Low carbohydrate diets- do they have a place?

Transcription

1 Low carbohydrate diets- do they have a place? Grant Schofield Professor of Public Health AUT University, Auckland

2 Atherogenic dyslipidemia is [primarily] driven by the glycemic environment, especially sugar and refined carbohydrate in the context of insulin resistance

3 A balanced diet [in the context of whole food] is one which normalises blood glucose and prevents the hypersecretion of insulin

4

5

6

7

8

9

10

11

12

13 Inflammation Insulin resistance Stress Poor sleep Genes/ethnicity Age? Obesity Too much exercise High insulin Low physical activity Gluten diet High trans fat diet Smoking Pollution High sugar diet High alcohol diet environmental toxins Too much/too little sun High iron Poor gut microbes

14 High insulin NEUROPSYCHIATRIC Alzheimers / other dementias Peripheral neuropathy Retinopathy Neuro-psychiatric disorders Parkinson s disease Autism GASTROINTESTINAL Diabetes: Type 2 / Gestational Hypertriglyceridaemia Non-alcoholic fatty liver disease Ulcerative colitis ENDOCRINE Chronic inflammation Fatty liver Obesity PCOS Tinnitus Vertigo Meniere s disease Periodontal disease CIRCULATORY Atherosclerosis Cardiomyopathy Endothelial dysfunction (microvascular disease and peripheral vascular disease) Stroke Thrombosis (DVT) Hypertension SKELETAL Osteoporosis CANCER Breast, ovarian colon bladder, pancreas, liver, prostate UROLOGY Nephropathy, erectile dysfunction INFLAMMATION Osteoarthritis Rheumatoid arthritis rofts, Zinn, Wheldon & Schofield. In submission: (2014).

15 Low carb Zone Learn Low fat

16 Percent change Insulin Insulin Resistantsensitive Insulin Resistant Insulin sensitive Low fat Low carb

17 Glycemic environment markers HbA1C (CHO) C peptide [insulin secretion] (CHO) TG (sugar, CHO) HDL (more SFA and less CHO) Apo-B (CHO)

18 The importance of HbA1C

19 HbA1C

20 HbA1C Diabetes CHD Stroke Cancer

21 HbA1C

22 CVD presence adjusted odds 1141 angiography Non-diabetic HbA1C CVD severity CVD complexity 1 0 <5.5% <5.7% <6.1% >6.1% HbA1C quartile

23 C peptide [insulin secretion]

24 Population incidence / C peptide [insulin secretion] No IR No glycemia IR No glycemia IR + glycemia

25 Population incidence / AMI No IR No glycemia IR No glycemia IR + glycemia

26 Population incidence / AMI CAD No IR No glycemia IR No glycemia IR + glycemia

27 LDL-C, mmol/l Triglycerides, mmol/l HDL-C, mmol/l Dietary Fats & Blood Lipids ApoB 0.00 TG 0.05 HDL MUFA SFA PUFA MUFA SFA PUFA Δ ApoB? SFA LDL MUFA PUFA Meta-analysis of 60 feeding RCTs. Mensink & Katan, AJCN 2003

28 Odds ratio AMORIS ApoB Risk of MI Male Female ApoB HDL LDL ` Decile Decile

29 Cumulative % frequency 100 Phenotype A Large buoyant (benign) Phenotype B small dense (harmful) ApoB

30 Eat more fat?

31 Percent change Eat more fat? Ad lib Low carb high fat 10 0 Body mass Ab Fat TG TG AUC HDL TG/ HDL ApoB ApoB/ ApoA-1Small LDL Insulin Glu HOMA Low fat calorie restricted Lepti n Total SFA Insulin

32 Percent change Ad lib Low carb high fat Eat more fat? Low fat calorie restricted IL-6 IL-8 TNF-a MCP-1 I-CAM E-selectin PAI

33 Triglycerides (mg.dl) Eat more fat? Low fat Meal Low carb high fat Pre

34 Case control odds of incident CHD in EPIC (Norfolk) cohort of

35 Total Fatty acids - no effect Saturated fatty acids - harm Odd chain fatty acids - protection Even chain fatty acids - harm

36 Dietary Fats & CHD Events Meta-analysis SFA n-3 Trans fats Chowdury et al, Annals Intern Med 2014

37 Saturated Fat & CHD Events Meta-analysis 16 prospective cohort studies from around the world SFA Siri-Tarino et al, AJCN 2010 No Significant Association RR comparing extreme categories (highest vs. lowest) of saturated fat intake

38 Meta-analysis

39 Jackobsen Prospective Hooper Cocnrane review RCTs Meta-analysis All cause CVD CV events Fat intake mortality mortality RR 0.86 ( ) Mod evid combined Modified fat intake Reduced fat intake Saturated fat intake Substitutions

40 Substitutions asked Meta-analysis Carbs for saturated fat Monounsaturated fat for saturated fat Polyunsaturated fat for saturated fat Polyunsaturated fat for carbs

41 High fat dairy?

42 Food Sources: Dairy & CVD Mortality Meta-analysis Milk RR = 0.96 (0.81, 1.13) Cheese RR = 1.00 (0.81, 1.24) O Sullivan et al., Am J Public Health 2013

43 Dairy Foods & Diabetes RR of 1. Diabetes 0.95 Among 340,234 Europeans from 8 countries, with 12,403 cases of incident diabetes P-trend= P-trend=0.06 Milk Yogurt Cheese Quintiles of Consumption P-trend=0.01 Adjusted for age, sex, center, education, smoking, physical activity, alcohol intake, and consumption of fruits, vegetables, red meat, processed meat, sugar sweetened beverages, coffee, cereals, and cerearl products. Sluijis et al., AJCN 2012

44 We need a new pyramid

45 Evidence? Science Biology EpidemiologyExperiments Culture Practice

46

47

48

49

50 6 things in Common 1. They Are Low in Added Sugar 2. They Eliminate Refined Carbohydrates 3. They Eliminate Industrial Vegetable Oils 4. They Eliminate Artificial Trans Fats 5. They Are High in Vegetables and Fibre 6. They Focus on Foods Instead of Calories

51 The REAL food guidelines Real food for real people, based on real evidence

52 The REAL food guidelines Real food for real people, based on real evidence 1. Enjoy nutritious foods everyday including plenty of fresh vegetables and seasonal fruit.

53 The REAL food guidelines Real food for real people, based on real evidence 1. Enjoy nutritious foods everyday including plenty of fresh vegetables and seasonal fruit. 2. Buy and prepare food from whole unprocessed sources of dairy, nuts, seeds, eggs, meat, fish and poultry.

54 The REAL food guidelines Real food for real people, based on real evidence 1. Enjoy nutritious foods everyday including plenty of fresh vegetables and seasonal fruit. 2. Buy and prepare food from whole unprocessed sources of dairy, nuts, seeds, eggs, meat, fish and poultry. 3. Keep sugar, added sugars, and processed foods to a minimum in all foods and drinks.

55 The REAL food guidelines Real food for real people, based on real evidence 1. Enjoy nutritious foods everyday including plenty of fresh vegetables and seasonal fruit. 2. Buy and prepare food from whole unprocessed sources of dairy, nuts, seeds, eggs, meat, fish and poultry. 3. Keep sugar, added sugars, and processed foods to a minimum in all foods and drinks. 4. If you drink alcohol, keep your intake low.

56 The REAL food guidelines Real food for real people, based on real evidence 1. Enjoy nutritious foods everyday including plenty of fresh vegetables and seasonal fruit. 2. Buy and prepare food from whole unprocessed sources of dairy, nuts, seeds, eggs, meat, fish and poultry. 3. Keep sugar, added sugars, and processed foods to a minimum in all foods and drinks. 4. If you drink alcohol, keep your intake low. 5. Prepare, cook, and eat minimally processed traditional foods with family, friends, and your community.

57 A note to physicians: Advise to restrict sugar and starches to the degree necessary to maintain stable BGL and to prevent hypersecreting insulin even with stable BGL

58