Caring for Our Brains Throughout Aging

The human brain accounts for approximately 2% of total body weight and comprises billions of neurons. These neurons are highly energy-dependent, consuming 20% of our metabolic energy, which is ten times greater than the energy demand of muscle tissue. As the saying goes, with great power comes great responsibility.

Even in individuals who are otherwise healthy, brain volume tends to decrease with age, leading to neuron loss and disrupted connectivity.

There is a strong correlation between cognitive health and brain volume, which is also closely linked to metabolic health. For instance, fatty liver disease, a common metabolic disorder often influenced by dietary choices, has been associated with accelerated decreases in brain volume and elevated risks for cognitive decline, including dementia.

Nutrition and Healthy Brain Aging

The connection between liver health and brain function highlights the importance of good nutrition for aging well. A recent brain-imaging study in older adults in 2024 analyzed nutrient intake against brain health indicators, revealing specific foods and nutrients associated with slower brain aging.

Omega-3 Fatty Acids

Individuals showing signs of delayed brain aging often have elevated levels of omega-3 fatty acids—eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA)—which are known for their anti-inflammatory properties. Inflammation is a significant contributor to brain aging, compromising the blood-brain barrier and making the brain vulnerable to damage over time.

EPA and DHA are abundant in oily fish like salmon, sardines, and trout, while ALA can be found in flaxseeds, hempseeds, chia seeds, soy products, and walnuts.

Carotenoids

Carotenoids are potent antioxidants that accumulate in the brain and eyes in proportion to their intake. By combating oxidative stress—a key factor in brain aging—higher diets rich in carotenoids are linked with improved brain health.

Sources of carotenoids include spinach, kale, bell peppers, tomatoes, watermelon, broccoli, carrots, grapefruit, and cantaloupe.

Vitamin E and Choline

A notable antioxidant, vitamin E has been widely studied and shown to correlate positively with cognitive health. It is primarily found in nuts, seeds, leafy greens, and various types of fish.

Choline plays a crucial role as a precursor to phosphatidylcholine, a compound integral to brain cell membranes and neurotransmitter regulation, which is essential for optimal brain function. Good sources of choline include eggs, edamame, cauliflower, beef, chicken, peas, pork, broccoli, and milk.

Additional Nutrients of Interest

As we age, the absorption of certain nutrients can decrease (for instance, iron), while others—such as potassium, magnesium, and calcium—may be under-consumed. This underconsumption can lead to health consequences, including high blood pressure, which is a significant risk factor for cognitive decline. Nutrients like potassium, calcium, and magnesium are known to assist in regulating blood pressure.

The Gut-Brain Connection

A discussion about healthy brain aging is incomplete without mentioning the gut-brain connection, mediated by trillions of bacteria and other microorganisms within our gut microbiome, which also evolves with age.

Older adults experiencing cognitive problems are often characterized by an imbalanced gut microbiome, marked by an excess of pro-inflammatory bacteria.

A healthy gut microbiome generates beneficial compounds known as short-chain fatty acids (SCFAs), which exert anti-inflammatory effects and support communication between the gut and the brain via various pathways.

These pathways include improved nutrient absorption and maintaining a robust intestinal barrier that prevents toxins from entering the bloodstream, further protecting the brain. This is where polyphenols become significant.

Polyphenols—The Gut-Brain Connectors

Polyphenols are a class of plant-derived compounds that stimulate gut bacteria to produce beneficial SCFAs.

A study published in 2018 in Neurology followed 1,329 older adults over 12 years and found that higher polyphenol intake was associated with a 50% lower risk of dementia compared to those consuming the least.

To enhance your dietary intake of polyphenols, consider foods like cocoa powder, ground flaxseed, artichokes, blueberries, and increase the use of herbs and spices in cooking.

Beyond Nutrition—Expert Insight

According to registered dietitian Barbie Boules, “If I had to pinpoint two fundamental tips for brain health that can yield immediate benefits and improve long-term outcomes, they would be ensuring you get a good night’s sleep and incorporating daily physical activity. Protecting eight quality hours of sleep and engaging in at least 30 minutes of movement each day can make a significant difference. It doesn’t have to be anything elaborate—walking is enough.”

Her guidance aligns with research findings that link poor sleep and inactivity to accelerated brain aging and diminished cognitive health.

This article was initially published in the March 2025 issue of alive magazine.