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Preventing Chronic Disease


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  • 1. Preventing Chronic Disease with Nutrition and Exercise Associate Professor Tim Crowe School of Exercise and Nutrition Sciences Deakin University @CroweTim Nutrition @ DEAKIN 1
  • 2. Learning Objectives 1. Explain the advantages of nutrition and exercise in reducing chronic disease risk 2. Describe the key factors in predicting sustainable behaviour changes 3. Identify the merits of different dietary approaches for weight loss Nutrition @ DEAKIN 2
  • 3. Topics to be Covered 1. Lifestyle factors and cancer risk 2. Diabetes: prevention by lifestyle changes 3. Metabolic syndrome, inflammation and insulin resistance – tying it all together 4. Obesity and weight loss diets Nutrition @ DEAKIN 3
  • 4. Cancer in Australia: 2009 Cancer in Australia: an overview. 2012. Cancer Series no. 74 AIHW. Nutrition @ DEAKIN 4
  • 5. Lifestyle Factors Contributing to Cancer Risk Fraction of cancer attributable to lifestyle and environmental factors in the UK in 2010 Parkin DM and Walker LC. Br J Cancer 2011;105:577-581 Nutrition @ DEAKIN 5
  • 6. Lifestyle Factors Associated with Reduced Cancer Risk Dietary Factor Cancer Fibre Oesophagus, colorectal* Fruits and Vegetables Oral cavity, oesophagus, lung, stomach, colorectal Physical Activity Colorectal*, breast, oesophagus, pancreas, liver, endometrial Lactation Breast* Calcium Colorectal Dairy foods Colorectal Fish Colorectal Garlic Colorectal Selenium Lung, colorectal, prostate Folate Oesophagus, pancreas, colorectal *Cancers bolded are where evidence is the strongest The Second Expert Report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective Nutrition @ DEAKIN 6
  • 7. Lifestyle Factors Associated with Increased Cancer Risk Dietary Factor Cancer Overweight and obesity Oesophagus, pancreas, colorectal, breast (postmenopausal), endometrial, kidney Alcohol Oral cavity, oesophagus, liver, colorectal, breast Salted foods Stomach, nasopharynx Red meat Colorectal Aflatoxin Liver Grilled/BBQ foods Colorectal, stomach Very hot foods and drinks Oral cavity, oesophagus *Cancers bolded are where evidence is the strongest The Second Expert Report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective Nutrition @ DEAKIN 7
  • 8. Obesity and Cancer • Cancers most likely: breast, • colorectal, kidney, endometrium, oesophagus and pancreas True incidence likely underestimated due to effect of smoking and self-reported height and weight in some studies (↑BMI = ↑under-reporting) Mechanism? • ↑ Insulin, insulin growth factor-1 and/or sex steroids • Reflux (for oesophageal cancer) • Chronic inflammation (↑ oxidative stress) Nutrition @ DEAKIN 8
  • 9. Does Red Meat Cause Cancer? • • • • ↑ risk estimates in the range of 20 to 50% for highest vs lowest intakes of red meat in prospective studies Not clear if it’s the intake of red meat (?excess Fe), form of meat (esp. processed), or the way meat is cooked Nitrosamines (endogenous and from nitrate preservatives) Cooking (charring) of meat produces two types of carcinogens – Polycyclic aromatic hydrocarbons (PAHs) – Heterocyclic amines (HCAs) World Cancer Research Fund rates the evidence as Convincing The Second Expert Report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective Nutrition @ DEAKIN 9
  • 10. Physical Activity and Cancer • Convincing evidence protects against colorectal cancer, and likely protects against breast, oesophageal, pancreatic, liver, and endometrial • bioavailable sex hormones ( SHBG) • insulin production • IGF • adiposity • colon cancer time • inflammation Nutrition @ DEAKIN 10
  • 11. Recommendations for Cancer Prevention The Second Expert Report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective 1. 2. 3. 4. 5. 6. 7. 8. Be as lean as possible within the normal range of body weight Be physically active as part of everyday life Limit consumption of energy-dense foods. Avoid sugary drinks Eat mostly foods of plant origin Limit intake of red meat and avoid processed meat Limit alcoholic drinks Limit consumption of salt. Avoid mouldy grains or legumes Aim to meet nutritional needs through diet alone rather than supplements 9. Mothers to breastfeed; children to be breastfed 10. For cancer survivors: follow the recommendations for cancer prevention Nutrition @ DEAKIN 11
  • 12. Adherence to WCRF Guidelines and Cancer Risk Hazard Ratios (95% CIs) for total cancer and specific cancer types associated with a 1-point increment in WCRF/AICR score (range: 0–6 in men, 0–7 in women) Romaguera D et al. Am J Clin Nutr 2012;96:150-163 Nutrition @ DEAKIN 12
  • 13. Lifestyle and Diabetes Risk As the number of positive lifestyle changes increase, the relative risk of developing diabetes decreases Nutrition @ DEAKIN 13
  • 14. Diabetes Prevention via Lifestyle Finnish Diabetes Prevention Study (DPS) • 522 people, av. age 55, BMI 31 kg/m2 • All with impaired glucose tolerance (risk factor) • Intervention: individual counselling for weight loss and dietary improvement ( total fat, fibre, exercise etc.) • Outcomes: after av. 3.2 years, intervention group lost 4.2 kg c.f. 0.8 kg in control group • Diabetes incidence: 11% in intervention group c.f. 23% in control group – 58% reduction in risk of developing diabetes Tuomilehto et al. New Eng J Med 2001;344:1343-50 Nutrition @ DEAKIN 14
  • 15. Achieving Goals in the DPS Nutrition @ DEAKIN 15
  • 16. Meta-analysis: Lifestyle Interventions 49% decrease in incidence of T2DM for lifestyle intervention vs standard advice Gillies CL et al. Br Med J 2007;334:299 Nutrition @ DEAKIN 16
  • 17. Metabolic Syndrome (MetS) Is there a connection between diabetes, CVD, obesity? YES Metabolic syndrome refers to the clustering of several cardiometabolic risk factors, including abdominal obesity, hyperglycaemia, dyslipidaemia and elevated blood pressure, that are linked to insulin resistance Nutrition @ DEAKIN 17
  • 18. Number of MetS Criterion and CHD and Diabetes Risk HR (95% CI) 25 No. of factors: 0 24.40 1 20 2 3 15 ³4 10 7.26 5 1 1.79 2.25 3.19 4.50 3.65 1 2.36 0 CHD n 10.8% 32.2% 30.8% 20.8% Sattar N et al. Circulation 2003;108:414-419 Diabetes 5.4% 10.8% 32.3% 30.5% 21.0% Nutrition @ DEAKIN 5.4% 18
  • 19. Central Adiposity and Diabetes Risk Relative risk (RR) of T2DM by waist circumference (WC) and waist-to-hip ratio (WHR) relative to baseline BMI in males Wang Y et al. Comparison of abdominal adiposity and overall obesity in predicting risk of type 2 diabetes. Am J Clin Nutr 2005;81:555-563 Nutrition @ DEAKIN 19
  • 20. Liposuction Does Not Improve MetS! Klein S et al. Absence of an effect of liposuction on insulin action and risk factors for coronary heart disease. New Eng J Med 2004;350:2549-57 Nutrition @ DEAKIN 20
  • 21. Beyond Traditional Risk Factors Nutrition @ DEAKIN 21
  • 22. What is Inflammation? • • • • • • Body's normal response to protect against infection, injury, or disease Involves activation of leukocytes and release of inflammatory mediators Without inflammation, wounds and infections would never heal Acute inflammation: Initial response to harmful stimuli and involves ↑movement of leukocytes to the injured tissues Chronic inflammation: Leads to a progressive shift in the type of leukocyte cells present at site of inflammation, particularly the presence of macrophages Macrophages: secrete coagulation factors, reactive O2 species, cytokines, growth factors, nitric oxide and also induce continued recruitment of monocytes from circulation Nutrition @ DEAKIN 22
  • 23. Chronic Inflammation and Disease • Impairs endothelial function • • • • • • and vascular lining Increases platelet activation and clotting Depletes intrinsic antioxidants Generates free radicals and amplifies oxidative stress Delays wound healing and tissue regeneration Promotes cell aging and premature cell death Suppresses or amplifies immune responses Nutrition @ DEAKIN 23
  • 24. Causes of Chronic Inflammation Unlike acute inflammation showing redness, swelling and pain, chronic inflammation can be invisible Causes • Autoimmune diseases e.g. such as rheumatoid arthritis, lupus • Infectious agents e.g. H. pylori, viruses • Atherosclerosis • Environmental e.g. smoking • Allergens • Central adiposity: more macrophages localised in fat will produce more inflammatory mediators Nutrition @ DEAKIN 24
  • 25. Treating Inflammation • Exercise: Negative association between physical activity and inflammation • Weight loss: ↓ body fat means reducing the ‘inflammatory factories’ being the fat cells • ↑fruit, vegetables, fish, olive oil • ↑fibre (inversely associated with CRP) • ↓trans and saturated fats • Moderate alcohol and quitting smoking Nutrition @ DEAKIN 25
  • 26. The Rising Tide of Obesity James WPT. J Int Med 2008;263:336-352 Nutrition @ DEAKIN 26
  • 27. Nutrition @ DEAKIN 27
  • 28. Benefits of 10% Weight Loss Mortality > 20% ↓ total mortality > 30% ↓ diabetes-related deaths > 40% ↓ obesity related cancer Blood Pressure ↓ 10 mmHg systolic ↓ 20 mmHg diastolic Diabetes 30-50% ↓ in fasting plasma glucose 50% ↓ in risk of developing T2DM 15% ↓ in HbA1c Lipids 10% ↓ in total cholesterol 15% ↓ in LDL-C 30% ↓ in TGs 8% ↑ HDL-C Jung R. Br Med Bull 1997;53:307-231 Nutrition @ DEAKIN 28
  • 29. Diet Fundamentals No matter what the claims, diets achieve success by restricting energy intake and adhere to one of the following four principles: 1.Reducing one of the major macronutrients (carbohydrate or fat) 2.Limiting serve size (portion control) 3.Changing eating frequency or restrict time of eating 4.Concentration on a single food Nutrition @ DEAKIN 29
  • 30. Comparison of Popular Diets in a RCT • 160 obese or overweight participants randomised to 4 diets (93 completed the study) for 12 months • Compared Atkins’, Weight Watchers, Zone (40% CHO, 30% protein, 30% fat) and Ornish (<10% fat) • Received ongoing support and advice for first 2 months then left to ‘go it alone’ for the remainder of the study to simulate the real world Dasinger M et al. J Am Med Assoc 2005;293:43-53 Nutrition @ DEAKIN 30
  • 31. % Weight loss % Drop-out Comparison of Popular Diets 60 Atkins’ Ornish WW 40 20 Zone 48% 50% 35% 35% 3.9% 6.2% 4.5% 4.6% 0 -1 -2 -3 -4 -5 -6 -7 Difference was Not Significant Dasinger M et al. J Am Med Assoc 2005;293:43-53 Nutrition @ DEAKIN 31
  • 32. Yet Another Weight Loss RCT – 2 Years Long! • • • • 811 overweight adults randomised to 4 different diets with ongoing group and individual support for 2 years (80% completion rate - excellent) Participants were well educated, motivated and supported by researchers and professionals – best case scenario! Diet type makes little difference and diet goals difficult to achieve Attending counseling sessions was predictive of weight loss Nutrition @ DEAKIN 32
  • 33. Meal Replacements • Portion controlled, vitamin and mineral enriched meal • • • • • • replacements Designed to replace 1-2 meals per day (partial meal replacements) ‘Work’ by decreasing portion sizes Provides a discrete option Relatively cheap, easy to administer and supervise Nutritionally sound More beneficial when part of a broader weight loss and education program Nutrition @ DEAKIN 33
  • 34. Meal Replacements: Meta-analysis of 6 RCTs 9 Weight Loss (kg) 8 7 Reduced Energy Diet Partial Meal Replacement 6 5 4 3 2 1 0 3 Months • • • 1 Year 2.5 kg greater weight loss for partial meal replacement (PMR) group Lower dropout rate for PMR group at 1 year No adverse events reported Heymsfield et al. Int J Obes 2003;27:537-49 Nutrition @ DEAKIN 34
  • 35. Successful Weight Losers US National Weight Control Registry • Founded in 1994 and tracks over 5,000 people who’ve lost >13 kg (self reported) and kept it off for >1 year • 45% lost weight alone, 55% got help on a program • 98% modified their food intake (mostly by ↓ fat) – 78% eat breakfast every day – 75% weigh themselves at least once a week – 62% watch less than 10 hours of TV per week (Av. American = 28 hours) – 90% exercise, on average, about 1 hour per day Nutrition @ DEAKIN 35
  • 36. Sustaining Weight Loss 1032 obese adults who lost >4 kg during a 6 month intervention (Phase 1) Randomised for 30 months maintence phase to: ○ Self-directed support ■ Interactive website ▲ Monthly personal contact Svetkey LP et al. JAMA 2008;299:1139-48 Nutrition @ DEAKIN 36
  • 37. The Role of Exercise • Exercise has a modest, but consistent benefit on body fat reduction and benefit is independent of dieting, and with evidence of a ‘dose’ effect (Nutr Rev 2007;65:1-19; ACSM Guidelines for Physical Activity and Weight Loss and Weight Regain Prevention. Med Sci Sport Exercise 2009;41:451-8) • Kahn et al: (Am J Public Health 1997;87:747)  Walking ≥4 hrs/wk protective of weight gain over 10 yrs • Nurses Health Study (Int J Obes 2001;25:1113)  ≥5 hrs/wk vigorous activity gained 0.5 kg less • Dose required? 30 mins/day?  ACSM 2009 Guidelines state that: “to lose weight or maintain weight loss, 60 to 90 minutes of physical activity may be necessary. The 30-minute recommendation is for the average healthy adult to maintain health and reduce the risk for chronic disease.” Nutrition @ DEAKIN 37
  • 38. Weight Regain and Exercise Levels • RCT of 202 overweight adults on 18 month weight loss program with goal of 30 or 90 min physical activity (HPA) per day ▲ Consistently HPA ● Other participants • HPA group lost more weight (2-3%) at study’s end • 12 months later, most weight regained, but those still achieving HPA goals were 12 kg lighter Tate DF et al. Am J Clin Nutr 2007;85:954-9 Nutrition @ DEAKIN 38
  • 39. Behaviour Change in a Nutshell Key elements: – Frequent contact and support (e.g. group, individual, family) – Achievable goals (SMART) and flexible – Self-monitoring, identification of internal triggers, nutrition education, cognitive restructuring, relapse management and coping strategies all useful – ‘Toolbox’ approach to barriers Nutrition @ DEAKIN 39
  • 40. Practice Recommendations • Weight loss ‘easy’ compared with weight maintenance • Best diet to follow is one that is sustainable and results in • long-term weight loss (no ‘one size fits all’ approach) Principles of low-CHO, low-fat, low-GI, low energy density can be used with a focus on nutritional quality – ↓ sugary foods/drinks will ↓ energy, glycaemic load, and CHO – ↑ fibre and↓ fat will ↓ energy density • Exercise 1 hr/day characteristic of long-term weight • • maintenance Regular monitoring of body weight and food intake characteristic of long term weight maintenance Ongoing support augments compliance Nutrition @ DEAKIN 40