April 30, 2015

expert reaction to study investigating sugary drinks and type 2 diabetes

Publishing in the journal Diabetologia, research based on more than 25,000 people in the UK has reported a link between a person’s energy intake provided by sweet drinks, and the risk of developing type 2 diabetes. The authors suggest that replacing sugary drinks with unsweetened drinks such as water or tea could help prevent developing the disease.

Prof. Tom Sanders, Professor emeritus of Nutrition and Dietetics, King’s College London, said:

“This is a sound paper taking further the observations made in the European Prospective Investigation into Cancer study which found around a 20% higher risk of developing type 2 diabetes among people who usually drink high amounts of sugary drinks compared to those who consume very little. A limitation of the findings is that in the early stages of diabetes people tend to drink more of all types of drink. Previous research has suggested that the consumption of low calorie drinks is associated with a greater risk of diabetes but this is generally attributed to increased fluid intake being associated with the early stages diabetes rather than a causal effect. As the authors correctly point out, overweight/obese individuals are more likely to choose artificially sweetened beverages. This is explains why low calorie drinks were no longer associated with risk when they adjusted for the degree of obesity.

“It is important to emphasise that this is not a trial of dietary modification but a comparison of risk of diabetes based on past patterns of intake recorded by a food frequency questionnaire which does not ask about the serving size of drink. Weight gain has a huge effect on diabetes risk compared to diet quality (even a small weight gain will increase risk several fold) compared to the small effects of high intakes of sugar or other aspects of diet such as high intakes of red and processed meat and white rice; coffee, dairy products, green leafy vegetable and wholegrain intake in contrast are associated with a lower risk (Ley et al. Lancet 2014; 383:1999-2007).

“Consequently, the data from this study show associations that may or may not be causal and could reflect other health related behaviour. For example, the choice to drink water, tea and fruit juice is associated with a healthy lifestyle as opposed to drinking soft drinks and sugary flavoured milk which are associated with fast food outlets. Fizzy full-sugar and sweetened milk drinks tend to provide more calories per serving than sweetened tea or coffee. Fizzy drinks tend to be sold in 330 ml or 500 ml bottles and contain about 40 kcal/100 ml which would supply between 160 and 200 kcal per serving; sweetened milk drinks (i.e. milkshakes) are sold in 400 ml or 500 ml bottles contain 88 kcal/100 ml and so would supply between 350-450 kcal per serving. A cup of white tea/coffee with two teaspoons of sugar would provide 48 kcal – assuming a typical intake of 3 cups daily this would provide around 150 kcal daily. In my experience, it is not uncommon for people with weight problems to be drinking 2-3 cans of fizzy drink a day, which would provide an additional 480 kcal per day.

“As risk of diabetes is more strongly and powerfully associated with weight gain than any other dietary component, it makes sense to advocate replacing high calorie beverages with those that contain fewer, or preferably to drink water.”

‘Prospective associations and population impact of sweet beverage intake and type 2 diabetes, and effects of substitutions with alternative beverages’ by Laura O’Connor et al. published in Diabetologia on Thursday 30 April 2015. 

Declared interests

Prof. Tom Sanders is a Scientific Governor of the charity British Nutrition Foundation, member of the scientific advisory committee of the Natural Hydration Council, and honorary Nutritional Director of the charity HEART UK.  Prof Tom Sanders is now emeritus but when he was doing research at King’ College London, the following applied: Tom does not hold any grants or have any consultancies with companies involved in the production or marketing of sugar-sweetened drinks.  In reference to previous funding to Tom’s institution: £4.5 million was donated to King’s College London by Tate & Lyle in 2006; this funding finished in 2011. This money was given to the College and was in recognition of the discovery of the artificial sweetener sucralose by Prof Hough at the Queen Elizabeth College (QEC), which merged with King’s College London. The Tate & Lyle grant paid for the Clinical Research Centre at St Thomas’ that is run by the Guy’s & St Thomas’ Trust, it was not used to fund research on sugar. Tate & Lyle sold their sugar interests to American Sugar so the brand Tate & Lyle still exists but it is no longer linked to the company Tate & Lyle PLC, which gave the money to King’s College London in 2006.