Bio45 nutrition and research

not 100% reliable, slanted to promote position, facts that support a predetermined opinion

reliable, fair and thorough, seeking truth

statements that sounds to good to be true

• "one product does it all"
• "satisfaction guaranteed"
• "quick and easy fixes"

research begins with a question, then it systematically conducts studies to collect data that will test the hypothesis

a factor that changes

the simultaneous increase or decrease in two variables. if A increases then B increases

the simultaneous decrease of two variables, if A decreases then B decreases

correlation proves only that variables are associated but does not prove cause and effect

1-epidemiological studies

2-experimental studies

epidemiological studies such as cross-sectional, case-control and cohort studies

experimental studies such as laboratory animal/human studies and human intervention/clinical studies

compares variables, shows only correlation not cause and effect. no experiment is done, people are not asked to take anything or stop taking something. There is no control factors

1-cross sectional studies

2-case controlled studies (retrospective)

3-cohort studies (prospective)

researchers observe how much and what kinds of food a group of people eat and how healthy those people are, findings ID factors that might influence the incidence of a disease in various populations.

Example is mediterranean people drink more wine and more fat from olive oil and have a lower incidence of heart disease

researchers compare people who do and do not have a given condition such as a disease. It closely matches them in age, gender and other key variables. Research tends to be retrospective.

Example is people with goiter lack iodine in their diets

researchers analyse date collected from a selected group of people (a cohort) at intervals over a period of time. studies follows people- looking at the future.

example is data collected over several decades reveals that the risk of heart attacks increase as blood cholesterol increases

subjects do something (change a variable) and a variable is measured before and after they do something. everything is the same except what you changed.

studies explore the effects of a specific variable on a tissue, cell or molecule. Often conducted in test tubes or on animals. It can determine effects of a variable but cannot apply results on animals or human beings

1- laboratory based animal studies

2-laboratory based in vitro studies

3-human intervention or clinical trials

researchers feed animals special diets that provide or omit specific nutrients and observe any changes in health

example is a mice fed high-fat diets and another a low fat diet with same Kcals but mice with high fat diet is severely obese

researchers examine the effects of a specific variable on a tissue, cell or molecule isolated from a living organism.

example is fish oils inhibit the growth and activity of bacteria implicated in ulcer formation

people are asked to adopt a new behavior that can help determine the effectiveness of such interventions on the development or prevention of disease

example is heart disease factors improve when men receive fresh squeezed OJ compared with those on a diet low in vitamin C

the variable that has been changed

because it proves cause and effect. It shows the controlled variable is responsible for the effects of the experiment

the power of belief, a change that occurs in response to expectation about the effectiveness of a treatment that actually has no pharmaceutical effects

give pills to all participants

an inert harmless medication given to provide comfort and hope. A sham treatment.

investigator bias is an unfair, unreliable conclusion that benefits the investigor

by having a third party code the pills and not revealing to the experimenters who belongs to the experimental or controlled group

a personal account of an experience or event

because it has not scientific proof of its effects

an experiment where subjects do not know whether they are members of the experimental group or the controlled group

an experiment where neither the subjects nor the researchers know which subjects are the experimental or controlled group

the placebo effect

the placebo effect and experimenter bias

the most accurate test possible without restrictions. gold standard test refers to a diagnostic test that is the best available under reasonable conditions.

a process is which a panel of scientist rigorously evaluate a research study to assure that the scientific method was followed

an academic periodical publication

peer review is evaluated by other scientist and popular magazines are evaluated by editor who makes sure publication will yield economic gains