What are the risk/benefits from high intake of carbohydrates?

Transcription

1 What are the risk/benefits from high intake of carbohydrates? Alan Barclay, PhD 2013 Australia other countries. All rights reserved

2 Prologue: the diabesity epidemic

3 The diabetes epidemic million Australians have diagnosed diabetes million Australians have pre-diabetes. Diabetes prevalence has increased ~8 % per annum since the year The crude diabetes rate has increased from 4.8% in 2006 to 5.6% in The average age of NDSS registrants has increased: 53.9 years in 1995 to 63.7 years in Barclay. Australian Diabetes Council, 2012

4 Total number of NDSS Registrants in NSW , with projections to ,400,000 1,200,000 1,000, , ,000 Total projected Total number Type 2 Type 1 GDM 400, , Barclay. Australian Diabetes Council, 2012

5 Rates of overweight and obesity Australian adults: Percent of population 2. Heart Foundation Australia (1980, 1989) and Australian Bureau of Statistics (1995, 2007, 2012)

6 Carbohydrate recommendations

7 Minimum carbohydrate requirements 3 The Institute of Medicine (IOM) RDA for carbohydrate is 130 g per day for adults and children. Based upon the amount of sugars and starches required to provide the brain with an adequate supply of glucose. Glucose is the only energy source for red blood cells and the preferred energy source for the brain, central nervous system, placenta, and foetus. 3. Hess et al. Food Function. 2012, 3, 477

8 Minimum requirements 3 If glucose is not provided in the diet and the body s storage form of glucose (glycogen) is depleted, the body will break down protein in muscles to maintain blood glucose levels and supply glucose to the brain. 3. Hess et al. Food Function. 2012, 3, 477

9 Global carbohydrate intake recommendations for optimal health 3,4 Organisation Carbohydrates sugars Institute of Medicine (IOM), USA 45-65% total energy <25% added sugars WHO 55 % total energy from a variety of carbohydrate sources Free added sugars 10 % total energy NHMRC, NRVs, Australia 45-65% total energy 10%-25% added sugars 3. Hess et al. Food Function. 2012, 3, 477; 4. NHMRC, 2006

10 Scientific rationale: total carbohydrate 3 The IOM also set an Acceptable Macronutrient Distribution Range (AMDR) for carbohydrate of % of total kilojoules. At the low end of this range it is very difficult to meet the recommendations for fibre intake. At the high end of the range, overconsumption of carbohydrates may result in high blood triglyceride levels and low HDL cholesterol levels. 3. Hess et al. Food Function. 2012, 3, 477

11 Benefits of a high carbohydrate diet 4 Lower total and LDL cholesterol ( wholegrain and soluble fibre (e.g., β-glucan)) Good sources of vitamins (B, C, E) minerals (magnesium, potassium), polyphenols, etc dietary fibre, if carbohydrate not refined 4. Hauner et al. Ann Nutr Metab

12 Dietary fibre 4 Most dietary fibre comes from plant foods Most plant foods are good sources of carbohydrate (e.g., grains, legumes, fruits, starchy vegetables) High fibre diets may decrease the risk of 3 : Obesity (in adults) Type 2 diabetes (cereal fibre) Coronary heart disease Colorectal cancer 4. Hauner et al. Ann Nutr Metab

13 Carbohydrates and weight gain US Health professional study 5-120,877 U.S. women and men who were free of chronic diseases and not obese at baseline and followed-up year weight change was most strongly associated with the intake of potato chips (0.77 kg), potatoes (0.6 kg), sugar- sweetened beverages (0.45 kg), - inversely associated with the intake of vegetables ( 0.11 kg), whole grains ( 0.17 kg), fruits ( 0.22 kg), and yogurt ( 0.37 kg) 5. Mozaffarian et al. N Engl J Med. 23;364(25): , 2011.

14 Sugar recommendations

15 Added sugars 3 IOM: Added sugars should comprise no more than 25% of total kilojoules. Ensuring sufficient intakes of essential micronutrients that are, for the most part, present in relatively low amounts in foods and beverages that are major sources of added sugars in North American diets. Reduced intakes of calcium, vitamin A, iron, and zinc were observed with increasing intakes of added sugars at intake levels exceeding 25% of energy. Not all micronutrients were examined. 3. Hess et al. Food Function. 2012, 3, 477

16 Added sugars 3 WHO: Added sugars should comprise no more than 10% of total kilojoules. The evidence linking dietary sugars to the risk of dental caries in the multiplicity of studies. When annual sugar consumption >15 kg per person per year (40 g per person per day), the incidence of dental caries increases with increasing sugar intake. Concluded that a daily intake of g per person, an amount comparable to 6% to 10% of energy intake, should not contribute to dental caries. 3. Hess et al. Food Function. 2012, 3, 477

17 Sugars and dental caries 3 systematic reviews published since 2003 Conclusion of the most recent 6 : The analysis showed that there is no reliable relationship of quantity of sugar used to dental caries. A significant relationship of frequency of use of sugar(s) to dental caries was reported in 19 out of the 31 papers considered. It can be postulated that the lack of significant relationships of sugar to dental caries is because it is the frequent use of the white flour-sugar combination in baked goods (cakes, biscuits etc.) and snack foods that is the true relationship. 6. Anderson et al. Obesity Reviews

18 Sugars, starches and dental caries 7 Historically, the prevalence of dental caries has increased when dietary patterns have changed to include more added sugars and foods containing refined starches. Fermentable carbohydrates (both sugars and starches) are a substrate for bacteria such as S. mutans and S. sobrinus, which increase the acidproducing potential of dental plaque. 7. NHMRC. Australian Dietary Guidelines, 2013, P78

19 Sugars and overweight/obesity 8 SLR and meta-analysis of 30 trials and 38 cohort studies intake of dietary sugars was associated with body weight (0.80 kg, 95% confidence interval 0.39 to 1.21; P<0.001); sugars intake was associated weight (0.75 kg, 0.30 to 1.19; P=0.001). Isoenergetic exchange of dietary sugars with other carbohydrates showed no change in body weight (0.04 kg, 0.04 to 0.13). 8. Te Morenga et al. BMJ 2013.

20 Fructose and overweight/obesity 9 A SLR and meta-analysis determined that in isoenergetic trials, fructose had no statistically significant effect on body weight in ideal-weight participants or those with diabetes. Statistically significant weight loss (-0.55 kg) occurred in the trials on overweight/obese individuals, however. 9. Sievenpiper et al. Annals of Internal Med 2012; 156:

21 Fructose and overweight/obesity 10 RCT of 131 patients to compare the short-term effects of 2 energy-restricted diets 1500, 1800, or 2000 Cal according to sex, age, and height. Low-fructose diet (<20 g/d) or moderate-fructose (50-70 g/d) 6-week follow-up period. Weight loss was higher in the moderate natural fructose group ( kg) than the low fructose group ( kg) (P = ). 10. Madero et al. Metabolism. 2012: 60;

22 Sweetened beverages and overweight/obesity Five systematic reviews Included evidence from a large range of clinical trials, cohort studies and cross-sectional analyses. Humans aged 1 99 years One 11 supported an independent role for sugar sweetened beverages (SSBs) in the aetiology of overweight/obesity in people who are not already overweight. One review found that in overweight individuals, SSBs contribute to weight gain Malik, V.S.; Schulze, M.B.; Hu, F.B. Am. J. Clin. Nutr. 2006, 84, Forshee, R.A.; et al. Am J Clin Nutr. 2008, 87, Gibson, S. Nutr. Res. Rev. 2008, 21, Wolff, E.; Dansinger, M.L. Medscape J. Med. 2008, 10, Mattes et al. Obesity Reviews. 2011, 12,

23 Sugar and type 2 diabetes 4 No association between total carbohydrate consumption and type 2 diabetes in 2 out 3 cohort studies Mono and disaccharides no, or ve association Fructose and glucose 2 positive, 2 no association Sucrose no, or ve association Lactose no association 4. Hauner et al. Ann Nutr Metab

24 Sugar sweetened beverages and diabetes 16 SSBs = soft drinks, carbonated soft drinks, fruitades, fruit drinks, sports drinks, energy and vitamin water drinks, sweetened iced tea, punch, cordials, squashes, and lemonade. SLR and meta-analysis of 310,819 participants and 15,043 cases of type 2 diabetes Individuals in the highest quantile of SSB intake (most often 1 2 servings/day) had a 26% greater risk of developing type 2 diabetes than those in the lowest quantile (none or < 1 serving/month) 16. Malik et al. Diabetes Care, 2010.

25 Lifestyle interventions to prevent type 2 DM RCT s with 8,084 participants Lifestyle interventions risk of type 2 by ~50% 17. Gillies et al. BMJ. 2007; 334(7588):299

26 Key characteristics of lifestyle programs 18,19 Moderate weight loss: 5-10% of initial weight Regular individual and/or group counselling Regular physical activity Key dietary intervention characteristics3,4: kj to achieve weight loss (~0.5 kg/wk) Fat 25-30% of kj Sat fat 7-10% of kj Fibre 3.5g / 1000 kj 18. Lindström J et al. Diab Care. 2003; 26(12): DPP research group. Diab Care. 2002; 25:

27 What about alternative sweeteners?

28 Health benefits of non-nutritive sweeteners 20 American Heart Association and the American Diabetes Association Systematic review: At this time, there are insufficient data to determine conclusively whether the use of NNS to displace caloric sweeteners in beverages and foods reduces added sugars or carbohydrate intakes, or benefits appetite, energy balance, body weight, or cardiometabolic risk factors. 20. Gardener et al. Diabetes Care

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30 Are we eating too much carbohydrate?

31 Carbohydrate consumption

32 National nutrition surveys 21, Difference Nutrient Male Females Average Male Females Average Male Female Average Energy (kj) 10,824 7,299 9,062 11,195 7,624 9, Total carbohydrate (g) Total carbohydrate (%E) 41% 43% 42% 46% 48% 47% 5% 5% 5% Starches (g) Starches (%E) 23% 22% 22% 26% 27% 26% 3% 5% 4% Sugars (g) Sugars (%E) 17% 20% 18% 18% 20% 19% 1% 0% 1% Added sugars (g) Added sugars (%E) 9% 10% 10% 10% 10% 10% 1% 0% 0% 21. Cook et al. AFNMU, 2001; 22. Dietary Guidelines for Australians, 2003.

33 Increased sugars consumption is not a plausible cause of diabesity in Australia

34 23. Green Pool, 2012 Apparent consumption of sugar (kg/person/yr) in Australia:

35 22. NHMRC, Dietary Guidelines for Australians, 2003 Apparent consumption of sugar (kg/person/yr) in Australia: Bags of sugar In manufactured foods Total added sugar

36 Are we drinking more sugar 24? Sugar from sugar sweetened beverages 24. Barclay and Brand-Miller. Nutrients. 2011

37 We are consuming more non-nutritive sweeteners : 51% 2003: 66% FSANZ non-nutritive sweetener surveys: 1994 and 2003 Food/Drink Soft drinks (ml) Diet Regular Cordials (ml) Diet Regular Flavoured milks (ml) Diet 4 10 Regular TT sweetener (g) Diet Regular 9 13 Yoghurt/mousse (g) Diet 4 10 Regular Jellies/puddings (g) Diet Regular FSANZ, Jams (g) Diet Regular 3 2

38 Popular fad diets since 2000 targeting carbohydrate

39 Are we eating the wrong kind of carbohydrate?

40 Don t Australians eat too many carbs? 1. We already eat close to the minimum recommended amount 3,21 : % of kjs = g a day for average weight stable Australian adult 2. We do eat the wrong type 27 Average daily GI Aim for GI ~ Hess et al. Food Function. 2012, 3, 477; 21. Cook et al. AFNMU, 2001; 27. Barclay, Petocz, Flood, Brand-Miller, AJCN. 2008;87:

41 High GI/GL diets and human physiology Barclay, A. PhD thesis. December, 2007.

42 GI and overweight and obesity

43 Cochrane review and meta-analysis of low GI diets in overweight/obesity 29 decreases in body mass of 1.1 kg total fat mass of 1.1 kg, body mass index of 1.3 kg/m 2 significantly greater in participants receiving low GI compared to standard low fat diets 29. Thomas et al. The Cochrane Library 2007, Issue 3.

44 Comparison of 5 weight maintenance diets 30 Body weight changes over 26 wks in adults (n = 773) after 11 kg wt loss HP (21.7% of kjs), LGI (56.5)(total carbs = 44% of kjs; total kjs = 7,400 kj) diet lost 0.38 kg, all others gained weight 30. Larsen et al. N Engl J Med 2010;363:

45 Low GI diets and weight loss in children Comparison of 5 weight maintenance diets 31 Body weight changes over 26 wks in children(n = 465) HP (21.4% of kjs), LGI (56.9)(total carbs = 50.6% of kjs; total kjs = 6,253 kj) BMI z score by kg/m 2, all others gained weight 31. Papadaki et al. Pediatrics 2010;126(5):e1-e10.

46 ILSI SEAR Aasia GI ( Region) and GLNC diabetes ( - Carbohydrate intakes prevention - high, low or irrelevant? Australia - March 2013

47 Low GI diets and Type 2 diabetes Glycemic Index, glycemic load, and dietary fibre intake and incidence of type 2 diabetes in younger and middle-aged women 32 Design Cohort study Participants 91,249 US Women, aged Results High GI diet increase risk by 59% Diet Carb intake 224 g/day (50% E) Fibre intake 18.5 g/day Median GI Schulze et al Am J Clin Nutr, 2004; 80:

48 Relative risk of Type 2 Diabetes p < for trend Glycemic Index 32. Schulze et al Am J Clin Nutr, 2004; 80:

49 Systematic review and meta-analysis of low GL diets and type 2 diabetes 33 All evidence available from prospective cohort studies People consuming a low GL diet (<95g/8,400kJ/day) Decrease risk of developing type 2 diabetes by 45% This can be achieved by either: consuming 200 g carbohydrates (~40% kjs) a day with a GI of 50, or 250 g carbohydrates (~50% kjs) a day with a GI of Livesey, et al. AJCN 2013.

50 ILSI SEAR GI Aasia ( and Region) cardiovascular and GLNC ( - Carbohydrate intakes - high, low or irrelevant? disease Australia - March 2013

51 Low GI diets and heart disease A prospective study of dietary glycemic load, carbohydrate intake, and risk of coronary heart disease in US women 34 Design Cohort study Participants 75,521 US Women, aged Results High GI diet increase risk by 31% Diet Carb intake 186 g/day (40% E) Fibre intake 17 g/day Median GI Liu et al Am J Clin Nutr, 2000; 71:

52 Relative risk of CHD p = for trend Glycemic Index 34. Liu et al Am J Clin Nutr, 2000; 71:

53 Systematic review and meta-analysis of low GI and risk of heart disease studies. 230,000 participants 35. Mirrahimi et al. JAHA, 2012.

54 Summary The recommended carbohydrate intake is 45-65% of kjs, with less than 10% from added sugars Australians total carbohydrate consumption is at the bottom end of the range Added sugar consumption is at the top end of the range, but has been decreasing, replaced by nonnutritive sweeteners Refined sugars are no better or worse than refined starches, with the possible exception of SSBs The GI and GL are stronger predictors of disease risk, and Australians need to lower the GI of their diet rather than further reduce their carbohydrate intake

55 Declaration of interest I am the Vice President and a consultant to the GI Foundation and Head of research at the Australian Diabetes Council I am a co-author of the Diabetes and Pre-diabetes Handbook.