Questions and Answers
What is the primary challenge for consumers of nutrition information?
What is the basis of nutrition facts and dietary practices in the past?
What do registered dietitian nutritionists (RDNs) do when the results of current scientific research no longer support conventional beliefs?
Why is it important to understand the scientific method in nutrition?
Signup and view all the answers
What is a major drawback of relying on anecdotes and testimonials for nutrition information?
Signup and view all the answers
Why is it important to have controls when performing experiments?
Signup and view all the answers
What is the goal of learning about the scientific method in nutrition?
Signup and view all the answers
What is the main difference between evidence-based information and misinformation?
Signup and view all the answers
What is the main goal of scientists when conducting research?
Signup and view all the answers
What type of experiment is conducted on cells or other components derived from living organisms?
Signup and view all the answers
Why do scientists divide subjects into two groups in an experiment?
Signup and view all the answers
What is the purpose of a control group in an experiment?
Signup and view all the answers
What is a variable in the context of an experiment?
Signup and view all the answers
Why do scientists need to control for variables in an experiment?
Signup and view all the answers
What do scientists examine regularly in an experiment?
Signup and view all the answers
Why do medical researchers need to be cautious when applying the results of in vivo animal studies to people?
Signup and view all the answers
What is the purpose of a literature review in the scientific method?
Signup and view all the answers
What do scientists use to test a hypothesis?
Signup and view all the answers
What is the purpose of randomly dividing participants into treatment and control groups in an RCT?
Signup and view all the answers
Why is a large group of human subjects needed in an RCT?
Signup and view all the answers
What is the purpose of a placebo in an RCT?
Signup and view all the answers
What was the main obstacle in Dr. Goldberger's research on pellagra?
Signup and view all the answers
What did Dr. Goldberger observe about pellagra that led him to question its cause?
Signup and view all the answers
What is the main advantage of using human subjects in nutrition research?
Signup and view all the answers
What is the purpose of instructing subjects to maintain their usual lifestyle during the study?
Signup and view all the answers
What is a common challenge in conducting RCTs with human subjects?
Signup and view all the answers
Why do scientists use inert ingredients in placebos?
Signup and view all the answers
What is the benefit of having a large number of subjects who fully participate in the study?
Signup and view all the answers
What was the dietary pattern observed by Dr. Goldberger in poor people in the southern United States?
Signup and view all the answers
What did Dr. Goldberger propose as the cause of pellagra?
Signup and view all the answers
What is the term for when a patient believes a medical treatment will be harmful and reports unwanted effects, even though the treatment was harmless?
Signup and view all the answers
What is the main purpose of epidemiological studies?
Signup and view all the answers
What was the outcome of Dr. Goldberger's experiment on healthy Mississippi prison inmates?
Signup and view all the answers
What can occur in the brain of subjects in a control group who believe they are receiving a real treatment?
Signup and view all the answers
What was the purpose of Dr. Goldberger's 'filth party' experiment?
Signup and view all the answers
Who isolated a form of the vitamin niacin from liver extracts?
Signup and view all the answers
What is the term for the number of people in a particular population who have a disease?
Signup and view all the answers
What do epidemiologists often use to determine factors that affect a population's health?
Signup and view all the answers
What is the purpose of maintaining secrecy in double-blind studies?
Signup and view all the answers
Why might participants in a single-blind study report no changes in their condition?
Signup and view all the answers
Why may people report positive or negative reactions to a real or sham treatment?
Signup and view all the answers
What is the study of the occurrence, distribution, and causes of health problems in populations?
Signup and view all the answers
What is the significance of Dr. Goldberger's experiment on himself and volunteers?
Signup and view all the answers
Why is it important for medical researchers to understand the placebo effect?
Signup and view all the answers
What did Dr. Goldberger and his colleague do in the 'filth party' experiment?
Signup and view all the answers
What type of study involves matching individuals with a health condition to persons with similar characteristics who do not have the condition?
Signup and view all the answers
What was the outcome of Dr. Elvehjem's discovery?
Signup and view all the answers
What might epidemiologists use to help study participants recall portion sizes of the foods and beverages they consumed?
Signup and view all the answers
What is the purpose of NHANES surveys?
Signup and view all the answers
What can produce beneficial physiological and psychological changes, particularly in conditions that involve pain?
Signup and view all the answers
What is the focus of nutritional epidemiologists?
Signup and view all the answers
What type of study involves collecting information about a group's past exposures and identifying current health outcomes?
Signup and view all the answers
Why do nutritional epidemiologists use multiple factors to study the development of chronic diseases?
Signup and view all the answers
What is the purpose of collecting data on personal and family medical histories in NHANES surveys?
Signup and view all the answers
What is the main advantage of cohort studies?
Signup and view all the answers
What is the limitation of retrospective dietary studies?
Signup and view all the answers
What do nutritional epidemiologists study in relation to health outcomes?
Signup and view all the answers
What is the purpose of identifying national standards for measurements associated with health status?
Signup and view all the answers
Why may the findings of retrospective cohort studies be limited?
Signup and view all the answers
What is the primary goal of a prospective cohort study?
Signup and view all the answers
What is an example of an inverse correlation?
Signup and view all the answers
Why may epidemiological studies not establish causation?
Signup and view all the answers
What is the limitation of drawing conclusions from correlations?
Signup and view all the answers
What is the purpose of the Framingham Heart Study?
Signup and view all the answers
What type of study design is the Framingham Heart Study an example of?
Signup and view all the answers
What is the term for a relationship between two variables that change in the same direction?
Signup and view all the answers
Why may correlations between variables not necessarily imply causation?
Signup and view all the answers
What is a limitation of relying on correlations in epidemiological studies?
Signup and view all the answers
What is the main purpose of peer review in scientific journals?
Signup and view all the answers
Why might the beef industry be interested in funding research on the benefits of high-protein diets?
Signup and view all the answers
What is the main limitation of the example about lemonade consumption and skiing accidents?
Signup and view all the answers
What led to the dismissal of John Yudkin's sugar hypothesis by the 1980s?
Signup and view all the answers
Why is it essential for scientists to avoid relying on personal attitudes and biases when conducting research?
Signup and view all the answers
What is a potential outcome of research bias in studies funded by private industries?
Signup and view all the answers
What is the main advantage of summarizing research findings in scientific articles?
Signup and view all the answers
Why did the sugar industry use its influence to divert attention away from sugar's role in heart disease?
Signup and view all the answers
What is the primary goal of analyzing data in nutrition research?
Signup and view all the answers
What is the significance of the shift from infectious diseases to chronic diseases in the mid-20th century?
Signup and view all the answers
What is the primary reason why pigs were not practical to raise as a food source among nomadic populations in the Middle East?
Signup and view all the answers
What health concern may have contributed to the development of the dietary pork taboo in Islam and Judaism?
Signup and view all the answers
Why were hogs not easy to control and herd from place to place?
Signup and view all the answers
What may have contributed to the development of religious laws that prohibited the consumption of pork?
Signup and view all the answers
What may have competed with people for food and water in the Middle East?
Signup and view all the answers
What was the purpose of the 1967 two-part paper published in The New England Journal of Medicine?
Signup and view all the answers
What is a potential conflict of interest for scientists whose research is funded by the food industry?
Signup and view all the answers
What is a key difference between peer-reviewed scientific journals and popular magazines?
Signup and view all the answers
Why is it important for authors of nutrition articles to disclose their sources of funding?
Signup and view all the answers
What is a common way that the media reports on the results of nutrition studies?
Signup and view all the answers
Why is it important to distinguish between peer-reviewed scientific journals and popular magazines?
Signup and view all the answers
What is the purpose of a literature review in the context of nutrition research?
Signup and view all the answers
Why is it important to be cautious when interpreting the results of nutrition studies?
Signup and view all the answers
What is a potential limitation of relying on popular sources of nutrition information?
Signup and view all the answers
Why is it important to evaluate the credibility of nutrition information?
Signup and view all the answers
What is a common reason for conflicting results generated by nutrition studies?
Signup and view all the answers
Why do nutrition scientists accept change when new evidence emerges?
Signup and view all the answers
What is a food taboo?
Signup and view all the answers
Why do consumers often become confused and disappointed when they hear about conflicting results from nutrition studies?
Signup and view all the answers
What is a key characteristic of the scientific method in nutrition?
Signup and view all the answers
Why do researchers need to control for variables in nutrition studies?
Signup and view all the answers
What can influence the results of nutrition research involving human subjects?
Signup and view all the answers
Why do consumers need to be cautious when interpreting sensational media coverage of a medical 'breakthrough'?
Signup and view all the answers
What is a potential limitation of nutrition research involving human subjects?
Signup and view all the answers
Why do scientists need to consider the results of multiple studies before making nutritional recommendations?
Signup and view all the answers
Study Notes
Nutrition: Science for Consumers
- The scientific method involves making observations, generating questions, developing a hypothesis, and testing the hypothesis through experiments and data analysis.
- Nutrition scientists use the scientific method to determine the effects of dietary practices on health.
The Scientific Method
- The scientific method involves the following steps:
- Make observations
- Generate questions
- Develop a hypothesis
- Review literature
- Design an experiment
- Conduct the experiment
- Analyze data
- Draw conclusions
- Laboratory experiments, including in vitro and in vivo experiments, are used to test hypotheses.
- In vivo experiments use whole living organisms, such as mice, to test the effects of a variable, such as a chemical, on the body.
- In vitro experiments use cells or components derived from living organisms to test the effects of a variable in a controlled environment.
Animal Experimentation
- Animal experiments are used to test hypotheses and provide evidence-based information about nutrition.
- Experiments involve dividing animals into treatment and control groups to compare the effects of a variable.
- Control groups are necessary to compare the results of the treatment group to a baseline.
- Variables must be controlled to ensure accurate results.
Human Research: Experimental (Intervention) Studies
- Experimental studies involving human subjects are used to test the effects of dietary interventions on health.
- Researchers use randomized controlled trials (RCTs) to randomly assign participants to treatment or control groups.
- Placebos are used in control groups to mimic the treatment being tested.
- Double-blind studies are used to prevent bias, where neither the researchers nor participants know who is in the treatment or control group.
Human Research: Epidemiological Studies
- Epidemiological studies are used to understand the occurrence, distribution, and causes of health problems in populations.
- Epidemiologists use data collected from physical examinations, laboratory tests, and surveys to determine factors that affect health.
- Types of epidemiological studies include:
- Case-control studies: compare individuals with a health condition to those without the condition.
- Cohort studies: follow a group of people over time to observe the development of health conditions.
Placebo and Nocebo Effects
- The placebo effect is a positive response to a treatment or intervention due to expectations.
- The nocebo effect is a negative response to a treatment or intervention due to expectations.
- Placebos can produce real physiological and psychological changes, especially in conditions involving pain.
Importance of Evidence-Based Information
- Nutrition information derived from anecdotes and testimonials is not evidence-based.
- It is important to critically evaluate nutrition information and consider the source and quality of the evidence.
- Scientific research provides a reliable basis for understanding the relationships between nutrition and health.### Epidemiological Studies
- Case-control studies: compare people with a health condition (cases) to those without the condition (controls) to identify long-term dietary practices that may be associated with the development of the health problem
- Cohort studies: collect and analyze information about a large group of people over time to identify associations between exposure to a specific factor and the subsequent development of health conditions
- Retrospective cohort studies: collect information about a group's past exposures and identify current health outcomes
- Prospective cohort studies: follow a group of healthy people over time to record any diseases that develop and analyze the data to identify links between exposures and diseases
Limitations of Epidemiological Studies
- Cannot establish causation, only identify correlations between variables
- Correlations can be direct (positive) or inverse (negative)
- Correlations do not necessarily indicate a cause-and-effect relationship between variables
- Results can be influenced by research bias, funding sources, and personal attitudes
Analyzing Data and Drawing Conclusions
- Nutrition researchers use statistical methods to analyze data and identify relationships between variables and health outcomes
- Results are summarized and published in scientific journals, which undergo peer review before acceptance
- Peer review involves critical analysis by experts in related research fields to ensure the study was well-conducted and the results are fairly represented
Research Bias
- Scientists are expected to avoid personal biases and report results objectively and honestly
- Funding sources can influence research outcomes and expectations
- Disclosure of funding sources and potential conflicts of interest are important for maintaining research integrity
Spreading the News
- Peer-reviewed journals publish reliable, scientifically-scrutinized information
- Popular sources of nutrition information, such as magazines and the internet, may feature faulty or biased information
- It's important to distinguish between peer-reviewed journals and popular sources of nutrition information
Confusion and Conflict
- Conflicting results from different studies can cause confusion and mistrust of the scientific community
- Differences in study design, subject populations, and statistical analysis can contribute to conflicting results
- The science of nutrition is constantly evolving, and old beliefs and practices are discarded when not supported by new evidence
Food Taboos
- Food taboos are practices that prohibit the consumption of certain foods or beverages, often based on cultural or religious beliefs
- Food taboos can have no scientific basis, but are often cultural traditions passed down through generations
- Religions often incorporate food prohibitions into their laws of personal conduct, such as the prohibition of pork in Islam and Judaism
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the scientific method, experiment design, and evidence-based nutrition information. Learn about controls, variables, and relationships in nutrition research.