Which blood biomarkers actually matter for longevity?

Short answer — several routine blood biomarkers are strongly associated with long-term health and mortality risk. They cluster around metabolic health (glucose/insulin), lipid/atherosclerosis risk, inflammation, kidney/liver function, hematologic status, micronutrients, and a few specialty markers and "biological age" tests. Below I list the most useful markers, why they matter, typical direction you want them to go, which test measures them, and a few services/companies that can run or interpret them.

Important disclaimer: this is general information, not medical advice. Discuss abnormal results and treatment decisions with your clinician.

Top-priority biomarkers for longevity (what to test and why)

• Hemoglobin A1c (A1c), fasting glucose, fasting insulin (or HOMA-IR)

  • Why: chronic higher glucose and insulin resistance drive diabetes, vascular disease, dementia.
  • Direction: lower within normal — A1c <5.7% is ideal; fasting glucose <100 mg/dL; lower fasting insulin and HOMA-IR indicate better metabolic health.
  • How to test: standard lab panels.

• Lipids: LDL-C, non‑HDL, triglycerides, HDL — and better predictors: ApoB and ApoA1

  • Why: lipid-related atherosclerotic risk is the main driver of premature cardiovascular death.
  • Direction: lower LDL-C/ApoB/non‑HDL; higher HDL (within reason); low triglycerides.
  • ApoB is often a better single-number predictor than LDL-C.
  • How to test: standard lipid panel + ApoB.

• Lp(a) (lipoprotein(a))

  • Why: genetically driven risk factor for atherosclerosis; important to know once.
  • Direction: lower is better; elevated Lp(a) increases lifetime CV risk.
  • How to test: single blood test.

• High-sensitivity CRP (hs‑CRP), and if available IL‑6 or fibrinogen

  • Why: markers of chronic systemic inflammation predict cardiovascular events and mortality.
  • Direction: hs‑CRP <1 mg/L is low-risk; higher indicates increased risk.

• Kidney function: serum creatinine, eGFR, and cystatin C when available

  • Why: kidney disease strongly increases mortality risk.
  • Direction: higher eGFR / lower creatinine (age-adjusted); cystatin C can detect impairment earlier.

• Liver enzymes: ALT, AST, GGT

  • Why: fatty liver and liver dysfunction are linked to metabolic disease and mortality.
  • Direction: lower or within normal range; elevated GGT often signals metabolic stress or alcohol use.

• Complete blood count (CBC) including red cell distribution width (RDW), hemoglobin, hematocrit

  • Why: anemia and elevated RDW correlate with mortality and frailty.
  • Direction: avoid anemia; lower RDW is better.

• Serum albumin and prealbumin

  • Why: markers of nutrition / physiologic reserve; low albumin predicts worse outcomes.
  • Direction: higher within normal range.

• Ferritin and iron studies (if iron disorder suspected)

  • Why: both iron deficiency and iron overload have health consequences.
  • Direction: context-dependent — treat deficiency; avoid excess.

• Vitamin D (25‑OH vitamin D)

  • Why: low vitamin D associates with higher mortality and multiple chronic diseases.
  • Direction: many experts aim for 30–50 ng/mL (discuss with clinician).

• Homocysteine

  • Why: associated with vascular risk and cognitive decline in some studies.
  • Direction: lower is better; treatable with B vitamins if elevated.

Specialty or advanced markers / biological aging tests

• ApoB/ApoA1 ratio and advanced lipoprotein testing (NMR)

  • Why: refines cardiovascular risk beyond standard lipids.
  • Services: Quest, LabCorp, and specialized labs.

• Lipoprotein(a) — see above (genetic risk)

• Cystatin C (more sensitive kidney marker)

• High-sensitivity troponin (in some research settings) for silent cardiac risk

• D‑dimer, NT‑proBNP in selected cases (cardiac/clotting risk)

• Telomere length, epigenetic clocks (DNAm GrimAge, DNAm PhenoAge)

  • Why: attempt to estimate biological age rather than chronological age. Research-useful but clinical utility is still emerging.
  • Providers: TruDiagnostic (epigenetic clock tests), Zymo Research / Chronomics (some services), EpiAging technologies. Expect higher cost and evolving interpretation.

Practical prioritization if you want to test only a few things

• Essentials: A1c (or fasting glucose), fasting lipid panel + ApoB, hs‑CRP, CBC, basic metabolic panel (creatinine/eGFR), ALT/AST, and vitamin D.
• If you have family history of early heart disease: add Lp(a) and advanced lipid testing.
• If concerned about biological age or prevention investment: consider epigenetic clock testing via TruDiagnostic or similar.

Where to get these tests and interpretation (brands/services)

• Local clinical labs: Quest Diagnostics and LabCorp — widely available, accepted by clinicians and insurers.
• Direct-to-consumer / at-home kits: Everlywell, LetsGetChecked — convenient for many standard tests (A1c, lipids, vitamin D, thyroid).
• Interpretation + coaching platforms: InsideTracker, WellnessFX, and Thorne’s personalized lab services — they provide interpretation, personalized recommendations, and repeat testing plans.
• Continuous glucose monitoring and metabolic coaching: Abbott FreeStyle Libre or Dexcom + Levels app (Levels provides CGM-based coaching) — useful for understanding glucose spikes in non-diabetics.
• Epigenetic/biological-age testing: TruDiagnostic — focused on DNAm clocks and provides longitudinal reports; other players include Chronomics and Zymo Research (myDNAge).
• Specialty / research labs: Mayo Clinic Laboratories for complex panels; Quest/LabCorp also offer advanced tests (ApoB, Lp(a), NMR lipoprofile).

How often to test

• Baseline and then annually for most markers if normal.
• Every 3–6 months if you’re making an intervention (starting statin, weight loss, diabetes therapy) or if values are abnormal.

What actually improves longevity (brief)

• Lowering long-term exposure to high glucose/insulin, lowering atherogenic lipoproteins (ApoB/LDL), reducing chronic inflammation, preserving kidney and liver function, avoiding anemia and severe micronutrient deficiencies, and maintaining muscle mass and physical fitness.
• Proven interventions include lifestyle (diet quality, regular physical activity, adequate sleep, smoking cessation), control of blood pressure and lipids (including statins when indicated), and glycemic control in people with diabetes. Work with your clinician for medication decisions.

If you want, I can:

• Suggest a compact “starter panel” tailored to your age/sex/family history.
• Point to which companies or test kits would be best for a specific marker (e.g., where to get ApoB, Lp(a), epigenetic clock).
• Explain target ranges in more detail for any one marker.

Which would you like next?