Most blood tests are designed to detect disease. Blood ranges are based on people who are unwell
If your goal is not simply to avoid disease, but to maximise energy, maintain cognitive function, preserve muscle mass and extend your healthy lifespan, then a different approach is required.
Many people are told their results are "normal" while still experiencing fatigue, declining performance, weight gain, poor recovery, low libido and increasing cardiovascular risk.
The reality is that normal and optimal are not the same thing.
Pathology reference ranges are designed to identify disease. Healthy aging requires a focus on optimal biomarker ranges associated with longevity, cardiovascular protection, metabolic health and resilience.
Nitric Oxide: The Master Molecule of Healthy Aging
If there is one molecule that sits at the centre of healthy aging, it is nitric oxide.
Nitric oxide (NO) is a signalling molecule produced naturally by the body that controls blood flow, oxygen delivery, nutrient transport, mitochondrial function and cellular communication.
Virtually every organ system depends on adequate nitric oxide production.
Nitric oxide supports:
• Healthy circulation
• Blood pressure regulation
• Oxygen delivery to tissues
• Mitochondrial energy production
• Brain function and cognition
• Exercise performance
• Muscle recovery
• Sexual health
• Immune function
• Nutrient delivery to cells
Research suggests nitric oxide production declines significantly with age. By middle age, many people have lost approximately 50% of their nitric oxide production capacity.
As nitric oxide declines:
• Blood vessels become less flexible
• Nutrient delivery decreases
• Mitochondrial energy production falls
• Recovery slows
• Blood pressure often rises
• Cardiovascular risk increases
This is why nitric oxide is often referred to as the master molecule of healthy aging.
Why Testing Nitric Oxide Matters
You cannot optimise what you do not measure.
Salivary nitric oxide testing provides a practical way to assess nitric oxide production and bioavailability.
General guide:
• Low: Below 150 mg/L
• Borderline: 150–300 mg/L
• Optimal: Above 350 mg/L
Many people with cardiovascular risk factors, metabolic dysfunction, poor oral health, chronic stress and aging-related symptoms have suboptimal nitric oxide levels.
Testing allows you to establish a baseline and monitor improvement over time.
The Four Pillars of Cardiovascular Longevity
While dozens of blood tests can provide useful information, four markers stand above the rest when assessing long-term cardiovascular health.
1. Nitric Oxide
Target: Above 350 mg/L
Nitric oxide influences blood flow, oxygen delivery and endothelial function. Without adequate nitric oxide, cardiovascular health becomes increasingly difficult to maintain.
2. ApoB
Target: Below 0.8 g/L
ApoB measures the number of potentially harmful lipoprotein particles circulating in the bloodstream.
Many experts now consider ApoB to be one of the most important cholesterol-related markers for assessing cardiovascular risk.
3. hs-CRP
Target: Below 1.0 mg/L
Ideal: Below 0.5 mg/L
High-sensitivity C-reactive protein measures inflammation.
Even when cholesterol appears healthy, elevated inflammation can significantly increase cardiovascular risk.
4. Coronary Artery Calcium (CAC) Score
Target: Zero
Unlike blood tests, a CAC scan measures actual calcified plaque within the coronary arteries.
A CAC score of zero is one of the strongest indicators of low cardiovascular risk.
Metabolic Health Markers
Metabolic dysfunction often develops silently for years before symptoms appear.
Fasting Glucose
Optimal: 4.2–4.9 mmol/L
HbA1c
Optimal: 4.8–5.2%
HbA1c reflects average blood glucose levels over approximately three months.
Higher levels are associated with accelerated aging, cardiovascular disease and cognitive decline.
Fasting Insulin
Optimal: 2–6 mIU/L
One of the most valuable early indicators of insulin resistance.
HOMA-IR
Optimal: Below 1.5
Provides insight into insulin sensitivity and metabolic efficiency.
C-Peptide
Optimal: 0.6–1.1 nmol/L
A useful marker of pancreatic insulin production.
Inflammation and Immune Resilience
Chronic inflammation is one of the strongest drivers of aging and disease.
hs-CRP
Optimal: Below 1.0 mg/L
Homocysteine
Optimal: 5–8 µmol/L
Elevated homocysteine is associated with cardiovascular disease, stroke and cognitive decline.
Fibrinogen
Optimal: 2.0–3.0 g/L
High fibrinogen may increase clotting risk and vascular inflammation.
Neutrophil-to-Lymphocyte Ratio (NLR)
Optimal: Below 2.0
An emerging marker of biological stress and systemic inflammation.
Lipid Markers for Longevity
Traditional cholesterol testing only tells part of the story.
ApoB
Optimal: Below 0.8 g/L
ApoB:ApoA1 Ratio
Optimal: Below 0.6
Lp(a)
Optimal: Below 75 nmol/L
Lp(a) is largely genetically determined and is increasingly recognised as an important cardiovascular risk factor.
HDL Cholesterol
Optimal: Above 1.5 mmol/L
Triglycerides
Optimal: 0.5–1.0 mmol/L
A low triglyceride-to-HDL ratio is one of the strongest indicators of metabolic health.
Nutrition and Micronutrient Markers
Nutrient deficiencies often contribute to symptoms long before disease develops.
Vitamin D
Optimal: 75–125 nmol/L
Supports immune function, bone health, hormone production and cardiovascular health.
Omega-3 Index
Optimal: 8–12%
Higher omega-3 levels are associated with improved cardiovascular and cognitive outcomes.
Vitamin B12
Optimal: 500–900 pmol/L
Critical for energy production, neurological function and methylation.
Ferritin
Optimal:
Men: 50–150 µg/L
Women: 40–120 µg/L
Reflects stored iron levels.
Magnesium (RBC)
Optimal: 0.85–1.10 mmol/L
Supports over 300 enzymatic reactions within the body.
Zinc
Optimal: 12–18 µmol/L
Important for immune function, hormone production and tissue repair.
Selenium
Optimal: 0.9–1.2 µmol/L
A powerful antioxidant mineral involved in thyroid function and cellular protection.
Hormones and Healthy Aging
Hormones play a significant role in vitality, body composition, cognition and resilience.
Total Testosterone
Optimal: 15–25 nmol/L
Free Testosterone
Optimal: 250–450 pmol/L
DHEA-S
Optimal: Upper third of the age-adjusted range
SHBG
Optimal: 30–60 nmol/L
Free T3
Optimal: Upper half of the reference range
Morning Cortisol
Optimal: Balanced within the upper physiological range
Hormonal optimisation is not about achieving extreme levels but maintaining healthy physiological function as we age.
Kidney and Liver Health
The health of your kidneys and liver strongly influences longevity.
eGFR
Optimal: Above 90
Albumin
Optimal: 42–50 g/L
ALT
Optimal: Below 25 U/L
GGT
Optimal: Below 30 U/L
These markers provide insight into detoxification capacity, metabolic health and overall physiological resilience.
The Goal Is Not Normal
One of the biggest mistakes people make is assuming that a normal result is automatically an optimal result.
Healthy aging requires a proactive approach.
The objective is to create an internal environment characterised by:
• Strong nitric oxide production
• Low inflammation
• Excellent insulin sensitivity
• Healthy blood flow
• Optimal nutrient status
• Hormonal resilience
• Strong mitochondrial function
Start With Nitric Oxide
If there is one marker that deserves greater attention in the healthy aging conversation, it is nitric oxide.
Nitric oxide influences virtually every aspect of cardiovascular health and cellular performance.
Without adequate nitric oxide, oxygen delivery declines, nutrient transport slows, blood vessels stiffen and cellular communication becomes impaired.
When nitric oxide production is restored, every organ system benefits.
Test it.
Measure it.
Optimise it.
Because healthy aging begins with healthy blood flow.
