September 10, 2014

Heart disease and stroke are serious public health concerns. Modifiable lifestyle risk factors include high blood pressure, high blood cholesterol, diabetes, being overweight, excessive alcohol consumption, physical inactivity, smoking and stress1. Adopting healthy behaviours, including a healthy diet, can help prevent early disease. 

On September 9, 2014, the Heart & Stroke Foundation released a position statement on "Sugar, Heart Disease and Stroke" recommending that "total intake of free sugars not exceed 10% of total daily calorie (energy) intake, and ideally less than 5%”. These recommendations mirror draft recommendations released by the World Health Organization (WHO) on March 5, 20142. However, the draft WHO recommendations were based on evidence related to dental caries only, not obesity or other diseases; the 10% ‘strong’ recommendation was based on evidence graded by the WHO as “moderate” and the ‘conditional’ 5% recommendation was based on evidence graded by the WHO as “very low quality”3

Unfortunately, this new position statement has not systematically reviewed the breadth of scientific evidence available with respect to sugar consumption and health effects. The references cited in the position statement either do not support associations between sugars and obesity, diabetes, or blood cholesterol; are not relevant to the issue under discussion; are observational studies providing very low quality evidence; or are narrative reviews rather than systematic reviews. All recent systematic reviews have not found support from the totality of the evidence to link sugar with heart disease or other lifestyle diseases, with the exception of dental caries, in which all fermentable carbohydrate play a role4-10. None of these systematic reviews has found evidence to set a specific limit on added sugars intake. Current estimated intakes of added sugars in Canada are in the range of 11-13% daily energy intake11, which is considered moderate and is well below the Institute of Medicine’s suggested maximum intake of 25% energy to prevent inadequate micronutrient intakes in some population subgroups12.

In terms of maintaining a healthy weight, the Heart & Stroke Foundation correctly observes that “While there are a variety of causes of obesity, researchers speculate that excess caloric intake may be the single largest driver”. Excess energy intake is associated with an increased risk of obesity, however the source of the calories has not been found to be a significant factor10. Therefore a singular focus on any one nutrient including sugar, which has not been identified as a unique contributor to excess calories or weight gain, will not address the problem of rising obesity rates in Canada.

The Canadian Sugar Institute, Nutrition Information Service supports public health approaches to reducing obesity that reflect the complexity of the disease and its multiple risk factors. Maintaining a healthy weight depends on regular physical activity and eating a healthy diet according to Canada's Food Guide, including avoiding fad diets, managing portion sizes, and moderating overall food intake13

 

References

  1. Heart & Stroke Foundation, Heart disease prevention.  June 2012. http://www.heartandstroke.com/site/c.ikIQLcMWJtE/b.3483919/k.EB14/Heart_disease__Prevention_and_risk_factors.htm
  2. WHO Draft Guideline: Sugars intake for adults and children.  March 2014. http://www.who.int/nutrition/sugars_public_consultation/en/
  3. Canadian Sugar Institute, Review of WHO draft guidelines on sugars. http://www.sugar.ca/News/Nutrition-Health/Review-of-WHO-Draft-guidelines-on-free-sugars-rele.aspx
  4. Gibson S, Gunn P, Wittekind A, Cottrell R.The effects of sucrose on metabolic health: a systematic review of human intervention studies in healthy adults. Crit Rev Food Sci Nutr. 2013;53(6):591-614.
  5. Sievenpiper JL, de Souza RJ, Mirrahimi A, Yu ME, Carleton AJ, Beyene J, Chiavaroli L, Di Buono M, Jenkins AL, Leiter LA, Wolever TM, Kendall CW, Jenkins DJ. Effect of fructose on body weight in controlled feeding trials: a systematic review and meta-analysis. Ann Intern Med. 2012 Feb 21;156(4):291-304.
  6. Cozma AI, Sievenpiper JL, de Souza RJ, Chiavaroli L, Ha V, Wang DD, Mirrahimi A, Yu ME, Carleton AJ, Di Buono M, Jenkins AL, Leiter LA, Wolever TM, Beyene J, Kendall CW, Jenkins DJ. Effect of fructose on glycemic control in diabetes: a systematic review and meta-analysis of controlled feeding trials. Diabetes Care. 2012 Jul;35(7):1611-20.
  7. European Food Safety Authority. Scientific opinion on dietary reference values for carbohydrates and dietary fibre. EFSA Panel on Dietetic Products, Nutrition and Allergies. EFSA Journal. 2010; 8(3):1462.
  8. Ruxton, C. H. S., Gardner, E. J. and McNulty, H. M.(2010) 'Is Sugar Consumption Detrimental to Health? A Review of the Evidence 1995—2006', Critical Reviews in Food Science and Nutrition, 50: 1, 1-19.
  9. Te Morenga L, Mallard S, Mann J. Dietary sugars and body weight: Systematic review and meta-analyses of randomised controlled trials and cohort studies. British Medical Journal. 2013;346:e7492.
  10. Langlois K, Garriguet D. Diet composition and obesity among Canadian adults. Statistics Canada Health Report 2009.
  11. Brisbois TD, Marsden SL, Anderson GH, and Sievenpiper JL. Estimated Intakes and Sources of Total and Added Sugars in the Canadian Diet. Nutrients, 2014, 6(5);1899-1912.
  12. Food and Nutrition Board, Institute of Medicine, National Academy of Sciences. Dietary reference intakes for energy, carbohydrates, fiber, fat, protein and amino acids. National Academic Press. Washington, 2005.
  13. Health Canada. Obesity, minimizing your risk. http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/life-vie/obes-eng.php