Pathways

How much body fat you carry, shown by body weight, BMI and waist size. ↗︎ studies

Master inflammatory switch; supporting its balance helps maintain a healthy inflammatory response. ↗︎ studies

How the body transports and handles cholesterol and other fats, not simply their level. ↗︎ studies

Blood-sugar handling and insulin sensitivity. ↗︎ studies

Master antioxidant and detox switch. ↗︎ studies

How much insulin your body runs to keep blood sugar steady — lower means less metabolic strain. ↗︎ studies

How well your cells respond to insulin and handle sugar. ↗︎ studies

Master energy sensor — switches on fat-burning and cellular cleanup. ↗︎ studies

Apprehension and physical arousal, and whether they settle once the situation that caused them has passed. ↗︎ studies

Nitric-oxide blood-vessel relaxation and flow. ↗︎ studies

An immune signal that guards the body's mucosal surfaces but, out of balance, drives inflammation against the self. ↗︎ studies

Body-wide inflammatory tone, measured in blood as CRP and IL-6. ↗︎ studies

Stress axis and cortisol regulation. ↗︎ studies

An immune messenger with two faces: chronically raised, it marks inflammation; released from working muscle, it aids metabolism. ↗︎ studies

Mood, calm and well-being. ↗︎ studies

Gut-lining integrity and microbiome. ↗︎ studies

Glutathione — the master cellular antioxidant. ↗︎ studies

The resilience and regenerative capacity of the body's central metabolic and detox organ. ↗︎ studies

The capacity to clear a germ before it takes hold. ↗︎ studies

Mitochondrial energy (ATP) output. ↗︎ studies

Longevity gene that repairs DNA and tunes metabolism. ↗︎ studies

Immune defense and balance. ↗︎ studies

The adaptation after training — where the gain from the workout is actually made. ↗︎ studies

Cellular recycling that clears damaged parts. ↗︎ studies

Spermatogenesis is the roughly 70-day production line for healthy sperm, highly sensitive to oxidative stress, heat and nutrient status. Protecting it supports count, motility and DNA integrity. ↗︎ studies

A master inflammatory messenger that, in inflamed fat tissue, also drives unwanted fat release. ↗︎ studies

The kidneys' filtration units — the glomeruli and their podocyte cells — clear waste and balance fluids. Protecting them from oxidative and metabolic stress preserves long-term kidney function. ↗︎ studies

Growth factor for new brain cells and plasticity. ↗︎ studies

Clears worn-out 'zombie' cells that drive aging. ↗︎ studies

Primary male hormone — drive, muscle, vitality. ↗︎ studies

The hypothalamic-pituitary-gonadal axis is the command chain (GnRH → FSH/LH → sex hormones) that runs fertility and sex-hormone output. Supporting it underpins libido, fertility and hormonal vitality. ↗︎ studies

A sensor of cellular stress that ignites inflammation driven by damage rather than by germs. ↗︎ studies

The shape of the night — deep sleep early for physical repair, dream sleep late for memory — not just its hours. ↗︎ studies

The retina depends on its pigment density (lutein and zeaxanthin), blood flow and antioxidant defense. Supporting these shields the macula from age-related and light stress. ↗︎ studies

H. pylori is the stomach bacterium behind most ulcers and chronic gastritis. Suppressing its virulence and protecting the stomach lining supports gastric and digestive health. ↗︎ studies

Excitatory signal; quieting overactivity protects neurons. ↗︎ studies

The enzyme chain ending in thrombin and the fibrin net that sets a clot solid. ↗︎ studies

Builds new mitochondria for more cellular power. ↗︎ studies

Endoplasmic-reticulum stress and the unfolded-protein response (PERK/IRE1α/ATF6), triggered by lipid overload, driving hepatic lipogenesis, inflammation and apoptosis. ↗︎ studies

Fat-derived hormone that improves insulin and burns fat. ↗︎ studies

Muscle mass is the balance between building signals (IGF-1) and the growth brake myostatin. Tipping the balance toward growth supports strength, recovery and healthy metabolism. ↗︎ studies

The mitochondrial pathway that dismantles fatty acids into cellular energy. ↗︎ studies

Estrogen balance — set largely by the aromatase enzyme that converts androgens into estrogen — shapes reproductive, bone, skin and metabolic health. The aim is healthy balance for the individual, not simply more or less. ↗︎ studies

Norepinephrine is the alertness and arousal neurotransmitter behind focus, drive and the stress response. Healthy tone supports attention, energy and mood. ↗︎ studies

Fat accumulation in the liver. ↗︎ studies

The signal that calls more inflammatory white cells into a tissue. ↗︎ studies

PI3K/AKT is the cell's main growth-and-survival signal. Chronically overactive, it accelerates aging and abnormal proliferation while blocking cellular cleanup — so restraining it is a core longevity and growth-restraint lever. ↗︎ studies

Motivation, drive and reward. ↗︎ studies

Scar-tissue / fibrosis driver. ↗︎ studies

Active thyroid hormone (T3) — the signal that sets metabolic rate, temperature and energy availability. ↗︎ studies

Ovarian reserve, ovulation and the endocrine sequence that governs both. ↗︎ studies

Core signaling relay carrying growth, stress and survival messages inside the cell. ↗︎ studies

Amyloid-β aggregation and clearance; a hallmark of neurodegeneration. ↗︎ studies

The making and storing of new fat; supporting its balance helps maintain healthy fat metabolism. ↗︎ studies

Not happiness — stability, and the whole positive dimension of how life feels. ↗︎ studies

The brain's main calming signal. ↗︎ studies

Mast-cell stabilization and histamine (H1) signaling behind allergic, sinus and skin flares. ↗︎ studies

A small protein the body makes to grab heavy metals and hold them where they cannot react. ↗︎ studies

The comfort and efficiency of digestion and nutrient absorption. ↗︎ studies

Corticotropin-releasing factor, the 41-amino-acid peptide that opens the HPA axis; drives stress-induced relapse. ↗︎ studies

Living tissue in constant turnover, built by osteoblasts and dismantled by osteoclasts. ↗︎ studies

Neuroinflammation — inflammatory activation within the brain that clouds cognition and depresses mood. ↗︎ studies

The machinery that decides a stressed cell repairs rather than dies. ↗︎ studies

Growth switch; restraining it is linked to longer healthspan. ↗︎ studies

Desire, arousal and function — three separable parts of sexual health. ↗︎ studies

A protein called UCP1 lets a fat cell release energy as heat rather than bank it. ↗︎ studies

Bile-acid → ileal FXR → FGF19 → hepatic FGFR4/β-klotho signaling that governs cholesterol, bile-acid and fat metabolism; blunted (low FGF19) in obesity and fatty liver. ↗︎ studies

Gut hormone for appetite control and steady blood sugar. ↗︎ studies

Sugar-damaged proteins that stiffen tissue. ↗︎ studies

Endurance and VO₂max, the whole-body measure of cardiovascular and metabolic fitness. ↗︎ studies

The messenger that carries the fat-release signal inside the cell. ↗︎ studies

The whole apparatus of thinking: taking information in, holding it, working with it, and getting it back out. ↗︎ studies

Hypoxia-inducible factor — master regulator of the cellular response to low oxygen; exercise adaptation and angiogenesis. ↗︎ studies

The fast pathway that breaks glucose down for quick cellular energy. ↗︎ studies

Memory and focus neurotransmitter. ↗︎ studies

The brain's capacity to rewire in response to use. ↗︎ studies

The fight-or-flight arm of the nervous system that quickens the heart and mobilizes the body. ↗︎ studies

The reactive-oxygen burden that ages the hair follicle and drives shedding and graying. ↗︎ studies

The calibrated restraint that keeps the immune system from turning on the self. ↗︎ studies

Pain and inflammation enzyme. ↗︎ studies

The liver's capacity to regenerate and restore its own mass. ↗︎ studies

A frontline immune sensor that detects microbial and danger signals and calls up the inflammatory response. ↗︎ studies

Tissue structure and remodeling. ↗︎ studies

Apoptosis is the body's orderly self-destruct program, run by BAX and the caspase enzymes, that removes damaged, senescent or dangerous cells before they cause harm. Restoring it lets the body clear cells that should not survive. ↗︎ studies

The fat layer beneath the skin. ↗︎ studies

Releases stored fat to be burned. ↗︎ studies

Botanical compounds that gently modulate the body's estrogen signaling. ↗︎ studies

Cellular fuel coenzyme that declines with age. ↗︎ studies

Packaging and export of liver triglyceride as VLDL (lipin-1/MTP); when export is overwhelmed, fat accumulates as steatosis. ↗︎ studies

CD36/FAT fatty-acid translocase imports lipids into the liver; upregulated in fatty liver, it drives steatosis, lipogenesis and inflammation. ↗︎ studies

The iron-and-lipid defense that keeps a cell membrane intact, held up by the body’s own antioxidant system. ↗︎ studies

The mitochondrial permeability transition pore springs open when a cell is overwhelmed, triggering its death. Keeping it shut protects heart and other high-energy cells during stress. ↗︎ studies

The liver's sugar production. ↗︎ studies

Protects insulin-producing pancreas cells. ↗︎ studies

The gap between what you intend and what your body will fund. ↗︎ studies

The switch inside the fat cell that opens its stores. ↗︎ studies

Catechol-O-methyltransferase — catecholamine (dopamine/norepinephrine) breakdown; prefrontal signaling tone. ↗︎ studies

Glutathione peroxidase — the enzyme family that spends glutathione to neutralize peroxides before they damage a cell. ↗︎ studies

Myelin / oligodendrocyte sheath maintenance; saltatory nerve conduction and repair. ↗︎ studies

Mesolimbic dopamine reward circuit (VTA–nucleus accumbens); motivation and addictive drive. ↗︎ studies

The body's own endorphin (opioid) system modulates pain, mood and reward. Supporting healthy tone eases discomfort and lifts mood without external opioids. ↗︎ studies

The body's 24-hour clock. ↗︎ studies

Skin resilience rests on its barrier, collagen scaffold and hyaluronic-acid hydration. Supporting these strengthens the body's largest protective organ and slows visible aging. ↗︎ studies

Hormone system that raises blood pressure. ↗︎ studies

Cartilage, the joint lining, the bone beneath them and the tissues that load them. ↗︎ studies

The force of blood against the vessel wall, a master gauge of cardiovascular health. ↗︎ studies

The relay cytokines use to direct immune and repair responses. ↗︎ studies

A master inflammatory messenger of the immune system. ↗︎ studies

Protective DNA caps that shorten with age. ↗︎ studies

Wnt/β-catenin signaling governs stem-cell renewal and tissue building in bone and hair follicles. Balanced activity supports bone formation and the active hair-growth phase. ↗︎ studies

Whether the vitamins and minerals the body runs on are present in sufficient amounts. ↗︎ studies

The calories the body actually spends in a day, measured directly rather than inferred from weight change. ↗︎ studies

Controls new fat-cell formation. ↗︎ studies

Leptin signaling and leptin resistance — the satiety-hormone axis (distinct from gut incretins and from general appetite signaling). ↗︎ studies

p53 is the genome's guardian — it pauses damaged cells to repair them or, if they are beyond repair, or clears those beyond repair. It is one of the body's most important tumor-suppressor safeguards. ↗︎ studies

The rate at which a meal leaves the stomach. ↗︎ studies

Hunger and fullness signaling. ↗︎ studies

Slows carb digestion to blunt post-meal spikes. ↗︎ studies

The small genome inside mitochondria that encodes thirteen essential parts of the energy chain. ↗︎ studies

How well your blood carries oxygen. ↗︎ studies

A cofactor for over three hundred enzymes, including every reaction that handles ATP. ↗︎ studies

The fat packed around the abdominal organs, the metabolically active store most closely tied to insulin resistance and inflammation. ↗︎ studies

The process by which a precursor cell commits to becoming a new fat cell. ↗︎ studies

The coordinated reflex that moves a swallow safely past the airway — measured on clinical swallowing scores. ↗︎ studies

Takes stored fat apart once the release switch is on. ↗︎ studies

Makes the first cut into stored fat, the step that sets the pace. ↗︎ studies

Sterol regulatory element-binding protein - the transcription factor driving de novo lipogenesis. ↗︎ studies

Drives fatty-acid burning for energy. ↗︎ studies

The chemical tags on DNA that drift with age, the basis of epigenetic clocks. ↗︎ studies

Selective clearance of damaged mitochondria via PINK1/Parkin — mitochondrial quality control (a targeted arm of autophagy). ↗︎ studies

Heat-shock proteins are molecular chaperones that refold damaged proteins and shield cells during stress. Briefly stressing the system (hormesis) raises them and builds lasting cellular resilience. ↗︎ studies

Hives that persist beyond six weeks, driven by mast-cell activation rather than a passing allergen. ↗︎ studies

CREB-mediated synaptic plasticity and gene transcription; learning, memory and addiction remodeling. ΔFosB needs CREB and SRF together — either alone leaves it intact (Vialou 2012), so this is one required factor, not the switch. ↗︎ studies

The birth of new neurons in the adult brain — concentrated in the hippocampus, tied to memory formation and to mood. ↗︎ studies

Involuntary, painful muscle contractions, often at night and often in the calf. ↗︎ studies

The adrenal precursor from which both androgens and estrogens can be made. ↗︎ studies

The capacity to keep focus on one task, shift it deliberately, and filter distraction over time. ↗︎ studies

One of the six DSM-5 cognitive domains: planning, decision-making, mental flexibility and self-regulation. ↗︎ studies

A subdomain of complex attention: the raw speed of taking information in and acting on it. ↗︎ studies

Lower urinary tract function — flow, frequency, urgency and waking at night to urinate. ↗︎ studies

An acute, fluctuating disturbance of attention and awareness — distinct from dementia, which arrives slowly. ↗︎ studies

Calcium movement through L-type channels governs heart rhythm, muscle contraction and nerve firing. Modulating it supports vascular tone and steady muscle and nerve function. ↗︎ studies

Sleep-onset and antioxidant hormone. ↗︎ studies

The quantity of opioid analgesia a person requires — a direct measure of how much pain was left unhandled. ↗︎ studies

Nerve damage from sustained high blood sugar, felt as numbness, burning or pain that begins in the feet. ↗︎ studies

A prostaglandin measurably elevated in balding scalp, where it suppresses hair growth. ↗︎ studies

When injury keeps repeating, collagen scar is laid down where working tissue used to be. ↗︎ studies

Fat in the liver caused by drinking rather than by diet. ↗︎ studies

The mitochondrial enzyme that turns acetaldehyde into harmless acetate. ↗︎ studies

Alcohol is broken down by the ADH and ALDH enzymes through a toxic intermediate, acetaldehyde. Supporting these enzymes and the liver eases the metabolic burden of alcohol. ↗︎ studies

A clot forming inside a vessel that should have stayed open. ↗︎ studies

Blood-clotting cells. ↗︎ studies

Heart, vessels and blood pressure taken together, as one picture. ↗︎ studies

Circulating fat in transit. ↗︎ studies

The clot-dissolving system that keeps blood flowing and clears fibrin from the vessels. ↗︎ studies

How readily the arteries flex with each heartbeat, measured as pulse wave velocity and pulse pressure. ↗︎ studies

Gut bacteria and the compounds that come from them, such as short-chain fatty acids and TMAO, that bear on blood pressure. ↗︎ studies

A pregnancy disorder of new high blood pressure with organ involvement, rooted in the endothelium. ↗︎ studies

Hydrogen sulfide, which alongside nitric oxide and carbon monoxide relaxes the muscle of blood vessels. ↗︎ studies

One of the six cognitive domains defined by the DSM-5: sustaining focus, filtering out distractions, dividing attention and processing information under time pressure. ↗︎ studies

The gums and the tissues that hold the teeth, a gateway to the rest of the body. ↗︎ studies

Irregular ovulation with an excess of male-type hormones, usually alongside insulin resistance. ↗︎ studies

One of the six DSM-5 cognitive domains: recognizing emotion, inferring intention and regulating social behavior. ↗︎ studies

The wakeful state that gates cognition rather than being part of it. ↗︎ studies

Airway reactivity — the allergic type of inflammation behind wheezy breathing. ↗︎ studies

The point at which fat overload stops being a metabolic problem and starts harming the cell itself. ↗︎ studies

Reactive oxygen — at low levels a signaling messenger that sharpens metabolism and defense; in excess, the oxidative fire that corrodes cells. ↗︎ studies

One of the body's earliest and loudest inflammatory signals. ↗︎ studies

Bone is continuously rebuilt through the RANKL/OPG balance — RANKL drives bone-dissolving osteoclasts while OPG restrains them. Estrogen loss tips this toward net loss; shifting it back preserves bone density. ↗︎ studies

The beta-3 adrenaline receptor, present in human fat, bladder, heart, vessels and brain. ↗︎ studies

Fat tissue's blunted response to adrenaline, the hormone signal that releases stored fat. ↗︎ studies

Adipose tissue inflammation — immune cells accumulating in fat, forming crown-like structures around dying adipocytes and releasing cytokines locally. ↗︎ studies

Obesogen exposure — endocrine-disrupting chemicals such as bisphenols, phthalates and organotins that alter fat-cell development and lipid storage. ↗︎ studies

FOXO transcription factors are longevity switches that turn on stress-defense, DNA-repair and self-recycling genes. Growth and insulin signaling suppress them; activating them echoes the benefits of calorie restriction. ↗︎ studies

Liver phase I/II detox enzymes. ↗︎ studies

Decomposes hydrogen peroxide to water and oxygen at extraordinary speed. ↗︎ studies

The liver's phase I and phase II enzyme systems that make foreign compounds ready to excrete. ↗︎ studies

Superoxide dismutase — converts superoxide to hydrogen peroxide. ↗︎ studies

Thioredoxin and thioredoxin reductase — a redox network parallel to glutathione. ↗︎ studies

The molecular clamp that holds the antioxidant master-switch Nrf2 in check until oxidative threat releases it. ↗︎ studies

UDP-glucuronosyltransferase conjugation — the highest-capacity route for making compounds water-soluble. ↗︎ studies

Lipocalin-2, an inflammatory adipokine elevated in obesity that worsens insulin resistance and metabolic inflammation. ↗︎ studies

Epigenetic dimmer that tunes which genes are switched on. ↗︎ studies

Sustained high blood sugar that arises when insulin stops working and the pancreas can no longer make up the difference. ↗︎ studies

The sorbitol pathway — where excess glucose is shunted when the normal routes saturate. ↗︎ studies

The post-meal hormone released by the ileum that tells the liver to stand down glucose production — an insulin-independent gut-to-liver dispatch. ↗︎ studies

The iron-carrying molecule at the center of hemoglobin and of the cell's energy enzymes. ↗︎ studies

Produced continuously, not only under oxygen debt, and shuttled between tissues as fuel and signal. ↗︎ studies

The signature phospholipid of the inner mitochondrial membrane, required for the respiratory chain to assemble. ↗︎ studies

Ubiquinone/ubiquinol — essential to the mitochondrial respiratory chain and a lipid-soluble antioxidant. ↗︎ studies

The master iron gatekeeper from the liver. ↗︎ studies

Iron status — body iron stores, read as ferritin, which carry oxygen and run the enzymes that make cellular energy. ↗︎ studies

Mitochondrial biogenesis — building new mitochondria rather than repairing old ones. ↗︎ studies

↗︎ studies

The transporter muscle moves to its surface to take glucose out of the blood. ↗︎ studies

TRPV1 capsaicin-sensitive nociceptor channel; peripheral pain and neurogenic inflammation. ↗︎ studies

The selenium-dependent enzymes that convert T4 into active T3 — and a third that switches it back off. ↗︎ studies

How the body holds its core temperature through metabolic rate, circulation and the brain's set-point. ↗︎ studies

The cold-stress input — the thermal challenge that recruits brown-fat thermogenesis and mitochondrial biogenesis. ↗︎ studies

The coat protein over stored fat that holds the fat-releasing machinery back until it is told to let go. ↗︎ studies

The messenger made in response to nitric oxide and heart-derived hormones that relaxes blood vessels. ↗︎ studies

Blood supply to fat tissue — the only route by which released fat can actually leave. ↗︎ studies

Released fatty acids put straight back into stored fat inside the fat cell. ↗︎ studies

The main blood protein, which carries released fatty acids through the bloodstream. ↗︎ studies

The parathyroid hormone receptor, which governs calcium and bone and also signals to fat cells. ↗︎ studies

The enzyme that completes triglyceride assembly, putting fatty acids back into the cell's fat droplet. ↗︎ studies

Proteins that carry fatty acids inside cells to where they are used or stored. ↗︎ studies

The liver making new glucose from building blocks such as glycerol, lactate and amino acids. ↗︎ studies

A receptor that senses long-chain fatty acids, including omega-3s — one of the ways fats signal back to the cells that release them. ↗︎ studies

A receptor on the fat cell for short-chain fatty acids — the things fermentable fiber produces. ↗︎ studies

The first chemical mark on hormone-sensitive lipase, the one that moves it onto the fat droplet. ↗︎ studies

A hormone the gut releases after eating that signals fullness to the brain. ↗︎ studies

The chemical mark that switches on hormone-sensitive lipase, the second fat-releasing enzyme, once it is on the fat droplet. ↗︎ studies

Monoglyceride lipase — the third fat-releasing enzyme, which cuts the last fatty acid free from the glycerol backbone. ↗︎ studies

The enzymes that attach coenzyme A to fatty acids, readying them to be burned for energy or stored. ↗︎ studies

The beta-1 and beta-2 adrenaline receptors, the ones that carry adrenaline's fat-release signal in people. ↗︎ studies

A gene switch that turns on quickly after growth signals and helps control the gene for the main fat-releasing enzyme. ↗︎ studies

A relay inside cells that passes growth and inflammation signals on to the nucleus. ↗︎ studies

A transporter that brings fatty acids into the tissues that burn them, such as muscle. ↗︎ studies

A gene switch that insulin turns off, and that helps control fat release and the liver's glucose production. ↗︎ studies

Cortisol's receptor route — a slower stress-hormone signal that also governs fat release. ↗︎ studies

Where the glycerol released from fat cells goes next — largely to the liver, which can turn it into glucose. ↗︎ studies

The cell breaking down its fat droplets inside lysosomes, a route separate from the fat-releasing enzymes. ↗︎ studies

A growth-signaling hub that insulin and nutrients switch on, which also slows the making of the main fat-releasing enzyme. ↗︎ studies

Hormones released by the heart that lower blood pressure and, through cGMP, also trigger fat release. ↗︎ studies

The receptor through which the heart's natriuretic hormones act on blood vessels, kidneys and fat cells. ↗︎ studies

The enzyme insulin uses to break down cAMP, the signal that starts fat release. ↗︎ studies

Protein kinase G — the enzyme cGMP switches on, carrying nitric oxide's and the heart hormones' signals. ↗︎ studies

The gene for a fat-droplet enzyme closely related to the main fat-releasing enzyme; a common variant raises liver fat. ↗︎ studies

A phosphatase that removes the activating marks from the fat-releasing machinery, ending fat release. ↗︎ studies

Sphingosine-1-phosphate — a lipid signaling molecule that acts through its own family of receptors. ↗︎ studies

The enzyme that makes cAMP, the messenger where the hormones that start fat release and the signals that stop it meet. ↗︎ studies

A receptor on fat cells for adenosine, a signal the fat cell makes itself, that tells the cell to slow fat release. ↗︎ studies

The activator protein the main fat-releasing enzyme needs, held by the fat droplet's coat until a release signal frees it. ↗︎ studies

A fat-cell protein that helps fat droplets merge and holds back the main fat-releasing enzyme. ↗︎ studies

A protein that binds the main fat-releasing enzyme and switches it off. ↗︎ studies

The backbone the fat cell needs to rebuild fat — made from glucose, and therefore abundant after a meal and scarce when fasting. ↗︎ studies

The enzyme that makes glycerol-3-phosphate, the backbone fatty acids are attached to when fat is stored. ↗︎ studies

The enzyme that makes cGMP, the messenger behind nitric oxide's and the heart hormones' signals. ↗︎ studies

Fatty acids activated inside the cell — the form in which they are burned or stored, and which also signals to slow further fat release. ↗︎ studies

The receptor that clears the heart's natriuretic hormones from the blood. ↗︎ studies

Soluble guanylate cyclase — the nitric oxide receptor enzyme that makes cGMP. ↗︎ studies

The first enzyme in building fat, which attaches the first fatty acid to the glycerol backbone. ↗︎ studies

The receptor through which nicotinic acid shuts fat release down. ↗︎ studies

Lysosomal acid lipase — the enzyme that breaks down fat inside the cell's lysosomes. ↗︎ studies

Membrane fats that help switch on protein kinase C, a family of signaling enzymes. ↗︎ studies

Diacylglycerol, the short-lived messenger that switches on protein kinase C enzymes. ↗︎ studies

The metabolic intermediate that signals fuel abundance by clamping the mitochondrial fat-import gate shut. ↗︎ studies

The two-carbon unit every fuel converges on and every synthesis starts from. ↗︎ studies

The ketone body the liver makes when glucose runs low — an alternative fuel that doubles as an anti-inflammatory signaling molecule. ↗︎ studies

Carries long-chain fatty acids across the inner mitochondrial membrane. ↗︎ studies

The aggregate handling of fuel — glucose, fat and the hormones that route them, taken as one picture. ↗︎ studies

Fibroblast growth factor 21 — a fasting/metabolic hormone driving fat oxidation, fat-browning and liver-fat clearance (distinct from the FGF19 bile-acid axis). ↗︎ studies

The liver turning fatty acids into ketones, a fuel the brain and muscles can burn. ↗︎ studies

An enzyme that helps build stored fat and, in the liver, boosts the genes for burning fat. ↗︎ studies

An organelle handling very-long-chain fatty acids, plasmalogen synthesis and bile acid intermediates. ↗︎ studies

The accumulated cell wear and epigenetic drift that mark true biological age. ↗︎ studies

Betaine from choline remethylates homocysteine without folate or B12. ↗︎ studies

Riboflavin-derived FAD and FMN — the carriers many energy-producing enzymes use to pass electrons. ↗︎ studies

The junction metabolite — remethylated back to methionine, or committed down transsulfuration to cysteine. ↗︎ studies

The folate and B12 cycle that carries single carbon units for methylation and nucleotide synthesis. ↗︎ studies

S-adenosylmethionine — the body's universal methyl donor, upstream of neurotransmitter synthesis, DNA methylation and glutathione production. ↗︎ studies

The senescence-associated secretory phenotype — the inflammatory signals a senescent cell sends to its neighbors. ↗︎ studies

Stem and progenitor cell number and function — the reserve tissues draw on to replace what they lose. ↗︎ studies

Sonic Hedgehog is an embryonic growth-and-patterning pathway that should stay quiet in adult tissue. Its inappropriate reactivation drives abnormal proliferation, so dialing it down supports healthy aging. ↗︎ studies

An enzyme that sits on immune cells and consumes NAD⁺. ↗︎ studies

An enzyme that detects broken DNA and spends NAD⁺ to mark the damage for repair. ↗︎ studies

The rate-limiting enzyme of the salvage pathway that recycles NAD⁺. ↗︎ studies

An enzyme that methylates nicotinamide and sends it toward excretion. ↗︎ studies

The protein quality-control network — the running balance between folding, chaperoning and clearing that keeps the proteome healthy. ↗︎ studies

The nutrient-deprivation input — the scarcity signal that flips the cell from growth to repair. ↗︎ studies

Spermidine, spermine and putrescine — polycations from ornithine, abundant in fermented foods. ↗︎ studies

The master transcription factor of the heat-shock response — the sentinel that, sensing proteotoxic stress, mobilizes the cell's chaperone defenses. ↗︎ studies

The capacity to meet a challenge and return to baseline. ↗︎ studies

The endocannabinoid system is the body's balance network for mood, pain, appetite and sleep. Supporting its tone helps the system return to equilibrium. ↗︎ studies

Adrenocorticotropic hormone — the pituitary messenger that carries the stress signal from brain to adrenal gland. ↗︎ studies

Social connection as a physiological input. ↗︎ studies

The body's mobilization response, built to be brief. ↗︎ studies

Kynurenine pathway of tryptophan metabolism; neuroactive metabolites linked to mood and inflammation. ↗︎ studies

The hormone and brain messenger involved in bonding, trust and calming the brain's threat response. ↗︎ studies

Vagal gut–brain signaling — the nerve highway relaying gut and microbial state to the brain. ↗︎ studies

Attention-deficit/hyperactivity disorder — a developmental condition of inattention, hyperactivity and impulsivity with high heritability. ↗︎ studies

Monoamine oxidase A, sitting on the outer mitochondrial membrane, breaks down serotonin and noradrenaline. ↗︎ studies

Monoamine oxidase B, the isoform concentrated in brain, liver and platelets. ↗︎ studies

The opening instruction of the stress axis. ↗︎ studies

Neuropeptide Y — a potent appetite-and-energy signal that drives feeding and body-weight gain. ↗︎ studies

Positive and negative symptoms of psychosis, scored on the standard psychiatric rating scales. ↗︎ studies

Agitation, apathy, anxiety and related symptoms accompanying cognitive decline, scored on standard inventories. ↗︎ studies

Instrumental activities of daily living — shopping, cooking, managing medications and finances, using transport. ↗︎ studies

Taking new information in and getting it back out later. ↗︎ studies

A subdomain of learning and memory: knowing something without remembering learning it. ↗︎ studies

A subdomain of learning and memory: retrieval supported by a prompt. ↗︎ studies

A subdomain of learning and memory: retrieving without a cue. ↗︎ studies

A subdomain of learning and memory: repeating back what was just presented. ↗︎ studies

Long-chain marine fatty acids that become cell membrane. ↗︎ studies

A subdomain of learning and memory: retaining new information over minutes to days. ↗︎ studies

A subdomain of learning and memory: identifying something as previously encountered, as opposed to recalling it unprompted. ↗︎ studies

An emerging construct: building and using a mental map of space. ↗︎ studies

Phosphorylated tau accumulation — the second defining Alzheimer's pathology. ↗︎ studies

An emerging construct: carrying out an intended action after a delay filled with other activity. ↗︎ studies

Blood–brain barrier tight-junction integrity; neuroprotection and CNS homeostasis. ↗︎ studies

Neurons killed by too much of the brain's own excitatory messenger — the failure mode shared by stroke, epilepsy and slow neurodegeneration. ↗︎ studies

The capacity to update a threat prediction when the threat stops arriving — what exposure therapy trains. ↗︎ studies

Trauma-linked persistence of the threat response long after the threat. ↗︎ studies

Nicotinic acetylcholine receptors; cholinergic reward and attention circuitry. ↗︎ studies

Builds sleep pressure for deep rest. ↗︎ studies

Wakefulness signal; lowering it aids sleep. ↗︎ studies

Inhibitory glycine-receptor tone and core-temperature lowering that support sleep onset (distinct from GABA). ↗︎ studies

Calcitonin gene-related peptide — a potent vasodilator released from trigeminal nerve endings. ↗︎ studies

Cortical spreading depression — the slow wave of neuronal silencing that opens a migraine. ↗︎ studies

Widespread pain from central amplification, not tissue damage. ↗︎ studies

A nerve-and-blood-vessel event in the brain, not a headache with extra force. ↗︎ studies

The network wrapping the brain's blood vessels — the structure every migraine mechanism acts through. ↗︎ studies

A potassium channel in the walls of blood vessels in the head, opened by nitric oxide, CGRP and PACAP. ↗︎ studies

The neuropeptide of pain transmission and neurogenic inflammation. ↗︎ studies

A liver enzyme that breaks down alcohol and, when induced, generates reactive oxygen and lipid damage. ↗︎ studies

Quiet liver cells that, once injury wakes them, make the collagen that becomes scar. ↗︎ studies

Ammonia, made by gut bacteria from protein and cleared by the liver into urea. ↗︎ studies

Fluid collecting in the abdomen because pressure in the portal system forces it out of the circulation. ↗︎ studies

Scarring so extensive the liver's architecture is replaced. ↗︎ studies

The turn at which a scarred liver can no longer keep up, marked by its first complication. ↗︎ studies

Toxins the liver normally clears, ammonia foremost, reaching the brain and changing how a person thinks, sleeps and behaves. ↗︎ studies

The liver cycle that converts ammonia to urea for excretion. ↗︎ studies

Pressure building in the route that carries all the blood from the gut through the liver. ↗︎ studies

When the liver route is blocked, blood carves alternative paths through thin-walled veins in the esophagus and stomach. ↗︎ studies

Fat in the liver joined by inflammation and liver-cell injury, the stage where scarring starts. ↗︎ studies

A liver cell that has taken on so much injury it swells and loses its normal shape. ↗︎ studies

How much lead, cadmium, mercury or arsenic is actually in the body, measured in blood, urine or tissue. ↗︎ studies

Metal actually leaving the body in urine or stool, not merely moved from one tissue to another. ↗︎ studies

Gut metal uptake — how much of the metal in food and water crosses the intestinal wall instead of passing through. ↗︎ studies

Eases the feeling of trapped gas and fullness. ↗︎ studies

Supports regular, complete bowel movements. ↗︎ studies

Quickens the journey food makes through the gut and out. ↗︎ studies

The heart as a pump and as a tissue that remodels. ↗︎ studies

Structural change of the heart muscle — wall thickening and fibrous scarring laid down in response to sustained load. ↗︎ studies

Cholesterol-laden plaque built into the artery wall over decades, stiffening and narrowing the vessel. ↗︎ studies

An amino sulfonic acid made from cysteine, found in bile salts and concentrated in the heart, retina and muscle. ↗︎ studies

The pathway that builds cholesterol — and, from the same intermediates, CoQ10, dolichol and prenylated proteins. ↗︎ studies

How far blood pressure falls while you sleep — the nightly dipping pattern. ↗︎ studies

How tightly the vessel wall grips, set by calcium channels in its smooth muscle. ↗︎ studies

Fluid volume and the ions dissolved in it. ↗︎ studies

Nitrate from food, which mouth bacteria turn into nitrite and the body then into nitric oxide. ↗︎ studies

The amino-acid substrate for nitric oxide synthesis. ↗︎ studies

Vascular and visceral smooth muscle — contraction and relaxation set vessel caliber, airway caliber and gut motility. ↗︎ studies

How much salt the diet delivers, best read alongside potassium intake. ↗︎ studies

Lipoprotein lipase — the enzyme anchored to blood-vessel walls that unpacks triglycerides out of circulating lipoproteins so tissue can take the fat up. ↗︎ studies

The mitochondrial signal that triggers the cell’s antiviral defense. ↗︎ studies

The body's danger-detection signals — molecular fingerprints of pathogens and damaged cells that trip the innate-immune alarm. ↗︎ studies

Vitamin D, a hormone misfiled as a vitamin. ↗︎ studies

Catalytic and structural cofactor for hundreds of enzymes and for zinc-finger transcription factors. ↗︎ studies

The immune signal the body uses to clear an infection — helpful early, harmful late. ↗︎ studies

The first-line antiviral response that puts cells into a defensive state. ↗︎ studies

The hunger signal from an empty stomach — the best-known circulating hormone that increases appetite. ↗︎ studies

A gut hormone released when fat and protein arrive; it slows the stomach and tells the brain the meal is done. ↗︎ studies

The brain's appetite and pigmentation relay. ↗︎ studies

One of the six DSM-5 cognitive domains: producing and understanding speech, reading and writing. ↗︎ studies

A subdomain of social cognition: identifying emotional states in others from face, voice and posture. ↗︎ studies

A subdomain of executive function: adjusting behavior based on reward and punishment received. ↗︎ studies

A subdomain of executive function: sequencing actions toward a goal before starting. ↗︎ studies

A subdomain of language: retrieving the intended word in flowing speech. ↗︎ studies

An emerging construct: the subjective cost of mental work and its accumulation into mental fatigue. ↗︎ studies

A subdomain of executive function: changing rule, strategy or task set when conditions change. ↗︎ studies

The brain's inward-facing default network, and how well it stands down when a task begins. ↗︎ studies

A subdomain of perceptual-motor function: recognizing objects, faces and sounds. ↗︎ studies

A subdomain of executive function: withholding a response you have already started to make. ↗︎ studies

Thought that drifts away from the task at hand. ↗︎ studies

One of the six DSM-5 cognitive domains: coordinating what you see and sense with how you move. ↗︎ studies

A subdomain of complex attention: locking onto what matters while ignoring what does not. ↗︎ studies

A subdomain of language: the rate and effort of speech output. ↗︎ studies

A subdomain of perceptual-motor function: assembling or drawing a figure. ↗︎ studies

A subdomain of executive function: keeping information available for seconds while you use it. ↗︎ studies

A subdomain of executive function: weighing options when outcomes are uncertain. ↗︎ studies

A subdomain of language: finding the name of an object, person or place on sight. ↗︎ studies

A subdomain of perceptual-motor function: performing learned skilled movements. ↗︎ studies

A subdomain of complex attention: splitting focus between concurrent tasks. ↗︎ studies

A subdomain of language: producing speech and writing. ↗︎ studies

An emerging construct: sensing the internal state of the body — heartbeat, breath, gut. ↗︎ studies

A subdomain of language: understanding what is said and written. ↗︎ studies

An emerging construct: judging duration and sequence. ↗︎ studies

A subdomain of social cognition: inferring another person's beliefs, intentions and knowledge — including that they may be different from your own. ↗︎ studies

An emerging construct beyond the six DSM-5 domains: judging how well your own thinking is working. ↗︎ studies

Vitamin C — required for collagen hydroxylation, iron absorption and as a reducing agent. ↗︎ studies

Inflammation in the skin's hair follicles and oil glands, where breakouts form. ↗︎ studies

Itchy, inflamed skin driven by the allergic arm of the immune system. ↗︎ studies

Skin cells driven by the immune system to divide far too fast, raising scaly plaques. ↗︎ studies

Keratin plates that grow out over about six months and can mirror the body's general health. ↗︎ studies

Repair as a scheduled sequence — clotting, inflammation, rebuilding and remodeling. ↗︎ studies

The enzyme that ends the nitric-oxide signal by degrading cGMP. ↗︎ studies

Scar deposition in erectile tissue, replacing compliant smooth muscle with stiff collagen. ↗︎ studies

The vascular tone pathway that opposes nitric-oxide relaxation. ↗︎ studies

Men's hormone system taken as a whole, not a single number. ↗︎ studies

The gland below the bladder whose enlargement with age can disturb urine flow and sleep. ↗︎ studies

The timing of ejaculation, measured on a stopwatch as intravaginal ejaculatory latency rather than by questionnaire. ↗︎ studies

The checkpoint that decides whether a cell may divide — the brake on uncontrolled growth. ↗︎ studies

Epithelial-to-mesenchymal transition — the program by which orderly tissue cells turn migratory, driving fibrosis and organ scarring. ↗︎ studies

The building of new blood vessels — restorative when it perfuses healthy tissue, pathological when it feeds disease. ↗︎ studies

A master proliferation network that drives cell growth and metabolic throughput — powerful for renewal, dangerous in overdrive. ↗︎ studies

Notch signaling — the arbiter of cell identity and tissue patterning, pivotal in renewal and miswired in disease. ↗︎ studies

The enzyme that carries out programmed cell death once the decision is made. ↗︎ studies

Checkpoints that govern when cells grow and divide. ↗︎ studies

The controlled removal of a mature fat cell, which lowers fat-cell number rather than fat-cell size. ↗︎ studies

↗︎ studies

The gene switch that works with PPAR-gamma to commit a precursor cell to becoming a fat cell. ↗︎ studies

An adrenal and ovarian androgen precursor that can be converted onward to either testosterone or estrogen. ↗︎ studies

Myo-inositol and D-chiro-inositol — the backbone of phosphoinositide signaling. ↗︎ studies

The hypothalamic neuropeptide that gates GnRH release — the switch sitting above the entire reproductive axis. ↗︎ studies

The pulse generator of reproduction. ↗︎ studies

Breaks and oxidized bases in DNA, and the signaling cascade that senses them and decides the cell's fate. ↗︎ studies

Immunosuppression — the immune system held below its own baseline by an outside force rather than by disease. ↗︎ studies

The enzyme that recycles spent glutathione back to its active form. ↗︎ studies

The selenocysteine-containing enzymes — glutathione peroxidases, thioredoxin reductases and the deiodinases. ↗︎ studies

Ether phospholipids that act as sacrificial antioxidants in the membrane itself — they are consumed protecting the lipids around them. ↗︎ studies

Extremely-low-frequency electromagnetic fields — the 50 and 60 Hz fields around mains wiring, appliances and power lines. ↗︎ studies

Alpha-tocopherol — the principal lipid-phase chain-breaking antioxidant. ↗︎ studies

Radiation energetic enough to strip electrons from atoms and break DNA strands outright — medical imaging, radiotherapy, radon, cosmic and occupational sources. ↗︎ studies

NADPH oxidase — an enzyme whose purpose is to make reactive oxygen species, unlike mitochondrial ROS which are a byproduct. ↗︎ studies

The total electromagnetic load a person takes on from their surroundings — ionizing radiation, ultraviolet, radiofrequency and power-frequency fields. ↗︎ studies

Radiofrequency electromagnetic fields — the non-ionizing band that phones, WiFi and broadcast equipment transmit in. ↗︎ studies

The ultraviolet band of sunlight — the part of the spectrum that reaches living skin cells and damages their DNA directly. ↗︎ studies

Homocysteine to cystathionine to cysteine — the rate-limiting supply line for glutathione. ↗︎ studies

The pentose phosphate pathway — the cell's main source of NADPH and of the sugar used to build DNA and RNA. ↗︎ studies

The physical-activity input — the adaptive load that provokes muscle and the cardiovascular system to grow more capable. ↗︎ studies

Leucine, isoleucine and valine — and leucine is a direct mTOR signal, not merely a building block. ↗︎ studies

Phosphocreatine — the fastest energy buffer the body has, recharging ATP in seconds. ↗︎ studies

Growth hormone — released in pulses from the pituitary, largest during deep sleep, and the signal that drives IGF-1 production. ↗︎ studies

Galectin-3 is a master driver of fibrosis (scarring) in liver, heart and kidney, and a recognized heart-failure biomarker. Blocking it limits the scarring that stiffens these organs. ↗︎ studies

The enzyme that opens the pressure cascade. ↗︎ studies

H. pylori's urease — the enzyme it uses to split urea into ammonia, neutralizing the stomach acid immediately around it. ↗︎ studies

How H. pylori clings to the stomach lining, holding on instead of being swept away with the mucus. ↗︎ studies

A yeast that normally lives in the body and becomes a problem when the ecology shifts. ↗︎ studies

Stomach contents rising back into the esophagus, where they should not be. ↗︎ studies

The most abundant free amino acid — fuel for enterocytes and lymphocytes and a nitrogen shuttle. ↗︎ studies

Thermal challenge as a hormetic input. ↗︎ studies

Adaptive strengthening in response to a mild stressor — exercise, fasting, heat, cold and plant xenobiotics all work this way. ↗︎ studies

The absorbable fraction of a nutrient — how much of what you take actually reaches the bloodstream to act. ↗︎ studies

The omega-6 fatty acid released from membrane phospholipids on demand. ↗︎ studies

Prostaglandins, thromboxanes and leukotrienes — messengers made from 20-carbon fatty acids. ↗︎ studies

Accumulates under ischemia and acts outside the mitochondrion as an inflammatory signal. ↗︎ studies

How much air the lungs move, and how fast. ↗︎ studies

Lasting inflammation of the nose and sinuses, with congestion, discharge and loss of smell. ↗︎ studies

An acute worsening of chronic obstructive pulmonary disease — the episodes that send breathing over a cliff and take lung function with them. ↗︎ studies

Made from histidine, released by mast cells, and also a neurotransmitter and gastric acid signal. ↗︎ studies

IL-4 and IL-13 signaling through the shared receptor — the branch of immunity behind allergic and atopic disease. ↗︎ studies

Sperm production and the hormonal axis that sustains it. ↗︎ studies

Follicle-stimulating hormone — the pituitary hormone that drives sperm production in men and egg-follicle growth in women. ↗︎ studies

Inflammation of the heart muscle, which runs in three phases. ↗︎ studies

A coxsackievirus, one of the classic viral causes of inflammation of the heart muscle. ↗︎ studies

A second virus that inflames the heart muscle, used in many of the classic experiments. ↗︎ studies

Antibodies raised against the virus that also fit heart proteins. ↗︎ studies

Heart-muscle inflammation caused by cancer drugs that release the immune system’s brakes. ↗︎ studies

A type of T helper immune cell that drives inflammation by making IL-17. ↗︎ studies

The cells that lay down scar where muscle used to be. ↗︎ studies

The enlarged, weakened heart that unresolved inflammation can leave behind. ↗︎ studies

A powerful blood-vessel–constricting signal made by the vessel lining. ↗︎ studies

An immune messenger that pushes immune cells toward an aggressive, inflammatory response. ↗︎ studies

A cell that ruptures instead of folding away quietly, spilling its contents and inflaming the tissue around it. ↗︎ studies

A heart muscle protein; its level in the blood is the standard test for heart muscle injury. ↗︎ studies

A contractile protein found only in heart muscle, which the immune system can mistake for a threat in heart inflammation. ↗︎ studies

The heart muscle cell, the cell that does the work of each heartbeat. ↗︎ studies

The enzyme that switches on the inflammatory messenger IL-1β and triggers an inflammatory form of cell death. ↗︎ studies

An immune signal that calls T cells into inflamed tissue, including the heart. ↗︎ studies

A molecular handhold on blood-vessel walls that lets immune cells leave the blood and enter tissue. ↗︎ studies

A protein-cutting enzyme from the cell's lysosomes that, when it leaks out, can set off inflammatory cell death. ↗︎ studies

The scaffold factor a cell needs to start making its own proteins, and one that some viruses cut to take over the cell. ↗︎ studies

An enzyme released by mast cells, used as a marker of their activation. ↗︎ studies

The process by which the immune system, after attacking one protein, learns to attack others released from damaged tissue. ↗︎ studies

A viral enzyme that cuts the cell’s antiviral alarm before it can sound. ↗︎ studies

The structural protein that anchors muscle cells, including heart muscle cells, to their surroundings. ↗︎ studies

The molecular safety catches that stop immune cells attacking the body’s own tissue. ↗︎ studies

Female sexual desire and response, measured across desire, arousal, lubrication, orgasm and satisfaction. ↗︎ studies

The few seconds in which the tension built during arousal is released, through rhythmic contractions of the pelvic floor. ↗︎ studies

A pituitary hormone, best known for milk production, that rises sharply after orgasm. ↗︎ studies

Hot flashes and night sweats — the temperature instability of the menopause transition. ↗︎ studies

The hormonal equilibrium behind cycle comfort and the menopausal transition. ↗︎ studies

The sling of muscle supporting the pelvic organs — the levator ani group, which contracts rhythmically at orgasm and can be trained deliberately. ↗︎ studies

The interval after orgasm during which another is not possible. ↗︎ studies

The macula, the part of the retina that carries straight-ahead vision, and the cells it can lose with age. ↗︎ studies

The retina's tiny blood vessels, which sustained high blood sugar can damage so they leak or bleed. ↗︎ studies

The ciliary muscle holds its contraction for as long as you hold your attention on something near. ↗︎ studies

The clarity of the eye's lens, which can cloud with age. ↗︎ studies

The tear film that keeps the eye's surface wet, smooth and comfortable. ↗︎ studies

The ache, the blur and the reluctance that arrive after a stretch of near work. ↗︎ studies

The optic nerve and the retinal cells whose fibers carry sight to the brain. ↗︎ studies

The lutein and zeaxanthin your retina concentrates into the macula. ↗︎ studies

Nearsightedness, driven by the eyeball growing too long from front to back. ↗︎ studies

The retina's light-catching cells, which rebuild their own working surface every day. ↗︎ studies

Vitamin A and its active forms — needed for vision and as signals that switch genes on. ↗︎ studies

Staying upright: the inner ear, body sense and vision, plus the muscle to act on them. ↗︎ studies

The health of the inner ear's hair cells, which turn sound into nerve signals. ↗︎ studies

Intraocular pressure — the fluid pressure the optic nerve must withstand. ↗︎ studies

A subdomain of perceptual-motor function: constructing a visual percept. ↗︎ studies

The pancreas's capacity to make new insulin-making beta cells, not only to protect the ones it has. ↗︎ studies

Cells that quietly store vitamin A until injury wakes them, then pour out collagen and scar the pancreas. ↗︎ studies

Digestive enzymes switching on inside the pancreas instead of in the gut, inflaming and scarring the organ. ↗︎ studies

The cells that make digestive enzymes — about 85% of the pancreas by mass. ↗︎ studies

C-peptide is released with insulin in equal amounts, so it measures how much insulin a person is still making themselves. ↗︎ studies

An enzyme that holds adult insulin-making beta cells back from dividing. ↗︎ studies

Regulatory T cells, the immune system's brake on itself. ↗︎ studies

Immune cells moving into the pancreatic islet and attacking the beta cells inside it. ↗︎ studies

The immune system's attack on the pancreas's insulin-making beta cells. ↗︎ studies

The glucagon-making cells that sit beside the insulin-making beta cells in the pancreas. ↗︎ studies

The arm of the immune system that signals through interferon-gamma to fight invaders inside cells. ↗︎ studies

Antiparasitic and anti-biofilm botanicals disrupt the protective films and life cycle that intestinal parasites rely on, supporting the body's ability to clear them. ↗︎ studies

Roundworms — unsegmented, cylindrical helminths, the group that includes hookworm. ↗︎ studies

Flukes — leaf-shaped flatworm parasites that settle in the bile ducts, liver, gut wall or blood vessels. ↗︎ studies

Single-celled gut parasites, such as Giardia, that multiply inside the host rather than merely residing there. ↗︎ studies

Ceramides are lipotoxic fats that build up in liver and blood-vessel walls, driving insulin resistance and arterial damage. Lowering their synthesis protects metabolic and cardiovascular health. ↗︎ studies

Sphingomyelinase — cuts ceramide straight out of sphingomyelin already sitting in the membrane, bypassing synthesis entirely. ↗︎ studies

Ceramide synthases — six enzymes that decide which kind of ceramide a cell builds. ↗︎ studies

Ceramidase — removes the fatty acid from ceramide, converting it to sphingosine and clearing it from the pool. ↗︎ studies

Serine palmitoyltransferase — the first and rate-limiting step of building ceramide from scratch, condensing serine with palmitate. ↗︎ studies

Return flow to the heart — the half of circulation nobody thinks about. ↗︎ studies

Circulating uric acid, whose oxidative and crystal burden falls on the joints and kidneys when it runs high. ↗︎ studies

Uric acid crystals settling in a joint, and the inflammation they set off. ↗︎ studies

Chronic inflammation of the gum and the tissue holding the teeth, driven by periodontal bacteria. ↗︎ studies

Hair growth depends on the follicle cycle, its blood supply, and the balance between follicle-shrinking DHT and growth-promoting Wnt signals. Shifting that balance supports thickness and retention. ↗︎ studies

The androgen that miniaturises hair follicles, made from testosterone by 5-alpha-reductase. ↗︎ studies

Insulin-like growth factor-1 — the dermal-papilla growth factor that drives follicle proliferation and prolongs anagen (the active growth phase). ↗︎ studies

5-alpha-reductase converts testosterone into dihydrotestosterone, the far more potent androgen. ↗︎ studies

Hormone-sensitive hair follicles that shrink over time and grow finer, shorter hairs. ↗︎ studies

The liver-made carrier protein that binds sex hormones in the blood and sets how much is free to act. ↗︎ studies

One of adenosine's four receptors, and the most abundant one on the dermal papilla cells at the base of each hair follicle. ↗︎ studies

Prostaglandin F2-alpha — a hormone-like lipid whose drug versions, used as glaucoma eye drops, are known to lengthen eyelashes. ↗︎ studies

VEGF and HIF-1α drive the growth of new blood vessels when oxygen runs low. The body needs this for healing and circulation, but excess fuels leaky retinal vessels and abnormal growth — so the right direction depends on the goal. ↗︎ studies

The enzyme bone-clearing cells use to cut old bone apart. ↗︎ studies

Hyaluronan, chondroitin and the other sulfated glycosaminoglycans that make up the matrix of cartilage and skin. ↗︎ studies

Matrix metalloproteinases — the extracellular collagenases that cut structural collagen outside the cell, where cathepsin K cuts it inside. ↗︎ studies

Progressive loss of joint cartilage with inflammation of the surrounding tissue. ↗︎ studies

The brake on bone formation, released by osteocytes under low load. ↗︎ studies

The vitamin that activates the Gla proteins: osteocalcin in bone and matrix Gla protein in arteries. ↗︎ studies

Cofactor for cytochrome c oxidase, SOD1, lysyl oxidase and ceruloplasmin. ↗︎ studies

The body's repair after alcohol exposure — liver, nervous system and nutrition at once. ↗︎ studies

The reactive compound alcohol is converted to, which sticks to proteins and DNA. ↗︎ studies

Thiamine pyrophosphate — cofactor for pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase and transketolase. ↗︎ studies

The pigment-making machinery — MITF, tyrosinase and TRP enzymes that build melanin and load it into the growing hair. ↗︎ studies

The follicle’s reserve of pigment stem cells and their renewal/movement; when these stall or run down, new hair grows in without color. ↗︎ studies

Loss of hair pigment as the melanocyte stem-cell pool in the follicle is spent. ↗︎ studies