Understanding Scientific Research and Nutrition Studies

1. 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

2. 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

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

4. 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

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

6. 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

7. Scientific Step 3. Design • Determine if finding correlationor 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

8. 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

9. 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.

10. Prospective study

11. Experimental Study • Researchers intervene • 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

12. 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

13. 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.”

14. 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.

15. 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?

16. 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

17. 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.

18. 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

19. 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?

20. 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.

21. Observational vs Experimental