Andrew Russell: Brain Food, Your Second Brain, and the Power of Lifestyle

Why they work: Multiple studies link higher omega-3 intake with improved memory, better mood regulation, and lower risk of cognitive decline. Two servings of fatty fish per week is one of the most consistently supported dietary recommendations across major health institutions.

Why they work: Rich in anthocyanins, flavonoid compounds that give berries their deep colour. These are powerful antioxidants that cross the blood-brain barrier and protect the brain from oxidative stress and inflammation, two key drivers of aging and neurodegeneration.

Why they work: Walnuts are one of the richest plant sources of ALA (alpha-linolenic acid), a plant-based omega-3. They also provide vitamin E, polyphenols, and antioxidants. Almonds provide vitamin E (a fat-soluble antioxidant that protects brain cell membranes), while Brazil nuts deliver selenium, which supports antioxidant defence systems in the brain.

Why they work: Egg yolks are one of the best dietary sources of choline, a nutrient essential for producing acetylcholine, a neurotransmitter critical for memory, attention, and muscle control. Eggs also deliver B12, folate, and fat-soluble vitamins D and K2.

Why they work: Packed with folate, vitamin K, lutein, and beta-carotene, all associated with slower cognitive decline.

Why they work: Rich in flavonoids, caffeine, and theobromine. Flavonoids accumulate in brain regions involved in learning and memory, particularly the hippocampus. Have a few squares of high-quality dark chocolate, not a full bar.

Why it works: Curcumin crosses the blood-brain barrier and has documented anti-inflammatory and antioxidant effects in brain tissue. A staple in traditional Okinawan (Blue Zone) diets for centuries.

Why it works: Contains L-theanine, an amino acid that crosses the blood-brain barrier and increases GABA, serotonin, and dopamine activity, promoting calm focus without drowsiness.

Why it works: Contains oleocanthal, a polyphenol that has been shown to help clear amyloid-beta plaques associated with Alzheimer’s disease. Also rich in monounsaturated fatty acids and vitamin E.

Why they work: Among the most nutrient-dense foods on the planet. Liver provides concentrated B12 (critical for myelin sheath maintenance and nerve function), iron (for oxygen transport to the brain), vitamin A, copper, and choline.

Why they work: Provide steady glucose delivery to the brain (low glycaemic index), plus B vitamins, iron, magnesium, and zinc

Why they work: Introduce beneficial bacteria that directly produce neurotransmitters including serotonin, dopamine, and GABA in the gut. They also improve gut barrier integrity, reducing systemic inflammation that can impair brain function.

The fact: Approximately 95% of the body’s serotonin is produced in the gut, not the brain.

Why it matters: Serotonin regulates mood, appetite, sleep, memory, and social behaviour. Low serotonin levels are associated with depression, anxiety, and sleep disorders.

Foods that support serotonin production: Turkey, chicken, eggs, salmon, tofu, nuts, seeds, cheese, and oats. These are all rich in tryptophan.

The fact: Approximately 50% of the body’s dopamine is produced in the gut.

Why it matters: Dopamine drives motivation, focus, pleasure, reward-seeking behaviour, and motor control. Dysregulation is linked to conditions from depression to Parkinson’s disease.

Foods that support dopamine production: Dopamine is built from the amino acid tyrosine. Rich sources include beef, chicken, fish, eggs, dairy, almonds, avocados, bananas, and dark chocolate.

The gut connection: A healthy gut microbiome ensures efficient conversion of dietary tyrosine into usable dopamine.

Why it matters: GABA deficiency is associated with anxiety, insomnia, restlessness, and heightened stress response. It is a calming chemical.

Foods that support GABA: Fermented foods (kimchi, miso, yogurt, tempeh) promote GABA-producing bacteria. Green tea contains L-theanine, which increases GABA activity in the brain. Whole grains, legumes, nuts, and citrus.

The fact: The gut contains 400 times more melatonin than the brain.

Why it matters: Melatonin regulates sleep-wake cycles, supports immune function, and acts as a powerful antioxidant. Disrupted melatonin production is linked to insomnia and metabolic disorders.

Foods that support melatonin: Tryptophan-rich foods (turkey, eggs, salmon, nuts, seeds) provide the raw building blocks. Tart cherries are one of the few foods that contain melatonin directly.

The fact: The vagus nerve is composed of 80% afferent (gut-to-brain) and 20% efferent (brain-to-gut) fibres. This means your gut sends four times more information to your brain than your brain sends to your gut. It is the fastest and most direct pathway for the microbiome to influence brain function.

How it works: Gut bacteria produce short-chain fatty acids (SCFAs) from dietary fibre, which activate vagal nerve endings and send calming, anti-inflammatory signals to the brain.

Foods and practices that support vagal health: High-fibre foods (legumes, whole grains, vegetables, fruits) feed the bacteria that produce SCFAs. Fermented foods introduce bacteria that produce neurotransmitters, activating vagal pathways. Omega-3 fatty acids from fish support vagal tone.

Why they matter: SCFAs strengthen the gut lining (preventing “leaky gut”), reduce systemic inflammation, improve insulin sensitivity, support immune function, and cross the blood-brain barrier where they influence brain inflammation and neurotransmitter production.

Foods that boost SCFAs: Legumes, oats, barley, garlic, onions, leeks, asparagus, artichokes, bananas, apples, and whole grains. The diversity of fibre sources matters — different bacteria prefer different fibres, so variety is key.

Meal timing matters as much as meal content. Insulin sensitivity is highest in the morning and declines as the day progresses. A 2025 study published in Nutrients found that early time-restricted eating (food intake confined to an 8:00 AM–2:00 PM window) led to significant reductions in body weight while preserving lean muscle mass — even without reducing calorie intake. Late-night eating disrupts glucose metabolism, impairs insulin sensitivity, and increases fat storage.

Light and food work as dual clock-setters. Light sets the central clock in the brain. Food sets the peripheral clocks in your organs. When these are aligned, eating during daylight hours, fasting during darkness, your metabolic system works optimally.

Practical takeaway: A lighter evening meal containing tryptophan-rich foods (such as a small portion of fish, eggs, or nuts with some complex carbohydrates) consumed 2–3 hours before sleep supports the natural melatonin rise without overloading the digestive system.

Why it works psychologically: This aligns with how the longest-lived populations actually eat. Blue Zone communities don’t follow rigid rules, they eat well most of the time, celebrate with food and wine, and don’t stress about occasional indulgences. The stress of dietary perfectionism may itself be counterproductive, raising cortisol and driving the inflammation that a good diet is supposed to prevent.

Sunlight as medicine: Morning sunlight regulates circadian rhythms, drives vitamin D synthesis, and supports serotonin production (which converts to melatonin at night). Research links adequate sun exposure to reduced risk of depression, cognitive decline, osteoporosis.

The consistency principle: Your circadian system craves consistency. Going to bed, waking up, and eating at roughly the same times each day strengthens circadian entrainment and improves every downstream metabolic process.