Unlocking Longevity: 11 Overlooked Blood Markers Your Doctor Should Be Testing For

Dr. Jon Repole

As the adage goes, knowledge is power. Nowhere is this more evident than in understanding your blood work. While it may seem like a cryptic set of numbers and abbreviations, deciphering your blood test results can offer invaluable insights into your health. In this article, we are going beyond the basics and will explore 11 hidden blood markers from an antiaging and longevity perspective. Ordering, monitoring, and optimizing theses markers may just help you to live longer!

Conventional vs. Optimal Ranges

Before we delve into specific markers, it's crucial to understand the difference between conventional and optimal ranges. Conventional ranges are determined by analyzing a large population and establishing norms based on statistical averages. However, these ranges may not necessarily reflect optimal health. Optimal ranges, on the other hand, aim for the levels associated with peak health and well-being, often falling within narrower parameters.

The 11 Key Markers and Their Interpretations

1. hs-CRP (High-Sensitivity C-Reactive Protein)

• Conventional Range: <1.0 mg/L (low risk), 1.0-3.0 mg/L (average risk), >3.0 mg/L (high risk).
• Optimal Range: <0.5 mg/L.
• Interpretation: This may be one of the most important of all the markers! hs-CRP is a marker of inflammation, the underlying cause of almost all health challenges. Optimal levels indicate lower risk for cardiovascular disease, other inflammatory conditions, and overall decreased mortality rates.  

2. HbA1c (Glycated Hemoglobin)

• Conventional Range: <5.7% (normal), 5.7-6.4% (pre-diabetes), ≥6.5% (diabetes).
• Optimal Range: <5.0%.
• Interpretation: HbA1c, or glycated hemoglobin, serves as a crucial marker for longevity due to its ability to reflect average blood glucose levels over the past two to three months. Classically, it has been used as a marker for diabetes. In addition, however, elevated levels of HbA1c indicate poor glycemic control, which is associated with an increased risk of various health complications, including cardiovascular disease, stroke, kidney disease, mitochondrial dysfunction, and nerve damage. By monitoring and managing HbA1c levels, individuals can effectively mitigate the risks of these chronic conditions, thus promoting overall longevity and well-being.

3. Insulin

• Conventional Range: Varies depending on the test method.
• Optimal Range: Fasting insulin <5 µIU/mL.
• Interpretation: Insulin levels play a significant role as a marker for longevity and anti-aging due to their influence on various metabolic pathways and cellular processes. Elevated insulin levels, often seen in conditions like insulin resistance and type 2 diabetes, are associated with accelerated aging and an increased risk of age-related diseases such as cardiovascular disease, cancer, and neurodegenerative disorders. Chronically high insulin levels can lead to systemic inflammation, oxidative stress, and cellular damage, all of which contribute to the aging process. Conversely, maintaining low and stable insulin levels through a whole foods plant-based diet, regular exercise, and weight management can help promote longevity by supporting metabolic health, reducing inflammation, and improving cellular repair mechanisms. Monitoring insulin levels and adopting lifestyle strategies to optimize them may thus serve as a valuable approach for promoting healthy aging and extending lifespan.

4. Cortisol/DHEA Ratio

• Interpretation: Cortisol and DHEA (dehydroepiandrosterone) levels are important markers for longevity and anti-aging due to their roles in stress response and hormone balance. Cortisol, often referred to as the "stress hormone," is released in response to stressors and plays a crucial role in regulating metabolism, immune function, and inflammation. Chronic elevation of cortisol levels, commonly seen in individuals experiencing chronic stress, can contribute to accelerated aging, impaired immune function, and increased risk of age-related diseases such as cardiovascular disease and cognitive decline. Conversely, DHEA, known as the "youth hormone," exhibits anti-aging properties by promoting cellular repair, immune function, and cognitive health. Maintaining a balance between cortisol and DHEA levels is essential for longevity, as excessive cortisol production and diminished DHEA levels are associated with accelerated aging. Lifestyle factors such as stress management, adequate sleep, regular exercise, and a balanced diet can help optimize cortisol/DHEA ratios, thus promoting healthy aging and longevity. Monitoring cortisol and DHEA levels may provide valuable insights into an individual's overall health status and their potential risk for age-related diseases.

5. Cholesterol/HDL Ratio

• Conventional Range: <5.0 (average risk), <3.5 (low risk).
• Optimal Range: <3.0.
• Interpretation: The cholesterol/HDL ratio serves as a valuable marker for longevity and anti-aging, with a lower ratio indicating a reduced risk of cardiovascular disease and better overall health outcomes. High levels of LDL cholesterol and an elevated cholesterol/HDL ratio are associated with increased cardiovascular risk and accelerated aging. Adopting a plant-based diet has been shown to positively impact this ratio by reducing LDL cholesterol levels and increasing HDL cholesterol levels. Plant-based diets, rich in fruits, vegetables, whole grains, nuts, and seeds, are low in saturated fats and cholesterol, making them effective in improving lipid profiles and promoting cardiovascular health. Additionally, plant-based diets are abundant in phytonutrients, antioxidants, and fiber, which further contribute to their anti-aging properties by reducing inflammation, oxidative stress, and cellular damage. Incorporating plant-based foods into one's diet can thus optimize the cholesterol/HDL ratio, mitigate cardiovascular risk factors, and support healthy aging and longevity. 

6. Triglycerides/HDL Ratio

• Conventional Range: <2.0 (ideal), 2.0-4.0 (borderline high), >4.0 (high risk).
• Optimal Range: <1.0.
• Interpretation: The triglyceride/HDL ratio is emerging as a valuable marker for longevity and anti-aging, particularly in assessing cardiovascular health. This ratio reflects the balance between triglycerides, a type of fat in the blood associated with metabolic health, and HDL cholesterol, which is considered protective against heart disease. Research suggests that a high triglyceride/HDL ratio is associated with insulin resistance, inflammation, and an increased risk of cardiovascular disease, all of which can impact longevity. The Framingham Heart Study, a landmark longitudinal study initiated in 1948, has played a pivotal role in elucidating the relationship between various cardiovascular risk factors, including triglycerides, HDL cholesterol, and their ratios, and their impact on long-term health outcomes. Findings from the Framingham study and subsequent research have highlighted the importance of monitoring the triglyceride/HDL ratio as a predictor of cardiovascular risk and overall mortality. Lifestyle modifications such as adopting a healthy plant-based diet, regular exercise, weight management, and smoking cessation can help improve triglyceride levels, raise HDL cholesterol, and optimize the triglyceride/HDL ratio, thus promoting cardiovascular health and extending lifespan. Monitoring this ratio alongside other cardiovascular risk factors provides valuable insights into an individual's risk of age-related diseases and guides preventive strategies for healthy aging.

7. White Blood Cell Differential

• Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils: These components provide insights into immune function and inflammation. Functional medicine often focuses on balance and optimal ratios rather than absolute values. 
  • Neutrophil elevations can indicate hidden bacterial infections. 
  • Lymphocytes and Monocytes elevations can indicate hidden viral infections. 
  • Eosinophils elevations can indicate hidden parasitic infections and food allergies. 
  • Basophils elevations can indicate hidden parasitic and other infections. 

8. Ferritin

• Conventional Range: 12-300 ng/mL (adult females), 12-500 ng/mL (adult males).
• Optimal Range: 50-150 ng/mL.
• Interpretation: Ferritin is a marker of iron stores in the body. Low levels may indicate iron deficiency anemia, malabsorption, or increased stress demands, while high levels could suggest iron overload, chronic or acute (think silent) inflammation, a high meat-centric diet, or liver-related diseases. 

9. IGF-1 (Insulin-like Growth Factor 1)

• Conventional Range: Varies by age and sex.
• Optimal Range: Age-adjusted within the higher end of the reference range. (generally, less than 140) 
• Interpretation: The IGF-1 blood marker has garnered attention in relation to longevity due to its intricate relationship with the MTOR gene and the influence of nutrition, particularly plant-based diets. Insulin-like growth factor 1 (IGF-1) is a hormone that plays a crucial role in cell growth, proliferation, and aging processes. Elevated levels of IGF-1 have been associated with increased risk of age-related diseases and diminished longevity. The MTOR gene, which regulates cell growth and metabolism, is activated by IGF-1 signaling. Overactivation of MTOR has been linked to accelerated aging and age-related diseases. Plant-based nutrition, rich in phytonutrients, fiber, and antioxidants, has been shown to downregulate IGF-1 signaling and MTOR activity, potentially promoting longevity and healthy aging. Plant-based diets have also been associated with lower levels of IGF-1 and reduced risk of chronic diseases such as cardiovascular disease, cancer, and neurodegenerative disorders. By adopting a plant-based diet, individuals may modulate IGF-1 levels, inhibit MTOR activity, and promote cellular health, thus enhancing longevity and overall well-being. However, individual dietary needs vary, and consultation with a healthcare professional is advisable before making significant dietary changes.

10. 25-Hydroxy Vitamin D

• Conventional Range: <20 ng/mL (deficiency), 20-30 ng/mL (insufficiency), ≥30 ng/mL (sufficient).
• Optimal Range: >50 ng/mL (note: if you have autoimmune disease, it may need to be closer to 100 ng/ml) 
• Interpretation: Vitamin D levels are intricately linked to various aspects of health, including anti-aging, longevity, hormonal health, and immunity. Often referred to as the "sunshine vitamin," vitamin D plays a crucial role in bone health by facilitating calcium absorption and bone mineralization. However, emerging research suggests that vitamin D also exerts profound effects on aging processes, hormonal balance, and immune function. Adequate vitamin D levels have been associated with improved longevity and reduced risk of age-related diseases such as cardiovascular disease, cancer, and neurodegenerative disorders. Vitamin D influences hormonal health by modulating the production of sex hormones and insulin, thereby affecting metabolism, fertility, and overall well-being. Moreover, vitamin D plays a vital role in immune function, with deficiency linked to increased susceptibility to infections, autoimmune diseases, and inflammatory conditions. Optimizing vitamin D levels through safe sun exposure, dietary sources, and supplementation may thus support anti-aging mechanisms, promote hormonal balance, and bolster immune resilience, ultimately contributing to overall longevity and healthspan. Regular monitoring of vitamin D levels and consultation with a healthcare professional can help ensure optimal vitamin D status and support healthy aging.

11. Homocysteine

• Conventional Range: <15 µmol/L (desirable), 15-30 µmol/L (intermediate risk), >30 µmol/L (high risk).
• Optimal Range: <8 µmol/L.
• Interpretation: Homocysteine levels are increasingly recognized as a significant marker for longevity, anti-aging, and cardiovascular health due to their association with methylation processes and heart disease. Elevated homocysteine levels have been linked to increased risk of cardiovascular disease, including coronary artery disease, stroke, and peripheral artery disease. Homocysteine contributes to atherosclerosis by promoting inflammation, oxidative stress, and endothelial dysfunction, all of which are key factors in the development of cardiovascular complications. Moreover, high homocysteine levels have been implicated in impaired methylation processes, which play crucial roles in gene expression regulation, DNA repair, and cellular function. Dysregulated methylation has been associated with accelerated aging and increased susceptibility to age-related diseases. Lowering homocysteine levels through dietary interventions, supplementation with B vitamins (such as folate, vitamin B6, and vitamin B12), and lifestyle modifications has been shown to mitigate cardiovascular risk factors and promote healthy aging. Monitoring homocysteine levels may thus provide valuable insights into an individual's cardiovascular health and overall longevity, guiding preventive strategies to support optimal aging and well-being.

Conclusion

Interpreting blood work is not merely about deciphering numbers on a page—it's about understanding the intricate dance of biochemical processes within the body and harnessing that knowledge to promote optimal health and well-being. By recognizing the significance of markers like ferritin, IGF-1, 25-hydroxy vitamin D, and homocysteine, individuals can take proactive steps to address underlying imbalances and cultivate a state of vibrant health. Remember, your blood work is a roadmap to better health—let it guide you on your journey to wellness.