Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

How APOE and rs405509 relate to concussion risk and recovery

A concussion is a mild traumatic brain injury that occurs when a blow or jolt to the head causes the brain to move rapidly within the skull. Common symptoms include headache, dizziness, confusion, memory problems, sleep disturbances, and balance issues. Recovery varies between people and can be influenced by age, prior injuries, overall health, and genetics. One gene that has been studied in relation to brain injury is APOE, which plays a central role in fat transport and metabolism in the brain and in repairing damaged neurons.

The single nucleotide polymorphism (SNP) rs405509 near APOE can affect how APOE functions. Different genotypes at rs405509 are sometimes described in terms of "effect alleles" that may modestly influence concussion susceptibility or recovery. Regardless of genotype, lifestyle choices and early, appropriate medical care have a large impact on outcomes after head injury.

Key things to remember

  • Genetics may influence vulnerability and recovery but do not determine destiny.
  • Preventing head impacts, recognizing symptoms early, and following medical guidance after a suspected concussion are essential.
  • Diet, sleep, hydration, exercise, and controlled return-to-activity plans support brain health and recovery.
  • PlexusDx provides educational genetic information and does not provide medical advice. Always consult your healthcare provider for diagnosis and treatment.

Genetic interpretation (expand for the genotype that matches you)

2 effect alleles — TT genotype

If your genotype at rs405509 is TT (two copies of the effect allele), research suggests you may have a slightly higher susceptibility to concussion and a potentially different recovery profile compared with people without the effect allele. APOE influences lipid transport and repair processes in the brain, and variation at this site may alter those processes after injury.

What this means for you:

  • Take extra precautions to avoid repeated head impacts, especially in contact sports or high-risk activities.
  • Report symptoms promptly and follow a medically supervised return-to-play or return-to-activity plan after any head injury.
  • Focus on proactive brain health strategies to support resilience and recovery.
1 effect allele — GT genotype

If your genotype at rs405509 is GT (one copy of the effect allele), you may have a modestly increased influence on how your brain responds to injury compared with people who carry no effect allele. This does not mean you will definitely have problems after a concussion; it means genetics may be one of several factors that influence outcome.

What this means for you:

  • Practice good head injury prevention and report any symptoms without delay.
  • Adopt brain-supportive lifestyle habits to reduce risk and aid recovery if an injury occurs.
  • Work with your healthcare team for individualized monitoring after head trauma.
0 effect alleles — GG genotype

If your genotype at rs405509 is GG (two copies of the non-effect allele), your APOE-related concussion risk is considered typical compared with general population baselines. Your APOE function is likely in the common range for lipid transport and neuronal repair.

What this means for you:

  • You do not carry the rs405509 variation that has been associated with altered concussion susceptibility, but that does not eliminate concussion risk.
  • Continue standard prevention, symptom monitoring, and brain-health practices to minimize risk and support recovery if needed.
  • Follow medical guidance after any suspected head injury.

Practical strategies to support brain health and reduce concussion risk

Dietary recommendations

  • Increase intake of omega-3 fatty acids — especially EPA and DHA — found in fatty fish (salmon, sardines, mackerel) or high-quality supplements. Omega-3s support neuronal membrane integrity and reduce inflammation.
  • Prioritize antioxidant-rich foods — colorful fruits and vegetables, berries, leafy greens, nuts, and seeds — to help limit oxidative stress after injury.
  • Include anti-inflammatory foods — olive oil, turmeric, ginger, and foods high in polyphenols — and limit highly processed foods, excess sugar, and trans fats.
  • Maintain consistent protein intake to support tissue repair and recovery.

Supplements to consider

Supplements can be helpful but should be discussed with your healthcare provider before starting. Potential options include:

  • High-quality fish oil providing EPA/DHA, at doses advised by a clinician.
  • Vitamin D if you are deficient, since optimal vitamin D supports overall brain and immune health.
  • Multivitamin or targeted B vitamins to support energy metabolism and neurological function if dietary intake is inadequate.
  • Curcumin or other anti-inflammatory phytonutrients, used under supervision due to interactions and absorption considerations.

Lifestyle recommendations

  • Sleep: Aim for consistent, restorative sleep (7 to 9 hours for adults). Sleep is critical for brain repair and cognitive recovery after injury.
  • Hydration: Even mild dehydration can worsen headache and cognitive symptoms. Drink fluids throughout the day, especially around physical activity.
  • Exercise: Regular aerobic exercise supports brain health when not acutely injured. After a concussion, follow a graded, clinician-guided return-to-exercise plan.
  • Injury prevention: Use appropriate protective equipment, practice safe techniques in sports, and reduce fall risk at home and work.
  • Mental health: Address stress, anxiety, and mood symptoms promptly, as they can impact recovery and symptom burden.

Monitoring and tests to discuss with your provider

  • Clinical concussion assessment and baseline neurocognitive testing if you participate in contact sports.
  • Follow-up evaluations for persistent or worsening symptoms including balance testing and cognitive assessments.
  • Blood tests as clinically indicated to check vitamin D, basic metabolic panel, thyroid function, or other contributors to fatigue and cognitive symptoms.

After a head injury — steps to take

  • Stop the activity and seek immediate medical attention if you suspect a concussion.
  • Rest initially, then follow a gradual, clinician-directed increase in cognitive and physical activity as symptoms improve.
  • Report any new or worsening symptoms to your healthcare provider quickly.
  • Keep a symptom diary to track progress and identify triggers that worsen symptoms.

Limitations and what this information means for you

The rs405509 genotype is one small part of a complex picture. Having an effect allele may slightly influence concussion susceptibility or recovery in some studies, but it does not predict outcomes with certainty. Environmental factors, prior injuries, age, overall health, and how quickly you receive appropriate care are typically more influential.

PlexusDx provides educational genetic information to help you understand possible predispositions and practical steps you can take to support brain health. This information is not medical advice. Always consult your healthcare provider for diagnosis, individualized recommendations, and any decisions about tests, treatments, or supplements.

If this genetic variant is present in your PlexusDx results, the following tests and reports are commonly used to explore it further:

🧬 Genetic Tests:

🧪 Blood Tests:

📄 Genetic Report:

Frequently Asked Questions About Concussion and APOE rs405509

How does the APOE SNP rs405509 influence concussion risk or recovery?

The rs405509 SNP near APOE may modestly affect how APOE functions, which can influence susceptibility and/or aspects of recovery in some studies. If you carry certain rs405509 genotypes (for example, an “effect allele” pattern), it may shift your brain’s response to injury, but it does not determine your outcome with certainty.

What should I do after a suspected concussion, regardless of my rs405509 genotype?

Stop the activity and seek prompt medical attention if you suspect a concussion. Rest initially, then follow a gradual, clinician-directed return to cognitive and physical activity as symptoms improve. Report any new or worsening symptoms quickly and consider keeping a symptom diary to track progress and triggers.

Which brain-supportive lifestyle strategies can help with concussion recovery?

Lifestyle choices can have a major impact on recovery for everyone, including diet, sleep, hydration, and exercise. Prioritize omega-3s (EPA/DHA), antioxidant- and anti-inflammatory foods, consistent protein intake, restorative sleep (about 7–9 hours), adequate hydration, and regular aerobic exercise only when not acutely injured—then use a graded return-to-activity plan after concussion guided by your clinician.

What tests can help me learn more about Concussion and APOE rs405509?

The Functional Health Genetic Test delivers over 750 personalized genetic insights across 10 in-depth genetic reports to support whole-body, systems-level health understanding. The Fitness and Injury Genetic Report translates your results into personalized, actionable guidance. Your healthcare provider can also recommend targeted blood tests based on your specific pathway results and health history to complement your genetic insights with current biomarker data.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.