What Is Longevity? The Science of Living Longer and Healthier
Longevity means more than simply living to an old age.
In modern health and ageing research, longevity increasingly refers to the pursuit of a longer life combined with more years of good physical, cognitive and emotional health.
This distinction is important because living longer does not necessarily mean living better. Advances in medicine, sanitation, vaccination, nutrition and healthcare have helped people survive conditions that would once have shortened life dramatically. But many people still spend a significant part of later life managing chronic disease, physical limitations or loss of independence.
The real aim of modern longevity science is therefore not just to extend lifespan, but to extend healthspan.
Harvard Health describes the goal of longevity in similar terms: more years of life, but crucially more of those years spent moving freely, thinking clearly, remaining independent and staying engaged with the people and activities that matter.
Read Harvard Health's guide to the five pillars of longevity
Longevity is the pursuit of a longer life while preserving health, function and independence for as much of that life as possible.
Longevity, Lifespan and Healthspan: What Is the Difference?
The terms are often used interchangeably, but they describe different ideas.
Lifespan is the simplest concept. It is the chronological period between birth and death.
Longevity refers more broadly to long survival, particularly survival beyond what is typical for a population.
Healthspan attempts to describe the part of life spent in relatively good health, without substantial chronic disease or loss of physical and mental independence.
| Term | Meaning |
|---|---|
| Lifespan | The total length of a person's life from birth until death. |
| Longevity | The capacity or tendency to live for a long time, often beyond the average for a population. |
| Healthspan | The period of life spent in relatively good health and without major functional decline or disabling disease. |
Healthspan sounds straightforward, but scientifically it is surprisingly difficult to define precisely.
A 2025 systematic review examined more than 200 scientific publications and found a very large number of different healthspan definitions. Some focused on chronic disease, others on disability or physical performance, while relatively few incorporated subjective quality of life.
Read the systematic review of healthspan definitions
That uncertainty does not make the concept meaningless. It simply shows that ageing is more complicated than dividing life neatly into "healthy" and "unhealthy" years.
For most people, the practical objective remains clear: delay major disease and disability while maintaining the ability to think, move, work, socialise and live independently.
Why Longevity Science Is Changing
For much of medical history, medicine has largely treated diseases individually.
Heart disease is treated as heart disease. Diabetes is treated as diabetes. Dementia is treated as dementia. Cancer is treated as cancer.
Ageing research increasingly asks another question:
Are there underlying biological processes of ageing that influence the risk of many different diseases at the same time?
Researchers are investigating processes involving inflammation, DNA damage, mitochondrial function, cellular senescence, epigenetic changes, nutrient sensing, protein maintenance and other biological systems.
This does not mean ageing has become one single treatable disease. Many proposed anti-ageing interventions remain experimental.
But the scientific question has shifted from simply asking how to treat diseases associated with old age towards also asking what determines why some people remain remarkably healthy at very advanced ages.
What Can a 117-Year-Old Teach Us About Longevity?
One of the most fascinating recent studies in longevity science examined Maria Branyas, who lived beyond the age of 117.
Researchers obtained biological samples from her and performed an unusually detailed analysis covering her genome, epigenome, proteins, metabolites, immune system and gut microbiome.
The peer-reviewed research, published in Cell Reports Medicine, found something particularly interesting.
Branyas did not simply appear biologically young in every respect.
Some parts of her biology showed unmistakable signs of extreme ageing. Her telomeres were very short, for example, and researchers identified age-associated changes within parts of her immune system.
Yet at the same time she exhibited characteristics that appeared unusually protective.
- Low systemic inflammation
- A gut microbiome rich in potentially beneficial bacteria
- Genetic characteristics associated with cardiovascular and neurological protection
- Favourable lipid metabolism
- Some epigenetic measurements suggesting a younger biological profile than her chronological age
This combination is important.
It suggests that extreme longevity may not require avoiding every biological feature of ageing. Instead, some extremely long-lived people may experience profound ageing while simultaneously possessing protective characteristics that reduce the likelihood of age-related disease.
Read the original supercentenarian study on PubMed
Read the ScienceDaily summary of the research
The researchers caution against treating a study of one exceptional individual as a recipe for living to 117.
It cannot tell us exactly which aspects of her biology resulted from genetics, lifestyle, environment or chance.
But the research helps illustrate an increasingly important idea:
Ageing and age-related disease are closely connected, but they are not exactly the same thing.
Is Longevity Determined by Genetics?
Genetics clearly influence how people age.
Some inherited variants influence cholesterol metabolism, cardiovascular risk, cancer susceptibility, inflammation, neurological disease and numerous other processes relevant to lifespan.
But genetics are not destiny.
Estimates of the genetic contribution to differences in human lifespan vary considerably depending on the population and methodology used.
Lifestyle, environmental exposure, healthcare, socioeconomic circumstances, behaviour and random biological events also contribute to how people age.
For individuals, that distinction matters enormously.
You cannot change the DNA you inherited.
You can influence many of the conditions in which that DNA operates.
The Five Pillars of Longevity
Harvard Health identifies five lifestyle domains that repeatedly emerge in longevity research:
- Movement
- Nutrition
- Sleep
- Stress management
- Social connection
Read the full Harvard Health longevity article
None of these is particularly exotic.
That may be one of the most important lessons in longevity science.
Despite enormous commercial interest in biological-age testing, supplements, drugs and advanced interventions, many of the strongest associations with long-term health still involve behaviours medicine has recommended for decades.
1. Movement and Fitness
Exercise is one of the strongest areas of longevity evidence.
This is not simply because exercise burns calories.
Physical activity influences cardiovascular fitness, insulin sensitivity, muscle mass, bone health, blood pressure, brain function and physical independence.
Cardiorespiratory fitness is particularly important.
A 2024 systematic review and meta-analysis encompassing more than 20 million observations found cardiorespiratory fitness to be a strong and consistent predictor of illness and mortality. Higher fitness was associated with substantially lower all-cause mortality risk.
Read the cardiorespiratory fitness and mortality review
Strength matters too.
A meta-analysis examining resistance training found that people who performed some resistance training had a lower risk of all-cause mortality than those who performed none, although observational findings like these cannot prove that resistance training alone caused the reduction.
Read the resistance training and mortality meta-analysis
For longevity, the objective is not simply being thin.
It is building enough physical capacity to remain capable as you grow older.
2. Nutrition
There is no scientifically established single "longevity diet".
However, dietary patterns consistently associated with better long-term outcomes tend to share common characteristics.
They generally emphasise foods such as:
- Vegetables
- Fruit
- Legumes
- Whole grains
- Nuts and seeds
- Fish
- Healthier sources of fat
- Adequate protein
They also tend to limit excessive consumption of highly processed foods, refined carbohydrates and foods with low nutritional value.
The Mediterranean diet is one of the most extensively studied dietary patterns in relation to healthy ageing.
A 2024 meta-analysis involving hundreds of thousands of older adults found that greater adherence to a Mediterranean dietary pattern was associated with lower all-cause and cardiovascular mortality.
Because much of the underlying evidence is observational, this should be interpreted as an association rather than proof that one specific diet directly extends human lifespan.
Read the Mediterranean diet and mortality meta-analysis
For older adults, nutrition also needs to support muscle preservation.
That makes sufficient protein, adequate overall nutrition and resistance training particularly important.
3. Sleep
Sleep is sometimes treated simply as recovery from life.
Biologically, it is part of life.
Sleep influences neurological function, metabolic regulation, appetite, stress hormones, cardiovascular physiology and immune function.
Harvard's longevity guidance recommends that most adults aim for roughly seven to eight hours of sleep each night, while also emphasising consistency.
Read Harvard's longevity guidance on sleep
Population research has found relationships between habitual sleep duration and mortality, although these findings need careful interpretation.
Very short and very long habitual sleep can both be associated with poorer outcomes. Long sleep can also occur because of underlying illness, meaning that association does not necessarily prove that sleep duration itself caused the increased risk.
The practical lesson is not that everyone must sleep exactly the same number of hours.
It is that chronic poor-quality or insufficient sleep should not be dismissed as harmless.
4. Stress and Recovery
Humans need a stress response.
Short-term stress helps us react to threats, concentrate, exercise and adapt.
The problem is persistent stress without adequate recovery.
Chronic psychological stress can interact with sleep, blood pressure, metabolism, behaviour and immune regulation.
Stress management therefore does not necessarily mean eliminating demanding work or avoiding every stressful situation.
It can mean building mechanisms for recovery.
Exercise, adequate sleep, time outdoors, relaxation, supportive relationships and genuine periods of mental disengagement can all contribute.
5. Social Connection
Social relationships may be one of the most underestimated parts of longevity.
People often monitor calories, protein, exercise, sleep and supplements while paying much less attention to relationships.
Yet loneliness and social isolation are repeatedly associated with poorer physical and mental health outcomes.
A 2025 systematic review covering 86 studies found loneliness, social isolation and living alone were associated with greater mortality risk in older adults.
Read the social isolation and mortality systematic review
This is one reason social connection belongs alongside exercise, nutrition and sleep rather than being treated merely as a lifestyle preference.
Healthy longevity is partly biological.
It is also social.
Preventive Healthcare and Longevity
Lifestyle is fundamental, but it does not replace medicine.
Blood pressure, cholesterol, diabetes, vaccination, cancer screening and other areas of preventive healthcare can have enormous effects on long-term health.
The most credible longevity strategy is therefore not a choice between "natural health" and conventional medicine.
It is usually a combination of:
- Preventive healthcare
- Healthy lifestyle habits
- Risk-factor management
- Early diagnosis where appropriate
- Evidence-based treatment
What Is Biological Age?
Your chronological age is straightforward.
If you were born 50 years ago, your chronological age is 50.
Biological age attempts to answer a different question:
How old does your biology appear to be?
Researchers have developed methods using DNA methylation patterns, blood biomarkers, physical performance, organ function and other measurements to estimate aspects of biological ageing.
Some of the best-known approaches are known as epigenetic clocks.
The science is interesting, but consumers should understand the limitations.
There is no universally accepted single measurement of biological age, and different tests can produce different answers because they measure different aspects of ageing.
The Maria Branyas research illustrates this complexity particularly well. Some parts of her biology looked extremely old, while other molecular characteristics appeared unusually youthful.
Biological age should therefore not be treated as one definitive number that summarises the entire human body.
What Is Longevity Medicine?
Longevity medicine is an emerging term for healthcare that attempts to preserve health and function before major age-related disease develops.
At its most evidence-based, this overlaps substantially with preventive medicine.
That can involve:
- Monitoring and controlling blood pressure
- Managing cholesterol
- Monitoring blood glucose
- Screening appropriately for disease
- Maintaining a healthy body composition
- Exercise
- Nutrition
- Sleep
- Smoking cessation
At the more experimental end of longevity medicine are interventions intended to influence specific biological pathways associated with ageing.
The quality of evidence varies enormously between these two ends of the spectrum.
This is why a credible longevity strategy should distinguish between interventions that already have strong human evidence and promising interventions whose effects on human healthspan remain uncertain.
What Role Do Supplements Play in Longevity?
Supplements are one of the most visible parts of the modern longevity industry, but they should not be confused with the foundations of longevity.
No supplement can fully compensate for smoking, severe inactivity, chronically poor sleep, uncontrolled high blood pressure or a consistently inadequate diet.
Supplement evidence also varies dramatically.
Some nutrients have well-established roles in correcting deficiency or supporting particular physiological functions.
Other compounds associated with longevity have interesting mechanistic or early-stage human evidence but have never been shown to extend human lifespan.
At The Longevity Shop, we believe longevity supplements should be evaluated according to:
- The quality of human evidence
- The actual ingredient and dose
- Manufacturing and testing quality
- Relevance to the individual
- Whether the claims being made are proportional to the evidence
This distinction is important because a supplement can have a measurable biological effect without being proven to make people live longer.
Does NMN Extend Lifespan?
NMN is a useful example of the difference between biological interest and proven longevity outcomes.
NMN, or nicotinamide mononucleotide, is involved in pathways that produce NAD+, a coenzyme involved in cellular metabolism.
Human clinical trials have demonstrated that oral NMN can increase NAD-related biomarkers.
However, NMN has not been shown to extend human lifespan.
That does not mean the research is unimportant.
It means the evidence should be described accurately.
If you want to explore NMN in greater detail, see our guides to the best NMN supplements in the UK and liposomal NMN vs regular NMN.
Can We Slow Ageing?
That depends on what is meant by "slow ageing".
There is strong evidence that people can reduce the risk of many diseases associated with ageing through exercise, good nutrition, avoiding smoking, controlling cardiovascular risk factors, maintaining social connection and obtaining appropriate healthcare.
Whether humans can directly and substantially alter the underlying rate of biological ageing is a much more difficult question.
Researchers are studying:
- Cellular senescence
- Epigenetic changes
- Mitochondrial biology
- Chronic inflammation
- Nutrient-sensing pathways
- DNA damage and repair
- Protein maintenance
Some interventions produce striking effects in laboratory animals.
Translating those findings into meaningful extensions of human healthspan or lifespan is considerably more difficult.
That gap between exciting biology and demonstrated human benefit is one of the most important things to understand about longevity science.
Is There a Secret to Living Longer?
Probably not one secret.
Extreme longevity appears to emerge from a complicated interaction between genetics, environment, lifestyle, healthcare and chance.
The Maria Branyas study did not reveal one magical biological pathway.
It identified a mixture of advanced ageing and unusual protection across many biological systems.
Likewise, lifestyle research does not identify one perfect food or one perfect exercise.
Longevity appears to be cumulative.
- Cardiovascular fitness matters.
- Strength matters.
- Nutrition matters.
- Sleep matters.
- Smoking status matters.
- Metabolic health matters.
- Relationships matter.
- Preventive healthcare matters.
Those factors operate together over years and decades.
The Future of Longevity Science
Longevity science is advancing rapidly.
Researchers can now study humans across the genome, epigenome, proteome, metabolome, microbiome and immune system at the same time.
This type of multi-omic research may eventually help scientists understand why some people remain unusually resilient despite advanced age.
The study of Maria Branyas provides one of the most detailed examples so far.
The next phase will be more difficult.
Scientists need to determine which biological characteristics actually cause healthier ageing, which merely accompany it, and which can safely be modified.
That will require larger longitudinal studies and carefully controlled clinical trials.
The goal should not be to turn every promising laboratory finding into an anti-ageing product.
It should be to identify interventions that meaningfully increase the years during which people remain healthy and functional.
Frequently Asked Questions About Longevity
What does longevity mean?
Longevity means living for a long time. In modern health science, it is increasingly discussed alongside healthspan, meaning the objective is not only longer survival but also maintaining health, independence and function for as much of life as possible.
What is the difference between lifespan and longevity?
Lifespan is the length of an individual's life from birth until death. Longevity describes the capacity or tendency to live for a long time, often beyond the average for a population.
What is healthspan?
Healthspan generally refers to the period of life spent in good health without major functional decline or disabling chronic disease. Scientists do not yet use one universally accepted definition.
What are the five pillars of longevity?
Harvard Health identifies movement, nutrition, sleep, stress management and social connection as five important lifestyle domains that repeatedly appear in longevity research.
Is longevity mostly genetic?
No. Genetics play an important role, but lifestyle, environment, healthcare, social circumstances and other factors also contribute to differences in how people age.
What is the most important factor for longevity?
There is no single universally dominant factor. However, cardiorespiratory fitness has one of the strongest associations with mortality seen in observational research, while resistance training, nutrition, sleep, avoiding smoking, social connection and cardiovascular risk management are also important.
Do longevity supplements make you live longer?
No currently available dietary supplement has been demonstrated to substantially extend lifespan in healthy humans. Individual supplements may have evidence for specific physiological effects, but those claims should not be confused with proof of longer human life.
Can you reduce your biological age?
Some interventions can change biomarkers used in biological-age algorithms, but biological age is not a single universally accepted measurement. A change in a test result should not automatically be interpreted as proof that ageing has literally been reversed.
Can humans live to 120?
Humans have reached ages of around 120 and beyond, although this is exceptionally rare. Research continues into the biological characteristics that allow certain individuals to survive to extreme ages.
What Longevity Really Means
The most useful definition of longevity is not simply living as long as possible.
It is:
Living longer while preserving the health, physical ability, cognitive function, independence and relationships that make those additional years worth having.
The science of ageing is becoming more sophisticated.
We are learning more about genetics, inflammation, epigenetics, cellular senescence, metabolism and the microbiome.
But the fundamentals remain remarkably practical.
Regular movement, cardiorespiratory fitness, strength, a nutritious diet, adequate sleep, stress recovery, strong relationships and preventive healthcare currently have much stronger human evidence behind them than most interventions marketed as anti-ageing breakthroughs.
The future may bring medicines capable of directly changing aspects of human ageing.
Until then, longevity is best approached as both a science and a long-term practice.
The objective is not merely more years.
It is more healthy years.
Research and Further Reading
1. Harvard Health: The 5 Pillars of Longevity
Overview of movement, nutrition, sleep, stress management and social connection in healthy ageing.
Read at Harvard Health
2. The Multiomics Blueprint of an Individual With Extreme Lifespan
Peer-reviewed study of Maria Branyas, who lived beyond 117 years.
View the original study on PubMed
3. ScienceDaily: Research on the Biology of a 117-Year-Old
Accessible summary of the Maria Branyas research.
Read at ScienceDaily
4. Definitions of Healthspan: A Systematic Review
Review examining how researchers define and measure healthspan.
View on PubMed
5. Cardiorespiratory Fitness and Mortality
Large systematic review and meta-analysis examining fitness as a predictor of health outcomes and mortality.
View on PubMed
6. Resistance Training and Mortality Risk
Meta-analysis examining resistance exercise and mortality.
View on PubMed
7. Mediterranean Diet and Mortality in Older Adults
Meta-analysis examining Mediterranean dietary patterns, cardiovascular outcomes and mortality.
View on PubMed
8. Social Isolation, Loneliness and Mortality
Systematic review and meta-analysis examining social connection and mortality in older adults.
View on PubMed
9. Healthy Longevity Clinic: What Is Longevity?
A general clinical overview of longevity and healthy ageing.
Read the overview
Important: This article is provided for general educational purposes only and does not constitute medical advice. Longevity and ageing research is evolving, and findings may change as new evidence becomes available. Consult an appropriate healthcare professional regarding medical conditions, medications or significant changes to diet, exercise or supplementation.