Sugar consumption and health: an update of the evidence

Transcription

1 Sugar consumption and health: an update of the evidence Dr Charlotte Evans Lecturer in nutritional epidemiology School of Food Science and Nutrition, University of Leeds FDIN 8 th May,

2 Sources of sugars

3 UK advice: Eatwell plate CHD 3

4 Sugars: recommended & consumed Nutrient UK Recommendation UK* consumption Energy intake KJ/kcal Women 9MJ/day (2000kcal) Men 11MJ/day (2500kcal) Women 1600kcal Men 2151kcal Total carbohydrate 50% of energy ~50% Non milk extrinsic (added) sugars 10% of total energy 11% of food energy 12-15% (higher in children) No recommendations for: Sugar sweetened beverages (SSB) Glycaemic index (GI) *NDNS 3 year summary

5 Percent contribution of sources of added sugar Other Savoury food Dairy Alcohol Biscuits & cakes Soft drinks Sweets Percent contribution of different sources of added sugars Information from NHS choices last reviewed

6 Background: CVD mortality trends UK Source: Global Atlas on Cardiovascular Disease Prevention and Control. Mendis S, Puska P, Norrving B editors. World Health Organization, Geneva 2011.

7 Background: risks for CVD High blood sugar/type 2 diabetes mellitus Associated with higher risk of CVD High blood pressure High Tryaclglycerol (TAG) Obesity

8 UK advice (NHS) for a healthy heart BMI 8

9 Objectives: Is there a relationship between sugars and cardiometabolic health? Observational evidence linking sugars with risk of diabetes and cardiovascular disease Evidence from RCTs looking at total sugar and sugar sweetened beverages and markers of cardiovascular disease (e.g. Body weight) Is there any difference between natural vs. added sugars? Is the evidence different for sugar sweetened beverages compared with total added sugars? Gaps in the knowledge 9

10 Hierarchy of evidence 10

11 Evidence: cohorts Dietary data Baseline dietary data collected Follow up data collected (optional) Heart & stroke events, DM Mortality data Hospital Episode Statistics Results are presented as the relative risk or risk ratio: RR<1 is a reduced risk RR>1 is an increased risk Specified intake is compared with reference intake, e.g. low vs high added sugar intake

12 Evidence: Trials Participants are randomly allocated to intervention group(s) and the control group Outcome can be binary (obese yes/no) or continuous (BMI)

13 From: Added Sugar Intake and Cardiovascular Diseases Mortality Among US Adults JAMA Intern Med. 2014;():. doi: /jamainternmed Figure Legend: Adjusted Hazard Ratio (HR) of the Usual Percentage of Calories From Added Sugar for Cardiovascular Disease Mortality Among US Adults 20 Years or Older: National Health and Nutrition Examination Survey Linked Mortality Files, Histogram of the distribution of usual percentage of calories from added sugar in the population. Lines show the adjusted HRs from Cox models. Midvalue of quintile 1 (7.4%) was the reference standard. The model was adjusted for age, sex, race/ethnicity, educational attainment, smoking status, alcohol consumption, physical activity level, family history of cardiovascular disease, antihypertensive medication use, Healthy Eating Index score, body mass index, systolic blood pressure, total serum cholesterol, and total calories. Solid line indicates point estimates; dashed lines indicate 95% CIs. Date of download: 4/1/2014 Copyright 2014 American Medical Association. All rights reserved.

14 Limitations of cohort studies Many differences between countries and populations Differences in duration of the cohort Difficult to measure habitual diet may only have been measured once with a food frequency questionnaire what is the comparator? Compare sweetened drinks with artificially sweetened drinks? Take out sugar and replace with something else? Residual confounding 14

15 Systematic review of trials Effect of increasing free sugars on measures of body fatness in adults. Te Morenga L et al. BMJ 2013;346:bmj.e by British Medical Journal Publishing Group

16 Fig 5 Isoenergetic exchanges of free sugars with other carbohydrates or other macronutrient sources. Te Morenga L et al. BMJ 2013;346:bmj.e by British Medical Journal Publishing Group

17 Limitations of trials on sugars Expensive so generally small Short duration Can infer causality but not possible for some health outcomes such as diabetes and CVD 17

18 Sucrose vs fructose Fructose in natural form (i.e. Fruit) does not increase risk of CVD and Diabetes Fructose as added sugar is similar to sucrose in terms of health outcomes 18

19 Effect of isocaloric exchange of fructose for other sources of carbohydrate on pooled postprandial triglyceride endpoints in diabetics and non-diabetics Effect of fructose on postprandial triglycerides: A systematic review and meta-analysis of controlled feeding trials D. David Wang, John L. Sievenpiper, Russell J. de Souza, Adrian I. Cozma, Laura Chiavaroli, Vanessa Ha, Aras... Atherosclerosis, Volume 232, Issue 1, 2014,

20 Sugar sweetened beverages (SSB)

21 Systematic review of SSB & CVD risk There are no systematic reviews of CVD risk and SSB intake Individual cohort studies suggest that there is 20% higher risk of CVD for highest quartile of intake (1-2 drinks per day) compared with lowest quartile (never or rare intake) (references Fung et al (2009) AJCN, Koning et al (2012) Circulation)

22 A: Forest plot of studies evaluating SSB consumption and risk of type 2 diabetes, comparing extreme quantiles of intake. Malik V S et al. Dia Care 2010;33: Copyright 2011 American Diabetes Association, Inc.

23 Risk for incident type 2 diabetes for highest versus lowest intake of fruit juice (by type of juice). Xi B, Li S, Liu Z, Tian H, et al. (2014) Intake of Fruit Juice and Incidence of Type 2 Diabetes: A Systematic Review and Meta- Analysis. PLoS ONE 9(3): e doi: /journal.pone

24 Glycaemic index (GI)

25 Weighted mean differences (95% CI) in weight change (kg) between the intervention and control regimens from randomized controlled trials in adults. Malik V S et al. Am J Clin Nutr 2013;98: by American Society for Nutrition

26 Gaps in the evidence (in red!) CVD and Diabetes No systematic reviews of cohorts to determine risk of total added sugars or sugar sweetened beverages on cardiovascular disease (there are individual cohorts available which report higher risk of CVD with higher total added sugar and sugar sweetened beverage consumption) Systematic review of cohorts reporting higher risk of type 2 Diabetes Mellitus with higher sugar sweetened beverage consumption (but not total added sugar) Fruit juice may also increase risk of type 2 Diabetes Obesity and other markers of CVD Systematic reviews of trials reporting higher risk of obesity or weight gain with higher total added sugars and sugar sweetened beverages in adults (in trials that are not isocaloric) Lack of evidence on effect of added sugar intake on other markers of cardiovascular disease such as blood pressure and insulin sensitivity in healthy populations 26

27 Recommendations around the world German Nutrition Society, Germany: High consumption of sugar-sweetened beverages increases the risk of obesity & type 2 diabetes mellitus High dietary fibre intake, mainly from whole-grain products, reduces the risk of obesity, type 2 diabetes mellitus & cardiovascular disease. WHO: Review of sugars and obesity. Honey, syrup and fruit juice are now included in added sugar. New target of sugars <5% of energy. UK: Currently updating recommendations for carbohydrates and cardio-metabolic health. Review document out for consultation summer 2014 by Scientific advisory committee on nutrition. European Food Safety Authority (EFSA): Have not updated their recommendations recently (45-60% of energy as carbohydrate, 25g of fibre). Insufficient evidence to set an upper limit on added sugar intake USA: Maximum upper limit on added sugars of 25%,, fibre intakes recommended are double the average intake. Wholegrain foods encouraged. 27

28 Industry Funding British Medical Journal guidelines for Industry-sponsored studies If you are submitting an original article reporting an industrysponsored clinical trial, post-marketing study, or other observational study please follow the guidelines on Good Publication Practice (GPP2) and on properly reporting the role of professional medical writers. Another resource, the Authors' Submission Toolkit: A practical guide to getting your research published summarises general tips and best practices to increase awareness of journals' editorial requirements, how to choose the right journal, submission processes, publication ethics, peer review, and effective communication with editors. Reference: BMJ research Good Publication Practice (GPP2, 2009) 28

29 Industry Funding GPP2 provides comprehensive guidance on a number of key issues, including: Roles of authors, sponsors, and other contributors Reimbursement and honoraria How to establish a publication steering committee Role of professional medical writers Recommendations for publication planning and documentation 29

30 Conclusions Higher intake of sugar sweetened beverages is associated with increased risk of diabetes and causes weight gain in adults Higher intake of total added sugars causes weight gain in adults There are some important gaps in the evidence - The difference between lack of evidence available and evidence of no association should be noted This area of research is fast moving and different countries/regions are reviewing their recommendations for added sugars taking new evidence into account

31 Thank you Dr Victoria Burley Professor Janet Cade Thanks also to my colleagues at the University of Leeds Dr Darren Greenwood Dr Diane Threapleton 31

32 Meta-Analysis of Dietary Glycemic Load and Glycemic Index in Relation to Risk of Coronary Heart Disease Figure 3 Forest plots show associations between dietary glycemic index and risk of coronary heart disease in men, women, and men and women combined. Comparison refers to mean/median in the highest versus lowest categories of glycemic index (white bread u... Jia-Yi Dong, Yong-Hong Zhang, Peiyu Wang, Li-Qiang Qin The American Journal of Cardiology, Volume 109, Issue 11, 2012, Similar results are seen with GI/GL and risk of diabetes.

33 Glycemic Index, Glycemic Load, Carbohydrates, and Type 2 Diabetes: Systematic review and dose-response meta-analysis of prospective studies. Glycemic Index, Glycemic Load, Carbohydrates, and Type 2 Diabetes: Systematic review and dose-response meta-analysis of prospective studies. Greenwood, Darren; Threapleton, Diane; Evans, Charlotte; Cleghorn, Christine; Nykjaer, Camilla; Woodhead, Charlotte; Burley, Victoria Diabetes Care. 36(12): , December 2013.DOI: /dc by the American Diabetes Association, Inc. Published by American Diabetes Association. 2

34 Weighted mean differences in BMI change (95% CI) between the intervention and control regimens from randomized controlled trials in children. Malik V S et al. Am J Clin Nutr 2013;98: by American Society for Nutrition