Roger Clemens, DrPH. Member, 2010 DGAC CSO, Horn President ( ), IFT Adjunct Professor, USC

Transcription

1 Roger Clemens, DrPH Member, 2010 DGAC CSO, Horn President ( ), IFT Adjunct Professor, USC 1

2 1. Is there a science base, and if so what's an overview of the science, to support the inclusion of a more robust DGA section on healthy fatty acids? 2. Considering the DGAC process, what tools and strategies can industry and other stakeholders use to influence this process? 3. What challenges and opportunities are there for communicating the benefits of healthy fats in future Dietary Guidelines? 2

3 Identify opportunities to increase consumer messaging on healthy fats. Identify current and future avenues to influence policymaking on this issue. Discuss how can industry most effectively impact avenues of communication. Discuss opportunities how the industry can provide positive consumer messages through the evidence-based policymaking process. 3

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5 Formulate Systematic Review Questions Exploratory searches Public comment Dialogue with experts Analytical framework PICO* Literature Search and Sort Identify study eligibility criteria Determine search strategy Search for relevant studies List included studies List excluded studies and rationale Extract Evidence from Studies Create evidence worksheets Summarize and Synthesize the Evidence Assess quality of individual studies Assess applicability Summarize and synthesize evidence Develop and Grade Conclusion Statements Define Research Recommendations * PICO: patient problem or population (P), intervention (I), comparison (C), and outcome(s) (O); see Sackett DL et al, Clin Orthop Relat Res. 2007;455:3-5, for background on evidence-based medicine 5

6 Strength of Evidence Grade I Grade II Grade III Grade IV Grade V Good/ Strong Fair Limited/Weak Expert Opinion Not Assignable Quality Scientific rigor/validity Considers design and execution Studies of strong design for question Free from design flaws, bias and execution problems Studies of strong design for question With minor methodological concerns, OR Only studies of weaker design for question Studies of weak design for answering question, OR Inconclusive findings due to design flaws, bias or execution problems No research studies available; Based on usual practice, expert consensus, clinical experience, opinion, or extrapolation from basic research No evidence that pertains to question being addressed Consistency of findings across studies Findings generally consistent in direction and size of effect or degree of association, and statistical significance with minor exceptions at most Inconsistency among results of studies with strong design, OR Consistency with minor exceptions across studies of weaker design Unexplained inconsistency among results from different studies OR single study unconfirmed by other studies Conclusion supported solely by statements of informed nutrition or medical commentators NA 6

7 Strength of Evidence Grade I Grade II Grade III Grade IV Grade V Good/ Strong Fair Limited/Weak Expert Opinion Not Assignable Quantity Number of studies Number of subjects in studies One to several good quality studies Large number of subjects studied Studies with negative results have sufficiently large sample size for adequate statistical power Several studies by independent investigators Doubts about adequacy of sample size to avoid Type I and Type II error Limited number of studies Low number of subjects studied and/or inadequate sample size within studies Unsubstantiated by published research studies Relevant studies have not been done Clinical Impact Importance of studied outcomes Magnitude of effect Generalizability To population of interest Studied outcome relates directly to the question Size of effect is clinically meaningful Significant (statistical) difference is large Studied population, intervention and outcomes are free from serious doubts about generalizability Some doubt about the statistical or clinical significance of the effect Minor doubts about generalizability Studied outcome is an intermediate outcome or surrogate for the true outcome of interest OR Size of effect is small or lacks statistical and/or clinical significance Serious doubts about generalizability due to narrow or different study population, intervention or outcomes studied Objective data unavailable Generalizability limited to scope of experience Indicates area for future research NA 7

8 Primary focus: Fatty acids and health outcomes Four questions: CVD, T2D, inflammation Two questions: tfa and stearic acid impact on cholesterol Three questions: n-3 fatty acids and health outcomes Two questions: foods (nuts, chocolate) and cardiovascular health 8

9 Review evidence and conclusion by 2005 DGAC Conduct evidence-based review using NEL and ADA Evidence Analysis Library (see New questions: published literature since 2000 Updated questions: published literature since June 2004 Additional resources: World Cancer Research report,

10 Modeling < 7%en SFA unintended nutritional consequences Modeling < 200 mg cholesterol unintended nutritional consequences Consumption of ruminant tfa at normal levels (<0.5%en) without health consequences Stearic acid (18:0) not associated with CVD Two servings (4 oz cooked; edible portion) seafood provide ~ 250 mg n-3 fatty acids with minimal risk of methylmercury exposure Two or more servings seafood (sources of n-3) important during pregnancy and lactation; low risk of methylmercury exposure 10

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12 Grams of Fats ** Analysis pending 0 NCFS * CSFII CSFII NHANES NHANES NHANES NHANES NHANES ** Total Fat (g) SFA (g) PUFA (g) MUFA (g) * Unpublished data from Food Surveys Research Group NCFS = Nationwide Food Consumption Survey; CSFII = Continuing Surveys of Food Intakes by Individuals; NHANES = National Health Nutrition Examination Surveys 12

13 5.8% 5.3% Percent Intake 9.0% 12.9% 53.1% Other fish and fish mixed dishes Eggs and egg mixed dishes 13.8% Chicken and chicken mixed dishes Tuna and tuna mixed dishes Shrimp and shrimp mixed dishes Other Sources of EPA and DHA Among the U.S. Population Risk Factor Monitoring and Methods Branch Website. Applied Research Program. National Cancer Institute. 13

14 Absolute CHD mortality rates vary more than 100-fold across different populations Relative effects of fish or fish oil are consistent Modest consumption ( mg EPA + DHA) is associated with lower risk of CHD death Increased consumption not associated with reduced risk of CHD Mozzafarian and Rimm. JAMA 2006;296:

15 Adapted presented by JR Hibbeln, September 22, 2009 Crustaceans White Fish Canned Tuna Molluscs Imitation Crab Trout and Halibut Oily Fish Grams selected food/d Most Canadian middle-aged women consume < 3 servings (4 oz/serv) of marine products per week Poor correlation between different marine species intake of EPA + DHA and RBC concentrations Lucas et al., Pub Hlth Nutr 2009;12:

16 Source: Institute of Medicine (IOM). Seafood Choices, National Academies Press, Washington, DC. Estimated EPA/DHA Content and Methyl mercury Content of 3 oz. Portions of Seafood 16

17 Source: Institute of Medicine (IOM). Seafood Choices, National Academies Press, Washington, DC. (adapted to 4 oz) Estimated EPA/DHA Content and Methyl mercury Content of 4 oz. Portions of Seafood 17

18 Moderate evidence indicates that increased maternal dietary intake of long chain n-3 PUFA, in particular DHA, from at least two servings of seafood per week during pregnancy and lactation is associated with increased DHA levels in breast milk and improved infant health outcomes, such as visual acuity and cognitive development. 18

19 Presented by JR Hibbeln, September 22, 2009 Percentage of children with low verbal IQ, WISC - III UK, 8y r 2 = 0.95; p< Estimated omega-3 fatty acids from seafood (%en) Mother at 32 wk gestation Hibbeln et al, Lancet 2007;369:

20 Presented by JR Hibbeln, September 22, 2009 U.S. Department of Health and Human Services and U.S. Environmental Protection Agency What You Need to Know About Mercury in Fish and Shellfish Advice Limit consumption to no more than 340 gm/wk of commercial species. ~ Avoid 4 species completely. (tilefish, swordfish, shark, king mackerel) Fish and shellfish are an important part of a healthy diet. So, women and young children should include fish or shellfish in their diets due to the many nutritional benefits. However, nearly all fish and shellfish contain traces of mercury. The risks from mercury in fish and shellfish depend on the amount of fish and shellfish eaten and the levels of mercury in the fish and shellfish. March 2004 EPA-823-R

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22 Systematic Review Questions 1. What is the relationship between consuming almonds and cholesterol levels in subjects with hyperlipidemia? (5 studies) 2. What is the relationship between consuming almonds and cholesterol levels in subjects with normal cholesterol levels? (4 studies) 3. What is the relationship between consuming almonds and the risk of coronary heart disease? (no evidence relative to this relationship) 22

23 Relative Risk Evidence: Literature since 2000 to April studies (4 strong prospective cohort studies [US, Europe], 10 RCTs [US], 3 strong reviews [international RCTs]) Conclusion: Moderate evidence suggests that modest consumption of unsalted peanuts and tree nuts, specifically walnuts, almonds, and pistachios, in the context of a nutritionally adequate diet and when total calorie intake is held constant, has a favorable impact on CVD risk factors, particularly serum lipid levels Frequency of Nut Consumption and CHD Risk Reduction* <1/month 1-4/month Adventist Health Study Nurses' Health Study 1-4/week >5/week Iows Women's Health Study Physician's Health Study * Sabaté J, Ang Y. Am J Clin Nutr 2009;89:1643S-48S 23

24 Consumption of almonds (100 g) by hypercholesterolemic subjects for 4 wks improved serum lipid profiles. Spiller et al., J Am Coll Nutr 1998;17(3): J Am Coll Nutr 2003;22(3): Similar results among hypercholesterolemic 64 yo * p<0.01 between groups subjects fed ~ 73 g almonds/d for 4 wks Jenkins et al., Circulation 2002;106: And 43 yo subjects whose isocaloric diets were 10%en or 20% en from almonds for 4 wks Sabaté J et al., Am J Clin Nutr 2003;77: Jambazian PR et al., J Am Diet Assoc 2005;105:

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26 Develop and expand safe, effective, and sustainable agriculture and aquaculture practices to ensure availability of recommended amounts of healthy foods to all segments of the population. (Policy document) Aquaculture: Globally, nearly 50% of the fish consumed relies on aquaculture farms Domestically, about 20% of aquaculture production is marine species; the remainder is freshwater species Some statistics suggest that harvesting of wild fish is not sustainable (need 155,000 tons edible portions of [low Hg] fish per year 345,000 tons of fresh fish, e.g., primarily salmon) Exceeds annual global salmon supply by ~50% Increase environmentally sustainable production of vegetables, fruits, and fiber-rich whole grains. (DGAC) 26

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28 Risk/benefits MUFA vs PUFA Mechanism(s) MUFA on serum lipids, glucose metabolism, insulin levels Mechanism(s) PUFA improve serum lipids, glucose metabolism, insulin levels Initiate RCTs and prospective observational studies assess risk of CVD relative to n-3 from marine and plant sources Investigate opposing interactions between EPA and DHA vs high methg, especially among high-risk populations Initiate RCTs different types of nuts and impact on biomarkers 28

29 1. Is there a science base, and if so what's an overview of the science, to support the inclusion of a more robust DGA section on healthy fatty acids? Urgent need for non-industry funding; Critical to communicate academic and NIH bias; 2. Considering the DGAC process, what tools and strategies can industry and other stakeholders use to influence this process? Identify and develop trusted spokesperson; identify and advocate well-established scientist for What challenges and opportunities are there for communicating the benefits of healthy fats in future Dietary Guidelines? Food and nutrition at health critical (possibly no-win) intersection; identify battle and establish staged strategy through continuous exposure; Need practical messaging 29

30 Simple messages; social media Policy without politics; advocate for lipids representative Aggressive, active involvement in scientificmedical-consumer community Identify and develop trusted third-party spokesperson/spokesorganization 30