The concept of longevity medicine has transformed how we think about health. Rather than waiting for disease to develop, proactive individuals are now using blood testing to monitor key biomarkers that influence how well – and how long – they live. By tracking these markers and making targeted lifestyle interventions, you can optimise your healthspan and potentially slow the ageing process.
Here are eight essential biomarkers that longevity experts consider crucial for anyone serious about living a longer, healthier life.
1. HbA1c (Glycated Haemoglobin)
HbA1c measures your average blood sugar levels over the past two to three months, making it one of the most important biomarkers for longevity. Chronically elevated blood sugar accelerates ageing through a process called glycation, where sugar molecules attach to proteins and damage tissues throughout your body.
Optimal range for longevity: Below 5.4% (36 mmol/mol)
Why it matters: High HbA1c is associated with increased risk of cardiovascular disease, dementia, kidney disease, and accelerated biological ageing. Even levels within the "normal" range (5.7-6.4%) indicate pre-diabetes and increased disease risk.
How to improve it: Reduce refined carbohydrates, increase fibre intake, exercise regularly, and maintain a healthy weight. For more detailed information, read our guide on understanding A1C testing.
2. High-Sensitivity C-Reactive Protein (hs-CRP)
Chronic low-grade inflammation is increasingly recognised as a driver of ageing and age-related diseases – a concept scientists call "inflammaging." High-sensitivity CRP is one of the best markers for detecting this silent inflammation.
Optimal range for longevity: Below 1.0 mg/L
Why it matters: Elevated hs-CRP is linked to increased risk of heart disease, stroke, cancer, and cognitive decline. It reflects systemic inflammation that damages tissues over time.
How to improve it: Anti-inflammatory diet (rich in omega-3s, vegetables, and antioxidants), regular exercise, weight management, adequate sleep, and stress reduction. Learn more in our comprehensive guide to the C-Reactive Protein test.
3. Fasting Insulin
While most people focus on blood glucose, fasting insulin provides an earlier warning of metabolic dysfunction. Elevated insulin levels indicate insulin resistance – a condition where your body needs more insulin to control blood sugar – which can precede diabetes by years or even decades.
Optimal range for longevity: Below 5 μIU/mL (ideally 2-5 μIU/mL)
Why it matters: High insulin levels promote fat storage, inflammation, and cellular ageing. Insulin resistance is associated with virtually every major age-related disease, including heart disease, cancer, and Alzheimer's.
How to improve it: Time-restricted eating, reducing carbohydrate intake, resistance training, and adequate sleep. For detailed information, see our guide on insulin blood testing.
4. Lipid Profile (ApoB and LDL-P)
Traditional cholesterol panels measure LDL cholesterol concentration, but advanced lipid testing measures the actual number of atherogenic particles (ApoB or LDL-P). This provides a more accurate assessment of cardiovascular risk.
Optimal ranges for longevity:
Why it matters: Cardiovascular disease remains the leading cause of death globally. The lifetime exposure to atherogenic particles determines plaque buildup in arteries. Lower is better for longevity.
How to improve it: Reduce saturated fat and refined carbohydrates, increase fibre and omega-3 intake, exercise regularly, and consider medications if lifestyle changes are insufficient. Read our detailed guide on cholesterol testing.
5. Vitamin D
Vitamin D is not just a vitamin – it is a hormone that influences the expression of hundreds of genes throughout your body. Deficiency is remarkably common, particularly in the UK, and is associated with numerous health problems.
Optimal range for longevity: 100-150 nmol/L (40-60 ng/mL)
Why it matters: Low vitamin D is linked to increased risk of infections, autoimmune diseases, cardiovascular disease, cancer, cognitive decline, and all-cause mortality. It plays crucial roles in immune function, bone health, and cellular processes.
How to improve it: Sensible sun exposure, vitamin D3 supplementation (often 2000-5000 IU daily depending on baseline levels), and regular testing to ensure optimal levels.
6. Homocysteine
Homocysteine is an amino acid produced during protein metabolism. Elevated levels damage blood vessel walls, promote clotting, and are associated with cognitive decline. It is influenced by B vitamin status, particularly folate, B12, and B6.
Optimal range for longevity: Below 8 μmol/L
Why it matters: High homocysteine is an independent risk factor for cardiovascular disease, stroke, and dementia. It also indicates potential B vitamin deficiencies that affect numerous metabolic processes.
How to improve it: Ensure adequate intake of folate, vitamin B12, and B6 through diet or supplementation. Consider methylated B vitamins if you have genetic variants affecting methylation (MTHFR).
7. Thyroid Function (TSH, Free T3, Free T4)
Your thyroid controls your metabolism – literally how fast your body runs. Both underactive and overactive thyroid function affect longevity, with emerging evidence suggesting that optimal thyroid function sits within a narrower range than traditional "normal" values.
Optimal ranges for longevity:
Why it matters: Thyroid dysfunction affects energy, metabolism, cardiovascular health, cognitive function, and mood. Subclinical thyroid problems (within "normal" ranges but not optimal) can significantly impact quality of life and long-term health.
How to improve it: Ensure adequate iodine and selenium intake, manage stress, address underlying autoimmune conditions if present. Read more about thyroid health in our thyroid function guide.
8. Liver Enzymes (ALT, AST, GGT)
Liver enzymes are often overlooked in longevity discussions, but they provide crucial insights into metabolic health. Elevated levels – even within the "normal" range – can indicate fatty liver disease, which affects up to 30% of adults and is strongly associated with metabolic dysfunction.
Optimal ranges for longevity:
Why it matters: Elevated liver enzymes often indicate non-alcoholic fatty liver disease (NAFLD), which is associated with insulin resistance, cardiovascular disease, and increased mortality. GGT in particular is a sensitive marker of oxidative stress.
How to improve it: Reduce alcohol, lose excess weight, limit fructose and refined carbohydrates, exercise regularly, and consider liver-supporting supplements like milk thistle.
How Often Should You Test?
For proactive health monitoring, consider testing these biomarkers:
Tracking trends over time is more valuable than any single measurement. This allows you to see how your body responds to interventions and make data-driven adjustments.
The Bigger Picture
While these eight biomarkers provide crucial insights, longevity is multifaceted. Other important factors include:
Blood testing provides objective data to guide your health decisions, but it should complement – not replace – attention to these broader lifestyle factors.
Start Your Longevity Journey
Understanding your biomarkers is the first step toward optimising your healthspan. At [Private Blood Tests London](/), we offer comprehensive health screening packages that include these key longevity markers. Our CQC-registered clinic in South Kensington provides accurate testing and secure, fast results.
Explore our [health screening packages](/health-screening), learn about [how regular blood tests prevent health problems](/blog/how-regular-blood-tests-can-help-prevent-serious-health-problems), and see why an [annual blood test is your best health investment](/blog/why-an-annual-blood-test-could-be-the-best-health-investment-you-make).
Take control of your health trajectory – book your longevity blood panel today and start making data-driven decisions for a longer, healthier life.