitamin C, vitamin E, and beta-carotene, which can protect brain cells from oxidative stress—one of the factors that can contribute to the degeneration of dopaminergic cells in the brain, responsible for the symptoms of Parkinson’s disease.	[46,47]
Olive Oil	It is rich in oleic acid, a monounsaturated fatty acid that may reduce the risk of cardiovascular and inflammatory diseases. It is rich in polyphenols, antioxidant compounds that can protect brain cells from oxidative damage. It appears to be able to reduce the formation of amyloid plaques in the brain.	It contains antioxidant compounds that may protect brain cells from oxidative stress and inflammation. Hidrox, a compound extracted from olives, can significantly ease Parkinson’s motor symptoms, reduce alpha synuclein buildup, and slow neurodegeneration in animal models of the disease.	[48,49]
Fruits	They contain antioxidants which help protect brain cells from oxidative damage. They also contain many anti-inflammatory compounds, including polyphenols. Chronic inflammation has been implicated in disease pathogenesis, and reducing inflammation may have protective effects on the brain. Certain compounds found in fruit, such as flavonoids, may help regulate the central nervous system and improve cognitive and motor function.	They can reduce the risk of amyloid-beta accumulation: Some studies have suggested that compounds found in fruit, such as polyphenols, may reduce the accumulation of amyloid-beta proteins in the brain.	[50,51]
Fish	It is rich in omega-3 fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which have been shown to have beneficial effects on brain health and disease prevention. Omega-3s can reduce chronic inflammation in the brain, improve cognitive function, including memory, protect brain cells from damage, and reduce the accumulation of abnormal proteins in the brain, such as tau and amyloid-beta proteins.	It contains vitamin D, which can influence the function of dopamine receptors in the brain and can have protective effects on brain cells. Omega-3 fatty acids can reduce inflammation in the brain and protect brain cells from oxidative damage.	[32,52,53,54]