Updated: Nov 12, 2021
Part 2 of Access to hope: The discovery of insulin 100 years on
Bec Johnson, Type 1 Diabetes Family Centre CEO
November 14, 2021
“The diabetic who knows the most, lives the longest” – Elliot P. Joslin
Knowledge is power, and the quality of information accessed by people with diabetes is critical. One area where quality information is of utmost importance is the dietary advice given to people with diabetes, which in Australia is to eat according to the Australian Dietary Guidelines.
Under the Guidelines, an adult’s daily intake should include of six serves of grain-based carbohydrate foods along with starchy vegetables and sweet fruits – a diet that is 45% to 65% carbohydrates. Following this advice, a person with diabetes’ daily challenge becomes to try to accurately count grams of carbohydrate – an exercise that has been proven to be nigh-on impossible - and match the carbohydrate grams with an appropriate insulin dose – a method that has no definitive evidence of efficacy behind it. Dr Belinda Lennerz, an endocrinologist at Boston Children’s Hospital, notes the inherent flaws in this approach, saying that “one of the big challenges in diabetes care is this mismatch that you always have between carb intake and estimating how much insulin you’ll need.” As a result, only a small minority of children (17%) and adults (13%) achieve satisfactory diabetes control.
The current dietary advice proves a fundamental departure from the diets originally recommended for people with diabetes by Joslin and other early diabetologists. Based on the logic that, if a person cannot easily metabolise carbohydrates, they should eat fewer of them, early dietary recommendations severely restricted carbohydrates in an attempt to prolong life. Elizabeth Hughes, who developed diabetes at age 11 in 1919, survived for three whole years on a very low-carbohydrate diet, until she received her first dose of newly-discovered insulin in 1922. Joslin wrote in his 1924 Diabetic Manual that ‘The task of the diabetic … is to learn how to live comfortably upon far less carbohydrate than that to which he has been accustomed, and upon far more fat.” The logic of the treatment held, and, although brutal in its early form (Joslin and others didn’t only limit carbohydrates – they limited overall calories and implemented a heavy exercise regimen too), was effective: life was extended, even in the absence of insulin. Joslin held firm on his recommendation for carbohydrate restriction even in the post-insulin era, stating in 1924 that with insulin “success in treatment is most easily attained by the selection of a diet which will keep the urine sugar-free”.
As the decades passed, however, thinking changed: a low-fat, high-carbohydrate diet came into vogue as the (seemingly) 'heart-healthy' diet after President Eisenhower had a heart attack in 1955. Carbohydrates, particularly from cereals, became the mainstay of the recommended diet for everyone across the western world, including people with diabetes. In the early 1950s, the American Diabetes Association (ADA), The American Dietetic Association, and the U.S. Public Health Service joined forces to make nationally applicable recommendations for people with diabetes. Their recommended carbohydrate percentages continued to increase, reaching a peak at 55-60% in 1986.
When such a profound about-face in health advice occurs, it should be based in evidence. It is fair to expect large-scale clinical trials comparing the original limited-carbohydrate approach with a high-carbohydrate approach, and the results to drive better, safer recommendations. This is especially important given the serious, known dangers of high blood glucose levels, which are directly related to carbohydrate consumption.
However, this work was never done: the Australian Dietary Guidelines and their equivalents in the USA and UK were brought in without being scientifically tested in the context of the management of type 1 diabetes. The diabetes clinical care guidelines themselves admit this: even though Diabetes UK recommends that people with type 1 eat “the same healthy, balanced diet [that] is recommended for everyone,” namely, a diet that is largely based upon starchy carbohydrate, its own Evidence-based Nutrition Guidelines state that “there is no convincing evidence for a recommended ideal amount of carbohydrate for maintaining long-term glycaemic control in people with Type 1 diabetes”. The Australian National Clinical Care Guidelines for people with diabetes concur, stating that “the evidence base for many aspects of dietary management of diabetes is limited and is often not of high quality.” Despite this, the Australian Dietary Guidelines are recommended, even though they themselves state that “[they] do not apply to people who need special dietary advice for a medical condition.”
A lack of evidence for recommending the Guidelines for people with diabetes is apparent, but to make matters worse, the Guidelines themselves are under attack for their questionable evidence base. 2020 Australian of the Year, eye surgeon Dr James Muecke, has called strongly for reform of the Guidelines, saying “clearly, the dietary advice is wrong,” describing their recommendations as biased and unscientific: “borne out of weak and unreliable epidemiological data.” His main issue with the Guidelines is that their low-fat, high-carbohydrate emphasis has effectively shifted consumption patterns towards low-fat, highly-processed products with added sugar, which has resulted in Australia’s epidemics of obesity and type 2 diabetes. The impact of these kinds of foods on the blood glucose levels of people with type 1 diabetes goes without saying.
Our dietary guidelines should not only be based on strong science, they must also be free from the influence of food manufacturers. This means the peak bodies that promote the guidelines must also be free of industry influence. Bending to mounting pressure to untangle itself from decades of industry partnerships with food companies such as Nestle, Unilever, Arnotts, McDonalds and Coca-Cola, Dietitians Australia finally announced in 2018 that it would wind up its food industry affiliations – a positive, but very belated step towards cleaning up its diet advice. Even today, however, diabetes organisations still work with processed food companies to promote their products. For example, the high-carbohydrate recipes for Sticky Date and Oat Cake, Apple and Raspberry Crumble, and Anzac Weetbix Cookies - in fact, one in five of the dessert recipes promoted on a major state diabetes agency’s website - were provided by Sanitarium. The Australian Department of Health is not immune to industry influence either. A 2017 report concluding that increasing Australia’s grain fibre intake could save the economy $3.3 billion dollars a year in health costs triggered a press release from the Australian Health Department entitled “Tackle chronic disease by eating more fibre”, which recommended that people eat more grains. The report was commissioned by cereal manufacturer, Kellogg Australia.
Even the slightest hint of industry influence over our peak health bodies begs the question: what does this mean for the integrity of their advice? There is much work to be done, not only to review and revise the Australian dietary guidelines, work that is thankfully underway thanks to Dr James Muecke, but also to discover the best diet to recommend to people with type 1 diabetes - this time based on thorough testing and research. Some researchers have made positive early inroads into testing the value of, and new applications for, low-carbohydrate advice from a century ago, but in the meantime, it is important that every person with type 1 diabetes does their own research.
 Multiple sources, for example: Australian Diabetes Society and Australasian Paediatric Endocrine Group (2011) National Evidence-Based Clinical Care Guidelines for Type 1 Diabetes in Children, Adolescents and Adults, p84. National Diabetes Services Scheme, Healthy Eating: https://www.ndss.com.au/living-with-diabetes/health-management/nutrition/healthy-eating/ Diabetes Australia, Be Healthy: https://www.diabetesaustralia.com.au/living-with-diabetes/diabetes-healthy/be-healthy/ which states “Healthy eating for people living with diabetes is no different to what is recommended for everyone else.” This video from Diabetes Victoria entitled Healthy Eating: https://www.youtube.com/watch?v=1tS9g3FY5vs&list=PLBV2m3gK4NQLcMOgeFLVGhRAHRt8zZlwp&index=4 https://pch.health.wa.gov.au/~/media/Files/Hospitals/PCH/General%20documents/Our%20Services/T1Dfolder_PCHTKI.pdf All links accessed 7 November 2021.  National Health and Medical Research Council and Department of Health. Eat for Health, Recommended Number of Serves for Adults. https://www.eatforhealth.gov.au/food-essentials/how-much-do-we-need-each-day/recommended-number-serves-adults. All links accessed 11 November 2021.  Smart, C et al. (2011) Biting off more than you can chew; Is it possible to precisely count carbohydrate? Nutrition and Dietetics 68(3).  Schmidt, S. Schelde, K. and Norgaard, K. (2014) Effects of advanced carbohydrate counting in patients with Type 1 diabetes: A systematic review. Diabetic Medicine: 31(8).  McCarthy, A. (8 January 2021) Low carb diets for diabetes: Rediscovering centuries-old wisdom. Boston Children’s Hospital. Online here: https://answers.childrenshospital.org/low-carb-diet-diabetes/ Accessed 4 November 2021.  Holmes-Walker D.J. et al. (2021).  Bliss, M. (1982) pp43-44, 151. Joslin, E.P (1924), p66. Joslin, E.P (1924), p22. Joslin, E.P (1924), p21. An example of the recommended daily intake: Four large portions of vegetables, two small oranges, half a pint of cream, two eggs, four strips of crispy bacon, one moderate portion of meat, three portions of butter, equivalent to 48g carbohydrates, 59g protein, 115g fat. Joslin, p131.  Stokes, A. When Science and Industry Collide. Boston University: https://www.bu.edu/articles/2016/when-science-and-industry-collide/. Accessed 11 November 2021. See also Kearns, C.E., Schmidt, L.A., Stanton, A.G. (2016). Special Communication: Sugar Industry and Coronary Heart Disease Research: A Historical Analysis of Internal Industry Documents. JAMA Internal Med: 176(11).  American Diabetes Association. (November/December 2015). Living History. Online here: http://main.diabetes.org/dforg/pdfs/2018/ada-timeline.pdf. Accessed 11 November 2021.  American Diabetes Association. (January 1987). Nutritional Recommendations and Principles for Individuals with Diabetes Mellitus: 1986. Diabetes Care: 10(1).  Diabetes UK. I have type 1 diabetes – what can I eat? https://www.diabetes.org.uk/guide-to-diabetes/enjoy-food/eating-with-diabetes/i-have-type-1-diabetes. Accessed 7 November 2021.  Diabetes UK. (2018). Evidence-based nutrition guidelines for the prevention and management of diabetes, p25. The British guidelines also state that “Intervention studies have failed to show any significant effect on glycaemic control of manipulating dietary quantity of carbohydrate” however for this statement it references four studies only, from 1976, 1979, 1985 and 2009, that studied a total of 62 people. Two out of four of these studies (Strycher, 2009 and Hollenbeck, 1985) had cardiovascular outcomes, not glycaemic management, as their primary outcomes. A search for keywords “dietary carbohydrate intervention type 1 diabetes” in PubMed returns 488 results. Australian Diabetes Society and Australasian Paediatric Endocrine Group (2011). National Evidence-Based Clinical Care Guidelines for Type 1 Diabetes in Children, Adolescents and Adults, p83.  National Health and Medical Research Council and Department of Health. Eat for Health: About the Australian Dietary Guidelines. https://www.eatforhealth.gov.au/guidelines/about-australian-dietary-guidelines. Accessed 11 November 2021.  Klun, R. (1 December 2020). Australian of the Year says dietary guidelines letting down millions with diabetes. Sydney Morning Herald. Online here: https://www.smh.com.au/politics/federal/australian-of-the-year-says-dietary-guidelines-letting-down-millions-with-diabetes-20201201-p56jmu.html. Accessed 7 November 2021.  Risso, A. (1 December 2020). Aussie of the Year demands diet rule overhaul. The Canberra Times. Online here: https://www.canberratimes.com.au/story/7036750/aussie-of-year-demands-diet-rule-overhaul/. Accessed 7 November 2021.  Simon, M. (February 2015). Eat Drink Politics: Is the Dietitians Association of Australia in the Pocket of Big Food? Report covered in brief here: http://www.eatdrinkpolitics.com/2015/02/17/is-the-dietitians-association-of-australia-in-the-pocket-of-big-food/. Accessed 7 November 2021.  Dietitians Australia (3 October 2018). Public Announcements: Conclusion of DA’s Corporate Partnership Program. Online here: https://dietitiansaustralia.org.au/voice-of-daa/public-statements/. Accessed 7 November 2021.  Recipes linked here: https://diabetesnsw.com.au/recipe/anzacish-weet-bix-cookies/ https://diabetesnsw.com.au/recipe/apple-and-raspberry-crumble/ https://diabetesnsw.com.au/recipe/sticky-date-and-oat-cake/ Accessed 7 November 2021.  Nutrition Research Australia and Deloitte Access Economics (2017). Healthcare expenditure and productivity cost savings resulting from increased intake of grain fibre in Australia. Available here: https://www2.deloitte.com/content/dam/Deloitte/au/Documents/Economics/deloitte-au-economics-expenditure-savings-increased-intake-grain-fibre-australia-291117.pdf. Read the Assistant Minister for Health’s comments in the Diabetes NSW and ACT press release here: https://diabetesnsw.com.au/news/increasing-australias-grain-fibre-intake-save-economy-3-3-billion-year/ and British academic Zoe Harcombe’s analysis here: https://www.zoeharcombe.com/2017/12/increasing-australias-grain-fibre-intake-could-save-the-economy-3-3-billion-a-year. All links accessed 7 November 2021.  Lennerz, B.S. et al. (2021). Carbohydrate restriction for diabetes: rediscovering centuries-old wisdom. The Journal of Clinical Investigation: 131(1). See also Lennerz, B.S. et al. (2018) Management of Type 1 Diabetes with a Very Low-Carbohydrate Diet. Pediatrics: 141(6).