Health Glossary
A comprehensive guide to the scientific terms you encounter in our articles. From A to Z, everything you need to better understand your body, nutrition, and longevity strategies.
4
4-7-8 Breathing
A relaxation breathing technique: inhale for 4 seconds, hold for 7, exhale for 8. Activates the parasympathetic nervous system, reducing anxiety and promoting sleep.
A
Adenosine
A neurotransmitter that builds up in the brain during waking hours, creating 'sleep pressure'. It is cleared during sleep. Caffeine works by blocking adenosine receptors.
AGEs
Advanced Glycation End-products. Harmful compounds formed when proteins or fats bind to sugar in the blood. They contribute to aging and chronic diseases.
Alpha Waves
Brain waves (8-13 Hz) associated with a state of relaxed wakefulness, calm and light 'flow'. Activated by closing your eyes and relaxing.
ApoB
Apolipoprotein B. The main protein found in 'bad' cholesterol particles (LDL, VLDL). Considered a more accurate indicator of cardiovascular risk than LDL cholesterol alone.
ATP
Adenosine Triphosphate. The universal 'energy currency' of cells. Every biological process — from muscle contraction to protein synthesis — requires ATP. Mitochondria are the primary producers.
Autophagy
A cellular 'cleanup' process where the cell degrades and recycles its own damaged or unnecessary components. Essential for cellular renewal and longevity.
B
BCAA
Branched-Chain Amino Acids. A group of three essential amino acids (leucine, isoleucine, valine) involved in muscle protein synthesis and post-exercise recovery.
Beta Waves
Brain waves (13-30 Hz) typical of active wakefulness, focused attention and logical thinking. If excessive, they can indicate anxiety.
Blue Zones
Regions of the world (like Sardinia or Okinawa) where people live significantly longer than average. Studies of these zones have revealed common longevity habits.
C
CBT-I
Cognitive Behavioral Therapy for Insomnia. A structured protocol considered the first-line treatment for chronic insomnia, more effective and longer-lasting than medication.
Cellular Senescence
A state where cells stop dividing but don't die. These 'zombie cells' accumulate damage and secrete inflammatory substances that harm nearby tissues.
Cortisol
A steroid hormone produced by the adrenal glands in response to stress. Chronically elevated levels can negatively affect metabolism, the immune system and mental health.
D
De novo Lipogenesis
The metabolic process by which the liver converts excess carbohydrates (especially fructose) into new fatty acids, contributing to fatty liver disease.
Deep Sleep
Or slow-wave sleep (NREM stage 3). The most regenerative sleep phase, where physical recovery, tissue repair, brain cleansing (glymphatic system) and growth hormone release occur.
Delta Waves
Slow brain waves (0.5-4 Hz) dominant during deep dreamless sleep. Essential for physical regeneration and growth hormone release.
Dysbiosis
An imbalance in the composition or function of the microbiome, often associated with gastrointestinal disorders, inflammation and other conditions.
E
EEG
Electroencephalogram. A technique for measuring the brain's electrical activity through electrodes placed on the scalp. It detects brain waves (Alpha, Beta, Theta, Delta, Gamma).
EPOC
Excess Post-exercise Oxygen Consumption. The phenomenon where the body continues to burn calories at an elevated rate even after exercise ends, to restore physiological balance.
F
Ferritin
A protein that stores iron in cells. Levels that are too low indicate iron deficiency (anemia), while levels that are too high can indicate inflammation or iron overload.
Fisetin
A plant polyphenol (found in strawberries) that acts as a potent senolytic, eliminating senescent cells and reducing inflammation.
FMD
Fasting Mimicking Diet. A low-calorie, low-protein dietary protocol designed to induce the beneficial effects of fasting (such as autophagy) while still eating.
Free Radicals
Unstable molecules produced during metabolism or from external factors (pollution, UV rays). They can damage cells (oxidative stress) if not neutralized by antioxidants.
Fructose
A simple sugar naturally found in fruit. Unlike glucose, it is metabolized almost exclusively by the liver. Excess fructose (from added sugars) can cause fatty liver.
G
GABA
Gamma-Aminobutyric Acid. The main inhibitory neurotransmitter in the brain, responsible for relaxation and reducing neuronal excitability.
Gamma Waves
The fastest brain waves (30-100 Hz), associated with peak concentration, insight, complex learning and memory.
Glucose
The primary energy source for the body's cells. Transported in the blood, its concentration is regulated by insulin.
GLUT4
A protein that transports glucose from the blood into muscle and fat cells. Exercise can activate GLUT4 independently of insulin.
Glycation
A process where excess sugar in the blood binds to proteins, damaging them and compromising their function. One of the main causes of tissue aging.
Glycemic Index
A value indicating how quickly a carbohydrate-containing food raises blood glucose levels compared to pure glucose.
Glycine
An amino acid that acts as a relaxing neurotransmitter in the brain. Essential for collagen production, sleep and detoxification.
H
HbA1c
Glycated Hemoglobin. A test that measures the average blood sugar levels over the past 3 months, providing a long-term view of glycemic control.
Healthspan
The length of time a person lives in good health, free from chronic diseases and disabilities. It is the true goal of longevity medicine, as opposed to simple Lifespan.
HIIT
High Intensity Interval Training. A form of cardiovascular training that alternates short periods of intense anaerobic exercise with less intense recovery periods.
HOMA-IR
Homeostatic Model Assessment for Insulin Resistance. An index used to estimate insulin resistance and pancreatic beta cell function.
Hormesis
A biological phenomenon where exposure to low doses of a stressor (such as cold, heat or exercise) stimulates beneficial adaptive responses that strengthen the organism.
HPA
Hypothalamic-Pituitary-Adrenal axis. The neuroendocrine system that regulates the stress response through cortisol release. Its chronic overactivation underlies many metabolic and mental health disorders.
HRV
Heart Rate Variability. The variation in the time interval between consecutive heartbeats. A key indicator of the autonomic nervous system's state and recovery.
hs-CRP
High-sensitivity C-reactive Protein. A protein produced by the liver that increases in the presence of inflammation. The high-sensitivity version is used to assess cardiovascular risk.
I
IGF-1
Insulin-like Growth Factor 1. A hormone similar to insulin that regulates cell growth. Reduced levels are associated with greater longevity in many model organisms.
Insulin Resistance
A condition where the body's cells don't respond adequately to insulin, leading to elevated blood glucose levels and increasing the risk of type 2 diabetes.
J
Journaling
The practice of regularly writing down thoughts, feelings and experiences. A powerful tool for stress management, emotional processing and improving mental health.
K
Ketones
Molecules produced by the liver from fats when glucose availability is low (fasting, ketogenic diet). They provide efficient energy for the brain and body.
L
L-Theanine
An amino acid found in green tea that promotes relaxation without drowsiness. Increases alpha brain waves and works synergistically with caffeine to improve focus.
Lactate
A byproduct of glucose metabolism produced during intense exercise. It is not waste, but fuel. Its concentration in the blood (lactate threshold) marks the boundary between Zone 2 and higher intensities.
Lifespan
The total length of an organism's life, from birth to death, regardless of the quality of health during those years.
M
MACs
Microbiota Accessible Carbohydrates. Complex carbohydrates (fiber) that are not digested by the host but are fermentable by gut bacteria, promoting a healthy microbiome.
Magnesium Bisglycinate
A form of magnesium bound to the amino acid glycine. Highly absorbable and gentle on the stomach. Ideal for promoting relaxation, sleep and muscle recovery.
MED
Minimum Effective Dose. The concept of finding the minimum amount of a stimulus (such as exercise or a supplement) needed to achieve the desired result, maximizing efficiency and reducing unnecessary stress.
Melatonin
The hormone that regulates the sleep-wake cycle. Produced by the pineal gland in response to darkness, it signals the body that it's time to sleep. Blue light (screens) inhibits its production.
Metabolic Flexibility
The body's ability to efficiently switch between using carbohydrates and fats as energy sources, depending on availability and exercise intensity.
Metabolic Syndrome
A cluster of conditions (high blood pressure, high blood sugar, excess abdominal fat, abnormal cholesterol) that increase the risk of heart disease, stroke and diabetes.
Microbiome
The collection of microorganisms (bacteria, viruses, fungi) living in a given environment, such as the human gut. It plays a crucial role in digestion, the immune system and vitamin synthesis.
Mitochondria
The 'power plants' of cells. Organelles responsible for energy production (ATP). Their health and efficiency decline with age but can be enhanced through exercise and diet.
Mitophagy
A specific form of autophagy that targets and degrades damaged or dysfunctional mitochondria, allowing them to be replaced with new, efficient ones.
mTOR
Mammalian Target of Rapamycin. A protein that acts as a central nutrient sensor, regulating cell growth and protein synthesis. Its inhibition is linked to autophagy and longevity.
Myokines
Signaling molecules (cytokines) released by muscle cells during contraction. They have anti-inflammatory effects and benefits for the brain, bones, and metabolism.
N
NAD+
Nicotinamide Adenine Dinucleotide. An essential coenzyme present in all living cells. Crucial for energy metabolism and sirtuin activity. Its levels decline with age.
NAFLD
Non-Alcoholic Fatty Liver Disease. Fat accumulation in the liver not caused by alcohol, often due to excess fructose and insulin resistance.
Nitric Oxide
A gaseous molecule produced in the paranasal sinuses (and in the endothelium). A potent vasodilator that improves oxygen absorption and has antimicrobial properties.
O
ORAC
Oxygen Radical Absorbance Capacity. A method of measuring the antioxidant capacity of foods and biological substances.
Oxidative Stress
An imbalance between free radical production and the body's ability to neutralize them with antioxidants. A key cause of aging and many diseases.
P
Parasympathetic Nervous System
The part of the autonomic nervous system responsible for 'rest and digest' functions. It slows the heart rate, stimulates digestion and promotes relaxation and recovery.
Polyphenols
Natural compounds found in plants with potent antioxidant and anti-inflammatory properties. Many polyphenols also act as prebiotics.
Prebiotics
Non-digestible substances (often fibers) that selectively stimulate the growth and/or activity of one or more bacteria in the colon, improving host health.
Probiotics
Live microorganisms that, when administered in adequate amounts, confer a health benefit to the host.
R
Rapamycin
An immunosuppressant drug that inhibits mTOR. Considered one of the most promising potential geroprotectors, although its use in humans for longevity is still experimental and controversial.
REM
Rapid Eye Movement. The sleep phase characterized by vivid dreams, muscle paralysis and brain activity similar to waking. Crucial for memory, learning and emotional regulation.
RHR
Resting Heart Rate. The number of heartbeats per minute when the body is at complete rest. A lower RHR generally indicates better cardiovascular efficiency.
S
Sarcopenia
The progressive loss of muscle mass, strength, and function linked to aging. It is a primary risk factor for frailty, falls, and early mortality.
SCFA
Short Chain Fatty Acids. Produced by bacterial fermentation of fiber in the gut. Essential for colon health and metabolism.
SCN
Suprachiasmatic Nucleus. A small region of the hypothalamus that acts as the body's 'master clock', coordinating circadian rhythms in response to light.
Sirtuins
A family of proteins (SIRT1-7) that regulate cellular health, DNA repair and metabolism. Their activity is stimulated by NAD+ and practices like fasting.
Spermidine
A natural polyamine that stimulates autophagy, the cellular cleanup process. Found in foods like wheat germ, mushrooms, and aged cheeses.
Sucrose
Common table sugar. A disaccharide composed of one glucose molecule and one fructose molecule bonded together.
T
Telomeres
The protective caps at the ends of chromosomes. They shorten each time a cell divides, and their length is considered an indicator of biological aging.
Theta Waves
Brain waves (4-8 Hz) linked to deep relaxation, meditation, creativity and the REM phase of sleep.
TRE
Time-Restricted Eating. A form of intermittent fasting that limits food intake to a daily window (typically 8-12 hours), aligning with the circadian rhythm to optimize metabolism.
U
Urolithin A
A metabolite produced by gut bacteria from ellagitannins (pomegranate, walnuts). Known for activating mitophagy and improving muscle function.
V
Vagus Nerve
The tenth cranial nerve and the main component of the parasympathetic nervous system. It connects the brain to the heart, lungs and gut, regulating heart rate, digestion and inflammation.
VO2 Max
The maximum volume of oxygen the body can use during intense exercise. Considered one of the best indicators of cardiorespiratory fitness and longevity.
Z
Zeitgeber
German for 'time giver'. Any external signal (such as sunlight or food) that synchronizes the body's biological rhythms with the Earth's 24-hour cycle.
Zone 2
Low-intensity training (60-70% of maximum heart rate) that improves mitochondrial function and fat oxidation capacity. Essential for metabolic health and longevity.
Zone 5
Very high intensity training (90-100% of maximum heart rate), typical of HIIT. Useful for improving VO2 Max and cardiac output.