Longevity glossary

The adaptive immune system is the body's learned, targeted defence. Its age-related decline — immunosenescence — is a key driver of the vulnerability that comes with getting older.

AMPK (AMP-activated protein kinase) is the cell's low-fuel sensor. When energy runs low it switches cells from growth to repair and maintenance — one of the core pathways behind the metabolic benefits of fasting and exercise.

Autophagy is the cell's recycling system: it breaks down and reuses damaged components. Maintaining it is linked to healthier ageing, and several longevity interventions act partly through it.

Cellular senescence is a state in which damaged cells permanently stop dividing but stay metabolically active, releasing inflammatory signals. Their build-up is a recognised hallmark of ageing.

Inflammaging is the chronic, low-grade inflammation that builds up with age and is thought to drive many age-related diseases.

Mitochondrial dysfunction is the age-related decline in the cell's energy factories. It is one of the hallmarks of aging and a target for several longevity interventions.

mTOR is a central nutrient-sensing protein that controls cell growth. Dialling it down — through caloric restriction or drugs like rapamycin — is one of the best-supported ways to extend lifespan in animals.

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme essential for energy metabolism and DNA repair. Its levels fall with age, which is why NAD+ precursors are a popular longevity intervention — though human longevity benefits remain unproven.

Partial (cellular) reprogramming briefly switches on the “Yamanaka factors” to make old cells behave younger without losing their identity. It rejuvenates tissues in animals but is experimental and carries cancer risk.

Proteostasis is the cell's system for keeping proteins correctly made, folded and cleared. Its gradual failure is a recognised hallmark of aging.

Senolytics are drugs designed to selectively clear senescent (“zombie”) cells that accumulate with age. They have extended healthspan in mice, but a longevity benefit in humans is not yet proven.

Sirtuins are a family of enzymes that depend on NAD+ to regulate metabolism, DNA repair and stress responses. They are a major focus of longevity research.

Telomeres are protective caps on the ends of chromosomes that shorten as cells divide. Their attrition is one of the hallmarks of aging, though longer telomeres are not simply “better”.

β-Hydroxybutyrate (BHB) is the main ketone body the liver makes during fasting and carbohydrate restriction. Beyond serving as fuel for the brain and muscle, it acts as a signaling molecule that influences gene expression, stress resistance and cellular repair.

Aerobic exercise — sustained activity like brisk walking, running or cycling — is among the most evidence-backed longevity interventions, driving cardiorespiratory fitness and lower mortality.

Caloric restriction is a sustained reduction in calorie intake without malnutrition. It extends lifespan in many animals; in humans it improves cardiometabolic markers, with lifespan effects unproven.

Exosomes are tiny vesicles cells release to communicate and shuttle cargo between cells. They are being explored as regenerative and anti-ageing therapies, but human longevity evidence is preliminary.

A fasting-mimicking diet (FMD) is a short, low-calorie, plant-based protocol — typically five days, repeated periodically — designed to trigger the biology of fasting (lower IGF-1, autophagy, cellular repair) while still allowing some food.

GLP-1 receptor agonists (e.g. semaglutide) are injectable drugs originally for type 2 diabetes, now major treatments for obesity. Large trials show they reduce cardiovascular events in specific populations.

Hormone replacement therapy restores hormones (e.g. testosterone, estrogen) that decline with age or deficiency. It is an established treatment for specific indications, not a proven general anti-ageing therapy.

Hyperbaric oxygen therapy (HBOT) delivers near-100% oxygen in a pressurised chamber. It is proven for specific medical conditions; its use as an anti-ageing treatment is still experimental.

Intermittent fasting cycles between eating and extended fasting windows. It can aid weight and metabolic health and engages the same pathways as caloric restriction, though long-term human longevity data are limited.

Metformin is a widely used, inexpensive type 2 diabetes drug being studied as a potential geroprotector. Its anti-ageing benefit in non-diabetics is unproven and is the subject of the planned TAME trial.

NMN (nicotinamide mononucleotide) is a precursor the body uses to make NAD+. It is sold to “boost NAD+” for anti-ageing, but human longevity evidence is early and limited.

Nootropics are substances taken to enhance cognition — memory, focus or mental energy. Interest is high in longevity circles, but evidence quality varies enormously.

Rapamycin (sirolimus) is an mTOR-inhibiting drug that extends lifespan in mice more reproducibly than any other compound. Its use for human longevity is promising but unproven, and it carries real side-effects.

Regular sauna bathing is a form of hormetic heat exposure. Large observational studies link frequent sauna use to lower cardiovascular and all-cause mortality.

An epigenetic clock estimates biological age from DNA-methylation patterns. These “aging clocks” are powerful research tools, but are not yet validated to guide individual medical decisions.

Grip strength is a simple measure of hand force that serves as a proxy for whole-body muscle strength. Lower grip strength predicts higher mortality and disability.

VO2 max is the maximum rate at which your body can use oxygen during intense exercise — a strong, measurable marker of cardiorespiratory fitness and one of the best predictors of longevity.

Alternative medicine covers practices used in place of conventional, evidence-based care. In longevity, the line between promising adjunct and unproven claim matters — so scrutiny is essential.

Biological age is an estimate of how old your body seems based on biomarkers, as opposed to chronological age. Several “clocks” aim to measure it, but methods and validation vary.

Cancer screening looks for cancer before symptoms appear. It's a cornerstone of preventive and executive-health longevity programmes — powerful when targeted, harmful when overdone.

Frailty is a state of reduced reserve and increased vulnerability to stressors. It predicts falls, disability and death — and, unlike chronological age, it can be improved.

The hallmarks of aging are a set of interconnected biological processes — such as genomic instability, telomere attrition and cellular senescence — that together drive how organisms grow old.

Health promotion is the practice of enabling people to increase control over and improve their health — the population-level counterpart to individual longevity medicine.

Sarcopenia is the age-related loss of muscle mass, strength and function. It's a strong predictor of frailty and mortality — and one of the most modifiable targets in longevity medicine.

Electromyography (EMG) records the electrical activity of muscles — a diagnostic tool for nerve and muscle function that intersects with the assessment of age-related muscle decline.

Epigenomics studies the chemical marks on DNA that switch genes on and off without changing the sequence itself. These marks change with age and underpin the epigenetic clocks used in longevity testing.

In vitro diagnostics (IVD) are tests run on samples of blood, tissue or other fluids outside the body — the lab backbone behind most longevity biomarker panels.

Metabolomics measures the small molecules your metabolism produces — a snapshot of current physiological state that longevity clinics increasingly use for personalised profiling.

Metagenomics sequences all the microbial DNA in a sample — the technology behind gut-microbiome profiling that longevity clinics use to personalise nutrition and health advice.

Pharmacogenomics studies how your genes affect your response to drugs — the basis for tailoring dose and drug choice, and increasingly relevant to longevity pharmacology.

Serology tests the blood for antibodies and other markers — a routine but powerful window into immune status, infection history and inflammation used across longevity diagnostics.