8-isoPGF2a

8-isoPGF2a is a biomarker of lipid peroxidation. It is measured to assess cardiovascular disease risk.

Adenosine Triphosphate

Adenosine triphosphate (ATP) is the “energy currency” of all living things. The body creates ATP through the breakdown of fats, carbohydrates, and proteins to supply the energy needed for muscle contraction, nerve conduction, and several other physiological processes.

Adequate Intake (AI)

Adequate intake is the level of daily intake for a specific nutrient that may ensure nutritional adequacy in most people without health conditions when there is insufficient evidence to develop an <a href="/glossary/estimated-average-requirement/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Estimated Average Requirement (EAR)&lt;/h6&gt;&lt;p&gt;&lt;em&gt;Estimated average requirement&lt;/em&gt; is the level of daily intake for a specific nutrient that meets the nutritional requirements of 50% of all people without health conditions.&lt;/p&gt;&lt;/div&gt;">estimated average requirement</a> and, therefore, a <a href="/glossary/recommended-dietary-allowance/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Recommended Dietary Allowance (RDA)&lt;/h6&gt;&lt;p&gt;&lt;em&gt;Recommended dietary allowance&lt;/em&gt; refers to the level of daily intake for a specific nutrient that meets the nutritional requirements of nearly all people without health conditions. This value for specific nutrients can vary by age, sex, and pregnancy status.&lt;/p&gt;&lt;/div&gt;">recommended dietary allowance</a> cannot be calculated.

ALT stands for “alanine aminotransferase,” a liver enzyme measured in the blood to estimate liver function.

Alternative Healthy Eating Index (AHEI)

The Alternative Healthy Eating Index (AHEI) was developed to expand on the Healthy Eating Index, which tracks how well Americans’ diets conform to the Dietary Guidelines for Americans. It takes into consideration the types of fat, forms of carbohydrates, and sources of protein.

AMPK

Adenosine monophosphate-activated protein kinase (AMPK) is an enzyme that helps regulate energy in the body.

Analgesic

An analgesic is something that acts to relieve pain.

Antiemetic

An antiemetic provides relief from nausea and vomiting, which are typically caused by motion sickness, pregnancy, stomach irritation, or side effects from certain drugs.

Area Under the Curve (AUC)

Area under the curve (AUC) represents the total quantity of the substance in the bloodstream over the duration of the measurement period. In nutrition research, AUC is commonly used to determine bioavailability and to measure a person’s glycemic response.

AST stands for “aspartate aminotransferase,” a liver enzyme measured in the blood to estimate liver function.

Beck Depression Inventory

The Beck Depression Inventory (BDI) is a self-reported questionnaire that can be used to screen for depression and assess depression severity. Clinicians may use the BDI, along with a person’s medical history, to make a diagnosis of depression.

Before-and-after study

A before-and-after study measures differences within a single group before and after an intervention. Unlike a randomized controlled trial, this type of study cannot provide definitive evidence that the intervention caused the differences seen in the study.

Bioavailability

Bioavailability refers to the amount of a substance that can be absorbed and utilized by the body. In the context of nutrition research, this term is generally interchangeable with “oral bioavailability”, which is the amount of a substance that is absorbed and utilized by the body when consumed orally.

Blood clotting

Blood clotting is a process that prevents excessive bleeding from an injury. When a blood vessel is injured, red blood cells, platelets, and clotting factors come together to help the blood to coagulate and stop flowing.

Bone resorption

Bone resorption is the process by which bone tissue is broken down so that its minerals can be reabsorbed. Osteoclasts are responsible for breaking down bone into more absorbable forms of calcium, phosphorus, and more. When bone resorption occurs at high rates, it can lead to <a href="/conditions/osteoporosis/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Osteoporosis&lt;/h6&gt;&lt;p&gt;Osteoporosis is a condition of having weak and brittle bones. The main goal for people with osteoporosis is to prevent bone fractures by strengthening the bones and by avoiding falls.&lt;/p&gt;&lt;/div&gt;">osteoporosis</a>.

Cohort Study

In a cohort study, researchers follow a group of participants who share similar demographic, occupational, or lifestyle characteristics for a certain period of time to investigate the association between an exposure and a particular outcome of interest, for example, the link between smoking and lung cancer.

Colony-forming unit (CFU)

A colony-forming unit estimates the number of viable bacterial or fungal cells in a sample, defined as the number of cells that are alive and will divide to produce more cells by binary fission.

Confounder

A confounder is a factor — either observed or unobserved — which affects the relationship between two variables being studied. Not accounting for the potential effect of a confounder may lead to incorrect conclusions about the relationship between the variables.

Control

A control provides a comparator that allows determination of the safety and effectiveness of a treatment. For example, a control group is a group of study participants that does not receive the experimental treatment. Instead, participants in the control group may receive a standard treatment, a <a href="/glossary/placebo/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Placebo&lt;/h6&gt;&lt;p&gt;A placebo is a substance with no therapeutic or active ingredient. Placebo agents are used in many studies as a glossary:control, to provide a comparator to the intervention under investigation.&lt;/p&gt;&lt;/div&gt;">placebo</a>, or nothing, while keeping all other aspects of the study the same for the control group as for the group receiving the experimental treatment.

Correlation

Correlation is a measure of the strength of the relationship between a pair of variables. It expresses the extent and direction to which two variables change together. Correlation does not imply causation.

Cross-Sectional Study

In a cross-sectional study, the outcome and exposure are measured at a single point in time in the population of interest. This type of observational study is valuable for determining the disease prevalence in a population or the association between exposures and outcomes, but it can’t determine causation or describe how an association changes over time.

Crossover Study

In a crossover study, the participants undergo each of a study’s treatment conditions (e.g., 4 weeks of taking a supplement and 4 weeks of taking a placebo) in random order, often with “washout” periods in between (during which they undergo no treatment). This study design allows for the participants to act as their own controls, eliminating the need for a designated control group.

CYP1A2 Inducers

CYP1A2 inducers include, but are not limited to, carbamazepine, cruciferous vegetables, omeprazole, nelfinavir, phenobarbital, phenytoin, rifampin, ritonavir, and tobacco. See glossary page for more information.

CYP1A2 Inhibitors

CYP1A2 inhibitors include, but are not limited to, allopurinol, amiodarone, ciprofloxacin, cimetidine, famotidine, fluvoxamine, oral contraceptives, propranolol, <a href="/supplements/quercetin/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Quercetin&lt;/h6&gt;&lt;p&gt;Quercetin is the most well researched of all bioflavonoids. It is not actually that good of a supplement on its own, but is an interesting research topic. Tons of interactions, and synergistic with other bioflavonoids and increases absorption of Resveratrol and Green Tea Catechins.&lt;/p&gt;&lt;/div&gt;">quercetin</a>, and verapamil. See glossary page for more information.

CYP1A2 Substrates

CYP1A2 substrates include, but are not limited to, caffeine, clozapine, duloxetine, lidocaine, mirtazapine, naproxen, olanzapine, propranolol, triamterene, and theophylline. See glossary page for more information.

CYP2A6 Inducers

CYP2A6 inducers include, but are not limited to, carbamazepine, dexamethasone, efavirez, oral contraceptives, phenobarbital, and rifampin. See glossary page for more information.

CYP2A6 Inhibitors

CYP2A6 inhibitors include, but are not limited to, letrozole, pilocarpine, and selegiline. See glossary page for more information.

CYP2A6 Substrates

CYP2A6 substrates include, but are not limited to, efavirenz, letrozole, nicotine, pilocarpine, tegafur, and valproic acid. See glossary page for more information.

CYP2B6 Inducers

CYP2B6 inducers include, but are not limited to, carbamazepine, efavirenz, nelfinavir, phenobarbital, phenytoin, ritonavir, and rifampin. See glossary page for more information.

CYP2B6 Inhibitors

CYP2B6 inhibitors include, but are not limited to, canagliflozin, clopidogrel, clotrimazole, sertraline, oral contraceptives, and voriconazole. See glossary page for more information.

CYP2B6 Substrates

CYP2B6 substrates include, but are not limited to, bupropion, cyclophosphamide, efavirenz, ketamine, methadone, nicotine, selegiline, sertraline, temazepam, and tramadol. See glossary page for more information.

CYP2C19 Inducers

CYP2C19 inducers include, but are not limited to, carbamazepine, efavirenz, enzalutamide, phenobarbital, phenytoin, rifampin, and St. John’s wort. See glossary page for more information.

CYP2C19 Inhibitors

CYP2C19 inhibitors include, but are not limited to, cimetidine, esomeprazole, fluconazole, fluvoxamine, fluoxetine, ketoconazole, loratidine, modafinil, omeprazole, and voriconazole. See glossary page for more information.

CYP2C19 Substrates

CYP2C19 substrates include, but are not limited to, amitriptyline, citalopram, clobazam, clopidogrel, clomipramine, imipramine, most proton pump inhibitors (e.g., omeprazole, pantoprazole, rabeprazole), and voriconazole. See glossary page for more information.

CYP2C8 Inducers

CYP2C8 inducers include, but are not limited to, carbamazepine, phenobarbital, and rifampin. See glossary page for more information.

CYP2C8 Inhibitors

CYP2C8 inhibitors include, but are not limited to, amiodarone, clopidogrel, fluoxetine, gemfibrozil, isoniazid, montelukast, nortriptyline, <a href="/supplements/quercetin/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Quercetin&lt;/h6&gt;&lt;p&gt;Quercetin is the most well researched of all bioflavonoids. It is not actually that good of a supplement on its own, but is an interesting research topic. Tons of interactions, and synergistic with other bioflavonoids and increases absorption of Resveratrol and Green Tea Catechins.&lt;/p&gt;&lt;/div&gt;">quercetin</a>, trimethoprim, and verapamil. See glossary page for more information.

CYP2C8 Substrates

CYP2C8 substrates include, but are not limited to, enzalutamide, imatinib, montelukast, paclitaxel, pioglitazone, repaglinide, and rosiglitazone. See glossary page for more information.

CYP2C9 Inducers

CYP2C9 inducers include, but are not limited to, aprepitant, bosentan, carbamazepine, enzalutamide, nelfinavir, phenobarbital, phenytoin, rifampin, ritonavir, and St. John’s wort. See glossary page for more information.

CYP2C9 Inhibitors

CYP2C9 inhibitors include, but are not limited to, amiodarone, capecitabine, fluconazole, fluvastatin, metronidazole, miconazole, sulfamethoxazole, and voriconazole. See glossary page for more information.

CYP2C9 Substrates

CYP2C9 substrates include, but are not limited to, candesartan, fluvastatin, gliclazide, losartan, non-steroidal anti-inflammatory drugs (e.g., celecoxib, diclofenac, ibuprofen, naproxen), phenytoin, and warfarin. See glossary page for more information.

CYP2D6 Inhibitors

CYP2D6 inhibitors include, but are not limited to, bupropion, carvedilol, doxepin, fluoxetine, mirabegron, paroxetine, duloxetine, quinidine, sertraline, and terbinafine. See glossary page for more information.

CYP2D6 Substrates

CYP2D6 substrates include, but are not limited to, amitriptyline, amphetamine, atomoxetine, codeine, dextromethorphan, duloxetine, fluoxetine, metoprolol, tamoxifen, and tolterodine. See glossary page for more information.

CYP2E1 Inducers

CYP2E1 inducers include, but are not limited to, isoniazid and ethanol. See glossary page for more information.

CYP2E1 Inhibitors

CYP2E1 inhibitors include, but are not limited to, disulfiram and <a href="/supplements/quercetin/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Quercetin&lt;/h6&gt;&lt;p&gt;Quercetin is the most well researched of all bioflavonoids. It is not actually that good of a supplement on its own, but is an interesting research topic. Tons of interactions, and synergistic with other bioflavonoids and increases absorption of Resveratrol and Green Tea Catechins.&lt;/p&gt;&lt;/div&gt;">quercetin</a>. See glossary page for more information.

CYP2E1 Substrates

CYP2E1 substrates include, but are not limited to, acetaminophen, ethanol, and theophylline. See glossary page for more information.

CYP2J2 Inhibitors

CYP2J2 inducers include, but are not limited to, ketoconazole. See glossary page for more information.

CYP2J2 Substrates

CYP2J2 substrates include, but are not limited to, amiodarone and cyclosporine. See glossary page for more information.

CYP3A4/3A5 Inducers

CYP3A4 and CYP3A5 inducers include, but are not limited to, carbamazepine, dexamethasone, efavirenz, enzalutamide, oxcarbazepine, phenobarbital, phenytoin, prednisone, rifampin, and St. John’s wort. See glossary page for more information.

CYP3A4/3A5 Inhibitors

CYP3A4 and CYP3A5 inhibtors include, but are not limited to, aprepitant, clarithromycin, ciprofloxacin, grapefruit juice, ritonavir, verapamil, and several azole antifungals (e.g., fluconazole, itraconazole, ketoconazole, voriconazole). See glossary page for more information.

CYP3A4/3A5 Substrates

CYP3A4/3A5 substrates include, but are not limited to, tacrolimus, and some benzodiazepines (e.g., alprazolam, diazepam, midazolam), statin medications (e.g., atorvastatin, lovastatin, simvastatin), and calcium-channel blockers (e..g, felodipine, nifedipine, diltiazem, verapamil). See glossary page for more information.

Cytochrome P450

Cytochrome P450 (CYPs) are a diverse family of enzymes involved broadly in cellular metabolism and detoxification. CYPs are the most well-recognized drug-metabolizing enzymes in the body. Many internal and external factors can influence their level of activity, which can contribute to the risk of drug interactions.

Cytochrome P450 Induction

CYP induction is an increase in the activity level of a CYP enzyme due to the presence of an inducer — a compound (e.g., medication, supplement, or other substance) that can increase the number of available CYP enzymes. CYP induction can result in increased drug metabolism, leading to drug interactions that may impact treatment outcomes and side effect risk.

Cytochrome P450 Inhibition

CYP inhibition is a reduction in the activity level of a CYP enzyme due to the presence of an inhibitor — a compound (e.g., medication, supplement, or other substance) that impairs normal enzyme activity. CYP inhibition can result in reduced drug metabolism, leading to drug interactions that may impact treatment outcomes and side effect risk.

Dental cavities

Dental cavities, also known as dental caries or tooth decay, are areas of erosion on teeth, usually caused by acid-producing bacteria. Cavities vary in severity depending on how deep they progress into the tooth.

Dietary acid load

A food’s acid load represents its content in acidifying and alkalizing nutrients. Whether a food’s acid load can affect our blood pH (or our health in general) is a topic of controversy.

Dietary Inflammatory Index

The Dietary Inflammatory Index (DII) is a model that attempts to predict the inflammatory potential of a diet based on its components.

Dietary Reference Intake (DRI)

Dietary reference intake describes a set of reference values for nutrient intakes that can be used for planning and assessing diets in people without health conditions. These reference values include the <a href="/glossary/estimated-average-requirement/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Estimated Average Requirement (EAR)&lt;/h6&gt;&lt;p&gt;&lt;em&gt;Estimated average requirement&lt;/em&gt; is the level of daily intake for a specific nutrient that meets the nutritional requirements of 50% of all people without health conditions.&lt;/p&gt;&lt;/div&gt;">estimated average requirement</a>, <a href="/glossary/recommended-dietary-allowance/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Recommended Dietary Allowance (RDA)&lt;/h6&gt;&lt;p&gt;&lt;em&gt;Recommended dietary allowance&lt;/em&gt; refers to the level of daily intake for a specific nutrient that meets the nutritional requirements of nearly all people without health conditions. This value for specific nutrients can vary by age, sex, and pregnancy status.&lt;/p&gt;&lt;/div&gt;">recommended dietary allowance</a>, adequate intake, and the tolerable upper intake level.

Dose-response

The term dose-response describes the relationship between the dose of a substance or stimulus and its effect. A dose-response study explores the dose-response relationship between an intervention and an outcome in terms of the efficacy and/or safety of a substance or stimulus.

DXA/DEXA

Dual energy X-ray absorptiometry (DXA, sometimes called DEXA) scans are a type of full-body X-ray scan used to determine bone mineral density and body composition.

Dysautonomia

Dysautonomia is characterized by over-activation or under-activation of automatic body functions run by the autonomic nervous system. The condition can present with symptoms related to involuntary functions like breathing and blood pressure.

Dysbiosis

Dysbiosis refers to an imbalance of microbial species in a microbial community. It occurs when the microbiome is disrupted in a way that shifts the type and/or ratio of microbial species, with unfavorable consequences for the host.

Effect Size

Effect size generally describes how large of an effect an intervention has, on average. It’s also used synonymously with “standardized mean difference”, which is an effect size that is independent of a particular measurement scale.

Ergogenic

An ergogenic is any training technique, mechanical device, nutritional ingredient, dietary practice, or supplement that improves physical performance or enhances training adaptations.

Estimated Average Requirement (EAR)

Estimated average requirement is the level of daily intake for a specific nutrient that meets the nutritional requirements of 50% of all people without health conditions.

Etiology

Etiology is the cause of a disease state or condition.

Eucaloric Diet

A eucaloric diet is one in which a person's energy consumption matches their energy expenditure. Over time, a eucaloric diet is expected to produce no change in bodyweight.

F2-Isoprostane

F2-isoprostanes are a group of molecules formed from the oxidation of polyunsaturated fat by free radicals. Higher levels are an indicator of oxidative stress.

Fibrosis

Fibrosis is the process in which repair of a tissue leads to thickening and scarring of that tissue. If this injury is linked to a specific organ or organ system, it can lead to further complications. An example of this would be pulmonary fibrosis, which is the scarring and injury of the lung tissues.

Glycemic index

The glycemic index of a food is a measurement of the ability of the carbs in that food to raise blood glucose when eaten. The higher the number, the more the food raises blood glucose.

Half-life

The half-life of a substance is the time it takes for half of the substance to be reduced.

Heterogeneity

In a meta-analysis, heterogeneity generally describes the degree to which the included studies vary. This term’s often used synonymously with “between-study heterogeneity”, which refers to the variation in studies’ outcomes above and beyond sampling error. The most common way to quantify between-study heterogeneity is using I2, which ranges from 0% (no heterogeneity) to 100% (considerable heterogeneity).

Histology

Histology is the study of tissue structures that are unable to be seen with the naked eye. Histology explores details of tissues to better understand how systems can function at a microscopic level.

HOMA-IR

The Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) is a measure of insulin resistance. A low HOMA-IR means that the body is sensitive to insulin and is able to manage blood sugar. A high HOMA-IR indicates that the body is resistant to insulin and may not be able to manage blood sugar levels effectively.

HPA axis

The hypothalamus-pituitary-adrenal (HPA) axis is the stress management system of the body. There are 3 main components of the axis: the hypothalamus, the pituitary gland, and the adrenal cortex.

Hydroperoxide

Hydroperoxides are a biomarker for oxidative stress. They are formed when one of the two hydrogen atoms of hydrogen peroxide is replaced by an organic (carbon-containing) chemical group.

Hypercaloric Diet

A hypercaloric diet is one in which a person's energy consumption exceeds their energy expenditure. Over time, a hypercaloric diet is expected to produce an increase in bodyweight.

Hypocaloric Diet

A hypocaloric diet is one in which a person's energy consumption is less their energy expenditure. Over time, a hypocaloric diet is expected to produce a reduction in bodyweight.

In Vitro Study

In vitro (Latin for “within the glass”) refers to studies that are performed outside of a living organism. In scientific research, this often involves performing experiments on bacterial, animal, or human cells growing in lab culture dishes.

Intention to Treat (ITT) Analysis

Two common ways data is analyzed in randomized controlled trials include the intention-to-treat (ITT) and per protocol (PP) principles. ITT analysis uses data from every participant who was randomized, regardless of whether they dropped out early or did not stick to the study regimen. A catchphrase for ITT is “once randomized, always analyzed”. PP analysis excludes participants who dropped out early or did not stick to the study regimen, so only the data from the participants who fully adhered to the trial protocol are included.<a href="#ref-1" id="ref-link-1" class="ref-link popover" data-tooltip='&lt;div&gt;&lt;p class="mb-3"&gt;McCoy CE. &lt;a href="https://pubmed.ncbi.nlm.nih.gov/29085540" target="\_blank" rel="noopener noreferrer"&gt;Understanding the Intention-to-treat Principle in Randomized Controlled Trials.
&lt;/a&gt;&lt;/p&gt;West J Emerg Med (2017 Oct)&lt;/div&gt;'>[1]</a>
<input id="sidebar-666b6c351556a" type="checkbox" class="peer hidden">
<div class="sidebar ">
<label for="sidebar-666b6c351556a">
<svg xmlns="http://www.w3.org/2000/svg" viewbox="0 0 20 20" fill="currentColor">
<path fill-rule="evenodd" d="M14.77 12.79a.75.75 0 01-1.06-.02L10 8.832 6.29 12.77a.75.75 0 11-1.08-1.04l4.25-4.5a.75.75 0 011.08 0l4.25 4.5a.75.75 0 01-.02 1.06z" clip-rule="evenodd"></path>
</svg>
</label>
<h3>🔎 Example</h3>
20 people were randomized to take ingredient A or a matched placebo daily for 4 months, and blood pressure was measured every month. Three people from the ingredient A group and 2 people from the placebo group withdrew from the study at the two-month mark. At the end of the trial, ITT analysis will include all 20 participants, typically using the 2-month mark values for the 5 people who left the study. PP analysis will only include the 15 people who completed the full 4-month trial. 
</div>
<h2>Why is ITT better than PP?</h2>
ITT analysis has less <a href="/glossary/confounder/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Confounder&lt;/h6&gt;&lt;p&gt;A confounder is a factor — either observed or unobserved — which affects the relationship between two variables being studied. Not accounting for the potential effect of a confounder may lead to incorrect conclusions about the relationship between the variables.&lt;/p&gt;&lt;/div&gt;">confounding</a> than PP because randomization is preserved. Excluding participants from the analysis after randomization introduces bias because the groups are no longer balanced in terms of known and unknown characteristics. The analysis becomes confounded.<a href="#ref-1" id="ref-link-1" class="ref-link popover" data-tooltip='&lt;div&gt;&lt;p class="mb-3"&gt;McCoy CE. &lt;a href="https://pubmed.ncbi.nlm.nih.gov/29085540" target="\_blank" rel="noopener noreferrer"&gt;Understanding the Intention-to-treat Principle in Randomized Controlled Trials.
&lt;/a&gt;&lt;/p&gt;West J Emerg Med (2017 Oct)&lt;/div&gt;'>[1]</a>
ITT is considered more pragmatic. It better reflects what would occur in real life, as some participants quit the trial early, others might not regularly submit questionnaires or attend trial sessions, while some don’t even start the study regimen. PP analysis is used for trials that want to measure the effect of a treatment under ideal experimental conditions, where it is not affected by nonadherence.<a href="#ref-2" id="ref-link-2" class="ref-link popover" data-tooltip='&lt;div&gt;&lt;p class="mb-3"&gt;Sedgwick P. &lt;a href="https://pubmed.ncbi.nlm.nih.gov/25663096" target="\_blank" rel="noopener noreferrer"&gt;Intention to treat analysis versus per protocol analysis of trial data.
&lt;/a&gt;&lt;/p&gt;BMJ (2015 Feb 6)&lt;/div&gt;'>[2]</a>
The risk of bias is increased whenever treatment groups are not analyzed according to the group to which they were originally assigned. If an intervention is truly effective, an intention-to-treat analysis will provide an unbiased estimate of the efficacy of the intervention at the level of adherence in the study. See <a href="https://pubmed.ncbi.nlm.nih.gov/29085540">this paper</a> for a more detailed review of ITT versus PP analysis and to see how how using the wrong method of analysis can lead to a significantly biased assessment of the effectiveness of an intervention.
<h2>What is a drawback of ITT analysis?</h2>
The risk with ITT analysis is that an effective intervention might be interpreted as less effective than it is. If the intervention is effective when taken exactly as recommended, including participants who did not take the intervention or took it incorrectly underestimates the <a href="/glossary/effect-size/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Effect Size&lt;/h6&gt;&lt;p&gt;Effect size generally describes how large of an effect an intervention has, on average. It’s also used synonymously with “standardized mean difference”, which is an effect size that is independent of a particular measurement scale.&lt;/p&gt;&lt;/div&gt;">effect size</a>. So the ITT analysis would show that the intervention is no better than a placebo, when under perfect experimental conditions, it is indeed effective. Still, the ITT analysis does show an accurate result in the case of imperfect use of the intervention — which is usually more akin to a real-world clinical outcome.<a href="#ref-1" id="ref-link-1" class="ref-link popover" data-tooltip='&lt;div&gt;&lt;p class="mb-3"&gt;McCoy CE. &lt;a href="https://pubmed.ncbi.nlm.nih.gov/29085540" target="\_blank" rel="noopener noreferrer"&gt;Understanding the Intention-to-treat Principle in Randomized Controlled Trials.
&lt;/a&gt;&lt;/p&gt;West J Emerg Med (2017 Oct)&lt;/div&gt;'>[1]</a>

Interstitial

Interstitial refers to something that is in between other things or spaces. In medicine, it usually refers to the spaces between tissues and cells.

Lipid hydroperoxides

Lipid hydroperoxides (LOOHs) are a step in the chemical process of oxidative damage of cell membranes and other lipid (fat) containing cell structures. They're a damage product that can oxidize further and can also cause damage itself.

Lipid Peroxidation

A form of oxidation that influences lipids. In the body, it tends to reflect damage to cell membranes and is assessed by biomarkers thought to represent lipid peroxidation (MDA and TBARS).

Macronutrients

Macronutrients are dietary elements that are required in large quantities to generate energy and build biological structures. In humans, macronutrients refer specifically to carbohydrates, proteins, and fats.

Malondialdehyde (MDA)

MDA is a marker of lipid peroxidation and thus of oxidative stress.

Mendelian Randomization

Mendelian randomization is a research technique that uses genetic data in an attempt to determine whether an exposure affects an outcome. This technique allows investigators to look for potentially causal relationships using observational data.

Meta-analysis

A meta-analysis is usually produced as part of a systematic review. It combines the numerical results from several studies into an average number. Studies that differ too much in design cannot be properly meta-analyzed.

Metabolite

A metabolite is a small, chemical substance that the body makes during natural biochemical reactions.

Microbiome

A microbiome consists of the <a href="/glossary/microbiota/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Microbiota&lt;/h6&gt;&lt;p&gt;The microbiota is the community of living microorganisms in a specific environment or location (e.g., the skin). This is different from the glossary:microbiome, which is composed of both the microbiota and with the ecosystem in which they live.&lt;/p&gt;&lt;/div&gt;">microbiota</a> in a particular environment along with their “ecosystem”, which includes many things, such as <a href="/glossary/metabolite/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Metabolite&lt;/h6&gt;&lt;p&gt;A metabolite is a small, chemical substance that the body makes during natural biochemical reactions.&lt;/p&gt;&lt;/div&gt;">metabolite</a>s from the host and other microorganisms, viruses, and free-floating genetic material.<a href="#ref-3" id="ref-link-3" class="ref-link popover" data-tooltip='&lt;div&gt;&lt;p class="mb-3"&gt;Berg G, et al. &lt;a href="https://pubmed.ncbi.nlm.nih.gov/32605663" target="\_blank" rel="noopener noreferrer"&gt;Microbiome definition re-visited: old concepts and new challenges.
&lt;/a&gt;&lt;/p&gt;Microbiome (2020-Jun-30)&lt;/div&gt;'>[3]</a> Thus, the <a href="/glossary/microbiota/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Microbiota&lt;/h6&gt;&lt;p&gt;The microbiota is the community of living microorganisms in a specific environment or location (e.g., the skin). This is different from the glossary:microbiome, which is composed of both the microbiota and with the ecosystem in which they live.&lt;/p&gt;&lt;/div&gt;">microbiota</a> is part of a microbiome.

Microbiota

The microbiota is the community of living microorganisms in a specific environment or location (e.g., the skin). This is different from the <a href="/glossary/microbiome/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Microbiome&lt;/h6&gt;&lt;p&gt;A microbiome consists of the glossary:microbiota in a particular environment along with their “ecosystem”, which includes many things, such as glossary:metabolites from the host and other microorganisms, viruses, and free-floating genetic material. Thus, the glossary:microbiota is part of a microbiome.&lt;/p&gt;&lt;/div&gt;">microbiome</a>, which is composed of both the microbiota and with the ecosystem in which they live.<a href="#ref-3" id="ref-link-3" class="ref-link popover" data-tooltip='&lt;div&gt;&lt;p class="mb-3"&gt;Berg G, et al. &lt;a href="https://pubmed.ncbi.nlm.nih.gov/32605663" target="\_blank" rel="noopener noreferrer"&gt;Microbiome definition re-visited: old concepts and new challenges.
&lt;/a&gt;&lt;/p&gt;Microbiome (2020-Jun-30)&lt;/div&gt;'>[3]</a>

Micronutrient

Micronutrients are dietary elements that are required in small amounts to support a wide variety of biological processes and functions. In humans, micronutrients generally refer to vitamins and dietary minerals such as vitamin D, folic acid, iron, or magnesium.

mTor

The mammalian target of rapamycin, also known as the mechanistic target of rapamycin (mTOR), is a protein in our body involved in cellular growth, metabolism, and energy use. It helps to regulate how cells are able to grow and function by sensing available nutrients and growth signals.

Multiple comparisons

The more outcomes a study measures, the greater the chance that at least one outcome will show a change, “proving” that the intervention had an effect. When a study doesn't adjust for multiple comparisons, its statistically significant results are less trustworthy.

Mycobiome

The mycobiome refers to the fungi that live in and on the body. These fungi, including yeasts and mold, play a part in maintaining the immune system, much like the bacteria in the <a href="/outcomes/microbiome/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Microbiome&lt;/h6&gt;&lt;p&gt;The microbiome includes communities of bacteria in our body, most of which live in our gut and have functions including the development of immunity, defense against pathogens, energy metabolism, fat storage, and vitamin synthesis.&lt;/p&gt;&lt;/div&gt;">microbiome</a> and microbiota do.

Neonatal

Neonate is the medical term for a newborn child (birth to 1 month of age). Neonatal is a descriptor that refers to the newborn period.

Network meta-analysis

A network meta-analysis is a pooled analysis of effects from a network of studies designed to estimate comparative benefits of different interventions.

Nitrotyrosine

Nitrotyrosine is a molecule that is formed in response to cellular damage.

Normal distribution

A normal distribution is an important type of probability distribution that describes how data are distributed around an average value, called the mean. The normal distribution is often called a “bell curve” because its shape resembles a bell.

Observational study

An observational study is designed to find a relationship between natural exposures and outcomes. There are no intentional interventions by researchers in observational studies and a cause-and-effect relationship usually cannot be determined.

Osteoblast

Osteoblasts are cells in the body that build and repair bone tissues.

Osteoclast

Osteoclasts are the cells that break down and remove old or damaged bone tissue. They actually help the bone stay healthy by removing old parts to make space for new bone growth and formation. Too much osteoclast and too little osteoblast activity can lead to bone weakening and <a href="/conditions/osteoporosis/" class="popover" data-tooltip="&lt;div&gt;&lt;h6&gt;Osteoporosis&lt;/h6&gt;&lt;p&gt;Osteoporosis is a condition of having weak and brittle bones. The main goal for people with osteoporosis is to prevent bone fractures by strengthening the bones and by avoiding falls.&lt;/p&gt;&lt;/div&gt;">osteoporosis</a>, though.

Glossary

Glossary