This Is the #1 Blood Test Dr. Peter Attia Says You Need if You Want To Live to 100

Key Takeaways

• This article explores why understanding your blood markers, especially those beyond a standard annual checkup, is essential to preventing disease before it starts.
• Learn the five core blood tests Dr. Attia considers most predictive of long-term health, plus the additional panels he uses to track inflammation, metabolism, and nutrient balance.
• You’ll discover how these tests fit into a preventive health strategy, how often to take them, and how to use your results to optimize your daily habits for longevity.

You Already Know How to Live Healthy but Are You Testing for It

When it comes to living longer, you probably have the basics down. Eating plenty of vegetables? Check. Getting your steps in? Check. Prioritizing sleep? Check.

These habits are all scientifically proven to extend lifespan, but there’s another longevity practice that often gets overlooked: getting the right blood tests. Many people rely on standard panels from their annual physical, but longevity medicine specialists say those basic tests miss crucial markers that predict your future health.

Dr. Peter Attia, a physician focused on longevity and author of the bestselling book Outlive, has spent years identifying which blood tests provide the most valuable insights for preventing disease and extending healthspan. Unlike traditional medicine, which often waits until you’re sick to intervene, Dr. Attia’s approach focuses on catching problems decades before symptoms appear.

The Number One Most Important Blood Test To Get for Longevity

According to Dr. Attia’s framework, the single most important blood test for predicting cardiovascular disease is Apolipoprotein B (ApoB). This test measures the number of atherogenic lipoprotein particles in your blood, which are the particles that actually cause plaque buildup in your arteries.

Here’s why this matters: Traditional cholesterol panels measure LDL cholesterol, but Dr. Attia explains that LDL cholesterol only tells you about the cargo these particles carry, not how many particles you have. Two people can have the same LDL cholesterol number but vastly different numbers of particles. The person with more particles has significantly higher cardiovascular risk, even if their standard cholesterol numbers look fine.

Dr. Attia recommends an ideal ApoB range of 20 to 30 mg/dL, with anything under 60 mg/dL considered acceptable. For context, many people walking around with “normal” cholesterol have ApoB levels well above 100 mg/dL, putting them at substantial risk for heart attack and stroke without even knowing it.

The beauty of ApoB is its simplicity. It’s a single number that gives you a clearer picture of cardiovascular risk than an entire standard lipid panel. Dr. Attia considers it such a crucial marker that he recommends tracking it regularly, especially as you age.

The 4 Other Blood Tests Dr. Attia Recommends Getting

Beyond ApoB, Dr. Attia has identified four other blood tests that provide critical insights into your longevity potential. Together, these five tests form what he calls his “top five” for disease prevention.

Lipoprotein(a)

This genetic marker for cardiovascular disease should be tested at least once in your lifetime to establish your baseline risk. Unlike other lipid markers, Lp(a) is primarily determined by genetics and doesn’t change much with diet or exercise.

Dr. Attia explains that Lp(a) acts as an independent risk factor for heart disease. An ideal level is below 14 mg/dL, while anything above 50 mg/dL indicates significantly elevated risk. If you have high Lp(a), you’ll need to be even more aggressive about managing other cardiovascular risk factors.

Oral Glucose Tolerance Test (OGTT) With Insulin Response

This test is Dr. Attia’s gold standard for evaluating metabolic health and catching insulin resistance years before it becomes diabetes. Unlike a simple fasting glucose test, the OGTT tracks both glucose and insulin levels over two hours after you consume a glucose drink.

Why does this matter? Many people have perfectly normal fasting glucose but already have significant insulin resistance. Their bodies are producing excessive amounts of insulin to keep blood sugar in check. This silent metabolic dysfunction can persist for years or even decades before showing up on standard tests.

Dr. Attia looks for glucose levels that stay below 140 mg/dL at the one-hour mark and return close to baseline by two hours. He also tracks insulin response, as excessive insulin spikes indicate your body is struggling to manage blood sugar efficiently.

Alanine Transaminase (ALT)

This liver enzyme provides crucial insights into liver health and metabolic function. Elevated ALT can signal liver injury, fatty liver disease, or other metabolic problems that often go undetected until they become serious.

Dr. Attia emphasizes that fatty liver disease has become epidemic, affecting up to 30% of adults in developed countries. The condition increases risk for cirrhosis, liver cancer, and cardiovascular disease, yet many people don’t discover they have it until significant damage has occurred. Regular ALT testing helps catch these issues early when they’re still reversible through lifestyle changes.

APOE Genotype

An APOE test assesses your risk for Alzheimer’s disease and cardiovascular disease by identifying which variants of the APOE gene you carry. The APOE4 variant, in particular, significantly increases Alzheimer’s risk.

Knowing your APOE status allows you to personalize your prevention strategy. People with APOE4 variants may benefit from more aggressive cardiovascular risk management, specific dietary approaches, and lifestyle interventions that research suggests may reduce Alzheimer’s risk. While some people prefer not to know their genetic risk, Dr. Attia argues that the information empowers you to take proactive steps while you’re still healthy.

Beyond the Top Five: Building a Complete Longevity Panel

Dr. Attia often recommends additional tests for a more comprehensive picture of healthspan potential. These include inflammatory markers like high-sensitivity C-reactive protein (hs-CRP), which tracks systemic inflammation, and markers like oxidized LDL and homocysteine that provide additional cardiovascular insights.

For metabolic health, he emphasizes tracking fasting insulin and hemoglobin A1c to catch insulin resistance early. Hormonal panels including testosterone, thyroid function, and cortisol help optimize energy, mood, and metabolic function. Nutritional markers like vitamin D, magnesium, and omega-3 index ensure you’re not developing deficiencies that could undermine longevity.

Some patients also benefit from continuous glucose monitors, which track blood sugar in real time and reveal how specific foods and activities affect metabolic health. This technology has revolutionized the way people understand their individual responses to diet and exercise.

How Often Should You Get These Tests?

The frequency of testing depends on your current health status and risk factors. Dr. Attia typically recommends comprehensive panels annually for most patients, with more frequent monitoring if you’re actively working to improve specific markers or have elevated risk factors.

The key is establishing your baseline numbers while you’re still healthy, then tracking changes over time. Longevity medicine isn’t about waiting until something goes wrong. It’s about optimizing your biology for the long game, catching subtle shifts before they become serious problems.

The Bigger Picture of Longevity

While blood work provides invaluable insights, Dr. Attia emphasizes that longevity extends far beyond lab numbers. The fundamentals still matter enormously: regular exercise (especially strength training), a nutrient-dense diet, quality sleep, stress management, and strong social connections all play crucial roles in healthspan.

Think of blood tests as your scorecard, showing whether your daily habits are moving you toward or away from your longevity goals. They provide objective feedback and early warnings, allowing you to adjust your strategy before problems become irreversible.

The exciting news is that many of the markers Dr. Attia tracks are highly responsive to lifestyle changes. Improving your diet, increasing physical activity, optimizing sleep, and managing stress can dramatically improve metabolic health, reduce inflammation, and lower cardiovascular risk. Even genetic risk factors like APOE4 can be partially offset through aggressive prevention strategies.

Taking Action for Your Future Self

Getting the right blood tests is an investment in your future health. While insurance may not cover all of Dr. Attia’s recommended panels, many longevity-focused physicians and direct-to-consumer lab services now offer comprehensive testing packages based on his framework.

The most important step is finding a healthcare provider who thinks about disease prevention rather than just disease treatment. Look for doctors who are willing to dig deeper than standard panels and who view optimal health as more than just the absence of disease.

Your body is constantly sending signals about its internal state. The right blood tests help you decode those signals, giving you the information you need to make choices today that will pay dividends for decades to come. When combined with healthy daily habits and regular medical care, comprehensive blood work becomes a powerful tool for extending not just lifespan, but healthspan, the years you live in good health.

A Simple Game Plan For Your Next Appointment

1. Put your annual checkup on the calendar.
2. Bring a short list of changes since your last visit such as energy, sleep, weight, exercise, and any new symptoms.
3. Ask for the core panel
   • ApoB
   • Lp(a) baseline if you have never checked it
   • Fasting insulin and A1c
   • Comprehensive metabolic panel with ALT and kidney function
   • Consider an oral glucose tolerance test with insulin if your metabolic risk is rising
4. If your risk is still unclear, ask whether hs CRP, homocysteine, or cardiac imaging would meaningfully change your plan.
5. Pick one lifestyle upgrade you can keep such as more daily steps or two strength sessions each week.
6. Book your follow up before you leave.
   • You can price and order many of these labs through Walk-In Lab where available. Coordinate results with your clinician so your plan stays personalized.

Quick Reference / Overview of Tests

Test	Primary biomarker(s)	Why it matters	Suggested target / flag (per article)	How often
Apolipoprotein B (ApoB)	ApoB (mg/dL)	Best single marker of atherogenic particle burden and CV risk.	Ideal: 20–30 mg/dL; Acceptable: <60 mg/dL. ≥100 mg/dL common but risky.	Every 3–6 months if optimizing; at least annually.
Lipoprotein(a) [Lp(a)]	Lp(a) (mg/dL or nmol/L)	Independent, largely genetic CV risk factor.	Ideal: <14 mg/dL; >50 mg/dL = high risk.	At least once in adulthood (repeat if therapy/risk changes).
OGTT + Insulin	Glucose & insulin over 2 hours	Detects early insulin resistance missed by fasting glucose.	1-hr glucose <140 mg/dL; ~baseline by 2 hr; avoid excessive insulin spikes.	Periodically (e.g., annually or when risk changes).
Alanine Transaminase (ALT)	ALT (U/L)	Liver injury & fatty liver screen; key metabolic risk.	Lower is better; elevations need follow-up.	Annually; more often if elevated.
APOE Genotype	APOE alleles (E2/E3/E4)	Guides Alzheimer’s & CV prevention strategy.	Presence of APOE4 increases risk.	One-time test.
High-sensitivity C-reactive protein (hs-CRP)	hs-CRP (mg/L)	Systemic inflammation marker linked to CV/overall risk.	Lower is better; track trends.	Annually.
Oxidized LDL	Oxidized LDL	Refines atherogenic/oxidative risk profiling.	Lower is better.	Annually / when refining CV risk.
Homocysteine	Homocysteine (µmol/L)	Elevations linked to vascular risk.	Lower is better.	Annually or as indicated.
Fasting insulin	Insulin (µU/mL)	Early signal of insulin resistance.	Lower is better; interpret with glucose/HOMA-IR.	Annually or during metabolic workups.
Hemoglobin A1c (HbA1c)	% glycated hemoglobin	3-month average glycemia; diabetes risk.	Lower/normal is better (no number provided in article).	Annually or more often if elevated.
Testosterone	Total & free testosterone	Energy, body composition, metabolic health context.	Optimize to clinical norms.	Annually or if symptomatic.
Thyroid panel	TSH, Free T4, Free T3 (± antibodies)	Metabolic rate, energy, mood; rule out thyroid disease.	Within healthy ranges.	Annually or if symptomatic.
Cortisol	AM serum cortisol (± pattern testing)	Stress/adrenal context affecting metabolism & sleep.	Interpret clinically.	As indicated; periodically.
Vitamin D	25(OH)D	Bone, immune, metabolic effects.	Optimize within normal range.	Annually or with supplementation changes.
Magnesium	Serum or RBC magnesium	Common deficiency; cardiac/metabolic roles.	Within normal range; RBC may be more informative.	Annually; re-check if supplementing.
Omega-3 Index	EPA+DHA % in RBC membranes	Cardiometabolic & inflammatory health context.	Higher/optimized within reference range.	Annually or semiannually.
(Adjunct) Continuous Glucose Monitor (CGM)	Real-time glucose (interstitial)	Personal glycemic responses to diet/activity.	Target stable post-meal patterns; minimize spikes.	Time-boxed trials or ongoing during interventions.

Disclaimer

Recommended ranges and testing frequencies are generalized guidelines and will always vary by laboratory methods, physician interpretation, and your individual medical history, genetics, and current health status. Normal values can differ between labs due to calibration standards and assay techniques, and optimal targets may change depending on your doctor’s clinical judgment and personal risk profile.

Always review your results and next steps with a qualified healthcare provider.