Longevity Term Glossary
Navigating the field of longevity and healthspan science can sometimes feel like learning a new language. From 'autophagy' to 'senolytics', the terminology can be complex.
Use this resource to better understand health articles, product information, and the science aiming to extend our lifespan and healthspan.
A
Advanced Glycation End-products (AGEs)
These are harmful molecules formed when sugars (like glucose) attach themselves to proteins or fats in your body without the help of enzymes. Think of it like sugar 'caramelising' your tissues over time. AGEs build up as we age and contribute to stiffness in blood vessels and skin, inflammation, and age-related problems like cataracts and diabetic complications.
Ageing (Aging)
The natural process of growing older, involving a gradual decline in the body's functions over time. This makes us less resilient to stress and more susceptible to diseases, eventually leading to death. It's a complex process influenced by genetics, lifestyle, and environment.
AKG (Alpha-Ketoglutarate)
A molecule naturally present in our bodies that plays a key role in how cells produce energy (in the Krebs cycle) and process amino acids. Early research in animals suggests that supplementing with AKG might help extend lifespan and healthspan, possibly by influencing how our genes are expressed (epigenetics).
AMPK (AMP-activated protein kinase)
Think of AMPK as a master energy sensor inside your cells. When it detects low energy levels (like during exercise or fasting), it springs into action, telling the cells to burn more fuel (like fat) and conserve energy by slowing down growth processes. Activating AMPK is often linked to health benefits and longevity.
Anoikis
A specific type of programmed cell death (apoptosis) that happens when cells become detached from their normal surroundings (the extracellular matrix). It's a safety mechanism that prevents cells from surviving and growing in places they shouldn't, which is important for stopping cancer spread.
Antagonistic Pleiotropy
An evolutionary theory suggesting that some genes might be beneficial early in life (helping us survive and reproduce) but have negative effects later on, contributing to ageing. Evolution tends to favour genes that help us pass on our DNA, even if they cause problems down the line.
Antioxidant
A substance that protects your cells from damage caused by unstable molecules called free radicals (or ROS). Antioxidants work by neutralising these free radicals, preventing them from causing 'oxidative stress'. Many vitamins (like C and E) and plant compounds act as antioxidants.
APOE Gene
This gene provides instructions for making a protein (apolipoprotein E) involved in transporting fats in the bloodstream. Certain versions (alleles) of this gene, especially APOE ε4, are linked to a significantly higher risk of developing late-onset Alzheimer's disease and cardiovascular problems.
Apoptosis
Often called 'programmed cell death', this is the body's natural and tidy way of getting rid of cells that are old, damaged, or no longer needed. Unlike messy cell death (necrosis), apoptosis doesn't cause inflammation and is crucial for development and preventing diseases like cancer.
Astaxanthin
A naturally occurring pigment that gives salmon, shrimp, and flamingos their pinkish-red colour. It's a powerful antioxidant belonging to the carotenoid family, known for its ability to combat oxidative stress and inflammation. It's often studied for benefits related to skin, eye, and joint health.
ATP (Adenosine Triphosphate)
The main energy 'currency' used by all cells in your body. ATP molecules store and release energy to power virtually every cellular activity, from muscle contraction to thinking. Most ATP is produced in the mitochondria through cellular respiration.
Autophagy
Literally meaning 'self-eating', this is your cells' built-in recycling and clean-up system. It breaks down and removes old, damaged, or unnecessary components (like misfolded proteins or worn-out mitochondria) to make way for new ones. Autophagy is vital for cellular health, tends to decline with age, and can be boosted by fasting.
Average Lifespan
The average number of years a person in a specific population or group is expected to live. This is influenced by factors like healthcare, lifestyle, and environment. Compare with Maximum Lifespan.
B
Berberine
A natural compound found in several plants, such as Barberry and Goldenseal. It's known for activating AMPK, improving the body's sensitivity to insulin, and helping to manage blood sugar levels. Its effects share some similarities with the diabetes drug metformin.
Beta-oxidation
The process where fatty acids are broken down inside the mitochondria to produce energy. It's the main way your body burns fat for fuel, especially during exercise or when carbohydrate intake is low.
Biological Age
An estimate of how old your body seems based on various biological markers (like DNA methylation or blood tests), as opposed to how many years you've actually lived (chronological age). It reflects your overall health and how well your body is functioning, and it can be influenced by lifestyle choices.
Biomarker (of Ageing)
A measurable indicator used to assess a biological state. Biomarkers of ageing are specific characteristics (e.g., blood pressure, cholesterol levels, epigenetic patterns, grip strength) that change predictably with age and can help estimate biological age or predict future health risks.
Blood Pressure
The force exerted by circulating blood on the walls of your arteries. It's measured with two numbers: systolic (pressure when the heart beats) over diastolic (pressure when the heart rests). High blood pressure (hypertension) is a major risk factor for heart disease and stroke.
Blue Zones
Regions in the world where people statistically live much longer and healthier lives than average. Examples include Okinawa (Japan), Sardinia (Italy), and Loma Linda (California). Studying the lifestyles, diets, and social structures in Blue Zones provides insights into factors promoting longevity.
C
Caloric Restriction (CR)
A dietary strategy involving consistently eating fewer calories (typically 20-40% less) than usual, but without becoming malnourished. It's the most well-documented intervention shown to increase lifespan and delay age-related diseases in many different animal species.
Cardiovascular Disease (CVD)
A group of conditions affecting the heart and blood vessels, such as heart attacks, strokes, heart failure, and narrowing of the arteries (atherosclerosis). CVD risk increases significantly with age and is a leading cause of death worldwide.
Carotenoids
A class of natural pigments produced by plants, algae, and some bacteria, responsible for bright yellow, orange, and red colours. Examples include beta-carotene, lycopene, lutein, and astaxanthin. Many carotenoids act as antioxidants in the human body.
Cell Cycle
The series of events a cell goes through as it grows and divides. It includes phases where the cell grows, copies its DNA, and then splits into two daughter cells. Proper regulation of the cell cycle is crucial to prevent uncontrolled growth (cancer); senescent cells permanently exit this cycle.
Cellular Respiration
The process by which cells convert fuel (like glucose) into usable energy (ATP), primarily occurring in the mitochondria. Aerobic respiration, which uses oxygen, is the most efficient form.
Cellular Senescence
A state where cells stop dividing permanently but don't die. These 'senescent' or 'zombie' cells accumulate with age and release a mixture of harmful inflammatory substances (known as the SASP) that can damage nearby tissues and contribute to ageing and various diseases.
Centenarian / Supercentenarian
A person who has reached the age of 100 years is a centenarian. A person who has reached the age of 110 years or more is a supercentenarian. Studying these individuals helps researchers identify genetic and lifestyle factors associated with extreme longevity.
Chaperones (Molecular Chaperones)
Specialised proteins that help other proteins fold into their correct three-dimensional shapes, prevent them from clumping together when damaged, and guide them to where they need to go in the cell or target them for disposal if they are beyond repair. They are essential for maintaining protein quality (proteostasis).
Cholesterol
A fatty substance essential for building cell membranes, producing certain hormones (like oestrogen and testosterone), and making vitamin D. It's transported in the blood by lipoproteins. High levels of LDL ('bad') cholesterol contribute to artery plaque buildup, while HDL ('good') cholesterol helps remove excess cholesterol.
Chromatin
The complex structure formed by DNA tightly wound around proteins called histones, located within the cell nucleus. The way chromatin is organised (condensed or open) affects which genes can be 'read' and activated. Changes to chromatin structure are a key part of epigenetics and the ageing process.
Chronological Age
Simply how old you are in years, months, and days, calculated from your date of birth. This is distinct from your Biological Age, which reflects your physical condition.
Circadian Rhythm
Your body's internal ~24-hour clock, located in the brain, which controls cycles of sleepiness and alertness. It also influences hormone levels, body temperature, digestion, and metabolism. Keeping this rhythm synchronised (e.g., through regular sleep patterns and light exposure) is important for health, while disruptions can negatively impact ageing.
Clinical Trial
A research study conducted with human volunteers to evaluate the safety and effectiveness of a medical intervention, such as a new drug, supplement, diet, or therapy. Clinical trials are essential for proving whether potential longevity interventions actually work in humans.
Cognitive Decline
A reduction in mental abilities, such as memory, attention, processing speed, reasoning, and language skills. Some cognitive decline is considered a normal part of ageing, but significant decline that interferes with daily life may indicate Mild Cognitive Impairment (MCI) or dementia.
Collagen
The main structural protein found in skin, bones, tendons, ligaments, and other connective tissues, providing strength and elasticity. Our body's natural collagen production decreases as we age, leading to wrinkles, sagging skin, and joint issues.
CoQ10 (Coenzyme Q10 / Ubiquinone / Ubiquinol)
A vitamin-like compound essential for generating energy (ATP) within the mitochondria. It also acts as a powerful antioxidant, protecting cell membranes from damage. CoQ10 levels tend to decrease with age and can also be lowered by certain medications like statins.
Creatine
A natural substance found mainly in muscle cells that helps supply energy for short bursts of intense activity by regenerating ATP. It's a popular supplement for improving strength, power, and muscle mass. Research also suggests it may have benefits for brain function.
Cross-linking
The formation of abnormal chemical bonds between proteins or other large molecules in the body. This process, often accelerated by glycation (AGEs), causes tissues to become stiff and less flexible over time, contributing to problems like hardened arteries and wrinkled skin.
CRP (C-reactive protein)
A protein produced by the liver in response to inflammation. A high-sensitivity CRP (hs-CRP) blood test can detect low levels of chronic inflammation, known as 'inflammaging'. Elevated hs-CRP is linked to an increased risk of heart disease, stroke, and other age-related conditions.
Curcumin
The bright yellow active compound found in the spice turmeric. It's well-known for its strong anti-inflammatory and antioxidant effects. However, standard curcumin is often poorly absorbed by the body, so formulations designed for better bioavailability are often preferred.
Cytokines
Small proteins released by cells, particularly immune cells, that act as chemical messengers to regulate inflammation, immune responses, and cell communication. An imbalance or excessive production of pro-inflammatory cytokines contributes to inflammaging and various diseases.
D
Dasatinib
A chemotherapy drug primarily used to treat certain types of leukaemia. It has also been identified as having senolytic properties (ability to kill senescent cells), particularly when used in combination with Quercetin (often referred to as D+Q).
Dementia
A general term for a decline in mental ability severe enough to interfere with daily life. Alzheimer's disease is the most common type. Dementia involves progressive damage to brain cells, affecting memory, thinking, orientation, comprehension, calculation, learning capacity, language, and judgement.
Detoxification
The metabolic process by which the body neutralises or eliminates harmful toxins or waste products, primarily carried out by the liver, kidneys, gut, lungs, and skin. Efficient detoxification pathways are important for health, involving enzymes and antioxidants like glutathione.
DHA (Docosahexaenoic Acid)
An essential omega-3 fatty acid crucial for brain health, eye development, and function. It's a major structural component of the brain and retina. Found mainly in fatty fish and algae oil supplements.
Diabetes (Type 2)
A chronic metabolic disorder characterised by high blood sugar levels resulting from insulin resistance (cells don't respond properly to insulin) and/or insufficient insulin production. Type 2 diabetes risk increases with age and is strongly linked to obesity and lifestyle factors.
DNA (Deoxyribonucleic Acid)
The molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms. It's organised into structures called chromosomes within the cell nucleus.
DNA Damage
Changes to the chemical structure of DNA, caused by various factors including metabolic byproducts (ROS), environmental toxins, radiation (like UV light), and errors during DNA replication. Accumulation of unrepaired DNA damage is a major driver of ageing and cancer.
DNA Methylation
An epigenetic process where a methyl group (a small chemical tag) is added to a DNA molecule, typically at a CpG site. This modification usually acts to silence gene expression (turn the gene 'off') without changing the DNA sequence itself. Patterns of DNA methylation change predictably with age and are used in epigenetic clocks.
DNA Repair
A collection of sophisticated cellular mechanisms that detect and correct damage to DNA molecules. Efficient DNA repair is vital for maintaining the integrity of the genome. Defects in DNA repair pathways can accelerate ageing and increase cancer risk.
Dysbiosis
An imbalance in the composition and function of the microbial community living in a particular environment, especially the gut microbiome. Gut dysbiosis can lead to increased gut permeability ('leaky gut'), chronic inflammation, and has been linked to numerous health problems, including those associated with ageing.
E
Electron Transport Chain (ETC)
A series of protein complexes located in the inner mitochondrial membrane. It's the final stage of aerobic cellular respiration, where electrons are passed along the chain, releasing energy that is used to generate the vast majority of the cell's ATP (energy currency). CoQ10 is a key component of the ETC.
Endocrine System
The network of glands (like the pituitary, thyroid, adrenals, pancreas, ovaries, testes) that produce and secrete hormones directly into the bloodstream. Hormones act as chemical messengers, regulating metabolism, growth, reproduction, mood, sleep, and many other bodily functions. Hormone levels often change significantly with age.
Endothelial Dysfunction
A condition where the endothelium (the thin layer of cells lining the inside of blood vessels) doesn't function properly. This impairs the blood vessels' ability to relax and contract appropriately, contributing to high blood pressure, atherosclerosis (plaque buildup), and increased risk of heart attack and stroke. It's common in ageing.
Epigenetic Clocks
Biomarkers that use patterns of epigenetic modifications (most commonly DNA methylation) across the genome to estimate an individual's biological age. Different clocks (e.g., Horvath clock, Hannum clock, GrimAge, PhenoAge) may correlate better with different health outcomes or aspects of ageing.
Epigenetics
The study of changes in how genes are expressed or function without changing the underlying DNA sequence. Epigenetic modifications (like DNA methylation and histone modification) act like switches that turn genes on or off. These modifications are influenced by lifestyle and environment, and they change throughout life, playing a crucial role in ageing.
EPA (Eicosapentaenoic Acid)
An essential omega-3 fatty acid found primarily in fatty fish and fish oil supplements. EPA is known for its anti-inflammatory properties and benefits for cardiovascular health. It can also be converted to DHA in the body, although often inefficiently.
Exercise
Any bodily activity that enhances or maintains physical fitness and overall health. Includes aerobic exercise (like running, swimming), resistance training (weight lifting), flexibility exercises (stretching), and balance training. Regular exercise is one of the most effective interventions for promoting healthspan and counteracting many aspects of age-related decline.
Exosomes
Tiny membrane-bound sacs (vesicles) released by cells that carry various molecules (proteins, lipids, RNA) to other cells, acting as a form of intercellular communication. They are involved in many physiological processes, and their role in ageing, disease spread, and potential therapeutic use is an active area of research.
Extracellular Matrix (ECM)
The network of proteins (like collagen and elastin) and other molecules that fill the spaces between cells, providing structural support to tissues and regulating cellular behaviour. Changes and stiffening of the ECM occur with age, affecting tissue function.
F
Fasting
Voluntarily abstaining from food (and sometimes drink) for a specific period. Different types exist, including intermittent fasting (cycling between eating and fasting periods) and prolonged fasting (lasting 24 hours or more). Fasting can trigger beneficial cellular processes like autophagy and improve metabolic health.
Fasting Glucose
A blood test measuring glucose (sugar) levels after an overnight fast (typically 8-12 hours). Elevated levels may indicate impaired glucose tolerance or insulin resistance, risk factors for type 2 diabetes and cardiovascular disease.
Fatty Acids
The building blocks of fats (lipids). They can be saturated (no double bonds, typically solid at room temperature), monounsaturated (one double bond, e.g., in olive oil), or polyunsaturated (multiple double bonds, e.g., omega-3 and omega-6). Essential fatty acids (like omega-3s) must be obtained from the diet.
Fisetin
A natural flavonoid antioxidant found in fruits and vegetables like strawberries, apples, persimmons, and onions. Research suggests it has senolytic potential (helps clear senescent cells), along with anti-inflammatory and neuroprotective properties.
Flavonoid
A large class of plant-derived compounds (polyphenols) known for their antioxidant and anti-inflammatory activities. Examples include quercetin, fisetin, catechins (in green tea), and anthocyanins (in berries).
FOXO Proteins
A family of transcription factors (proteins that regulate gene activity) crucial for longevity and stress resistance. They control genes involved in DNA repair, antioxidant defence, metabolism, and cell survival, often becoming active under conditions of nutrient scarcity or cellular stress.
Frailty
An age-related state of increased vulnerability to stressors, characterised by declines in strength, endurance, and physiological function. Frailty increases the risk of falls, hospitalisation, disability, and death. Sarcopenia is a major contributor.
Free Radicals
Highly reactive and unstable molecules with an unpaired electron, making them 'eager' to react with other molecules in the body. This can cause damage to DNA, proteins, and cell membranes (oxidative stress). Reactive Oxygen Species (ROS) are the most common type in biology.
Functional Medicine
An approach to healthcare that focuses on identifying and addressing the root causes of disease, rather than just treating symptoms. It emphasizes a personalised approach, considering genetic, environmental, and lifestyle factors.
G
Gait Speed (Walking Speed)
How fast a person typically walks. It's a simple but powerful predictor of overall health, functional decline, cognitive impairment, and mortality risk, especially in older adults. Often considered a 'vital sign' of ageing.
Gene
A specific sequence of DNA that contains the instructions for making a protein or functional RNA molecule. Genes are the basic units of heredity, passed from parents to offspring.
Gene Expression
The process by which the information encoded in a gene is used to create a functional product, typically a protein. Gene expression involves transcription (copying DNA into RNA) and translation (synthesising a protein from the RNA). Epigenetics regulates which genes are expressed when.
Genome
The complete set of genetic material (DNA) present in an organism or cell.
Genomic Instability
An increased tendency for mutations and other alterations to occur in the DNA. This is considered a primary hallmark of ageing, as accumulated damage to the genome over time can impair cellular function and increase cancer risk.
Gerontology
The scientific study of the biological, psychological, and social aspects of ageing.
Geroprotector
Any substance or intervention (drug, supplement, lifestyle change) believed to slow down the ageing process and protect against age-related diseases, thereby potentially extending healthspan or lifespan.
Geroscience
A research field focused on understanding the fundamental biological mechanisms that drive ageing and how these mechanisms link ageing to the development of multiple chronic diseases. The core idea is that targeting ageing itself could prevent or delay many diseases simultaneously.
Glucagon
A hormone produced by the pancreas that raises blood glucose levels, primarily by signalling the liver to release stored glucose. It generally has effects opposite to insulin.
Glucocorticoids
A class of steroid hormones produced by the adrenal glands (e.g., cortisol in humans) that are involved in regulating metabolism, immune responses, and stress reactions. Chronic high levels of glucocorticoids due to stress can have detrimental effects associated with ageing.
Glucose
A simple sugar that is the primary source of energy for the body's cells. Blood glucose levels are tightly regulated by hormones like insulin and glucagon.
Glutathione (GSH)
Often called the body's 'master antioxidant', glutathione is a tripeptide produced naturally in cells. It plays a critical role in neutralising free radicals, detoxifying harmful substances, regenerating other antioxidants (like vitamins C and E), and supporting immune function. Levels tend to decrease with age.
Glycation
The non-enzymatic process where sugar molecules (like glucose) randomly attach to proteins or fats, impairing their function. This process contributes to the formation of Advanced Glycation End-products (AGEs) and accelerates ageing, particularly in the presence of high blood sugar.
Glycine
A simple amino acid involved in building proteins (especially collagen), synthesising creatine, and producing the antioxidant glutathione. Some research suggests glycine supplementation may improve sleep quality and potentially influence longevity pathways.
Glycogen
The storage form of glucose in animals, primarily stored in the liver and muscles. The liver releases glycogen to maintain blood sugar levels, while muscles use it for energy during activity.
Grip Strength
A measure of the maximum force produced by squeezing the hand. It's a widely used indicator of overall muscle strength and a strong predictor of future disability, morbidity, and mortality, often used as a simple biomarker of biological ageing.
H
Hallmarks of Ageing
A framework identifying key, interconnected biological processes thought to underlie ageing. These include: genomic instability, telomere shortening, epigenetic alterations, loss of proteostasis, altered nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication (including inflammaging).
HbA1c (Glycated Haemoglobin)
A blood test measuring the percentage of haemoglobin (in red blood cells) that has sugar attached to it. It provides an estimate of average blood sugar control over the previous 2-3 months. Higher HbA1c levels indicate poorer control and higher risk for diabetes complications and AGE formation.
HDL Cholesterol (High-Density Lipoprotein)
Often called 'good' cholesterol. HDL particles transport excess cholesterol from the arteries back to the liver for removal. Higher levels of HDL are generally associated with a lower risk of cardiovascular disease.
Healthspan
The portion of an individual's life spent in relatively good health, free from debilitating chronic diseases or disabilities. A major goal in longevity research is to extend healthspan, allowing people to live healthier for longer, even if total lifespan isn't dramatically increased.
Heart Rate Variability (HRV)
The natural variation in the time interval between consecutive heartbeats. Higher HRV generally indicates better cardiovascular health and adaptability of the nervous system. HRV tends to decrease with age and stress.
Histone Modification
Chemical changes made to histone proteins (around which DNA is wrapped), such as adding or removing acetyl or methyl groups. These epigenetic modifications alter chromatin structure, influencing whether genes are 'switched on' or 'off'. Patterns of histone modification change during ageing.
Homeostasis
The body's ability to maintain a stable internal environment (e.g., temperature, blood pressure, pH) despite changes in external conditions. The efficiency of homeostatic mechanisms tends to decline with age, making older individuals more vulnerable to stressors.
Hormesis
A biological principle where exposure to a mild, temporary stressor (that would be harmful at high doses) triggers adaptive responses that strengthen the organism and make it more resistant to future, more severe stresses. Examples include exercise, intermittent fasting, and exposure to certain plant compounds.
Hormones
Chemical messengers produced by endocrine glands that travel through the bloodstream to target cells or organs, regulating a vast array of bodily functions including growth, metabolism, mood, and reproduction. Many hormone levels change significantly with age (e.g., growth hormone, sex hormones, melatonin).
I
IGF-1 (Insulin-like Growth Factor 1)
A hormone crucial for growth during childhood and adolescence. In adults, it plays roles in metabolism and tissue maintenance. However, persistently high levels of IGF-1 signalling are linked to accelerated ageing and increased cancer risk in many studies. Reducing IGF-1 signalling is a conserved longevity pathway.
Immune System
The complex network of cells, tissues, and organs that defend the body against pathogens (like bacteria and viruses) and abnormal cells (like cancer). The immune system's function changes with age, often becoming less effective at fighting infections while also promoting chronic inflammation (immunosenescence and inflammaging).
Immunosenescence
The age-related decline in the effectiveness of the immune system, leading to increased susceptibility to infections, poorer response to vaccinations, and potentially increased risk of cancer and autoimmune diseases.
Inflammaging
A chronic, low-grade, background inflammation that develops with age, even without obvious infection. It's driven by factors like accumulating senescent cells, gut dysbiosis, and cellular debris, and it significantly contributes to the development of most age-related diseases.
Inflammation
The body's natural response to injury or infection, involving redness, swelling, heat, and pain. Acute (short-term) inflammation is protective and helps healing. Chronic (long-term) inflammation, however, is damaging and underlies many age-related conditions.
Insulin
A hormone produced by the pancreas that allows cells (especially muscle, fat, and liver cells) to take up glucose from the blood for energy or storage. It plays a key role in regulating blood sugar levels.
Insulin Resistance
A condition where cells become less responsive to the effects of insulin. This means the pancreas has to produce more insulin to keep blood sugar levels normal. Over time, this can lead to high blood sugar, prediabetes, type 2 diabetes, and increased risk of cardiovascular disease. Insulin resistance often increases with age and obesity.
Insulin Sensitivity
The opposite of insulin resistance. High insulin sensitivity means cells respond readily to insulin, efficiently taking up glucose from the blood. Maintaining good insulin sensitivity is crucial for metabolic health and longevity.
Intermittent Fasting (IF)
An eating pattern that involves regularly cycling between periods of eating and voluntary fasting. Common methods include time-restricted eating (e.g., 16/8 schedule), alternate-day fasting, or the 5:2 diet. IF can trigger beneficial processes like autophagy and improve metabolic markers.
Intervention (Longevity Intervention)
Any action taken – such as a diet, exercise regime, supplement, drug, or therapy – with the aim of slowing the ageing process, preventing age-related diseases, or extending healthspan or lifespan.
K
Ketogenic Diet (Keto)
A very high-fat, moderate-protein, extremely low-carbohydrate diet. This dietary pattern shifts the body's primary energy source from glucose to fatty acids and ketone bodies. It's studied for potential benefits in weight management, neurological disorders, and possibly influencing longevity pathways.
Ketones (Ketone Bodies)
Molecules (like beta-hydroxybutyrate) produced by the liver from fat breakdown when carbohydrate intake is very low (e.g., during fasting or on a keto diet). Ketones can serve as an alternative fuel source for the brain and other tissues.
Ketosis
A metabolic state where the body primarily uses fat and ketones for energy instead of glucose, due to limited carbohydrate availability. This occurs during prolonged fasting, strenuous exercise, or adherence to a ketogenic diet.
Klotho
A protein that functions as a hormone and enzyme, primarily produced in the kidneys and brain. Klotho plays a role in regulating mineral metabolism (calcium and phosphate) and insulin/IGF-1 signalling. Higher levels of Klotho are associated with longevity in animal models, and it's considered a potential 'anti-ageing' protein.
Krebs Cycle (Citric Acid Cycle)
A central series of chemical reactions occurring in the mitochondria that finishes the breakdown of fuel molecules (derived from carbohydrates, fats, and proteins) to release energy, which is then used to produce ATP.
L
LDL Cholesterol (Low-Density Lipoprotein)
Often called 'bad' cholesterol. LDL particles transport cholesterol from the liver to cells throughout the body. High levels of LDL cholesterol can lead to the buildup of plaque in arteries (atherosclerosis), increasing the risk of heart attack and stroke.
Lifespan
The total duration of an individual's life, from birth until death. Compare with Healthspan.
Lipid
A broad term for naturally occurring molecules including fats, waxes, sterols (like cholesterol), and fat-soluble vitamins. Lipids are essential components of cell membranes, serve as energy storage, and act as signalling molecules.
Lipofuscin
An aggregate of oxidised proteins and lipids that accumulates inside cells, particularly long-lived cells like neurons and heart muscle cells, as we age. It appears as yellowish-brown granules and is often considered a biomarker of cellular ageing or 'wear and tear'.
Longevity
The quality or state of having a long life. In research, it often refers to the study of extending both lifespan and healthspan beyond the typical average.
M
Macronutrients
The nutrients the body needs in large amounts: carbohydrates, fats (lipids), and proteins. They provide energy (calories) and are the building blocks for tissues.
Maximum Lifespan
The oldest age achieved by any individual member of a species. For humans, the verified maximum lifespan is just over 122 years.
Mediterranean Diet
A dietary pattern based on the traditional foods of countries bordering the Mediterranean Sea. It's rich in fruits, vegetables, whole grains, legumes, nuts, seeds, herbs, spices, and olive oil. Fish and poultry are consumed moderately, while red meat and sweets are limited. Widely associated with improved cardiovascular health and longevity.
Melatonin
A hormone produced mainly by the pineal gland in the brain, primarily at night. It regulates the sleep-wake cycle (circadian rhythm). Melatonin also has antioxidant and anti-inflammatory properties. Its natural production tends to decrease with age.
Metabolism
The sum of all chemical processes that occur in living organisms to maintain life. This includes breaking down nutrients to produce energy (catabolism) and using energy to build cellular components (anabolism).
Metabolite
A small molecule involved in metabolism, either as an intermediate or end product. Studying changes in metabolite levels (metabolomics) can provide insights into health, disease, and ageing.
Metformin
A common, safe, and inexpensive oral medication used primarily to treat type 2 diabetes by improving insulin sensitivity and reducing liver glucose production. Due to its effects on metabolic pathways (like AMPK) and observational data suggesting other health benefits, it's being studied in trials like TAME for its potential to delay ageing-related diseases in non-diabetics.
Methylation
See DNA Methylation.
Microbiome (Gut Microbiome)
The collection of trillions of microorganisms (bacteria, fungi, viruses, etc.) living in the digestive tract. The gut microbiome plays vital roles in digestion, nutrient synthesis, immune system regulation, and even mood. An unhealthy or imbalanced microbiome (dysbiosis) is linked to inflammation and various diseases, and its composition changes with age.
Micronutrients
Vitamins and minerals that the body needs in smaller amounts compared to macronutrients, but which are essential for proper physiological function, including metabolism, immune defence, and cellular repair.
Mitochondria (Singular: Mitochondrion)
Often called the 'powerhouses' of the cell, these organelles generate most of the cell's ATP (energy) through cellular respiration. They also play roles in signalling, cell death, and calcium storage. Their function declines with age (mitochondrial dysfunction).
Mitochondrial Dysfunction
A decline in the performance of mitochondria, leading to reduced energy production, increased generation of damaging reactive oxygen species (ROS), and impaired cellular function. It's a key hallmark of ageing and contributes to many age-related conditions like fatigue, muscle weakness, and neurodegenerative diseases.
Mitohormesis
A specific type of hormesis where a mild stress affecting the mitochondria (e.g., increased ROS production during exercise) triggers adaptive responses that ultimately improve mitochondrial function, stress resistance, and overall cellular health.
Mitophagy
The selective removal and recycling of damaged or dysfunctional mitochondria through the autophagy process. This is a critical quality control mechanism to maintain cellular energy efficiency and prevent the buildup of harmful mitochondrial byproducts.
Model Organism
A non-human species extensively studied to understand particular biological phenomena (like ageing), with the expectation that discoveries made will provide insight into the workings of other organisms, including humans. Common model organisms in ageing research include yeast, worms (C. elegans), fruit flies (Drosophila), and mice.
Morbidity Compression
The idea of shortening the period of illness and disability experienced towards the end of life. The goal is to increase the proportion of life spent in good health (healthspan), 'compressing' the time spent sick into a shorter phase just before death.
mTOR (Mammalian Target of Rapamycin)
A key protein kinase that acts as a central signalling hub, integrating signals about nutrient availability (especially amino acids and energy levels) and growth factors to regulate cell growth, proliferation, protein synthesis, and autophagy. Chronic overactivation of mTOR signalling is linked to accelerated ageing, while inhibiting it (e.g., with rapamycin) extends lifespan in many species.
N
NAC (N-Acetylcysteine)
A modified form of the amino acid cysteine, often taken as a supplement. NAC acts as an antioxidant itself and, more importantly, serves as a precursor for the body to produce glutathione, the master antioxidant. It's also used medically as a mucus-thinning agent.
NAD+ (Nicotinamide Adenine Dinucleotide)
A vital coenzyme found in every cell, essential for hundreds of processes, including converting food into energy (ATP) and acting as a fuel for critical enzymes like sirtuins (involved in DNA repair and stress resistance) and PARPs (involved in DNA repair). NAD+ levels naturally decline significantly with age, and strategies to boost NAD+ are a major focus of longevity research.
NAD+ Precursors
Molecules that the body can use to synthesise NAD+. Common examples available as supplements include Nicotinamide Mononucleotide (NMN), Nicotinamide Riboside (NR), and Niacinamide (a form of Vitamin B3). The goal of taking these is to counteract the age-related decline in NAD+ levels. You can view our NAD+ Precursor range here.
Necrosis
A form of cell death resulting from acute injury or infection, where the cell swells and bursts, spilling its contents and triggering inflammation in the surrounding tissue. It's generally considered a messy and uncontrolled form of cell death, unlike apoptosis.
Neurodegenerative Disease
A progressive loss of structure or function of neurons (nerve cells), leading to conditions like Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic Lateral Sclerosis (ALS). The risk for most neurodegenerative diseases increases dramatically with age.
Neurogenesis
The process of generating new neurons from neural stem cells. While most prevalent during development, neurogenesis continues on a smaller scale in specific brain regions (like the hippocampus) throughout adulthood. It's thought to be important for learning, memory, and mood regulation, and tends to decline with age.
Neuron
A nerve cell; the basic working unit of the brain and nervous system, responsible for transmitting information through electrical and chemical signals.
Neurotransmitter
A chemical messenger that transmits signals across a synapse (junction) from one neuron to another target neuron, muscle cell, or gland cell. Examples include serotonin, dopamine, acetylcholine, and GABA.
NMN (Nicotinamide Mononucleotide)
A direct precursor molecule used by cells to make NAD+. Found naturally in small amounts in foods like broccoli and avocado. NMN supplements are popular for potentially boosting NAD+ levels to support energy metabolism and cellular repair pathways affected by ageing.
NR (Nicotinamide Riboside)
Another precursor molecule that cells can convert into NAD+, often considered an alternative pathway to NMN. NR is also available as a supplement aimed at raising NAD+ levels, which decline with age.
Nrf2 (Nuclear factor erythroid 2-related factor 2)
A transcription factor that acts as a master switch for the body's antioxidant defence system. When activated (e.g., by oxidative stress or certain plant compounds), Nrf2 promotes the production of numerous protective antioxidant and detoxification enzymes.
Nutraceutical
A term combining 'nutrition' and 'pharmaceutical', referring to food-derived products (supplements, fortified foods) that may provide health benefits beyond basic nutrition, potentially aiding in preventing or treating disease. The regulatory definition can vary.
Nutrient Sensing Pathways
Cellular signalling networks that monitor the availability of nutrients (like glucose, amino acids, fats) and energy levels (ATP/AMP ratio). Key examples include the insulin/IGF-1 pathway, mTOR, AMPK, and sirtuins. These pathways coordinate metabolism and growth with nutrient status and are strongly linked to ageing and longevity.
O
Omega-3 Fatty Acids
A type of essential polyunsaturated fat crucial for health, which the body cannot produce itself. Important omega-3s include EPA and DHA (found in oily fish and algae) and ALA (found in flaxseeds, chia seeds, walnuts). They are known for their anti-inflammatory effects and benefits for heart, brain, and eye health.
Omega-6 Fatty Acids
Another type of essential polyunsaturated fat (e.g., linoleic acid, found in many vegetable oils). While essential, modern diets often contain an excessive amount of omega-6 relative to omega-3, which may promote inflammation. A balanced omega-6 to omega-3 ratio is considered important.
Organelle
A specialised structure within a living cell that performs a specific function (e.g., mitochondria for energy, nucleus for DNA storage, lysosome for waste disposal).
Osteoarthritis
A degenerative joint disease characterised by the breakdown of cartilage in the joints, leading to pain, stiffness, and reduced mobility. The risk increases significantly with age and wear and tear.
Osteoporosis
A condition where bones become weak and brittle due to loss of bone density and quality, making them more susceptible to fractures. It's particularly common in older adults, especially postmenopausal women, due to hormonal changes and reduced calcium absorption.
Oxidation
A chemical reaction involving the loss of electrons from a molecule. In biological systems, uncontrolled oxidation by free radicals can damage cellular components, leading to oxidative stress.
Oxidative Stress
An imbalance between the production of damaging free radicals (or ROS) and the body's ability to counteract them with antioxidants. Chronic oxidative stress damages cells, DNA, proteins, and lipids, contributing significantly to ageing and the development of many diseases.
P
Parabiosis (Heterochronic Parabiosis)
An experimental technique where two living organisms (usually mice) are surgically joined so they share a single circulatory system. When an old mouse is joined with a young mouse (heterochronic), factors in the young blood have been shown to have rejuvenating effects on some tissues of the old mouse, sparking interest in blood-based therapies.
PARPs (Poly(ADP-ribose) polymerases)
A family of enzymes involved primarily in DNA repair and programmed cell death. They consume large amounts of NAD+ when activated by significant DNA damage. Their activity is crucial for genomic stability but excessive activation can deplete NAD+ levels.
Pathogen
A microorganism, such as a bacterium, virus, fungus, or parasite, that can cause disease.
Phenotype
The observable characteristics or traits of an organism, resulting from the interaction of its genotype (genetic makeup) with the environment. Examples include physical appearance, development, behaviour, and susceptibility to disease.
Phytochemicals
Chemical compounds produced by plants ('phyto' means plant). Many phytochemicals, such as polyphenols and carotenoids found in fruits and vegetables, have beneficial effects on human health, often acting as antioxidants or influencing signalling pathways.
Plasma
The liquid component of blood, making up about 55% of its total volume. It's mostly water and contains dissolved proteins, glucose, ions, hormones, and carbon dioxide. Plasma exchange involves removing and replacing or treating this component.
Plasma Exchange / Plasmapheresis
A medical procedure where blood is removed from the body, plasma is separated from blood cells, and the cells are returned, often with replacement fluids. 'Plasma dilution' is an experimental variation being explored for potential anti-ageing effects, aiming to dilute potentially harmful factors that accumulate in old blood.
Polyphenols
A large group of naturally occurring compounds found in plants, including fruits, vegetables, tea, coffee, and wine. They generally have antioxidant properties. Major classes include flavonoids (e.g., quercetin, catechins) and stilbenoids (e.g., resveratrol).
Polyunsaturated Fatty Acids (PUFAs)
Fatty acids containing more than one double bond in their carbon chain. Omega-3 and Omega-6 fatty acids are key examples. They are important components of cell membranes and precursors for signalling molecules.
Prebiotics
Non-digestible fibres (found in foods like onions, garlic, bananas, whole grains) that act as food for beneficial gut bacteria (probiotics), helping them grow and thrive. They promote a healthy gut microbiome.
Probiotics
Live microorganisms (usually bacteria, sometimes yeasts) that, when administered in adequate amounts, confer a health benefit on the host. Found in fermented foods (like yoghurt, kefir, sauerkraut) and supplements, they can help restore balance to the gut microbiome.
Programmed Cell Death
See Apoptosis.
Protein
Large, complex molecules made up of chains of amino acids, essential for the structure, function, and regulation of the body's tissues and organs. Proteins perform a vast array of roles, including acting as enzymes, hormones, antibodies, and structural components.
Proteome
The entire set of proteins expressed by a genome, cell, tissue, or organism at a certain time. Studying the proteome (proteomics) helps understand cellular functions and changes during ageing.
Proteostasis (Protein Homeostasis)
The cellular network responsible for maintaining the health and proper function of all proteins. This involves ensuring correct protein folding, preventing aggregation, repairing damage, and degrading proteins that are old or misfolded. Failure of proteostasis is a key hallmark of ageing and contributes to diseases like Alzheimer's.
Pterostilbene
A natural compound found in blueberries and grapes, structurally related to resveratrol. It is also a polyphenol with antioxidant properties and is thought to activate sirtuins. Some studies suggest it may be better absorbed by the body than resveratrol.
Q
Quercetin
A common flavonoid antioxidant found abundantly in onions, apples, berries, capers, and tea. It has anti-inflammatory and antioxidant effects and is being studied as a potential senolytic (especially combined with Dasatinib) to help clear senescent cells.
R
Rapamycin (Sirolimus)
A drug initially discovered as an antifungal agent, now used mainly as an immunosuppressant to prevent organ transplant rejection. It works by inhibiting the mTOR pathway. Rapamycin is famous in longevity research as it consistently extends lifespan in various animal models. Its potential anti-ageing effects in humans are under investigation.
Reactive Oxygen Species (ROS)
Chemically reactive molecules containing oxygen, including free radicals like superoxide and non-radicals like hydrogen peroxide. They are natural byproducts of metabolism (especially energy production in mitochondria) but can cause damage (oxidative stress) if levels become excessive.
Regenerative Medicine
A field of medicine focused on repairing, replacing, or regenerating damaged tissues or organs, often using approaches like stem cell therapy, tissue engineering, and growth factors. It holds potential for addressing age-related tissue degeneration.
Resveratrol
A natural polyphenol found in the skin of red grapes, blueberries, and peanuts. It gained attention for its potential role in the health benefits associated with red wine. Resveratrol activates SIRT1 (a longevity-linked enzyme) and has antioxidant properties, though its effects in humans are still being clarified.
ROS
See Reactive Oxygen Species.
S
Sarcopenia
The age-related loss of skeletal muscle mass, strength, and function. It's a major cause of frailty, reduced mobility, increased risk of falls, and poorer quality of life in older adults. Resistance exercise and adequate protein intake are key strategies to combat sarcopenia.
SASP (Senescence-Associated Secretory Phenotype)
The mix of pro-inflammatory cytokines, growth factors, and tissue-degrading enzymes released by senescent ('zombie') cells. This toxic secretion contributes to chronic inflammation (inflammaging), damages surrounding tissues, and can even push nearby healthy cells into senescence, creating a vicious cycle that promotes ageing.
Saturated Fat
A type of fat where the fatty acid chains have no double bonds, making them 'saturated' with hydrogen atoms. Typically solid at room temperature (e.g., butter, lard, coconut oil). High intake is generally associated with increased LDL ('bad') cholesterol and cardiovascular risk.
Senescence
See Cellular Senescence.
Senolytics
A class of drugs or natural compounds designed to selectively target and eliminate senescent cells from the body. By clearing these 'zombie' cells and reducing the SASP, senolytics aim to alleviate inflammaging and improve tissue function, potentially treating various age-related conditions.
Senomorphics / Senostatics
Substances that don't necessarily kill senescent cells (like senolytics) but aim to suppress their harmful effects, particularly by reducing the secretion of the inflammatory SASP. This is another therapeutic strategy targeting cellular senescence.
Sirtuins (SIRTs)
A family of seven proteins (SIRT1-SIRT7 in mammals) that act as enzymes regulating key cellular processes, including metabolism, DNA repair, stress resistance, and inflammation. They require NAD+ to function, and their activity is strongly linked to longevity pathways. Their function tends to decline with age as NAD+ levels drop.
Sleep Apnoea
A sleep disorder where breathing repeatedly stops and starts during sleep. This disrupts sleep quality and reduces oxygen levels, increasing the risk of high blood pressure, heart disease, stroke, and cognitive impairment. It becomes more common with age and obesity.
Spermidine
A natural polyamine compound found in all living cells and certain foods (like wheat germ, aged cheese, soybeans, mushrooms). Spermidine is known to induce autophagy (cellular cleanup) and has been linked to increased lifespan and improved cardiovascular health in various studies. Levels decline with age.
Stem Cell
An undifferentiated cell capable of dividing to produce more stem cells (self-renewal) and differentiating into specialised cell types (e.g., muscle cells, nerve cells, blood cells). Adult stem cells are crucial for tissue repair and maintenance throughout life.
Stem Cell Exhaustion
A key hallmark of ageing where the number or functional capacity of adult stem cells declines over time. This impairs the body's ability to repair damaged tissues and regenerate cells, contributing to functional decline and frailty.
Stem Cell Therapy
A medical approach using stem cells to treat or prevent disease or injury. In the context of ageing, research explores using stem cells (often mesenchymal stem cells) to potentially rejuvenate tissues or modulate the immune system, though many claimed anti-ageing stem cell treatments lack rigorous scientific proof.
Stress (Biological)
Any factor that disturbs the body's internal balance (homeostasis). Stressors can be physical (injury, infection, intense exercise), psychological (anxiety, fear), or environmental (toxins, temperature extremes). The body's response to stress involves hormonal and nervous system changes. Chronic stress is detrimental to health and can accelerate ageing.
T
TAME Trial (Targeting Aging with Metformin)
A landmark clinical trial designed to test whether the diabetes drug metformin can delay the development or progression of multiple age-related chronic diseases (like cardiovascular disease, cancer, and cognitive decline) in older adults without diabetes. It aims to provide proof-of-concept for interventions targeting fundamental ageing processes.
Taurine
An organic acid found abundantly in animal tissues, playing roles in bile formation, nerve transmission, and antioxidant defence. Levels decline with age, and recent research in animals suggests that restoring taurine levels can improve healthspan and extend lifespan, making it a molecule of significant interest in ageing research.
Telomerase
An enzyme that can add DNA repeats to the ends of chromosomes, thereby lengthening or maintaining telomeres. While active in stem cells and cancer cells (allowing them to divide more), telomerase activity is very low in most normal adult human cells, contributing to telomere shortening with each division.
Telomeres
Protective caps made of repetitive DNA sequences found at the very ends of chromosomes. They prevent the loss of genetic information during cell division and stop chromosomes from fusing together. Telomeres naturally shorten each time a cell divides; critically short telomeres trigger cellular senescence or death.
Therapies (Category)
Treatments or interventions designed to address health conditions, including those related to ageing. This can range from established medical procedures to experimental drugs or lifestyle modifications.
Time-Restricted Feeding/Eating (TRF/TRE)
A type of intermittent fasting where eating is confined to a specific window of time each day (e.g., 8-10 hours), followed by a fasting period for the remaining hours (e.g., 14-16 hours). This approach aligns eating with circadian rhythms and may offer metabolic benefits.
Tissue Engineering
A field combining cells, engineering methods, and biomaterials to restore, maintain, or improve damaged tissues or whole organs. Part of regenerative medicine, it holds potential for treating age-related tissue degeneration.
Transcription Factors
Proteins that bind to specific DNA sequences to control the rate at which genetic information is transcribed from DNA into messenger RNA (mRNA), essentially turning genes 'on' or 'off'. Examples relevant to ageing include FOXO proteins and Nrf2.
Triglycerides
A type of fat (lipid) found in the blood, used for energy storage. High triglyceride levels, often associated with high carbohydrate intake, obesity, and inactivity, are a risk factor for cardiovascular disease.
U
Ubiquinol / Ubiquinone
See CoQ10 (Coenzyme Q10). Ubiquinone is the oxidised form, while ubiquinol is the reduced, active antioxidant form. Supplements are available in both forms.
Unsaturated Fat
A type of fat containing one (monounsaturated) or more (polyunsaturated) double bonds in the fatty acid chain. Typically liquid at room temperature (e.g., olive oil, sunflower oil). Replacing saturated fats with unsaturated fats is generally considered beneficial for heart health.
V
Vascular Ageing
The age-related changes occurring in blood vessels, including stiffening of arteries (arteriosclerosis), endothelial dysfunction, and increased susceptibility to plaque buildup (atherosclerosis). This increases the risk of hypertension, heart attack, and stroke.
Vitamin D
A fat-soluble vitamin essential for calcium absorption, bone health, immune function, and cell growth regulation. It's unique because the body can synthesise it when skin is exposed to sunlight (UVB). Deficiency is common and linked to numerous health problems, particularly in older adults.
Vitamins
Organic compounds that are essential micronutrients needed in small quantities for proper metabolic function. They must generally be obtained from the diet as the body cannot synthesise them sufficiently. Examples include Vitamin C, Vitamin D, and B vitamins.
VO2 Max
The maximum rate at which your body can consume oxygen during intense exercise. It's the gold standard measure of cardiorespiratory (aerobic) fitness. VO2 max naturally declines with age, but regular endurance training can help maintain or improve it. Higher VO2 max is strongly linked to better health and longevity.
W
Walking Speed
See Gait Speed.
Whole Grains
Grains (like oats, brown rice, whole wheat) that contain the entire grain kernel – the bran, germ, and endosperm. They are rich in fibre, vitamins, minerals, and phytochemicals, and consuming them is associated with better metabolic health and reduced risk of chronic diseases compared to refined grains.
X
Xenohormesis
The idea that consuming molecules produced by stressed plants (phytochemicals) can trigger beneficial stress-response pathways (hormesis) in the consumer, enhancing health and potentially longevity. The plant's stress signals are interpreted as cues for the consumer to activate its own protective mechanisms.
Y
Yamanaka Factors
A set of four specific transcription factors (Oct4, Sox2, Klf4, c-Myc) discovered by Shinya Yamanaka that can reprogram specialised adult cells (like skin cells) back into an embryonic-like pluripotent state (induced pluripotent stem cells, or iPSCs). This cellular reprogramming technology has profound implications for regenerative medicine and is also being explored for potential partial reprogramming strategies to reverse aspects of cellular ageing.
Z
Zombie Cells
A common, informal term for Cellular Senescence or senescent cells, emphasising their state of being neither fully alive and dividing nor properly dead, while causing harm to their surroundings.
Disclaimer: This glossary provides general information and definitions. It is not intended as medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.