Presentation on theme: "Diet, Exercise, and Cancer Risk"— Presentation transcript:
1Diet, Exercise, and Cancer Risk Diane Baer Wilson, EdD, MS, RDAssociate Professor Division of Quality HealthcareDepartment of Internal MedicineCo-Director Cancer Prevention and ControlMassey Cancer CenterVirginia Commonwealth UniversityI am delighted to be here to share a bit about the work I am doing in SC related to nutrition and cancer prevention.Have been involved in this area of research for the last five years when Dr Dan Nixon brought a focus on the role of nutrition in cancer when he arrived at MUSC.CCFellows
2Today’s objectivesExamine dietary-related factors and physical activity related to cancer riskDiscuss dietary fat as a model for dietary studies related to cancer riskReview nutrition measurement methodsExamine recent research related to BMI and breast cancer
9Dietary Fat/Breast Cancer Animal studies Proportionate level of tumor growth recorded in laboratory rats related to level of dietary fat fed animals over designated period of time.( ’s)
10Dietary Fat/Breast Cancer Human studiesCross sectionalNurses Health Study-Willett, et al, 2000.
11Dietary Fat/Breast Cancer Randomized Clinical Trial “Low-fat Dietary Patterns and Risk of Invasive Breast Cancer”The Women’s Health Initiative Randomized Controlled Dietary Modification TrialPrentice, Caan, Chlewbowski, et al. JAMA2006;295: (2/8/06)
12Participant Flow in the Dietary Modification Component of the Women's Health Initiative Prentice, R. L. et al. JAMA 2006;295:Copyright restrictions may apply.
13Baseline Demographics of Participants in Women's Health Initiative Dietary Modification Trial* Prentice, R. L. et al. JAMA 2006;295:Copyright restrictions may apply.
14Nutrient Consumption Estimates and Body Weight at Baseline and Year 1 Prentice, R. L. et al. JAMA 2006;295:Copyright restrictions may apply.
15Blood Biomarkers for Baseline and Year 3* Prentice, R. L. et al. JAMA 2006;295:Copyright restrictions may apply.
16Risk of Invasive Breast Cancer and Other Major Clinical Outcomes Prentice, R. L. et al. JAMA 2006;295:Copyright restrictions may apply.
17Breast Cancer Risk by Baseline Dietary Factors Prentice, R. L. et al. JAMA 2006;295:Copyright restrictions may apply.
18Breast Cancer Risk Based on Baseline Demographics, Medical History, and Health Behavior Variables Prentice, R. L. et al. JAMA 2006;295:Copyright restrictions may apply.
20Dietary Assessment Twenty-four hour dietary recall Food frequency questionnaireDiet recordDiet history
21Data Collection Methods 24 hour recall methodMost common method used for national dietary surveysInformation on everything consumed over past 24 hours-relies on memoryTrained interviewersnon-judgmentalneutral
22Food Record MethodDetailed record of all foods consumed on one or more days at time consumedLess dependent on memoryFace to face training on completeness and accuracy essentialAccurate portion reporting essentialFinal record reviewed by professional
23Food frequency questionnaires Food frequency surveys most common measurement method in nutrition epi researchAverage intake, “usual” intakeEasy to completeFoods, clarity, format important
24Approaches for Evaluating Dietary Questionnaires Compare mean of nutrient intakeProportion of intake accounted forReproducibilityValidityCompare to biochemical indicatorCompare to physiologic indicatorAbility to predict disease
25Food Recalls/Records Foods Recalls and Records Based on specific foods consumedAttempt to get data on one’s “true intake”, open-endedCan be representative if enough days testedBest method for comparing intake to recommendationsMost used to validate FFQ
26Designing and Administering Questionnaires Motivated subjectsClear instructionsCorrect foodsStandardized proceduresInterview or telephonePortion sizes?
27Determining best method Individual intake or group mean?Actual intake or relative ranking?Open-ended method or structured list?Age limitations?Literacy considerations?
28Overweight and breast cancer Women who are overweight are more likely to:Develop breast cancerBe diagnosed at a later stageHave higher mortality rates
29Overweight and Breast Cancer Review of 26 studies examining the association of pre-morbid weight or weight at diagnosis with recurrent disease or survival (Rock and Wahnefried, 2002)17 found increased BMI significantly associated with increased risk of death2 null findings7 inverse findings
30Overweight and Breast Cancer Weight gain and increased riskObesity increases peptide hormones-insulin and steroid hormones-estrogenHeaviest women have 3x level of estrogen than lean women without HRTObesity increases risk of death from breast cancer about as much as mammography reduces it.
33Breast Cancer Survivorship With early diagnosis, the survival rate has significantly increased22% of all cancer survivors are breast cancer survivorsBreast cancer survivors comprise the largest proportion of cancer survivorsSurvival rate is lalargely due to diagnosis occurring at a local stage, associate with a 96% 5 year survival rate
34Weight Gain Weight gain 60% of women report weight gain after diagnosismore prevalent:premenopausal at diagnosisreceived adjuvant chemotherapyin African Americanscaloric intake
35Reasons for weight gain: Likely to be at least “peri menopausal”Being told to “keep your strength up” during therapyComfort foodsLess exerciseNeeds more research….
36Exercise Type of exercise Breast cancer Walking vs. more rigorous formsBreast cancerMulti beneficialMental, physical, emotionalIntegration
37Addressing weight gain in African American breast cancer survivors African American women have higher mortality from breast cancer when compared to Caucasian womenSome 60% of all women report gaining weight after being diagnosed with breast cancer. However, African American women are especially at risk for this weight gain, after diagnosis of breast cancer, placing them at greater risk for cancer recurrence and shorter survival time.
38Testing an exercise intervention in African American breast cancer survivors (Study 1) Study Aim: Determine the feasibility and impact of a cognitive, behavioral theory-based walking intervention, Walking Counts! in a sample of AA breast cancer survivors.Feasibility: Attendance, compliance, process measuresOutcomes: Integration of regular exercise (steps/day)change in BMI, waist, hip, forearm circumferences, body fat %, blood pressure, attitude toward exercise and cancer stress.
39Walking Counts!-Methods Eligibility:Breast cancer diagnosis>3 months past cancer treatmentMobile<70 years oldDescription of the intervention:Health Belief ModelEight week community-based, 75 minute sessionsBenefits, barriers, relationship to cancer risk,Personal assessment/problem solvingPedometers, scheduling, and tracking of steps/dayWilson et al; Preventing Chronic Disease 2005
40Walking Counts!-Results FeasibilityAttendance-70% attended > 7 sessionsRetention: 92% retained1 dropped after enrollment due to scheduling1 recurredPedometersSteps only mode25% needed replacement
41Walking Counts!-Results Characteristics of the Sample(n=22)Age (yrs)55 (39 – 66)Weight (lbs)191 (142 – 271)BMI (kg/m2)32.7 (25.2 – 47.2)Education: (%)< high schoolHigh school graduatePost high school4.590.9Marital Status: (%)MarriedSingle/Divorced/Widowed50
42Characteristics of the Sample Menopausal Status (%)PrePost13.686.4Time Since Diagnosis: (%)1-6 years7-10 yearsMore than 10 years59.127.3Type of Treatment: (%)ChemotherapyRadiation therapyBothNeither18.245.5Tamoxifen: (%) YesNo22.777.3Alcohol: (%) Yes72.7Smoking: (%) Yes9.190.9
43Walking Counts! Pre/Post Measures Baseline (N=22) Change p value*Anthropometric measures:Steps/day <0.001BMI (kg/m2)Weight (lb.)Body Fat (%)Waist circumference (in.)Hip circumference (in.)Arm circumference (in.)Systolic B/P (mm Hg)Diastolic B/P(mm Hg)Waist to Hip ratioAttitudinal measures:Exercise Attitude TotalCancer Stress Total* Paired “t-test” for difference in group means.
44Steps/day at Baseline, Post and 3 Month Post Intervention p<.001 B/P***, p=.001*** B/3mth
45Other research addressing obesity Nutrigenomics: Studies to help understand the mechanism by which genes may influence chronic disease risk related to nutrients and obesity
46Genes and obesity in breast cancer Study Aim: Measure breast cancer gene expression profiles and analyze differences in tumor gene expression according to ethnicity in lean (BMI <25) and overweight (BMI >30) womenMethods: Using tissue samples taken at diagnosis of breast cancer, we will study microarray expression of selected genes in 100 AA and 100 Caucasian women.Co-variates, include menopausal status, serum markers for insulin resistance and obesity, dietary intake and level of physical activityImplications: Study results may help to identify molecular changes and or genetic pathways in lean vs overweight women that contribute to breast cancer outcomes.(O’Connell P, Penberthy L, Wilson DB, Dumur K)
47Other dietary trials: Women’s Intervention Nutrition Study (WINS) Tests effect of low-fat intervention on recurrence in 2500 breast cancer survivorsWomen’s Healthy Eating and Living intervention3,109 survivors tests increased fr/veg intake, low fat, high fiber on progression of disease
51Omega-3 fatty acids Slow growth of tumors in animals May increase efficacy of chemopreventive agentsCold water fish-Variable even within fish typesFlax seedCanola oil
52SupplementsCancer patients start consuming more supplements and herbal products after diagnosisHealth claims on labels are not all official termsWatch the research-many products are in trials
53What to eat? Emphasize plant based foods Eat 5-10 servings of fruits/vegetableschemopreventive constituentsfiberantioxidantsEat less red-meatPay attention to type of fatDon’t eliminate fatEat more fish
54SummaryNutrient driven hypotheses have significant measurement threats to validityProviding the public with sound nutritional guidelines requires a thorough examination of “the evidence”The evidence for the role of obesity and that for the role of exercise are among the strongest for providing advice to the publicMuch more scientific research is needed to better understand the role of macro and micro nutrients related to specific cancer risk.
55“Nutrition is one of the most significant determinants of health and one of the most modifiable.” The US Surgeon General