Longevity Glossary

Cumulative physiological wear-and-tear from repeated stress responses. Higher load predicts faster biological aging.

A pigment in berries and purple vegetables with antioxidant properties.

The active compound in garlic with antimicrobial and anti-inflammatory properties.

The progressive decline in physiological function and increased vulnerability to disease with time. Driven by the twelve hallmarks.

AMP-activated protein kinase, a metabolic master switch. Activation improves energy metabolism and extends lifespan.

The cellular process of breaking down and recycling damaged or dysfunctional organelles and proteins. Activation of autophagy is associated with longevity in multiple model organisms.

Stimulation of cellular recycling through fasting, exercise, or compounds like spermidine. Associated with longevity.

A molecule that neutralizes reactive oxygen species (ROS). Examples: vitamin C, vitamin E, glutathione.

When the combined effect of two compounds is less than the sum of individual effects.

An unintended harmful effect of a drug or intervention. Monitored in clinical trials.

Journal focused on cellular and molecular mechanisms of aging.

A naturally occurring substance in food with biological activity in the body.

A measurable indicator of biological state or condition. Epigenetic clocks, NAD+ levels, and mitochondrial function are aging biomarkers.

Keeping participants and/or researchers unaware of treatment assignment. Reduces bias in clinical trials.

The fraction of an ingested compound that reaches systemic circulation. Important for supplement efficacy.

A state of permanent cell cycle arrest triggered by stress or aging. Senescent cells accumulate with age and secrete inflammatory factors (SASP) that damage neighboring tissues.

An amino acid derivative that improves muscle energy metabolism and cognitive function. Tier I evidence for longevity.

The active compound in turmeric with anti-inflammatory properties. Limited bioavailability but studied for longevity.

A flavanol found in green tea with antioxidant properties.

A pigment in plants with antioxidant properties. Examples: beta-carotene, lycopene, lutein.

A compound that activates the same pathways as caloric restriction without requiring reduced food intake. Examples include rapamycin and metformin.

Sustained reduction in calorie intake without malnutrition. Extends lifespan in multiple model organisms.

An observational study following a group of people over time. Can show associations but not causation.

An observational study comparing people with and without a condition. Useful for rare outcomes.

A factor that influences the outcome but is not the variable being studied. Can bias study results.

Stages of drug testing: Phase I (safety), Phase II (efficacy), Phase III (confirmation), Phase IV (monitoring).

A condition or factor that makes a treatment inadvisable or dangerous.

Harmful effects from repeated or long-term exposure to a substance.

The ability of a substance to cause cancer.

Top-tier journal publishing cell biology and molecular research.

A healthcare provider who treats patients. In longevity, clinicians prescribe evidence-based interventions.

Imbalance in the gut microbiome composition. Associated with inflammation, metabolic dysfunction, and aging.

A tyrosine kinase inhibitor with senolytic activity. Used in combination with quercetin in senolytic protocols.

An epigenetic measure of the rate of biological aging derived from the Dunedin longitudinal cohort. Reports years-of-aging-per-calendar-year.

The relationship between the amount of a compound and its biological effect. Important for determining optimal dosing.

When one drug affects the action of another drug.

Digital Object Identifier, a unique code for academic papers. Allows permanent linking to papers.

An amino acid antioxidant produced by fungi. Declines with age and is associated with age-related disease.

Epigallocatechin gallate, the most abundant catechin in green tea.

A biomarker of biological age derived from DNA methylation patterns. Predicts mortality and healthspan better than chronological age.

The magnitude of the difference between groups. Important for assessing practical significance.

Characteristics that disqualify a person from participating in a clinical trial.

The ability of an intervention to produce the desired effect under ideal conditions.

The ability of an intervention to produce the desired effect in real-world conditions.

A flavonoid with senolytic properties. Studied in Mayo Clinic and Wake Forest trials for removing senescent cells.

A type of polyphenol found in plants. Examples: quercetin, fisetin, hesperidin.

A type of flavonoid found in cocoa and tea with cardiovascular benefits.

Regulatory approval by the US Food and Drug Administration for safety and efficacy.

Medical approach focusing on identifying and addressing root causes of disease.

Accumulation of DNA damage and mutations with age. One of the twelve hallmarks of aging.

GlyNAC, a combination that boosts glutathione synthesis. Improves mitochondrial function and reduces oxidative stress.

The active compound in ginger with anti-inflammatory properties.

A small molecule, intervention, or behaviour shown to slow biological aging or extend healthspan in pre-clinical or clinical studies.

A second-generation epigenetic clock that integrates DNA methylation patterns with plasma protein surrogates to predict mortality risk.

Growth differentiation factor 11, a circulating factor whose decline with age was once proposed to drive aging. Subsequent studies have produced mixed results.

The ability of a substance to damage DNA and cause mutations.

Generally Recognized As Safe. FDA classification for food additives with a history of safe use.

Journal publishing research on aging and age-related disease.

A scientist or clinician who studies the biological, psychological, and social aspects of aging.

A conceptual framework grouping the molecular and cellular processes driving aging into twelve distinct categories. Proposed by López-Otín et al. in 2023.

The number of times a normal somatic cell can divide before senescence. Approximately 50 divisions for most human cells.

Surgical joining of young and old animals to share circulation. Used to identify systemic factors that promote or reverse aging.

The period of life spent in good health, free of chronic disease and disability. Distinct from lifespan, which counts total years of life.

The time required for a compound's concentration to reduce by half in the body.

Chronic, low-grade systemic inflammation with age. Characterized by elevated IL-6, TNF-α, and CRP. Contributes to age-related disease.

Signaling between cells via hormones, cytokines, and growth factors. Altered with age, contributing to age-related disease.

A sulfur-containing compound from cruciferous vegetables. Example: sulforaphane.

Sinclair's hypothesis that aging is driven by loss of youthful epigenetic information, not genetic mutations. Suggests aging may be reversible.

Periodic fasting (16-24 hours) alternating with normal eating. Activates autophagy and improves metabolic health.

Characteristics that qualify a person to participate in a clinical trial.

Agreement to participate in research after being fully informed of risks and benefits.

Institutional Review Board, which reviews and approves clinical research protocols.

Combining conventional medicine with evidence-based complementary approaches.

Journal of the American Medical Association, publishing clinical and translational research.

An anti-aging protein expressed primarily in kidney and brain. Higher circulating klotho is associated with longer lifespan.

Metabolic state where the body burns fat for fuel instead of glucose. Achieved through low-carb diets or fasting.

Total length of life from birth to death. Maximum lifespan in humans is approximately 122 years.

Extended lifespan and healthspan. The scientific study of aging and interventions to slow or reverse it.

The dose that kills 50% of test animals. Used to assess acute toxicity.

Clinical practice focused on extending healthspan and lifespan through evidence-based interventions.

Impaired energy production and increased oxidative stress in mitochondria. A key driver of age-related disease and a target for longevity interventions.

A biguanide drug that activates AMPK and extends lifespan in animal models. Most-studied longevity drug in humans.

Mechanistic target of rapamycin, a nutrient-sensing protein that regulates growth and autophagy. Chronic over-activation shortens healthspan; inhibition extends lifespan.

Selective autophagy of damaged mitochondria. Activated by compounds like urolithin A and improves mitochondrial health.

The community of microorganisms (bacteria, fungi, viruses) living in the gut. Influences metabolism, immunity, and aging.

How a drug or compound produces its biological effect.

Statistical combination of results from multiple studies. Provides stronger evidence than individual studies.

Nicotinamide mononucleotide, a precursor to NAD+. Supplementation raises tissue NAD+ in humans and improves metabolic health.

A NAD+ precursor that raises tissue NAD+ levels. Similar effects to NMN.

A compound that the body converts to NAD+. Examples: NMN, NR (nicotinamide riboside).

A food or food component with medicinal or health benefits beyond basic nutrition.

Nicotinamide adenine dinucleotide, a coenzyme essential for energy metabolism and DNA repair. NAD+ levels decline ~50% between ages 20 and 60.

Premier scientific journal publishing high-impact research across all disciplines.

New England Journal of Medicine, one of the most prestigious medical journals.

Journal dedicated to aging research across all biological scales.

EPA and DHA, essential polyunsaturated fats with anti-inflammatory and cardiovascular benefits. Tier I evidence for longevity.

Imbalance between reactive oxygen species (ROS) and antioxidant defenses. Contributes to aging and age-related disease.

Partial epigenetic reprogramming using OCT4, SOX2 and KLF4 to roll back age markers without inducing pluripotency. Pioneered for in vivo rejuvenation by Sinclair and others.

The balance between protein synthesis, folding, and degradation. Loss of proteostasis is a hallmark of aging.

Accumulation of misfolded proteins that form toxic aggregates. Associated with neurodegenerative diseases and aging.

A truncated form of lamin A protein that accumulates in Hutchinson–Gilford progeria. Causes nuclear envelope defects and rapid aging.

A polyphenol similar to resveratrol with better bioavailability. Found in blueberries.

A class of plant compounds with antioxidant and anti-inflammatory properties. Examples: quercetin, resveratrol, curcumin.

The active compound in black pepper that enhances bioavailability of other compounds.

A bioactive compound produced by plants. Examples: polyphenols, carotenoids, sulfides.

An epigenetic clock trained on a composite of nine clinical biomarkers that predicts disease and mortality more accurately than chronological age.

Replacement of plasma with saline or albumin to remove pro-aging factors. Pre-clinical evidence suggests rejuvenating effects on multiple tissues.

Improvement in symptoms due to expectation rather than the active treatment.

The tendency for positive results to be published more often than negative results. Can overestimate treatment effects.

Evaluation of research by experts in the field before publication. Ensures quality and credibility.

How the body absorbs, distributes, metabolizes, and excretes a drug or compound.

Free database of biomedical literature maintained by the National Library of Medicine.

Tailoring medical treatment to individual genetic, environmental, and lifestyle factors.

Similar to precision medicine; customizing treatment based on individual characteristics.

Medical practice focused on preventing disease before it occurs.

A flavonoid with senolytic properties. Often combined with dasatinib for enhanced senolytic effect.

A polyphenol found in red wine and grapes. Activates sirtuins but has limited human trial data.

An mTOR inhibitor that extends lifespan in every model organism tested. Used at low doses for longevity; immunosuppressive at high doses.

Unstable molecules produced during metabolism that damage DNA, proteins, and lipids. A driver of aging.

Randomized controlled trial. The gold standard for clinical evidence. Participants randomly assigned to treatment or placebo.

Random assignment of participants to treatment or control groups. Reduces bias in clinical trials.

Senescence-associated secretory phenotype. The inflammatory cytokines secreted by senescent cells that damage neighboring tissues.

Decline in the number and function of stem cells with age. Reduces tissue regeneration and repair capacity.

A polyamine that activates autophagy and extends lifespan in yeast and mice. Found in aged cheese and mushrooms.

An isothiocyanate from cruciferous vegetables. Activates Nrf2, a master regulator of antioxidant defenses.

A product containing vitamins, minerals, amino acids, or other compounds intended to supplement the diet.

A supplement formulation where the active compound is quantified and standardized.

A drug or compound that selectively eliminates senescent cells. Fisetin and quercetin are natural senolytics; dasatinib is a pharmaceutical senolytic.

A family of NAD+-dependent enzymes that regulate cellular stress responses and longevity. Activation is linked to lifespan extension.

When the combined effect of two compounds is greater than the sum of individual effects.

A comprehensive review of all available evidence on a topic using predefined criteria.

A result unlikely to occur by chance (p < 0.05). Does not necessarily mean clinical significance.

The overall pattern of adverse events associated with a drug or intervention.

Flagship journal of the American Association for the Advancement of Science.

Protective caps at the ends of chromosomes that shorten with each cell division. Telomere length is associated with cellular age and lifespan.

A conditionally essential amino acid with antioxidant and anti-inflammatory properties. Declines with age.

Multiple well-controlled human randomized controlled trials (RCTs). Highest standard of evidence for longevity interventions.

Human trials in early stages or limited sample sizes. Promising but requires larger RCTs for confirmation.

Mechanism studies, animal models, or in vitro evidence. Theoretical basis but lacking human trial data.

The degree to which a substance is poisonous or harmful.

The ability of a substance to cause birth defects.

Leading medical journal publishing clinical trials and health policy research.

A polyphenol metabolite that activates mitophagy (selective autophagy of mitochondria). Improves muscle endurance and mitochondrial function.

Fat-soluble vitamins that regulate calcium metabolism and bone health. Tier I evidence for longevity.

A rare genetic disorder of premature aging caused by mutations in the WRN gene. Used as a model for studying accelerated aging.

OCT4, SOX2, KLF4 and c-MYC — the four transcription factors that reprogramme adult cells to pluripotency. Subset (OSK) is used for partial reprogramming research.