May 31, 2013

The Canadian Sugar Institute’s Manager of Nutrition and Scientific Affairs, Dr. Tristin Brisbois, chaired a symposium "Nutrition Misconceptions - The role of the media and the researchers: Sugar - a case study" on Friday May 31, 2013 at the Canadian Nutrition Society Annual Meeting in Quebec City, QC. This symposium reviewed available Canadian data on sugars consumption and explored the scientific findings regarding sugars' effect on body weight and other health outcomes. Various issues in sugar-related research were addressed and compared to media headlines to help participants critically evaluate nutrition-related media articles.

Dr. Brisbois and Dr. John Sievenpiper were the speakers. Dr. Brisbois presented sugars consumption data in Canada and introduced some media headlines that pertain to common misconceptions about sugar in her presentation entitled "Common misconceptions about sugars – consumption and dietary goals. Dr. John Sievenpiper's presentation entitled "Maintaining perspective in research and the media: The not so toxic truth about sugar" drew from his key findings on sugars' effect on body weight and other health outcomes and addressed the limitations of various sugar-related research.

Common misconceptions about sugars – consumption and dietary goals

Dr. Tristin Brisbois, PhD

Sugars are an integral part of our diets and food supply; they occur naturally in fruits, vegetables, and milk products and are added to foods to contribute various sensory, functional and food safety properties. The media suggests that we are consuming too much sugar; however, rarely are accurate statistics cited, creating several misconceptions regarding actual consumption patterns. Few published studies estimating sugars consumption exist, especially among the Canadian population. The lack of studies may be in part due to the complications associated with estimating added sugars consumption. Such difficulties include estimating waste adjustment factors to determine apparent consumption from food availability data; missing availability data for some sources of added sugars (notably corn sweeteners) and the lack of a comprehensive database of added sugars content in foods. Since there is limited published Canadian data on added sugars intake, US statistics are often cited, which overestimate Canadian consumption. Finally, the global misuse of sugars terminology and the misinterpretation of data also make it difficult to determine actual added sugars consumption levels. For instance, scientific reports and media often use the term “sugar” to describe total sugars, which can lead to overestimates of added sugars consumption. All of these reasons may lead to the common belief that sugars consumption has increased over the last few decades. However, analysis of Statistics Canada availability data show added sugars intakes to be stable or modestly declining as a percent of total energy over the past 3 decades; this trend is shared by other developed countries such as Australia, the UK, and the US. Both Statistics Canada data and Canadian Community Health Survey (CCHS) nutrition survey data estimate added sugars to contribute approximately 11-13% of total daily calories among Canadians. Unlike other nutrients, there is no quantitative recommendation for total or added sugars intake in Canada. Canadian-US dietary reference intakes suggest a maximum of 25% of total energy from added sugars. CCHS data show Canadians are consuming sugars from a variety of foods within the four food groups, including milk, fruits and vegetables and grains. Taken together these data suggest that added sugars consumption in Canada is not increasing and is within dietary recommendations.

Learning objectives:

  1. To understand sugars terminology and the functional role of sugars in foods and in the diet.
  2. To learn the main sources of sugars in Canadians’ diets and estimates of added sugars intakes among Canadians and how these compare to dietary recommendations.
  3. To understand the complications involved in estimating added sugars intakes and how this affects what is presented in both scientific and popular articles.

References:

  1. Barclay AW, Brand-Miller J. The Australian Paradox: A Substantial Decline in Sugars Intake over the Same Timeframe that Overweight and Obesity Have Increased. Nutrients 2011;3:491-504.
  2. Hall KD, Guo J, Dore M, Chow CC. The progressive increase of food waste in America and its environmental impact. PLoS One 2009;4:e7940.
  3. Institute of Medicine. Dietary Reference Intakes (DRI) for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, D.C.: The National Academies Press, 2005.
  4. Langlois K, Garriguet D. Sugar consumption among Canadians of all ages. Health Rep 2011;22.
  5. Ruxton CH, Gardner EJ, McNulty HM. Is sugar consumption detrimental to health? A review of the evidence 1995-2006. Crit Rev Food Sci Nutr 2010;50:1-19.
  6. Welsh JA, Sharma AJ, Grellinger L, Vos MB. Consumption of added sugars is decreasing in the United States. Am J Clin Nutr 2011.

Maintaining perspective in research and the media: The not so toxic truth about sugar

Dr. John L Sievenpiper MD, PhD

Fructose has become a focus of intense concern regarding its role in the epidemics of obesity and cardiometabolic disease. Strong parallels are being drawn between fructose-containing sugars and tobacco with the suggestion that fructose-containing sugars are to obesity and cardiometabolic disease as tobacco smoke is to lung cancer and cardiovascular disease. There have been dozens of editorials, commentaries, and letters in the scientific literature and numerous pieces in the lay media calling for efforts to regulate its intake like tobacco. Uncontrolled ecological studies which have linked increasing fructose intake with increasing obesity rates since the 1970s along with animal models and human trials of fructose overfeeding at levels of exposure far beyond actual population levels of intake have been used to underpin this debate. Despite the limitations in extrapolating from these data, international diabetes and heart associations in their most recent recommendations have taken a risk reduction approach to fructose-containing sugars and in particular fructose, setting upper thresholds for intake. To address the uncertainty in the evidence, we and others have conducted a series of systematic reviews and meta-analyses of controlled feeding trials to assess the effect of fructose (the presumed culprit) on 6 areas of cardiometabolic control: lipids, body weight, glycemia, blood pressure, uric acid, and NAFLD. Contrary to the concerns expressed, our synthesis shows that there is a reasonable body of consistent evidence from controlled feeding trials that fructose in isocaloric exchange for other sources of carbohydrate at low-to-moderate doses near the average population intake (10% total energy) does not harm serum lipids, body weight, blood pressure, uric acid, or markers of NAFLD and may even benefit glycemia and blood pressure. There is, however, an emerging body of consistent evidence that fructose providing excess energy (+18-97% excess energy) at extreme doses (>100-g/day) well above the 95-percentile for intake may promote dyslipidemia, weight gain, raised uric acid levels, and NAFLD, an effect which may be more attributable to excess energy than fructose. The shorter duration, poor quality and unexplained inter-study heterogeneity among the available trials indicate the need for larger, longer-term, “real world” feeding trials to guide our understanding of fructose’s true metabolic consequences.

Learning Objectives

  1. To appreciate differences in fructose metabolism between animals and humans.
  2. To understand the limitations of the ecological analyses linking fructose to cardiometabolic risk and to assess the evidence from prospective cohort studies linking fructose-containing sugars with cardiometabolic disease.
  3. To discuss the effect of fructose on cardiometabolic risk factors in “isocaloric” versus “hypercaloric” feeding trials.

References

  1. Cozma AI, Sievenpiper JL, de Souza RJ et al. Effect of Fructose on Glycemic Control in Diabetes: A systematic review and meta-analysis of controlled feeding trials. Diabetes Care 2012;35:1611-20.
  2. Ha V, Sievenpiper JL, de Souza RJ et al. Effect of Fructose on Blood Pressure: A Systematic Review and Meta-Analysis of Controlled Feeding Trials. Hypertension 2012.
  3. Sievenpiper JL, Chiavaroli L, de Souza RJ et al. 'Catalytic' doses of fructose may benefit glycaemic control without harming cardiometabolic risk factors: a small meta-analysis of randomised controlled feeding trials. Br J Nutr 2012;1-6.
  4. Sievenpiper JL, de Souza RJ, Mirrahimi A et al. Effect of Fructose on Body Weight in Controlled Feeding Trials: A Systematic Review and Meta-analysis. Ann Intern Med 2012;156:291-304.
  5. Wang DD, Sievenpiper JL, de Souza RJ et al. The Effects of Fructose Intake on Serum Uric Acid Vary among Controlled Dietary Trials. J Nutr 2012.