What is Biological Age? Understanding Health Age vs. Chronological Age

• People of the same chronological age may have different “ Biological Ages ” because the body is affected by behaviors and lifestyle accumulated over many years. Knowing one’s Biological Age helps us understand our health more deeply than just the age number and use that information to plan personalized health care.

What is Biological Age?

Biological Age (Biological Age or BioAge) is an assessment of “how old our body is in terms of health,” based on biological data (biomarkers) and the function of various body systems to reflect health status and bodily changes that may differ from chronological age (age by birthdate).

How is Biological Age assessed?

Currently, Biological Age can be evaluated from multiple biological dimensions, including genetic testing and biomarkers that reflect the function of different body systems, providing a deeper understanding of health beyond chronological age.

Have you ever wondered why people of the same age look differently healthy?

Some 60-year-olds remain strong, agile, and have physical performance similar to 45-year-olds, while some 45-year-olds suffer from multiple chronic diseases or feel their bodies age faster than expected.The answer maynot lie solely in the age on their ID card but in their “Biological Age,” reflecting whether their internal body is aging faster or slower than their actual age.

How do chronological age and Biological Age differ?

Chronological Age is the age counted from day, month, and year of birth. This number increases over time and cannot decrease.Meanwhile,Biological Age (BioAge) assesses the level of deterioration of cells, organs, and various body systems, based on biomarkers and body function, offering a clearer picture of internal health than the age on an ID card.

In other words, chronological age tells how long we have lived, while Biological Age tells how much our body has deteriorated.

Why does Biological Age vary among individuals?

Even if born in the same year, Biological Age can differ because the body is affected by behaviors and lifestyle accumulated over many years, such as

• Regular diet

Consuming high sugar, processed foods, fried foods, or excessive saturated fat can accelerate inflammation and cell deterioration, causing Biological Age to increase faster than expected.

• Exercise habits

Regular exercise, especially combining muscle strength training with aerobic activities, improves metabolism, reduces inflammation, and slows bodily deterioration.

• Sleep and stress

Insufficient sleep and chronic stress affect cell repair, hormone function, and immune system performance, potentially causing the body to age faster even when chronological age is still young.

What more does Biological Age testing reveal beyond just an age number?

Testing Biological Age is not only to show whether the body is “ older ” or “ younger ” than chronological age, but helps us understand deeper health dimensions such as how the body is changing and which signals deserve attention, to help plan personalized health care.

Currently, Biological Age assessment can be done through various methods such as epigenetic analysis or DNA methylation clocks, which study epigenetic changes associated with age, blood protein analysis (proteomics), and evaluation of biomarkers reflecting the function and health status of body systems.Key systems used in assessing Biological Age include:

Cardiovascular system

1. Assessed by blood vessel flexibility, lipid levels, and proteins indicating heart deterioration, helping evaluate if heart and vessel health matches chronological age and long-term cardiovascular risk. Brain and nervous system
2. Assessed for nerve cell deterioration, signal transmission ability, and risk of dementia. Immune and inflammatory systems
3. Assessed by natural killer (NK) cell integrity and inflammation markers. Chronic low-grade inflammation is linked to aging processes and many chronic diseases. Metabolic system
4. Assessed through blood sugar control, insulin resistance, lipid levels, and body composition such as abdominal fat, reflecting metabolic efficiency and future non-communicable disease risk. Liver system
5. Assessed for detoxification ability, fatty liver condition, and liver enzyme levels. Kidney system
6. Assessed for waste filtration efficiency and markers of kidney tissue deterioration. Respiratory system
7. Assessed for lung capacity, function, and respiratory epithelial cell deterioration. Musculoskeletal system
8. Assessed by bone density, muscle mass, strength, and recovery ability. Combining data from multiple systems helps identify which health areas need special care and enables doctors to design personalized health plans rather than one-size-fits-all approaches.

What does it mean if Biological Age is higher than chronological age?

If the evaluation shows Biological Age is higher than chronological age, it may indicate the body is experiencing some biological changes faster than peers or that certain health and behavioral factors require more attention.

However,

Biological Age is not a fixed number and should not be used alone to judge overall health because it can be influenced by many factors including sleep, diet, exercise, stress, metabolic health, risk factors, and chronic conditions. The important point

is not just knowing “how old our body is,” but discovering “ what might be accelerating our body’s aging and what we can do to change it.” Can Biological Age be lowered? How to reduce Biological Age? Biological Age can be improved because it varies with lifestyle and health care.

Health care principles are something everyone can start, but each person’s body may have systems that deteriorate faster and different aging accelerators. Some may need to focus on increasing muscle mass, others on improving sleep or stress, while some may need to prioritize metabolism, heart, or inflammation management.

What are the benefits of Biological Age testing and how to begin health care?

Biological Age testing reveals which systems are deteriorating faster than expected and where to start care. Doctors analyze test results along with health history and behaviors to design personalized care plans based on the 6 Pillars of Lifestyle Medicine, including:

1. Healthy Eating: Choose foods that slow deterioration

Reduce foods that accelerate cell aging such as sugar, highly processed foods, and trans fats, while increasing anti-inflammatory foods like colorful vegetables, antioxidants, and healthy fats like Omega-3. The goal is to reduce molecular-level inflammation, a key factor accelerating cell aging.

2. Exercise: Tailor physical activity to the body

Appropriate exercise varies per individual due to differences in body, fitness, and risk factors. Doctors use data on cardiovascular health, muscle mass and strength, and bone health to design personalized exercise plans to improve heart fitness, maintain muscle mass and strength, and support long-term bone health.

3. Restorative Sleep: Quality sleep for full body recovery

Maintain deep, continuous sleep for about 7–8 hours per night, as this is when the body releases growth hormone to repair tissues and support brain function.

4. Positive Social Connections: Good relationships promote physical and mental health

Having strong bonds with family, friends, or community that foster trust and support reduces stress hormone secretion and helps maintain telomere length, which is linked to cell lifespan.

5. Minimizing Risky Substances: Reduce factors that accelerate aging

Quit or reduce smoking, limit excessive alcohol, and avoid pollution such as PM2.5, as these generate free radicals that damage DNA and accelerate organ deterioration like liver and blood vessels.

6. Stress Management: Control stress before it harms health

Practices like meditation, deep breathing, or relaxing hobbies help manage stress. Chronic stress causes excess cortisol release, affecting immunity and accelerating system deterioration. Managing stress is like “stepping on the brakes” to prevent rapid Biological Age increase.

Who should consider Biological Age testing?

Biological Age testing may be an option for those wanting deeper health understanding beyond routine check-ups, especially to know if their internal health matches their chronological age and identify factors to prioritize for long-term health.

Testing is suitable for:

People with normal routine health check results but who want deeper health insights and preventive planning.Those noticing bodily changes such as easy fatigue, slower recovery, poor sleep, or reduced performance.

• People under high stress, with insufficient rest, or lifestyles that may affect long-term health.
• Individuals focusing on preventive health and seeking detailed data to adjust diet, exercise, sleep, and behaviors appropriately.
• Those prioritizing healthy aging and Healthspan, aiming to maintain good health and function as long as possible.
• The goal is not just longevity but maintaining health for as long as possible.

Modern health care focuses not only on Lifespan—the number of years lived—but increasingly on Healthspan—the period of life spent in good health and quality.

Understanding Biological Age helps us grasp our body’s status beyond chronological age. When doctors combine test data with health history, lifestyle, and risk factors, they can identify which health aspects require attention and which factors can still be changed. This information supports personalized health plans covering nutrition, exercise, sleep, stress management, and appropriate risk monitoring.

The purpose of Biological Age testing is not just to answer “How old is my body today?” but to use the information to answer “What should I care for or change today to maintain good health as long as possible?” This is the essence of Healthspan, focusing not only on adding years to life but adding healthy years to living.

Information by: Dr. Jitkae Thepchatree, MD.27727, Specialist in Preventive Medicine, Samitivej Sukhumvit Hospital