Relationship Between Food and Brain Aging

These vibrant foods are helpful for the brain aging process as they contain a pigment called carotenoid. Carotenoids can prevent brain deterioration by serving as a neuroprotective agent against inflammation and having antioxidant properties. Such effects are helpful at fighting off neurotoxins associated with neurodegeneration. 

Berries contain flavonoids, which are antioxidants that directly impact the brain’s memory centers, including the hippocampus, cerebral cortex, cerebellum, and striatum; these are the areas where most brain aging occurs. Particularly, in the hippocampus, flavonoids are essential for slowing brain aging by increasing the production of brain-derived neurotrophic factor (BDNF). This is important as BDNF helps to regulate neuronal growth and survival. 

Fish contain omega-3, which is a polyunsaturated fatty acid (PUFA). Specifically, the types of omega-3 found in fish are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The body cannot produce EPA and DHA on its own, meaning we can only obtain them through consuming omega-3-rich foods, such as tuna and salmon. DHAs are particularly important for brain health as they increase neuronal production, which is crucial for improving cognitive function and memory deficits. 

Like fish, these foods also contain omega-3 and are suitable for vegans or vegetarians. The type of omega-3 found in these foods is alpha-linolenic acid (ALA), which is another compound the body cannot produce on its own. Aside from their omega-3 properties, seeds, nuts, and legumes contain other beneficial nutrients, including vitamin E, B vitamins, choline, magnesium, and zinc. These nutrients are widely believed to reduce cognitive decline symptoms through their antioxidant and anti-inflammatory properties.

Whole grains contain large amounts of B vitamins and fiber, which can promote healthy brain aging. Not only will these foods help us feel full, which can lessen the consumption of unhealthy fats, refined sugars, and highly processed foods, but they can also reduce neuroinflammation. A type of B vitamin known to induce such positive effects is vitamin B_6, a water-soluble micronutrient. If individuals do not consume enough vitamin B₆ nutrient-dense foods, this can lead to elevated levels of homocysteine, an amino acid found to be strongly correlated with dementia when present at abnormally high levels. 

Alcohol consumption is linked to abnormally rapid aging via brain atrophy (i.e., reduction in brain size and volume) and damage to the brain’s prefrontal cortex, cingulate cortex, insula, striatum, and cerebellum corpus callosum. These regions are responsible for executive functioning, emotional regulation, movement, and communication between the brain’s hemispheres. When their functioning is impaired, we can experience difficulties with thinking, social and emotional processing, decision-making, judgment, and memory, among others. To test this relationship between alcohol and brain aging, researchers analyzed the UK Biobank, a data system that contains the genetic and medical information of British adults. There, they found that going from zero cups of alcohol per day to one was equal to approximately half a year of aging. To augment that statistic, zero cups to four was equivalent to 10+ years of cognitive aging. 

Excessive sugar consumption can be detrimental for the body, as it can make us more insulin resistant and prone to developing other related conditions, such as diabetes. Having diabetes, especially type 2, is connected with negative brain health outcomes and accelerated brain aging, especially if it is mismanaged. Similar to alcohol consumption, foods high in sugar can cause brain atrophy (i.e., brain shrinkage) and lead to small-vessel disease. Small-vessel disease is dangerous as it limits the amount of blood flow to the brain and can cause vascular dementia in severe cases. Furthermore, sugary foods may have artificial trans fats, especially if they contain hydrogenated vegetable oils. When consumed, trans fats negatively impact memory and word recall recognition and increase inflammation, insulin, and cholesterol levels in the brain. 

Refined carbohydrates, such as white flour, are high in glycemic index (GI), meaning the body quickly absorbs them and increases blood sugar levels. When eating these foods more consistently, refined carbohydrates can increase glycemic load (GL), which refers to how many serving sizes are needed to spike blood glucose levels. Having elevated levels of GI and GL is associated with accelerated brain aging, as they both negatively impact the hippocampus and prefrontal cortex, two areas associated with memory and decision-making abilities. Refined carbohydrates also affect the gut-brain axis (i.e., gut and brain communication), which can heighten neuroinflammation and negatively impact our thinking patterns. For that reason, it is recommended that we replace refined carbohydrates with whole grains to receive neuroprotective benefits. 

Red meats are high sources of saturated fats and are linked to conditions (e.g., type 2 diabetes and heart disease) that promote neurodegenerative brain aging, memory deficits, learning difficulties, and spatial awareness problems. In one study, researchers found that when participants replaced processed red meat with nuts and legumes, they reported a 19% lower risk of dementia and 1.37 fewer years of cognitive aging compared to those who did not make this substitution. When fish and chicken were substituted for red meat, participants expressed a 28% and 16% lower risk of dementia. For that reason, the American Academy of Neurology recommends that patients reduce their consumption of red meat and swap it with other sources of protein, such as poultry, seafood, and nuts. 

These foods are high in added sugars, fats, sodium, and other preservatives that negatively impact the brain’s executive functioning. They do this by increasing inflammation and reducing the size of the hippocampus, the brain’s spatial memory center. A research study expanded upon this relationship as it found that eating ultra-processed foods is linked with a 16% higher risk of cognitive impairment, whereas a diet with little to no food processing is associated with a 12% lowered risk. Processed foods also weaken the protective abilities of the blood-brain barrier, which is the membrane that surrounds the brain and prevents harmful substances from entering. Foods in this category can do this because they are often high in calories and have little nutritional value. This means that they are not able to keep us full, which can cause us to eat them in large quantities, especially if we think they’re tasty. As a result, our caloric intake will increase, thus accelerating the rate of brain aging.