Glossary

• Alleles

  alternate forms of the same gene. For organisms with two sets of chromosomes like humans, an individual can have two copies of the same allele (i.e. homozygous for the allele) or two different alleles (i.e. heterozygous for the alleles).

• Antioxidant

  A chemical that inhibits oxidation and reacts with free radicals to form a harmless product. An antioxidant will have one or more unpaired electrons.

• Apolipoprotein

  The protein component that combines with a lipid to form a lipoprotein.

• Atherosclerosis

  The progressive narrowing and hardening of the arteries over time; often used to describe a condition where lipids (fats) collect under the inner lining of damaged artery walls.

• Bifidobacteria

  Lactic acid producing microorganisms that inhabit the gastrointestinal tract.

• Bioactivation

  The conversion of an inactive compound into an active one within a living organism.

• Bioactive

  A chemical (often found in various foods) that interacts with the molecular components of a living organism.

• Bioinformatics

  The collection, storage, manipulation, management, and retrieval of biological data.

• Biomarker

  A substance sometimes found in the blood, other body fluids, or tissues that can be used to measure the presence or progress of disease or the effects of treatment.

• Calorie (food)

  The amount of heat (i.e. energy) needed to raise the temperature of 1 gram of water from 15 to 16 degree Centrigrade or 4.184 absolute joules. One food calorie is equivalent to 1000 calories or 1 kilocalorie. Calories are used to describe the energy content of various foods. For nutrition, a food calorie can be defined practically as the amount of energy consumed by a 150 lb individual during 1 minutes of sleep.

• Carcinogen

  A substance or chemical agent that perturbs normal cellular processes leading to unscheduled cell division and cancer, or the increased risk of cancer.

• Carcinogenesis

  The molecular processes that result in cancer.

• Catechins

  Natural plant compounds belonging to the class of polyphenols present in high concentrations in green tea or rooibos (red leaf) tea. Catechins like EGCG are potent antioxidants and have been shown to block signaling pathways that lead to cell proliferation in human and animal cells

• Chemoprotective agent

  A chemical constituent, drug, or food supplement that prevents disease by interrupting deleterious biological reactions or processes.

• Cytochrome P450s

  A family of enzymes found primarily in the liver but also in the kidney and gastrointestinal tract involved in the metabolism of exogenous and endogenous chemicals.

• Detoxification

  Any process that removes a toxin; in a biological systems, a process that usually requires enzymes for modifying reactive chemicals. For example, the liver enzyme NAT2 can detoxify aromatic amines found in tobacco smoke.

• Diet

  The sum total of all the nourishing materials (food, drink and supplements) consumed by an organism. In humans (and most animals), a proper diet requires certain essential vitamins, minerals, proteins and fats. The balance between starvation and obesity depends on the amount of nourishing materials consumed as fuel and the amount of energy expended.

• Dietary phytosterols

  Plant-derived chemicals with a typical ring structure similar to sterols found in animals.

• Dyslipidemia

  Abnormal lipid profiles usually characterized by high triglyceride concentrations, low HDL cholesterol, and increased concentrations of small, dense LDL cholesterol; associated with metabolic disorder characterized by insulin resistance, obesity and type 2 diabetes.

• Enhancers

  A set of short sequence elements that stimulate transcription of a gene and whose function is not critically dependent on their precise position or orientation.

• Epidemiology

  Classically, the study of occurrence of a disease in a population, especially the factors that influence the incidence, severity and distribution of the disease.

• Epigenetics

  The study of heritable changes in gene function that occur without a change in the sequence of nuclear DNA.

• Etiology

  The causes or origins of disease

• Exon

  DNA sequences that occur in mRNAs, which contain ribosomal binding sites, protein coding sequences and information for mRNA stability and perhaps cellular function.

• Folic acid

  A yellowish-orange, bitter tasting compound of the vitamin B-complex group, found in green plants, fresh fruits, liver, and yeast; also called folacin and folate.

• Functional genomics

  The study of genes, their resulting proteins and the role these proteins play in biochemical processes of the organism.

• Gene activity

  Transcription, translation, stability, physical association, or enzymatic function of molecules ultimately attributable to the same segment of DNA.

• Genetic association studies

  Statistical analyses that link chromosomal regions with disease subphenotypes or incidence.

• Genetic epidemiology

  The study of genetic components in complex biological system.

• Genetic interaction

  The nonadditive effect that variation (gene deletion) at one genetic locus has on the phenotypic response of a biological system to a defined perturbation. Interactions can be synergistic (enhancing effect of perturbation) or antagonistic (suppressing effect perturbation).

• Genetic polymorphism

  The difference in DNA sequence from a reference sequence.

• Genistein

  A chemical of the isoflavone class found in plants that has a structure similar to estrogen. Therefore, it is a phytoestrogen.

• Genomics

  The high-throughput, highly parallel study of all the genes ( and gene products such as RNA and protiens) as a dynamic system, over time, determining how they interact and influence biological pathways, networks, and physiology in a global sense.

• Gut microflora

  All of the microbes in the gastrointestinal tract.

• Haplotype

  A contraction of the phrase “haploid genotype.” A specifc collection of linked polymorphisms (e.g. SNPs, simple tandem repeats, or insertions and deletions) within a cluster of related genes or region of a chromosome.

• Hepatocarcinogenesis

  The formation of cancer in the liver.

• Hepatocyte

  A cell of the liver.

• Heritability

  The degree to which the variance in the distribution of a phenotype is attributable to genetics. For example, height and weight in humans are from 40% to 70% heritable or due to genetics.

• Heterocyclic amines

  A class of chemicals with a ring structure and amine group; can be formed by cooking food.

• Homologous genes

  Two or more genes whose sequence are significantly related because of a close evolutionary relationship either between species or within a species.

• Hyperforin

  A chemical found in St. John’s wort (and other plants) that is bioactive. I can bind and activate expression of genes involved in drug metabolism.

• Hypertension

  Aterial disease in which chronic high blood pressure is the primary symptom.

• Insulin resistance

  Reduced sensitivity to insulin by the body’s insulin dependent processes (e.g. glucose uptake, lipolysis, and inhibition of glucose production by the liver) that results in lowered activity of these processes or an increase in insulin production or both. Insulin resistance is typical of type 2 diabetes but can often occur in the absence of diabetes.

• Isoflavones

  A class of plant metabolites similar in structure to estrogen. The isoflavones, diadzin and genistein are found in soybeans and other legumes and are believed to provide health benefits.

• Ligand

  A molecule that binds to a specific site on a protein such as a nuclear hormone receptor, membrane receptor, enzyme or antibody. A ligand can be an activator or inhibitor.

• Lipogenesis

  The synthesis of lipids from nonlipid precursors.

• Lumen

  The central cavity of a cell.

• Metabolite

  Any substance produced by metabolism or by a metabolic process.

• Metabolome

  The sum total of all metabolites or by a metabolic process

• Metabolomics

  Defined as the global synthesis of metabolties—small molecules generated in the process of metabolism—that represent the sum total of all the metabolic pathways in an organism with the focus on the identification of each pathway and its role in an organism’s function.

• Micronutrient

  A substance such as a vitamin or mineral that is essential in minute quantities for the proper growth and metabolism of a living organism.

• Molecular epidemiology

  A science that focuses on the contribution of potential genetic and environmental risk factors, identified at the molecular level, to the etiology, distribution, and prevention of disease within families and across populations.

• Molecular markers

  Any DNA, protein, RNA or metabolite that is used as a surrogate for a phenotype or more complex biological process.

• Natural selection

  The process in nature by which only the organism best adapted to their environment tend to survive and transmit their genetic information in increasing numbers to succeeding generations, while those less adapted tend to be eliminated.

• Nuclear receptors

  Ligand-inducible transcription factors. Their natural ligands are in various chemical classes such as steroid hormones, dietary lipids and their derivatives, oxysterols, bile acids, eicosandoids, and lipid-soluble vitamins.

• Nutrigenetics

  A subdiscipline of nutritional genomics usually referring to the association of a gene variant (e.g. single nucleotide polymorphism) with an intermediate risk factor (e.g. cholesterol level or glucose response) that is influenced by a particular nutrient (e.g. saturated fat). Because gene-gene Interactions (epistasis), nutrigenetics is most informative when viewed in the context of the entire genome.

• Nutrition

  A three-step process by which nourishing materials (food, drink, and supplements) are ingested, broken down (digestion), assimilated and utilized in metabolism to achieve health by sustaining normal cellular activity (anabolism and catabolism). As a discipline, nutrition is the study of these processes in the context of health and disease.

• Nutritional genomics or Nutrigenomics

  The study of how foods affect the expression of genetic information in an individual and how an individual’s genetic makeup metabolizes and responds to nutrients and bioactives.

• Omega-3 fatty acid

  Any of the various polyunsaturated fatty acids that are found primarily in fish, fish oils, vegetable oils and leafy green vegetables.

• Omics technologies

  High-throughput technologies used to analyze simultaneously various kinds of marcromolecules. For example, transcriptomics measures many transcripts, proteomics measures many proteins and metabolomics measures many metabolites.

• Osteoporosis

  A condition characterized by a decrease in bone mass and density.

• Oxidative damage

  Damage to cells caused by oxidants.

• Penetrance

  The frequency with which a genotype manifests itself in a given phenotype.

• Pharmacogenetics

  Investigating how inheritance impacts a person’s response to drugs.

• Pharmacogenomics

  The study of genetic variability and its relationship to a person’s response to drugs, non-prescription and OTC medications and steroids.

• Phenotype

  The observable characteristics of an organism produced by the interaction of the organism’s genotype and its environment. Height, eye color, enzyme activity or disease state are all examples of phenotype.

• Phytochemicals

  A nonnutritive bioactive plant substance such as a flavonoid or polyphenol considered to be beneficial to human health.

• Phytonutrients

  Nonessential bioactive dietary chemicals derived originally form the plant kingdom.

• Pluripotent cell

  Cells capable of differentiating into numerous cell types. An example is a stem cell.

• Polymorphism

  Difference between otherwise identical macromolecules; usually refers to changes in DNA.

• Polyphenol

  A group of chemicals usually from plants characterized by the presence of more than one phenolic group.

• Prebiotics

  A dietary constitutent or food supplement that nourishes and promotes the growth of beneficial bacteria already in the digestive system.

• Probiotics

  Live, active cultures of necessary bacteria that are actually ingested and promote health. Live culture yogurt is an example of a probiotic.

• Promoter

  A region in DNA, usually 5 ‘ to the coding sequence of the gene that encodes regulatory sequences needed for gene transcription.

• Proteome

  The total collection of proteins in a cell or cellular substructure.

• Proteomics

  The study of all proteins in a cell or organism.

• Proteosome

  A collection of proteins in a defined structure involved in degradation of proteins.

• Pseudogenes

  A nonfunctional gene derived from a ancestral active gene.

• Response elements

  Response elements are sequence-specific recognition sites of transcription factors. Many response elements are located with 1kb from the transcription start site.

• Robutness

  Constancy or resilience to change. Cellular robustness is the maintenance of stable phenotypic outputs in response to perturbation, which is presumed to result from natural selection for buffering interactions between genes, other genes and the environment.

• RT-PCR

  Real-time polymerase chain reactions; a method for monitoring the amplification of RNA molecules from a particular sample into many copies of DNA molecules.

• Signal transduction

  A network of cellular enzymatic reactions stimulated by an extracellular signal interacting at the cell surface. The reactions alter signaling molecules that cause changes in a level of other proteins, enzymes, or metabolites and ultimately modulate a change in the cell’s function.

• Single Nucleotide Polymorphism

  Any variation of a single nucleotide in an otherwise identical DNA sequence.

• Sir2

  An NAD-dependent histone deacetylase enzyme and a member of the sirtuin gene family which is associated with longevity.

• Systems biology

  An approach of studying biological systems that analyzes multiple macromolecular species (DNA polymorphisms, RNA, protein, metabolites, etc) in one experiment; a holistic approach to studying biological systems.

• Transactivation

  Activation of gene transcription, which is induced by binding of a transcription factor or nuclear receptor to a DNA regulatory sequence.

• Transcription coactivator

  Coactivators which can potentiate transcriptional properties, mediated by nuclear receptors. Many coactivators are associated in large multiprotein complexes.

• Transcription corepressor

  Certain nuclear receptors when bound in absence of their ligand to their target genes can inhibit gene transcription initiation.

• Transcription factor

  Generally, a protein that functions to initiate, enhance, or inhibit the transcription of a gene. Transcription factors bind to DNA regulatory sequences of target genes to modify the rate of gene transcription initiation.

• Trans fatty acid

  A fatty acid that has been produced by hydrogenating an unsaturated fatty acid (and so alters its shape); found in processed foods such as margarine, fried foods, puddings and commercially baked products and partially hydrogenated vegetable oils.

• Transgenerational epigenetic inheritance

  Inheritance of somatic DNA methylation patterns from parents to offspring.

• Transrepression

  Processes through which nuclear receptors can antagonize the transcriptional activity of other transcription factors without DNA binding or altering the DNA activity.

• Ubiquitin pathway

  A series of enzymatic reactions that ultimately degrade proteins. Ubiquitin is added to proteins targeting them for degradation.

• Xenobiotic chemicals

  A chemical that is not a natural component of the organism or its diet.