The 5 Most Critical Blood Tests for Longevity According to Biohacker Siim Land

Longevity expert Siim Land distills hundreds of biomarkers down to five essential blood tests that provide maximum insight into health span and disease risk. These markers matter because they predict the major causes of mortality - cardiovascular disease, diabetes, cancer, and neurodegeneration - while being practical and affordable to monitor regularly.

Land's top five are HbA1c (optimal 4.5-5.2%), which reflects average blood sugar over 2-3 months and predicts cardiovascular events, diabetes, and skin aging through glycation. Triglycerides (optimal under 50 mg/dL) indicate metabolic health and insulin sensitivity. High-sensitivity CRP measures chronic inflammation, with levels below 0.2 mg/L being ideal since inflammation drives atherosclerosis, cancer, and biological aging. Cystatin C (optimal under 0.84 mg/L) assesses kidney function and strongly predicts all-cause mortality. ApoB measures atherogenic particles and cardiovascular risk better than standard cholesterol panels.

These markers work synergistically - elevated levels indicate systemic dysfunction affecting multiple organ systems. Land notes that optimal ranges are often much stricter than standard medical references, as even "normal" levels can indicate increased disease risk. He emphasizes the ApoB to ApoA1 ratio (optimal under 0.6) as particularly powerful for cardiovascular risk assessment.

The practical implications are significant for health optimization. These five tests can guide lifestyle interventions around diet, exercise, stress management, and supplementation. However, Land cautions against over-testing without willingness to change behaviors based on results, and emphasizes that fundamental lifestyle factors remain more important than expensive biomarker panels.