YOU ARE WHAT YOU EAT: THE ROLE OF DIET IN CANCER PREVENTION

Transcription

1 College of Public Health and Human Sciences Moore Family Center for Whole Grain Foods, Nutrition and Preventive Health YOU ARE WHAT YOU EAT: THE ROLE OF DIET IN CANCER PREVENTION Emily Ho, PhD Director, Moore Family Center College of Public Health and Human Sciences Principal Investigator, Linus Pauling Institute Oregon State University

2 Change in the US Death Rates* by Cause, 1950 & Rate Per 100, Heart Diseases Cerebrovascular Diseases Pneumonia/ Influenza Cancer * Age-adjusted to 2000 US standard population. Sources: 1950 Mortality Data - CDC/NCHS, NVSS, Mortality Revised Mortality Data NVSR-Death Final Data 2001 Volume 52, No. 3.

3 Causes of Cancer Smoking ~ 30% Diet ~35% Infection ~20% Occupation ~2% Pollution ~1% Doll and Peto. J Natl Cancer Inst Jun;66(6):

4 Genetics vs Lifestyle? Rates of colon cancer are much lower in other parts of the world such as Japan. 80 Colon Cancer Cases (Number of new cases per 100,000 people) 5 Japan Japanese U.S. families in U.S. Migrant studies suggest colon cancer risk is modifiable and that differences in population rates may be due to lifestyle or environmental factors.

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9 CNN.com homepage

10 Heterocyclic Amines (HCA) Polyaromatic Hydrocarbons (PAH) Nitrosamines Cadmium Arsenic Benzene

11 Heterocyclic Amines (HCA) Polyaromatic Hydrocarbons (PAH) Nitrosamines

12 Polycyclic aromatic Hydrocarbons (PAH) Heterocyc lic Amines (HCA)

13 Do you like your meat rare, medium or well-done? Food safety? Women who consumed hamburger, beef steak or bacon very well done have a 4.62 times higher risk for breast cancer than those who consumed the same meats rare or medium done. JNCI 90: , 1998

14 PAH and HCA s in food Smoked foods Charred food Barbequed meat: 164 ppb Polluted urban air: ppb Meat cooked over an open flame PAH function of both fat content and proximity to heat source

15 How can you lower? Cook at lower temps Increasing temperatures to (about ) increases mutagenicity 6-7 fold Pre-microwave Pour off clear liquid, removes creatine Significantly reduces mutagen formation even if well-done.

16 Marinate your meat!

17 Asian vs. American Diets Soy Japanese diet = mg/day American diet = 1-3 mg/day Tea (green) Asian= 3 to 4 Cups (120mL/cup)/day American (only 8% of population)= 1 cup (180mL)/day Vegetables (cruciferous vegetables) Japanese diet= ~55g/day American= <12g/day More than 3 servings per week of cruciferous vegetables associated with 72% decrease in risk (compared to <1 serving per wk)

18 INITIAT ION DNA DAMAGE Repair is incomplete DNA replication PROMOTION PROGRESSIO N RAPID DIVISION OF CELLS CLONAL EXPANSION OF INITIATED CELLS TUMOR FORMATION BENIGN TUMOR Still reversible Rapid division, more mutations irreversible METASTASI MALIGNANT S TUMOR

19 The Epigenetic Revolution

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21 glucosinolate myrosinase SULFORAPHANE

22 Sulforaphane slows tumor growth Xenograft measurements Day 1 Implant PC-3 cells Begin SFN diet Day 3 Day 8 Day 16 Day 19 Day 21 Day 12 Mice consumed ~ 7.5 umol SFN per day Terminate study PC-3 xenograft volume (mm 3 ) Control mice SFN fed mice ** * ** *** *** *** Days post implantation Xenograft HDAC activity ** 0 Controls SFN Prostate HDAC activity ** 0 Controls SFN PBMC HDAC Activity PBMC Controls Myzak et al (2007) Exp Biol Med232(2): ** SFN

23 Broccoli sprout diets delay prostat tumor progression 1. normal 2. PIN 3. cribriform 4. early adenocarcinoma 5. moderate adenocarcinoma 6. poorly differentiated adenocarcinoma

24 Broccoli Sprouts 50 times higher glucosinolates Than mature plant What about people?

25 Proliferation Marker (Ki-67) decreases in breast cancer patients following broccoli sprout supplementation Evidence that SFN may reduce proliferative activity in human breast tissue Benign DCIS 2 IDC 3 Ki-67 n = 48/62 4 n = 19/28 n = 13/16 Supplement (-2.23, -0.55) 0.42 (-1.18, 2.02) 0.98 (-3.89, 5.85) p-value Placebo 0.23 (-0.61, 1.07) (-1.69, 0.72) 0.28 (-3.22, 3.78) p-value DCIS, ductal carcinoma in situ; IDC, invasive ductal carcinoma; ADH, atypical ductal hyperplasia; SFN, sulforaphane Changes from pre- to post-intervention levels within groups Atwell et. al. Cancer Prevention Research, 2015 Dec;8(12): Supplement vs. placebo, p = 0.01

26 How do Typical American Diets Compare to Recommended Intake Levels or Limits? Dietary Intakes Compared to Recommendations. Percent of the U.S. Population Ages 1 Year and Older Who Are Below, At, or Above Each Dietary Goal or Limit Source: Dietary Guidelines for Americans 2015(Health.gov)

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