Overview of Current Issues in Overview of Current Issues in
NutritionNutrition
What are the questions?What are the questions?
What are the challenges?What are the challenges?
How might risk assessment help?How might risk assessment help?
Shiriki Kumanyika, PhD, RD, MPHShiriki Kumanyika, PhD, RD, MPHCenter for Clinical Epidemiology and BiostatisticsCenter for Clinical Epidemiology and Biostatistics
Graduate Program in Public Health StudiesGraduate Program in Public Health Studies
University of Pennsylvania School of MedicineUniversity of Pennsylvania School of Medicine
OutlineOutline
•• Framing the questionsFraming the questions
–– Types of riskTypes of risk
–– Food and nutrition variablesFood and nutrition variables
–– Population considerationsPopulation considerations
–– OutcomesOutcomes
•• Quantification of riskQuantification of risk
•• ChallengesChallenges
Who poses questions about Who poses questions about
nutritional risk (U.S. context)nutritional risk (U.S. context)
•• IOM Food and Nutrition Board and related committeesIOM Food and Nutrition Board and related committees
•• Dietary Guidelines Committees that are convened by the Dietary Guidelines Committees that are convened by the
DHHS and USDADHHS and USDA
•• DiseaseDisease--focused organizations such as the American Heart focused organizations such as the American Heart
Association, American Diabetes Association, and American Association, American Diabetes Association, and American
Cancer Society Cancer Society
•• “Life stage interest groups”, e.g., AAP or the March of Dimes.“Life stage interest groups”, e.g., AAP or the March of Dimes.
•• Food safety agenciesFood safety agencies
•• Food regulatory agenciesFood regulatory agencies
•• The food industry The food industry
•• ConsumersConsumers
Risk ConsiderationsRisk Considerations
•• AdequacyAdequacy--ToxicityToxicity
•• Food borne illness, including allergiesFood borne illness, including allergies
•• Disease prevention and management Disease prevention and management
(mid(mid--range of continuum; harm or lack range of continuum; harm or lack
of benefit)of benefit)
Population ConsiderationsPopulation Considerations
•• Life stage (growth; development; aging)Life stage (growth; development; aging)
•• Reproductive stateReproductive state
•• GeneticsGenetics
•• Environmental stressorsEnvironmental stressors
•• Behaviors (smoking)Behaviors (smoking)
•• Health statusHealth status
••Food and Nutrition BoardFood and Nutrition Board
••Dietary Guidelines Advisory CommitteeDietary Guidelines Advisory Committee
••Disease Interest GroupsDisease Interest Groups
••Life Stage Interest GroupsLife Stage Interest Groups
What should What should
people eat to be or people eat to be or
stay healthy?stay healthy?
Is this changing?Is this changing?
How does this vary How does this vary
among population among population
groups and by life groups and by life
stagesstages
What and how are What and how are
people eating? people eating?
Where are the Where are the
potential harms in potential harms in
these patterns?these patterns?
How should we How should we
react to new foods react to new foods
as they emerge?as they emerge?
What is available for people What is available for people
to eat? Is it sufficient? Safe?to eat? Is it sufficient? Safe?
What new products can be What new products can be
developed? developed?
How can products be How can products be
improved?improved?
What ingredients can be What ingredients can be
added?added?
What should be removed?What should be removed?
••U.S.D.A.U.S.D.A.
••Food IndustryFood Industry
••Food scientistsFood scientists
••NCHSNCHS
••FDAFDA
••NIHNIH
••Health ResearchersHealth Researchers
Food and Nutrition VariablesFood and Nutrition Variables
•• Macronutrients, fiber, and energy balanceMacronutrients, fiber, and energy balance
•• Vitamins in foodVitamins in food——naturally occurringnaturally occurring
•• Vitamin added to foods or taken as supplementsVitamin added to foods or taken as supplements
•• MineralsMinerals
•• Minerals added to foods or taken as supplementsMinerals added to foods or taken as supplements
•• Other naturally Other naturally ––occurring food constituentsoccurring food constituents
•• Contaminants, toxins, mutagensContaminants, toxins, mutagens
•• Other dietary supplements, e.g. botanicalsOther dietary supplements, e.g. botanicals
•• Foods and beverages, food preparation, food Foods and beverages, food preparation, food
processing, food groups, and whole dietary patternsprocessing, food groups, and whole dietary patterns
•• AlcoholAlcohol
Types of Variables: Constituents in Types of Variables: Constituents in
Fruits and VegetablesFruits and Vegetables
•• Sulfides (Sulfides (alliumallium))
•• CarotenoidsCarotenoids
•• FlavonoidsFlavonoids
•• Glucosinolates/IndolesGlucosinolates/Indoles
•• PhytoestrogensPhytoestrogens
•• IsothiocyanatesIsothiocyanates
•• PhytosterolsPhytosterols
•• Protease InhibitorsProtease Inhibitors
•• SaponinsSaponins
•• PhenolsPhenols
•• CapsaicinCapsaicin
•• ResveritrolResveritrol
•• AnthocyaninsAnthocyanins
•• TanninsTannins
•• TerpenesTerpenes
•• Dietary fiberDietary fiber
•• Vitamins/mineralsVitamins/minerals
–– C, E, Folic acid, K, C, E, Folic acid, K,
SeSe
Van Van DuynDuyn MS and MS and PivonkaPivonka E. J Am Diet Assoc 2000;100:1511E. J Am Diet Assoc 2000;100:1511--15211521
LOGIC FRAMEWORK
ILLUSTRATING
CONCEPTUAL
APPROACH TO
NUTRITION &
COMMUNITY HEALTH:
Intake Variables and Intermediate Outcomes
POPULATION FOOD INTAKE
Food Consumption Patterns
(e.g. fruits, vegetables)
Intake of Nutrients and Food
Components
Vitamins
Minerals
Fiber
Fats
Other food constituents
Dietary supplements
AlcoholEnergy balance
Life Stage
Requirements
Pregnancy
Lactation
Childhood
Adolescence
Adulthood
Older Adulthood
PhysiologicIndicators
GrowthAdipose tissue
Musculoskeletal
Gastrointestinal
Metabolic
Cardiovascular
Reproductive
Immunological
Neurological
Genetics,
Co-morbidities
Physical
ActivityPatterns
Diseases of InterestDiseases of Interest
•• Cardiovascular DiseasesCardiovascular Diseases
•• CancersCancers
•• Type 2 DiabetesType 2 Diabetes
•• ObesityObesity
•• Dental CariesDental Caries
•• OsteoporosisOsteoporosis
Example Of Diet-disease Pathways Explored For Cardiovascular Diseases
High cal dietHigh fat dietDietary fatty acidsSedentary lifestyle
Hypertension
Left ventricular hypertrophy
Heart rate
EKG abnormalities
Subclinical disease(atherosclerosis))
Impaired glucose tol
Type 2 diab. mellitus
Hyperuricemia
Elevated serum chol
Elevated LDL-C
Decreased HDL-C
Elevated TG
Plasma homocysteine
Other risk factors
CHD
Hypertensive heart disease
Other CVD
Na K
Alcohol, Cigarettes
Dietary/lifestyleReversible
intermediatesMorbid and fatal
outcomes
Overwt, ObesityAbdominal/
central obesityWeight history
Vit C, Vit E; carotenoids; flavonoids)Folic Acid, vit B6, B12
- Ca, Mg- Fruits and vegs
Ischemic Stroke
Hemorrhagic Stroke
Adapted from
Kumanyika and Adams-
Campbell, 1991
Cellular and Biochemical Mechanisms That Play a Role in the Pathogenesis of Major Chronic Diseases
Cancer Athero-
sclerosis Obesity Diabetes
Insulin resistance + + + +
Cell proliferation + + - +
Inflammation + + - +
Apotosis + + - +
Changes in signal
transduction, gene
expression
+ + + +
DNA modifications/
mutations/genetic variation
+ + + +
A plus sign indicates association; minus sign, no specific body of evidence is available to suggest that a specific mechanism or pathway correlates with the indicated disease. Adapted from; Adapted from; DeckelbaumDeckelbaum RJ, Fisher EA, Winston M, Kumanyika S, Lauer RM, PiRJ, Fisher EA, Winston M, Kumanyika S, Lauer RM, Pi--SunyerSunyer FX, St FX, St JeorJeor
S, Schaefer EJ, Weinstein IB. Summary of a scientific conferenceS, Schaefer EJ, Weinstein IB. Summary of a scientific conference on preventive nutrition: pediatrics to on preventive nutrition: pediatrics to
geriatrics. Circulation. 1999 Jul 27;100(4):450geriatrics. Circulation. 1999 Jul 27;100(4):450--6 6
Possible Matrix of Food and Nutrient Possible Matrix of Food and Nutrient
Variables, by Type of IssueVariables, by Type of Issue
XXXXXXXXXXXXXX33
XXXXXX22
XXXXXXXXXXXX11
Foods; Foods;
PatternsPatternsSuppleSupple--
mentsmentsPathogens; Pathogens;
ContaminantsContaminants
OtherOther
ConstiConsti
tuentstuentsMineralsMineralsVitaminsVitamins
MacroMacro
nutrients nutrients
1=adequacy or toxicity, both, or quality1=adequacy or toxicity, both, or quality
2=2=foodbornefoodborne illness and allergiesillness and allergies
3=disease prevention and management3=disease prevention and management
Quantification of Risk Quantification of Risk
Dietary Reference IntakesDietary Reference Intakes
Dietary GuidelinesDietary Guidelines
Dietary Reference Intakes (DRI)Dietary Reference Intakes (DRI)
•• Estimated Average Requirements (EAR)Estimated Average Requirements (EAR)
•• Adequate Intake (AI)Adequate Intake (AI)
•• Recommended Dietary Allowances (RDA)Recommended Dietary Allowances (RDA)
•• Tolerable Upper Intake Level (UL)Tolerable Upper Intake Level (UL)
•• Elements of adequacy and toxicity and disease Elements of adequacy and toxicity and disease preventionprevention
•• Age and gender groupsAge and gender groups
See See OttenOtten JJ, JJ, HellwigHellwig JP, Meyers LD, eds. Dietary Reference Intakes. The Essential GJP, Meyers LD, eds. Dietary Reference Intakes. The Essential Guide to uide to
Nutrient Requirements. Washington DC: National Academies Press,Nutrient Requirements. Washington DC: National Academies Press, 20062006
DRI ElementsDRI Elements
•• Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Energy, Carbohydrate, Fiber, Fat, Fatty Acids,
Cholesterol, Protein, and Amino Acids Cholesterol, Protein, and Amino Acids
•• Water, potassium, sodium, chloride, and sulfateWater, potassium, sodium, chloride, and sulfate
•• Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Vitamin A, Vitamin K, Arsenic, Boron, Chromium,
Copper, Iodine, Iron, Manganese, Molybdenum, Copper, Iodine, Iron, Manganese, Molybdenum,
Nickel, Silicon, Vanadium, and Zinc Nickel, Silicon, Vanadium, and Zinc
•• Vitamin C, Vitamin E, Selenium, and Vitamin C, Vitamin E, Selenium, and CarotenoidsCarotenoids
•• Thiamin, Riboflavin, Niacin, Vitamin B6, Thiamin, Riboflavin, Niacin, Vitamin B6, FolateFolate, ,
Vitamin B12, Vitamin B12, PantothenicPantothenic Acid, Biotin, and Acid, Biotin, and CholineCholine
•• Calcium, Phosphorus, Magnesium, Vitamin D, and Calcium, Phosphorus, Magnesium, Vitamin D, and
Fluoride Fluoride
2005 Dietary Guidelines Nine 2005 Dietary Guidelines Nine
Focus AreasFocus Areas
•• Adequate Adequate
Nutrients within Nutrients within
Calorie NeedsCalorie Needs
•• Weight Weight
ManagementManagement
•• Physical ActivityPhysical Activity
•• Food Groups to Food Groups to
EncourageEncourage
•• FatsFats
•• CarbohydratesCarbohydrates
•• Sodium and Sodium and
PotassiumPotassium
•• Alcoholic Alcoholic
BeveragesBeverages
•• Food SafetyFood Safety
Common Themes in Recent Dietary and Lifestyle
Recommendations
Recommendations ACS AHA ADA AdiabA NIH AAP USDA/ HHS/FDA
§ Calories to achieve
desirable weight
+ + +† + + + +
§ Total and saturated fat
and cholesterol
+ + +‡ +§ + + +
§ Variety of foods;
emphasize plant
sources
+ + + + + + +
§ Moderate sugars and
salt
+ + + + + + +
§ Adequate physical
activity
+ + + + + + +
§ Do not smoke + + + NR + + +
§ Alcohol in moderation + + + + + NR +
SOURCE: Deckelbaum et al, Circulation, July 1999
Issues to be addressedIssues to be addressed
•• Inconclusive or absent dataInconclusive or absent data
•• Adverse effects between adequacy and Adverse effects between adequacy and toxicity toxicity
•• Biphasic or variable effectsBiphasic or variable effects
•• Food safety risks of recommended Food safety risks of recommended foods foods
•• Evidence paradigmsEvidence paradigms–– for chronic disease outcomesfor chronic disease outcomes
–– for risk defined by foods or dietary patternsfor risk defined by foods or dietary patterns
Research Needs Identified by 2005 Research Needs Identified by 2005
Dietary Guidelines CommitteeDietary Guidelines Committee
•• Food componentsFood components
•• Vitamin D in vulnerable groupsVitamin D in vulnerable groups
•• Vitamin EVitamin E
•• Added sugarAdded sugar
•• GlycemicGlycemic loadload
•• Macronutrient ratio and body weightMacronutrient ratio and body weight
•• Contradictions, e.g., mercury in fishContradictions, e.g., mercury in fish
•• Food groups and whole dietsFood groups and whole diets
U.S. Dietary Guidelines Advisory Committee, 2005U.S. Dietary Guidelines Advisory Committee, 2005
Specific exposuresSpecific exposures
Dietary Supplements: A Framework for Evaluating Safety.
Committee on the Framework for Evaluating the Safety ofthe Dietary Supplements, National Research Council. www.iom.edu
Diet and Chronic DiseaseDiet and Chronic Disease
•• Ecological, crossEcological, cross--
sectionalsectional
•• Cohort; caseCohort; case--control control
studiesstudies
•• Clinical trials of efficacyClinical trials of efficacy
•• Randomized effectiveness Randomized effectiveness
trialstrials
•• MetaMeta--analysesanalyses
•• Animal studiesAnimal studies
•• Biochemical studiesBiochemical studies
•• Small scale clinical Small scale clinical
studiesstudies
Evolution of Evidence for Selected Nutrient andDisease Relationships
Committee on Examination of the Evolving Science for
Dietary Supplements, Institute of Medicine
INCREASED CERTAINTY
•Fluoride and dental caries•Calcium and bone status•Vitamin D and bone status
DECREASED CERTAINTY
•Beta carotene and lung CA •Vitamin C and gastric cancer•Vitamin E and cancer
SummarySummary•• Questions are framed from several different Questions are framed from several different
perspectivesperspectives
•• Types of risk X number of variables X number Types of risk X number of variables X number of endpoints X interactions among these of endpoints X interactions among these factors results in very complex questions factors results in very complex questions
•• Risk assessment approaches are being used Risk assessment approaches are being used where the questions relate to direct effects of where the questions relate to direct effects of single or relatively specific and selective single or relatively specific and selective exposures exposures
•• Applicability to circumstances of Applicability to circumstances of complex,complex,common exposures and multiple possible common exposures and multiple possible endpoints is less clearendpoints is less clear
Top Related