Glossary
This glossary contains the definition of the main terms used and highlighted in this website. They are displayed in alphabetical order for your convenience. In the English version of the website glossary terms are underlined by default but you can deselect this option by activating the MY EUFIC feature.
Adipose tissue
Tissue, found throughout the body, in which fat is stored as an energy reserve. Excessive expansion leads to obesity.
Alcohol
The common name for the substance with the chemical names ethyl alcohol or ethanol. Produced during fermentation of sugars by yeasts, it is the characteristic component of alcohol beverages.
Alcohol dehydrogenase
The enzyme, present in most tissues of the body, that catalyses the oxidation of alcohol to acetaldehyde. There are several genetically determined forms of the enzyme, whose pattern differs among individuals.
Allergen
A substance which provokes an allergic response.
Allergy
An inappropriate and exaggerated immune response
Amines
Organic compounds, usually derived from amino acids, that contain nitrogen and hydrogen and play a prominent role in biochemical systems.
Analytical epidemiology
Epidemiological investigations specifically aimed at studying the determinants of diseases in study populations.
Anaphylaxis
A generalised inflammatory immune reaction to a foreign protein in a sensitised individual which may be severe enough to be life-threatening.
Angioedema
Swelling of the skin or mucous membrane and underlying tissue
Anion
A negatively charged ion such as a chloride ion, C1-.
Antibody
A protein molecule produced and secreted by B cells in response to an antigen, which is capable of binding to that specific antigen.
Antigen
A foreign substance or protein that, when introduced into the body, is recognised by the immune system.
Antioxidant
Any substance which can delay or prevent oxidation in the presence of oxygen.
Asthma
Breathing difficulty caused by narrowing of the air passages that is reversible.
Atherosclerosis
A degenerative disease of arteries in which there is thickening caused by an accumulation of material (plaque) beneath the inner lining, eventually restricting blood flow. The material characteristically contains cholesterol and macrophage cells.
B cells
(B lymphocytes) White blood cells derived from stem cells in bone marrow and elsewhere that produce antibodies.
Basophil
A type of white blood cell that contributes to inflammatory reactions and symptoms of allergy.
b-Carotene
The most abundant of the carotenoids. b-Carotene has strong provitamin A activity. Unlike vitamin A itself, b-carotene is a strong antioxidant.
b-Cryptoxanthin
A carotenoid pigment found in a biological system.
Bias
Systematic error resulting in over or underestimation of the strength of the association between an exposure and an outcome.
Biomarker
An effect in a biological system. Measurements in the human body or its products. Some biomarkers, such as the levels of certain vitamins in blood serum, are used as indices of nutritional status. Others are used as indices of the risk or progression of disease.
Blood pressure
The pressure exerted by the circulating blood on the walls of arteries and veins and in the heart chambers. When the heart contracts, the maximum pressure exerted is the systolic pressure; during relaxation, the minimum pressure is the diastolic.
Bulimia
An eating disorder consisting of an insatiable craving for food, often resulting in voracious eating followed by self-induced vomiting.
Carbohydrates
Components of food containing carbon, hydrogen and oxygen. The term carbohydrate encompasses simple sugars, monosaccharides (eg. Glucose) and disaccharides (eg. Sucrose), oligosaccharides (containing several monosaccharide units) and polysaccharides. Starch is the only important food polysaccharide that can be digested in the small intestine. Starch and simple sugars are "available carbohydrates". The indigestible polysaccharides are the main components of "dietary fibre".
Carcinogen
A substance capable of inducing cancer; carcinogenesis is the complex, multistep process of cancer development.
Carcinogenesis
The complex, multistep process of cancer causation.
Cardiovascular disease (CVD)
Any one of numerous abnormal conditions characterised by dysfunction of the heart and blood vessels (see also coronary heart disease and stroke). Other types of CVD are congestive heart failure and sudden cardiac death.
Carotenoids
A group of red, orange and yellow pigments found in plant food and in the tissues of organisms that consume plants. Carotenoids have antioxidant activity. Some, but not all, can act as precursors of vitamin A; the principal of these is fs0 carotene, the most common of the carotenoids.
Case-control study
A study design in which persons with a disease (cases) are compared with those without the disease (controls) to see how their exposures to causative factors may have differed.
Cataract
A disorder in which the lens of the eye becomes partly or completely opaque as a result of the precipitation of proteins.
Cation
A positively charged ion such as a sodium ion, Na+.
Challenge test
Reintroduction of a food previously eliminated from the diet on suspicion that it caused an adverse reaction.
Cholesterol
A lipid (sterol) made in the body from acetyl-CoA and present in the diet; a constituent of cell membranes (especially in nervous system tissues), blood and atherosclerotic plaques.
Chylomicrons
Large particles composed mainly of triglycerides stabilised with a protein and phospholipid surface, which carry fats recently absorbed from a meal in the bloodstream.
Cirrhosis
A chronic degenerative disease of the liver. Fat infiltration occurs, the cells degenerate, the liver architecture is destroyed by fibrous tissue, blood supply is reduced and liver function deteriorates.
Cis fatty acid
The form of most naturally occurring unsaturated fatty acids, where the hydrogen bonds are on adjacent sides of double bonds, resulting in a bend in the hydrocarbon chain at that point.
Co-Carcinogen
A chemical substance that enhances the action of a carcinogen but does not itself initiate cancer.
Co-enzyme
An organic compound which combines with an enzyme and plays an essential part in its catalytic reaction.
Cognitive ability
Knowledge, perception
Cohort or follow-up study
A study design in which data on exposures to possible risk factors for disease are collected from a group of people (cohort) who do not have the disease under investigation. The subjects are then followed for a period of time to see whether the later development of disease is related to the factors that were measured.
Complement
Blood proteins that amplify the action of antibodies.
Confidence interval
The range of values within which a variable is likely to lie.
Confounding factors
Factors that distort an association because they are associated with an exposure as well as a disease or other outcome.
Congestive heart failure
See cardiovascular disease
Coronary heart disease (CHD)
A condition in which the main arteries supplying the heart are blocked and no longer able to supply sufficient blood, and therefore oxygen, to the heart muscle (myocardium), which may then quickly die. The main cause of reduced blood flow is the accumulation of plaques, a disease known as atherosclerosis.
Dental caries
A disease affecting the hard tissues of the teeth resulting in progressive decay. Bacteria that accumulate in a dense mass known as plaque on the surface of the teeth ferment dietary carbohydrates (see fermentation) to form acids that de-mineralise the hard tissues underneath. Hence, cariogenicity refers to the capacity of a food or drink to lead to caries in those who consume it. Periodontal disease is a related bacterial infection that affects the softer supporting tissues of the teeth.
Descriptive epidemiology
The study of variations in the occurrence of disease in terms of person, place and time, without the purpose of establishing causal inference.
Diabetes mellitus
A metabolic disorder in which the hormone insulin is ineffective either because of a failure of the pancreas to secrete it (type I, insulin-dependent, (IDDM), or juvenile onset) or because target tissues are relatively insensitive to its action (type II, non-insulin-dependent (NIDDM), or maturity-onset, diabetes). In IDDM, patients require regular administration of insulin. In contrast, patients with NIDDM may actually have a high blood concentration of insulin (hyperinsulinaemia) and the condition is frequently associated with obesity and hyperlipidaemia.
Diet History
A method of dietary assessment in which subjects are asked open-ended questions about their usual dietary intakes.
Dietary recall
A method of dietary assessment in which subjects are asked to recall their food consumption over a specific period of time.
Dose-response assessment
The determination of the relationship between the magnitude of exposure (dose) to a biological, chemical or physical agent and the severity and\or frequency of associated adverse health effects (response).
Double-blind food challenge
Food challenge test where neither the patient nor the clinical investigator knows the identity of the administered substance.
Ecological study
A study that compares the rates of exposures and diseases in different populations using aggregate data on exposure and disease, not individual data.
Eczema
An itching red rash, often on the face, hands or skins folds, which oozes and crusts if scratched.
Electrolytes
Positively or negatively charged ions dissolved in the extracellular or intracellular water (see also Anion + cation).
Endogenous
Originating from within the body.
Energy Density
Energy content per gram of food.
Energy Expenditure
Utilisation by the body of chemical energy from food components or body stores during the process of metabolism which is eventually dissipated as heat plus the heat generated by muscular activity, either in shivering or in physical activity. Usually used to mean the day's total energy (calorie) loss as heat.
Energy Intake
The chemical energy in foods that can be metabolised to produce energy available to the body; usually used to mean the day's total energy (calories) supplied by all the food and drink consumed.
Enterocytes
Cells which line the small intestine. They have three major functions of secretion, digestion and absorption.
Enzymes
Proteins which catalyse the reactions of metabolism, speeding them up without themselves being used up in the reaction. Each enzyme is specific for a given substrate and/or reaction.
Epidemiology
The study of associations between patterns of disease in populations and environmental, lifestyle or genetic factors.
Epithelium
The surface layer of the skin or the lining layer of the intestinal mucosa or air passages of the lungs.
Experimental design
Nutrition science advances by observation (for example, nutritional epidemiologists observe statistical associations between what people eat and their patterns of health and disease) and by experiment, in which subjects are given specifically formulated diets and certain effects are noted. For example, to test the metabolic effects of components of diets, experiments are performed in which a diet containing the test substance (treatment) is compared against a reference diet (control) which, if possible, is the same in all respects other than the test substance and in which the test substance is substituted by a suitable placebo. Subjects should be allocated randomly to diets so that factors other than those tested, and which may otherwise confound the results, are equalised between treatments. Ideally, neither the subjects nor the experimenters should be aware of the identity of treatment and placebo groups (double-blind).
Exposure assessment
The qualitative and\or quantitative evaluation of the likely intake of biological, chemical and physical agents via food as well as exposures from other sources, if relevant.
External validity
The generalisability of a study's findings to persons other than the study subjects.
Extracellular
Inside the body but not within cells; hence, extracellular compartment refers to the space, mainly water, outside the cells.EczemaAn itching red rash, often on the face, hands or skins folds, which oozes and crusts if scratched.
Fat
Triglycerides (triacylglycerol) that are either solid (e.g. in margarine, shortening, lard, etc.) or liquid (e.g. vegetable or fish oil) at room temperature (see also oil).
Fat mimetics
Compounds that carry out only some of the functions of fat in foods.
Fat substitutes
Compounds that can replace conventional fat in foods and carry out all of the same functions.
Fat-soluble vitamins
Vitamins - organic substances that cannot be produced in the body but are essential for cellular functions and must be obtained from the diet - carried in fat and usually acquired from fatty foods. Vitamins A, D, E and K are the fat-soluble vitamins (see also vitamins).
Fatty acids
Organic acids with a hydrocarbon chain of varying length; constituents of triglycerides and related lipids.
Fatty liver
An abnormal accumulation of fat in the liver associated, in extreme cases, with abdominal discomfort. It often precedes other liver diseases such as cirrhosis.
Fatty streaks
Slightly raised fatty deposits in arteries that do not cause obstruction; possibly but not definitely precursors of atherosclerotic plaque.
Fermentation
Metabolism to extract energy from substrates. In the context of dietary fibre, fermentation involved anaerobic (without oxygen) degradation of indigestible carbohydrates by the microflora (mainly bacteria) of the large intestine. Fermentation may also involve the degradation of sugars or starches (following enzymatic digestion by saliva) in the mouth by cariogenic bacteria.
Fermented foods
Foods that have been subjected to processing involving the action of yeasts or bacteria.
Fibrosis
A condition in which there is a proliferation of fibrous or connective tissue. It is often associated with the information of scar tissue following an injury or infection.
Foetal alcohol syndrome
Defects in the growth and development of the foetus resulting from excessive consumption of alcohol by the mother or possibly even the father.
Food frequency questionnaire
A method of dietary assessment in which subjects are asked to recall how frequently certain foods were consumed during a specified period of time.
Food record
A method of dietary assessment in which subjects records the foods that they consume.
Food safety objective
A government-defined target considered necessary to protect the health of consumers (this may apply to raw materials, a process or finished products).
Food safety requirement
A company-defined target considered necessary to comply with a food safety objective.
Free radical
A highly reactive chemical species that normally exists for a relatively short time. Some free radicals are formed in the body during processes of oxidation and may be useful, e.g., in killing infectious organisms. Free radicals are also capable of doing extensive damage to tissues unless kept in check by antioxidants. The latter can be enzymes or chemicals, many of which are vitamins obtained from the diet (e.g., vitamins C and E).
Gastrointestinal tract
The organ along which food travels from the mouth until the undigested remnants emerge as stools. Mixing and some digestion occur in the stomach where the environment is acidic; most digestion and absorption of nutrients occurs in the small intestine; the large intestine, principally the colon, contains very large numbers of micro-organisms capable of fermenting food components that have escaped digestion in the small intestine.
Gel
A complex solid and liquid food system, interconnected to give a network of intermingled particles.
Gene
The smallest sequence of a DNA molecule capable of directing protein synthesis or performing a regulatory function.
Genetic
Inherited; a genetic disease is one that is inherited via a faulty gene.
Genetic Modification
The addition, deletion, substitution, rearrangement or recombination of heritable genetic material using techniques defined in Directive 90\220\EEC.
Genetic stability
A measure of the resistance to change, with time, of the sequence of genes within a DNA molecule or of the nucleic acid sequence within a gene.
Glucose tolerance test
A test of the body's ability to metabolise carbohydrate by administering a standard dose of glucose under controlled conditions and measuring the blood and urine for sugar at regular intervals thereafter. The glucose tolerance test is usually used to assist in the diagnosis of diabetes or other disorders that affect carbohydrate metabolism.
Glutathione
A small-molecular-weight antioxidant molecule produced naturally in the human body and present in some foods.
Gluthathione peroxidases
A family of antioxidant molecule produced naturally in the human body and present in some foods.
Glycaemic index
A method for assessing the comparative effects of different carbohydrates on the pattern of changes in the concentration of glucose in the blood following a meal. A dose of 50 g of glucose is assigned a glycaemic index of 100, given by integrating the area under the curve when blood glucose concentration is plotted against time.
Glycogen
The animal equivalent of starch, that is, a storage polysaccharide composed of glucose molecules linked in a branched-chain structure. It is stored in the liver but is also present in muscle, and is readily broken down to be used as an energy source in metabolic pathways.
Hazard
A biological, chemical or physical agent in a food, or condition of a food, with the potential to cause an adverse health effect.
Hazard characterisation
The qualitative and/or quantitative evaluation of the nature of the adverse health effects associated with biological, chemical and physical agents which may be present in food. For chemical agents, a close response assessment should be performed. For biological or physical agents, a dose-response assessment should be performed if the data are obtainable.
Hazard identification
The identification of biological, chemical and physical agents capable of causing adverse health effects which may be present in a particular food or group of foods.
Hedonic
Generally involving the psychological range of feelings from pleasant to unpleasant.HepatitisInflammation of the liver, generally accompanied by abdominal discomfort. There may be many causes, including bacterial or viral infections and various drugs, including alcohol.
Hepatitis
Inflammation of the liver, generally accompanied by abdominal discomfort. There may be many causes, including bacterial or viral infections and various drugs, including alcohol.
Heterocyclics
Cyclic organic molecules containing one or more hetero atoms (e.g., nitrogen, sulphur, oxygen, etc.)
High density lipoproteins (HDL)
Plasma lipoproteins containing relatively low concentrations of cholesterol and other lipids; thought to be beneficial because they cycle cholesterol out of tissues.
Histamine
An amine found in all tissues of the body. Large amounts are released by mast cells when the body encounters a substance to which it is sensitive, thereby triggering symptoms of inflammation.
Homeostasis
A relative constancy in the internal environment of the body, naturally maintained by adaptive responses that promote healthy survival.
Hydrolyse
To split a chemical compound into its constituents by the addition of water. Hydrolysis may be purely chemical or catalysed by enzymes. Digestion is normally achieved by enzyme-catalysed hydrolysis.
Hypercholesterolaemia
Concentrations of cholesterol in the blood higher than normal (or reference) values. Causes include dietary and genetic.
Hyperglycaemia
A greater than normal concentration of glucose in the blood, most frequently associated with diabetes mellitus.
Hyperlipidaemia
A condition arising from an increased concentration in the blood of cholesterol, triglycerides or both. These lipids are in the form of lipoproteins.
Hypertension
A disorder characterised by elevated blood pressure persistently exceeding systolic\diastolic pressures of 140\90 mm Hg. There may be no visible signs, but the condition poses an increased risk for several diseases such as stroke and coronary heart disease.
Hypertriglyceridaemia
Concentrations of tryglycerides in the blood higher than normal (or reference) values.
Immunoglobulins
Large proteins from which anti-bodies are formed, and which are then capable of combining with foreign substances (antigens).
In Vitro
From the Latin meaning "in glass". The term is applied to biological processes studied experimentally in isolation from the organism, as distinct from in vivo, which refers to the study of processes in the living organism.
In Vivo
A reaction or study carried out in the living organism.
Inserted genes
Genes introduced into the DNA of a recombinant organism which are not present at the same position in the DNA of the organism before genetic modification.
Insulin
A hormone secreted by the pancreas in response to consumption of food. It circulates in the blood and assists in the transport of glucose into cells and activates or suppresses the activities of various enzymes.
Interleukins
Molecules which relay signals between cells of the immune system.
Internal validity
The accuracy of a study's findings with regard to the study subjects.
Intervention trial
A study in which exposure to the factor under investigation is modified by the investigator; an experimental study.
Intervention trials
Trials in which one or more factors that may affect health are altered, with the aim of demonstrating beneficial effects compared with a control group not receiving the intervention.
Intracellular
Within cells; the intracellular compartment refers to the space, mainly water, inside cells.
Ischaemia
Reduced or inadequate blood, and thus oxygen, supply to a part of the body.
Leukotrienes
Chemical mediators of the inflammatory response, released by various white blood cells and by mast cells.
Life expectancy
Expected further number of years of life measured at any age.
Lipid
General name for fatty materials insoluble in water (nonpolar), including fats, oils, phospholipids and cholesterol.
Lipid peroxidation
A process in which unsaturated fat-soluble substances (lipids) are oxidised to form radicals and therefore capable of causing extensive tissue damage. The polyunsaturated fatty acid components of lipids are particularly prone to oxidation in this way. The process can occur in foods before they are eaten or can take place in the body.
Lipoproteins
Particles composed of specialised proteins and lipids (triglycerides, phospholipids and ccholesterol) which enable lipids (which are water insoluble) to be carried in blood plasma.
Low-density lipoproteins (LDL)
Plasma lipoproteins containing high concentrations of lipids (which are low in density compared to that of water), including cholesterol. Increased concentrations are a risk factor for coronary heart disease.
Lumen
The channel within a tubular organ; for example, the lumen of the intestine.
Lutein
A carotenoid found primarily in green leafy vegetables. Lutein has no provitamin A activity.
Lycopene
A carotenoid found primarily in tomatoes. Lycopene has antioxidant activity but does not act as a precursor of vitamin A.
Neuroepithelial
Forming connections of neurons at the epithelium.
Neuron
Nerve cell, especially with all its processes.
Non-coding linker sequences
Short pieces of DNA between genes which do not direct protein synthesis or perform a regulatory function.
Non-insulin-dependent diabetes mellitus. (NIDDM; 'maturity onset diabetes')
See Diabetes mellitus.
Nutrient density
Nutrient content of a food expressed in relation to energy content (e.g. Mg per 1000 kcal).
Obesity
An excessive accumulation of body fat, often defined as a body mass index (BMI) greater than 30. BMI is the ratio of body weight in kilograms to height in metres squared.
Oestrogen (estrogen)
One of a group of hormonal steroid compounds that promote the development of female secondary sex characteristics; sometimes used in the prevention of osteoporosis.
Oil
Triglycerides (fats) that are liquid at room temperature.
Oligosaccharide
See carbohydrate.
Osmotic pressure
The pressure exerted when ions flow across a membrane from one cellular compartment to another to equalise the ionic concentration, which is normally close to what is obtained by adding 9 g salt (Na+C1-) to 1 litre distilled water.
Osteoporosis
A disorder characterised by an abnormally low density of the bone mineral. The condition predisposes to fracture of certain vulnerable bones and occurs most frequently in women after menopause.
Oxidation
A chemical reaction that involves the loss of electrons; it usually but not always involves direct participation of oxygen and is an important process by which food components are utilised by the body's metabolism.
Oxidative stress
A condition in which the production of oxidants and free radicals exceeds the body's ability to inactivate them.
Papillae
Minute elevations of the upper surface of the tongue in which nerves end.
Permeability
Degree of leakiness of membranes.
Pharmacological
Pertains to drug-like actions of chemical substances.
Phasic activity
Activity which is demonstrated in various phases.
Phospholipid
A lipid that contains phosphorus, most commonly a compound of glycerol with two fatty acids and one phosphate group. Normally the phosphate is also linked to a small molecule such as choline, serine, ethanolamine or inositol.
Placebo
A harmless and pharmacologically inactive substance, usually disguised, given to compare its effect with that of an active material.
Plaque (atherosclerotic)
Term used for the area on the inside of an artery affected by atherosclerosis is not uniform but occurs in small patches, or plaques.
Polysaccharide
A carbohydrate polymer formed by the linking of many monosaccharides.
Post transcriptional changes
Changes to a protein that occur after DNA has been copied to form messenger RNA and this has been translated to produce protein - for example, to facilitate excretion of the protein from the cell.
Prevalence
The number of existing cases of a disease in a defined population at a specified time.
Prospective (cohort) study
A study in which the study population is characterised at the start of the study and followed into the future. A population of people who do not (yet) have the disease under investigation is identified, and information is collected on the subjects' exposure to risk factors generally including nutritional factors. The frequency of the disease among subjects exposed to a particular risk factor during the follow up period is compared with the frequency among those who were not exposed.
Prostaglandins
Fatty acids synthesised by various white blood cells and at the surface of mast cells, that can cause either contraction or relaxation of smooth muscles in the airways and in certain blood vessels.
Protease
Enzyme that breaks down proteins.
Psychophysical
Concerning the relationships between measurable stimuli and the corresponding responses.
Quality
The totality of characteristics of an entity that bear on its ability to satisfy stated or implied needs.
Quality assurance
All the planned and systematic activities implemented within the quality system, and demonstrated as needed, to provide adequate confidence that an entity will fulfil requirements for quality.
Quality control
The operational techniques and activities used to fulfil requirements for quality.
Quality management
All activities of the overall management function that determine the quality policy, objectives and responsibilities and that implement them by means such as quality planning, quality control, quality assurance and quality improvement within the quality system.
Quality system
The organisational structure, procedures, processes and resources needed to implement quality management.
Ratio scaling
Method for quantification of effects through magnitude estimation of how many times the effect of a sample is compared to a standard.
Reactive oxygen species (ROS)
Forms of oxygen that have enhanced chemical reactivity compared with the normal oxygen molecule; many are free radicals (see also free radical).Risk factorPhysical condition or lifestyle that in epidemiological studies appears to increase susceptibility to a particular disease.
Recombinant organism
An organism in which the DNA has been made by joining together segments of DNA using the techniques of genetic modification described in Directive 90\220\EEC.
Relative risk
The ratio of the outcome rate among persons exposed to a certain factor divided by the outcome rate among persons not exposed.
Reperfusion
The reoxygenation of tissue that has been deprived of adequate oxygen (ischaemia) as a result of either surgical procedures or physiological dysfunction. Vital organs can tolerate only a brief period of oxygen deprivation before cell injury and death occur. Subsequent reperfusion, however, can also cause tissue damage. Ischaemia reperfusion damage can be prevented or decreased in the presence of antioxidants.
Risk analysis
A process consisting of three components: risk assessment, risk management and risk communication.
Risk assessment
A scientifically based process consisting of the following steps: (I) hazard identification, (II) hazard characterisation, (III) exposure assessment and (IV) risk of characterisation.
Risk characterisation
The qualitative and\or quantitative estimation, including attendant uncertainties, of the probability of occurrence and severity of known or potential adverse health effects in a given population based on hazard characterisation and exposure assessment.
Risk communication
The interactive exchange of information and opinions concerning risk among risk assessors, risk managers, consumers and other interested parties.
Risk factor
Physical condition or lifestyle that in epidemiological studies appears to increase susceptibility to a particular disease.
Risk management
The process of weighing policy alternatives in light of the results of risk assessment and, if required, selecting and implementing appropriate control options, including regulatory measures.
Safety policy
The overall intentions and direction of an organisation with regard to safety as formally expressed by top management.
Satiation
The term for the physiologic processes that bring eating a meal to an end and control meal size.
Saturated fatty acid
Fatty acid whose hydrocarbon chain contains no double bonds.
Sequence characterisation
Determination of the order in which the nucleic acids making up a DNA molecule, or the amino acids making up a protein molecule, are linked together.
Short-chain fatty acids
Fatty acids with chain lengths of two to six carbon atoms.
Specificity of gene expression
A measure of the extent to which the ability of an organism to produce a particular gene product is determined by factors affecting the cell, for example, its function, phase of growth or environmental pressures.
Stem cell
Precursor cell in various systems which is capable of producing the various functional cells of that system by cell division and differentiation, e.g., stem cells which differentiate into lymphocytes.
Stroke
Interference with blood circulation in the brain, starving one or more parts of the brain of oxygen. The medical term is cerebrovascular accident.
Substrate
The substance on which a specific enzyme exerts its effects.
Sucrose
A disaccharide of glucose and fructose.
Sugars
Simple carbohydrates, generally with a sweet taste and soluble in water. The term is usually reserved for mono- and disaccharides (see carbohydrates). In non-scientific English, the disaccharide sucrose is referred to as sugar.
Sulphites
Preservatives commonly used in, for example, wine.
Sweeteners
Substances which taste sweet.
T cells (T lymphocytes)
White blood cells involved in the immune response.
Thrombosis
Blockage of an artery resulting from aggregation of platelets and fibrin, a fibrous protein.
Tocopherols, tocotrienols
Forms of vitamin E.
Total quality management
An organisation's management approach centred on quality, based on the participation of all its members and aimed at long-term success through customer satisfaction and benefits to the members of the organisation and to society.
Toxin
Poisonous substance.
Trans fatty acid
A form of unsaturated fatty acid that is straight (rather than bent, i.e cis) at the double bond; not abundant in natural edible oils but occurring in ruminant fats and formed during some manufacturing processes.
Triacylglycerols
Compounds of glycerol and three fatty acids also called triglycerides; the main constituents of dietary and body fat.
Triglycerides
Compounds of glycerol and three fatty acids. Synonymous with triacylglycerols (the official chemical name). See oil.
Ubiquinol
An antioxidant produced by normal metabolism. Ubiquinol is the only known fat-soluble antioxidant synthesised by animal cells. It is believed to play an important role in cellular defence against oxidative damage. Ubiquinol can also contribute to the antioxidant defence system by regenerating the active form of vitamin E after that vitamin has reacted with a free radical. (The water-soluble vitamin C can also perform this function.)
Univariate analysis
Techniques for studying the effects of a single factor on an outcome variable.
Unsaturated fat
Triglyceride with a preponderance of unsaturated fatty acids.
Unsaturated fatty acid
Fatty acid whose hydrocarbon chain contains at least one double bond. Monounsaturated fatty acids contain one double bond; polyunsaturated fatty acids contain tow or more.
Urticaria
A raised, itching rash, often with well-circumscribed areas (wheals).
Vector
The agent, such as a plasmid or virus, used to carry new DNA into a cell during genetic modification.
Vegan
Strict vegetarian who does not eat any food containing ingredients derived from animals.
Vitamin
Organic substances that cannot be produced in the body but are essential for cellular functions and must be obtained from the diet.
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