Clinical Studies

Animal research - research conducted on any species of animals, for example, rats, mice, sheep, pigs, dogs, etc. Animal research is often the first line of experimental evidence for a dietary supplement, and may or may not have relevance for humans. Data from animal studies helps researchers develop protocols for human trials.

Human Research - research conducted on humans. In many cases, subjects consist of healthy males, however, research can be conducted on a variety of clinical populations (e.g., postmenopausal women with osteoporosis), races, etc. Usually, the results from a study should only be extrapolated to people with characteristics similar to the original research subjects.

Randomized, placebo-controlled study - Randomization means that study participants are assigned to groups in such a way that each participant has an equal chance of being assigned to each treatment (or control) group. Since randomization ensures that no specific criteria are used to assign any patients to a particular group, all the groups will be equally comparable. A placebo is an inactive substance designed to resemble the drug (or supplement) being tested. It is used as a control to rule out any psychological effects testing may present. Most well-designed studies utilize randomization and a placebo group concurrently and are thus referred to a randomized, placebo-controlled, double-blind designs. This design is considered by many experts to be the 'gold standard' in medical and supplement research.

Randomized, placebo-controlled, double-blind study - same as above.

Journal article - a research manuscript that was submitted to a professional research journal, underwent peer-review, and was accepted for publication. Oftentimes indexed in PubMed and available in abstract form for free to consumers. Journal articles may discuss research conducted on animals, humans, or even in-vitro. Hence the relevance of a journal article is a function of the type of research it reports.

Unpublished research - research that has not yet been submitted and accepted for publication in a professional research journal. Unpublished research can remain unpublished for two main reasons: 1) the research was never submitted to a journal; and 2) the research was submitted but rejected for publication. Unpublished research that has been submitted and accepted for publication is referred to as 'in press' until it appears in print. Until such time as unpublished research is peer-reviewed, there is no way to validate the credibility of the research.

In-vitro research - non-clinical testing conducted in an artificial environment such as a test tube or culture medium. Because of the tight experimental control in this type of research, in-vitro data are often used to uncover the mechanism(s) of an observed effect (i.e., if subjects lost weight, why it happened from a cellular standpoint). In-vitro research may or may not have relevance for humans. Until such time as human research is conducted, this cannot be established.

Presented at a conference and published as an abstract - in the initial stages of research, many trials are written up in abstract form and presented at a professional conference. Oftentimes the professional organization sponsoring the conference publishes the abstracts in its professional research journal. Although most abstracts have undergone some peer-review prior to presentation and publication, the level of scrutiny is less than that of a full research manuscript.

Clinical study - Study of drug, biologic or device in human subjects with the intent to discover potential beneficial effects and/or determine its safety and efficacy. Also called clinical research and clinical investigation. Note that this term is used in its narrow sense as used by the FDA. Thus, it does not encompass all the research that is carried out in the clinical setting (e.g., health services research). Usually, research trials conducted by medical doctors or at medical facilities are referred to as 'clinical studies'. The design of a clinical study may be 'double-blind,' 'randomized, placebo-controlled, double-blind' or some other design.

Double-blind study - The design of a study in which neither the investigator or the subject knows which medication/supplement (or placebo) the subject is receiving. A double-blind design allows researchers to rule out possible psychological effects that might occur from a subject ingesting a supplement.

Controlled clinical trial - same as clinical study.

Published monograph - a scholarly piece of writing on a specific subject. Can be published in peer-reviewed format. Usually a good (reliable) source of information for consumers.

Patented - A patent means that a product or ingredient has legal protection for a particular use or process. It does not necessarily mean that the product or ingredient has undergone extensive human research to support its intended use. There may have been some research, but it may not have been published. If it has undergone extensive human research that has been published in a peer-reviewed journal, then the research will typically be cited from that journal, rather than from the patent.

Review paper - a peer-reviewed scientific paper, usually prepared by an expert in the field, that summarizes various aspects of research and forms conclusions about safety, efficacy, and directions for future research. Oftentimes indexed in PubMed and available in abstract form for free to consumers.

Reference for several of the above terms: www.centerwatch.com/patient/glossary.html