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Body System

Brain

Cognition, mood, memory, and neurological health.

Last reviewed
July 2026
Version
1.0
Review cadence
Annually

Overview

The brain and nervous system govern thought, memory, mood, movement, and the automatic control of the body. Brain health depends heavily on the health of the blood vessels, sleep, and metabolism that supply and protect it.

Why it matters

Cognitive decline and mood disorders are among the most feared and consequential health outcomes, yet a large share of risk is modifiable through vascular health, sleep, activity, and engagement — often decades before symptoms appear.

Start Here

New to this? Read these first

  1. FoundationBrain & Cognitive HealthThe best place to understand what actually protects the brain — and why most nootropics don't.
  2. ConditionAlzheimer's DiseaseThe most common cause of dementia
  3. BiomarkerBlood PressureThe most impactful modifiable vital sign
  4. Signal RecordAntidepressants (SSRIs & SNRIs)They work — but not for the reason you were told
  5. Body SystemCardiovascular
Typical Journey

How this usually unfolds

  1. Understand the system
  2. Know the key biomarkers
  3. Learn the common conditions
  4. Apply evidence-based interventions

An orientation to how this topic is typically approached — not medical advice.

Major functions

  • Cognition, learning, and memory
  • Mood and emotional regulation
  • Movement and coordination
  • Sensory processing
  • Autonomic control of organs

Common conditions

Evidence-based

Prevention

  • Control blood pressure and ApoB
  • Stay physically active
  • Protect sleep
  • Treat hearing loss
  • Avoid smoking and excess alcohol
Evidence-based

Improvement strategies

  • Aerobic exercise for cognition and mood
  • Treating depression and sleep disorders
  • Managing vascular risk factors
  • Ongoing learning and social connection
Explore

Explore this system across BioSignal

Related body systems

Related lifestyle interventions

  • Regular aerobic exercise
  • Consistent, sufficient sleep
  • Cognitive and social engagement
  • Mediterranean-style diet
  • Not smoking

Related diagnostics

  • Cognitive testing
  • Brain MRI/CT (when indicated)
  • Vascular risk markers (ApoB, blood pressure)
  • Sleep assessment

Frequently asked questions

Can I really lower my dementia risk?

A meaningful share of dementia risk is linked to modifiable factors — blood pressure, hearing, activity, smoking, and more. None guarantees prevention, but together they shift the odds.

Do brain-training games work?

They mostly improve the specific game you practice, with little proven transfer to general cognition. Exercise, sleep, and vascular health have stronger evidence.

Educational information — not medical advice

Body System hubs orient you across the evidence; they don't diagnose or treat. Interpret your own health with a qualified clinician. See our Medical Disclaimer.

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