How Not to Age Book: Key Biomarkers to Measure

You have read How Not to Age by Dr. Michael Greger and are now wondering how to actually measure your personal status quo. Greger’s core message is clear: aging is not an inescapable fate, but a biological process that we can influence. The book provides the scientific foundation and evidence-based recommendations for diet and lifestyle. However, to know whether your efforts are truly making a difference, you need the right How Not to Age blood tests.

Many of the biological systems and risk factors discussed in the book can be assessed through measurable biomarkers in your blood. With the right tests, you can establish a baseline and track how relevant physiological markers change over the years.

This article translates the science from How Not to Age into a concrete diagnostic roadmap: which blood values relate to crucial aging processes, why a standard primary care blood panel is insufficient, and where you can undergo comprehensive longevity diagnostics in Berlin.

What 'How Not to Age' Says About Measurable Aging Processes

Dr. Michael Greger, founder of the non-profit organization nutritionfacts.org, evaluated thousands of longevity studies for his book. The central thesis: aging is driven by a series of biological mechanisms known as the "Hallmarks of Aging."

Greger describes over a dozen of these aging pathways. They include the regulation of nutrient sensors like mTOR and AMPK, chronic low-grade inflammation ("inflammaging"), the accumulation of cellular waste due to declining autophagy, and damage to proteins caused by sugar-related glycation.

These processes cannot usually be measured directly through a simple blood test. However, laboratory tests can show how several relevant physiological systems and risk factors currently look in your body and which areas may deserve closer attention.

Note: This article is for informational purposes only and does not replace individual medical advice. Biomarkers are valuable reference points but must always be evaluated in your overall clinical context by a physician.

The Central Aging Pathways From the Book—And What They Mean Biologically

To understand which How Not to Age blood tests are relevant, we first need to briefly look at the biological mechanisms Greger describes.

• mTOR (Mechanistic Target of Rapamycin): This signaling pathway is one of the cell's central regulators of growth. When highly active, it promotes cell growth and division. In childhood and youth, this is essential. Persistent activation of mTOR signaling can suppress autophagy and is implicated in several biological processes associated with aging.
• AMPK (AMP-activated Protein Kinase): AMPK is the cell's "energy sensor" and becomes active during energy deficits, such as during fasting or intense exercise. Activated AMPK can promote pathways involved in energy regulation, insulin sensitivity, and cellular maintenance. As we age, AMPK signaling may become altered.
• Chronic Inflammation ("Inflammaging"): This is not an acute inflammation in response to an injury, but a persistent, systemic, low-grade inflammatory state. It is associated with many major age-related diseases, including cardiovascular disease, dementia, and cancer.
• Glycation: Sugar molecules can react with proteins and fats to form Advanced Glycation Endproducts (AGEs). AGE accumulation and protein cross-linking can contribute to impaired tissue function and increased stiffness in structures such as blood vessels.
• Autophagy: The cellular recycling system. It breaks down damaged or misfolded proteins and old cell components. Well-functioning autophagy is important for cellular maintenance and can be influenced by factors such as nutrient availability and exercise.

Other pathways Greger describes include the IGF-1 signaling pathway, which interacts with mTOR, oxidative stress, and telomere shortening. These pathways are closely interconnected: mTOR, AMPK, autophagy, inflammation, and metabolic regulation influence one another in complex ways.

Because of this complexity, there is no single "longevity blood test." A meaningful picture only emerges through a panel of biomarkers that assesses several interacting physiological systems and risk factors.

Which Blood Tests and Biomarkers Make These Aging Pathways Measurable

1. Glycation and Glucose/Insulin Metabolism

Poor glucose regulation can increase glycation and is closely linked to metabolic dysfunction.

• HOMA-IR (Homeostasis Model Assessment): Calculated from fasting glucose and fasting insulin, HOMA-IR is a surrogate estimate that can provide evidence of reduced insulin sensitivity even when fasting glucose remains within the normal range. The cited 2021 study found that higher HOMA-IR was associated with increased coronary artery disease risk over long-term follow-up (Lee et al., Diabetes Res Clin Pract 2021).
• Oral Glucose Tolerance Test (OGTT): Measures how your body reacts to a defined glucose solution and can detect impaired glucose tolerance that may not be apparent from fasting glucose alone.
• Fasting Insulin: Elevated fasting insulin in the presence of normal glucose can indicate compensatory hyperinsulinemia and should be interpreted together with other metabolic parameters.
• HbA1c ("Long-term blood sugar"): Provides information about average blood glucose exposure over approximately the previous 8–12 weeks. It is an established marker of long-term glycemic status but does not capture every aspect of early insulin resistance.

1. Chronic Inflammation (Inflammaging)

• hs-CRP (High-sensitivity C-reactive protein): hs-CRP allows more precise measurement of low CRP concentrations than standard CRP assays and can provide information about low-grade systemic inflammatory activity. Elevated values are associated with increased cardiovascular and all-cause mortality risk, but hs-CRP remains a nonspecific marker.
• Interleukin-6 (IL-6): An inflammatory cytokine involved in immune signaling and frequently studied in research on chronic inflammation and aging. It is not a specific clinical test for "inflammaging."
• Homocysteine: Elevated homocysteine is associated with cardiovascular and neurological risk, although randomized trials of homocysteine-lowering therapy have not consistently shown corresponding reductions in cardiovascular events.

1. mTOR-Related Growth Signaling

• IGF-1 (Insulin-like Growth Factor 1): IGF-1 is involved in growth and nutrient-sensing pathways that interact with mTOR signaling. Circulating IGF-1 is not a direct measure of mTOR activity. Human studies suggest a complex, often U-shaped relationship between IGF-1 and health outcomes, meaning that both very low and very high levels may be unfavorable depending on age and clinical context.

1. Cardiovascular Risk

• ApoB (Apolipoprotein B): ApoB reflects the number of atherogenic lipoprotein particles. Because every major atherogenic particle carries one ApoB molecule, ApoB can provide a more direct estimate of atherogenic particle burden and may reveal elevated risk even when LDL cholesterol appears relatively normal.
• Lp(a) (Lipoprotein(a)): A predominantly genetically determined, independent risk factor for atherosclerotic cardiovascular disease that is not routinely included in the statutory German health check-up.
• Oxidized LDL: Oxidized LDL participates in atherosclerotic biology, although its routine clinical value as an individual risk marker is less established than that of ApoB or Lp(a).

1. Nutrient Status

• Omega-3 Index: Measures the percentage of the omega-3 fatty acids EPA and DHA in red blood cells. In an observational analysis from the Framingham Heart Study, a higher Omega-3 Index was associated with lower all-cause mortality (Harris et al., J Clin Lipidol 2018). This association does not by itself prove that increasing the index causes a corresponding reduction in mortality.
• Vitamin D3: Vitamin D plays an established role in bone and mineral metabolism and also participates in immune regulation. Its interpretation should depend on clinical context rather than being treated as a universal longevity target.

1. Metabolism and Hormone System

• Thyroid Hormones (TSH, fT3, fT4): Thyroid dysfunction can affect metabolism, cardiovascular health, energy levels, and multiple organ systems.

Why a Standard Primary Care Blood Panel Falls Short

If you visit your primary care physician motivated by How Not to Age and ask for a blood panel, you will typically receive a standard preventive assessment such as the statutory health check in Germany. While this is an important baseline examination covered by health insurance, it is not designed as a comprehensive longevity assessment.

A statutory health check-up from age 35 includes medical history and risk assessment, physical examination including blood pressure, a lipid profile and glucose measurement, plus urine testing.

What is missing are several of the more specialized markers discussed above:

• No hs-CRP: Low-grade systemic inflammatory activity is not specifically assessed through this marker.
• No ApoB: Atherogenic particle burden may be less precisely characterized in people with discordant lipid values.
• No Lp(a): This genetic cardiovascular risk factor is not routinely included.
• No HOMA-IR or fasting insulin: Early compensatory changes in insulin metabolism are not routinely assessed.
• No IGF-1: This growth-factor pathway is not routinely assessed.
• No Homocysteine: This marker is not routinely included.
• No Omega-3 Index or Vitamin D3: These markers are not routinely part of the statutory health check-up.

This has practical consequences. You could eat according to the principles of How Not to Age for months, walk 8,000 steps a day, and optimize your sleep without knowing how specific biomarkers have changed over time. Laboratory testing can help assess whether relevant metabolic, inflammatory, or cardiovascular markers are moving in the intended direction.

Which of These How Not to Age Blood Tests YEARS Core® and Evolve® Cover

Specialized preventive medicine clinics like YEARS bridge exactly this gap. The programs measure biomarkers related to many of the physiological systems discussed in the book and embed them in a comprehensive medical evaluation.

The YEARS Core® Program (€1,900, 6 hours) is a starting point for establishing a broad baseline. It includes 87 biomarkers, featuring:

• Glycation/Insulin Resistance: HOMA-IR and a complete Oral Glucose Tolerance Test (OGTT)
• Inflammation: hs-CRP
• Cardiovascular Risk: ApoB and Lp(a)
• Nutrient Status: Omega-3 Index, Vitamin D3, and Ferritin
• Metabolism: Complete thyroid hormones (TSH, fT3, fT4), liver, and kidney values

Core® also captures functional data related to health and aging: maximum oxygen uptake (VO₂max, one of the strongest functional predictors of all-cause mortality), Heart Rate Variability (HRV), lung function via body plethysmography, and imaging techniques like cardiac and abdominal ultrasound.

The YEARS Evolve® Program (€7,600, 9 hours) includes everything from Core® and expands the lab panel to over 120 biomarkers. More specialized markers include:

• In-depth Inflammation: Interleukin-6 (IL-6) and Homocysteine
• Growth Signaling: IGF-1
• Advanced Heart Risk: Oxidized LDL and Lp-PLA2
• Stress Axis and Hormones: DHEA-S and Cortisol

Evolve® complements the lab work with two additional diagnostic modules:

• Whole-Body MRI: Radiation-free imaging from head to toe that can visualize structural abnormalities.
• Liquid Biopsy (truCheck): An emerging multi-cancer detection blood test based on circulating tumor-associated cells. Evidence for its use in asymptomatic screening is still developing. It does not replace established cancer screening, and positive findings require conventional diagnostic confirmation.

The YEARS Ultimate® Program adds genomics, epigenetics, and microbiome analysis, including epigenetic clocks that provide statistical estimates related to biological aging.

All data flows into a 60+ page health report authored by a physician. About two weeks after your visit, you discuss this report in a detailed strategy session with a YEARS doctor. You don't just get a stack of lab results; you receive a prioritized action plan that places your values into your personal context, covering all identified health risks.

How to Use Your Lab Values as a Longevity Compass

A comprehensive blood panel is not a report card; it is a tool. Four principles will help you use it effectively:

1. Measure a baseline: Without a documented starting point, any change remains speculation. The first measurement is the most important.
2. Reference ranges require context: A value within a laboratory reference interval does not automatically mean that it is optimal for every clinical situation. Interpretation depends on the marker, individual risk factors, symptoms, and the clinical question.
3. The trend beats the single value: A single measurement is a snapshot. Repeated measurements can show whether biomarkers such as HOMA-IR or hs-CRP are moving in the intended direction over time.
4. Biomarkers are not a diagnosis: An abnormal value is a signal, not a disease. It is the starting point for medical contextualization and targeted next steps.

The interventions described in the book—more whole-food plant-based nutrition, exercise, and adequate sleep—are the levers. Lab diagnostics can help assess how relevant physiological markers change over time.

From the Book to Measurable Change

How Not to Age gives you the scientific framework and the motivation. But without data, you don't know where you stand.

Several physiological systems related to aging biology, including glucose metabolism, systemic inflammation, lipid-related cardiovascular risk, and growth-factor signaling, can be assessed using laboratory biomarkers. A standard primary care blood panel covers only part of this.

The YEARS Core® Program provides a broad baseline and captures key biomarkers relevant to heart health, inflammation, and metabolism. The YEARS Evolve® Program adds specialized markers such as IGF-1 and Interleukin-6, alongside whole-body MRI and liquid biopsy. The YEARS Ultimate® Program adds genomics, epigenetics, and microbiome analysis.

Frequently Asked Questions (FAQ)

Which blood tests does 'How Not to Age' recommend checking regularly?

Dr. Greger does not provide a fixed clinical testing panel. Based on the biological pathways discussed in the book, relevant clinical assessments can include markers related to insulin and glucose metabolism, systemic inflammation, cardiovascular risk, growth-factor signaling, and selected nutrient markers.

What is the HOMA-IR index and why is it relevant for aging research?

The HOMA-IR index is a surrogate estimate calculated from fasting glucose and fasting insulin. It can provide information about insulin sensitivity even when fasting glucose remains within the normal range.

What is the difference between hs-CRP and standard CRP?

hs-CRP is designed to measure lower CRP concentrations more precisely than standard CRP assays and is therefore commonly used when assessing low-grade systemic inflammatory activity and cardiovascular risk. Like standard CRP, it remains a nonspecific inflammatory marker.

Can I get my longevity biomarkers tested by my primary care doctor or only at a specialized clinic?

Individual markers like Vitamin D3 or HbA1c can often be requested as out-of-pocket services at a primary care physician. However, a comprehensive panel including markers such as ApoB, Lp(a), HOMA-IR, hs-CRP, and IGF-1 is not routinely included in the statutory health check-up. Specialized preventive clinics like YEARS bundle these measurements into an integrated program, complete with medical interpretation and a strategy session.

This article is for general informational purposes only and does not replace individual medical advice or diagnosis. The interpretation of biomarkers must always be done in an overall clinical context by a qualified physician.

Sources

• Bundesgesundheitsministerium. (2024). Der Gesundheits-Check-up. Abgerufen von der Website des Bundesgesundheitsministeriums.
• Harris, W. S., Tintle, N. L., Etherton, T. D., & Vasan, R. S. (2018). Erythrocyte long-chain omega-3 fatty acid levels are inversely associated with all-cause and cause-specific mortality: The Framingham Heart Study. Journal of Clinical Lipidology, 12(3), 748–757.e4.
• Kunutsor, S. K., Kieneker, L. M., Laukkanen, J. A., & Dullaart, R. P. (2017). C-reactive protein and risk of future mortality: an umbrella review of systematic reviews and meta-analyses of prospective cohort studies. European Journal of Epidemiology, 32(9), 755–768.
• Lamina, C., & Kronenberg, F. (2019). Lipoprotein(a) and its significance for all-cause and cardiovascular mortality. Current Opinion in Lipidology, 30(4), 316–324.
• Lee, S. H., Park, J. H., Kim, S. H., et al. (2021). Homeostasis model assessment of insulin resistance is a predictor of coronary artery disease in individuals with normal fasting glucose and normal glucose tolerance: a 12-year follow-up study. Diabetes Research and Clinical Practice, 173, 108688.
• Wald, D. S., Law, M., & Morris, J. K. (2002). Homocysteine and cardiovascular disease: evidence on causality from a meta-analysis. BMJ, 325(7374), 1202.