Nutrition Research Overview From Research Study to the Media Secondary & Primary Sources Explore How Research is Conveyed in the News Scientific Method 7 Steps 2 Main Types of Research Design Observational Experimental One Study Doesn’t Prove a Finding Nutrition 10

Sources of Scientific Information Secondary Sources & Media: Resource that informs us of scientific research Scientific news from websites, blogs, TV, magazines, friends… Primary Source: Original Research Best research is published in scientific (peer-reviewed) journals As scientific research gets interpreted by others, less detail is provided and more opinion and sensationalism is introduced Nutrition 10

Journalists who interpret scientific findings… Journalists who interpret scientific findings….some qualified and many not qualified Important to know if the information you receive is accurate.

News Headline: Lack of Vitamin D Makes Kids Fat Research at U of M (published in JCN) followed 479 youngsters over 30 months. “We found that the kids with the lowest Vitamin D levels…tended to gain weight faster than the kids with higher levels.” “Our findings suggest that low vitamin D status may put children at risk of obesity.” www.naturalnews.com

Scientific Method Process all scientists follow to gain scientific knowledge. There are 7 steps in the scientific method Nutrition 10

Scientific Steps: Question or observation Purpose of study or hypothesis (a testable statement) Design the study: Develop a plan to test the hypothesis Choose design type: observational or experimental Implement the research design Collect & analyze data Interpret results State results or accept/reject hypothesis Nutrition 10

Scientific Step 3. Design Determine if finding correlation or cause/effect Correlation (Association): When a change in one variable is RELATED to a change in another variable. Cause and Effect: When a change in one variable CAUSES a change in another variable 2 Main Types of Research Design Observational Prospective Experimental Clinical Trial Nutrition 10

Observational Study Scientists do NOT ask people to change their behaviors or undergo any treatment. Data collected by recording observations & data Minimal risk to participants Can suggest association, NOT cause & effect Nutrition 10

Prospective Study Prospective Study – type of observational study Follow a group of healthy people with different levels of exposure and observe effects on health or disease. Risk factor: a condition or behavior that increase the likelihood that a particular disease or condition will develop. Framingham Study Began in 1948 to determine relationship between diet, lifestyle and heart disease. Nutrition 10

Prospective study Nutrition 10

Experimental Study Researchers intervene Random assignment Participants divided into treatment or control (no treatment) group Can suggest cause & effect Random assignment Participants have equal chance to be in treatment or control group Factors that may affect the outcome are distributed equally among the two groups Single-blind: Participants in control group are given a placebo The participants do not know who receives treatment but researchers do know Opportunity for bias Nutrition 10

Experimental Study, cont. Double Blind Neither the researcher nor participants knows whether treatment or placebo is given A member of research team holds code for group assignments and does not participate in data collection If significant difference found between treatment & control group treatment caused the effect Nutrition 10

Headline: Lack of Vitamin D Makes Kids Fat Research at U of M (published in Journal of Clinical Nutrition) followed 479 youngsters over 30 months. “We found that the kids with the lowest Vitamin D levels…tended to gain weight faster than the kids with higher levels.” “Our findings suggest that low vitamin D status may put children at risk of obesity.”

Ice Cream & Drowning Studies have shown that in the U.S. drowning rates are highest in areas with high ice cream sales. The higher the ice cream sales…the more likely people are going to drown.

Headline: Ice Cream Makes you Drown Does ice cream make you drown…cause drowning? If you eat ice cream, are you more likely to drown? What is the connection between ice cream & drowning?

Water Ice cream sales tend to be high near water (pools and beaches) – people more likely to drown near water. The connection is between water & drowning…NOTHING to do with ice cream. Headline: ICE CREAM MAKES YOU DROWN is incorrect and misleading

Vitamin D & Weight Gain The research found there is an association (link) between kids with low Vitamin D & weight gain. The weight gain may or may not be due to low Vitamin D levels. More studies are needed. One credible (peer-reviewed) study isn’t fact.

Scientific Steps: Question or Observation Purpose or Hypothesis (testable statement) Design: Develop a plan to test the hypothesis 2 main types: observational & experimental Implement the research design Collect & analyze data Interpret results State results or accept/reject hypothesis Nutrition 10

Scientific Steps: 4. Implement, 5. Analyze, 6. Interpretation Implement: Data collected on each participant Analyze data to see if the difference between “Group A & Group B” is “statistically significant” Statistical Significance: The difference between groups did not happen by chance. Interpret: What new knowledge was gained by this research? Nutrition 10

Scientific Step 7. State results & accept/reject hypothesis If there is a “statistically significant” difference, then results show a correlation or cause & effect Findings reviewed by board of scientists. If conclusions are accurate, study results are published in a peer-reviewed scientific journal. One study doesn‘t prove a finding. Findings need to be repeated in several kinds of studies, by different researchers. News media may report new findings before confirmed by other research. Nutrition 10

Observational vs Experimental Type of study Ethical? Results Random Assign? Dbl Blind? Observational Experimental Nutrition 10