Sugary drinks are such sweet sorrow
A study in the last issue of Diabetologia contributes further evidence to the harms of consuming to much sugar sweetened drinks. Using data obtained in the prospective EPIC-Norfolk study, Laura O'Connor and colleagues from Cambridge University show that for each 5% increase of a person’s total energy intake provided by sweet drinks including soft drinks, the risk of developing type 2 diabetes may increase by 18%. Conversely, replacing the daily consumption of one serving of a sugary drink with either water or unsweetened tea or coffee can lower the risk of developing diabetes by between 14% and 25%, so there is hope for those who see the error of their ways.
This research is based on the large EPIC-Norfolk study which included more than 25,000 men and women aged 40–79 years living in Norfolk, UK. Study participants recorded everything that they ate and drank for 7 consecutive days covering weekdays and weekend days, with particular attention to type, amount and frequency of consumption, and whether sugar was added by the participants. During approximately 11 years of follow-up, 847 study participants were diagnosed with new-onset type 2 diabetes. In an analysis that accounted for a range of important factors including total energy intake the researchers found that there was an approximately 22% increased risk of developing type 2 diabetes per extra serving per day habitually of each of soft drinks, sweetened milk beverages and ASB consumed, but that consumption of fruit juice and sweetened tea or coffee was not related to diabetes. After further accounting for body mass index and waist girth as markers of obesity, there remained a higher risk of diabetes associated with consumption of both soft drinks and sweetened milk drinks, but the link with ASB consumption no longer remained, likely explained by the greater consumption of ASB by those who were already overweight or obese.
Finally, they found that each 5% of higher intake of energy (as a proportion of total daily energy intake) from total sweet beverages (soft drinks, sweetened tea or coffee, sweetened milk beverages, fruit juice) was associated with a 18% higher risk of diabetes. The association between the total intake of sugar sweetened drinks and the risk of type 2 diabetes is shown in figure 1.
Figure 1. The relation between total intake of sugar sweetened drinks (as a percentage of daily total energy intake) and hazard ratio for type 2 diabetes. The authors estimated that if study participants had reduced the energy they obtained from sweet beverages to below 10%, 5% or 2% of total daily energy, 3%, 7% or 15% respectively of new-onset diabetes cases could have been avoided.
In line with previous studies, natural fruit juice intake did not increase diabetes risk so the problem seems to arise mainly from added sugars. Interestingly, there was no association between intake of sweetened tea or coffee and diabetes risk, but here the risk of adding sugar is probably offset by the intrinsic diabetes risk reduction that is associated with coffee and tea consumption. This seems to be confirmed by the fact that replacing sugar sweetened tea/coffee with unsweetened tea/coffee leads to a 4% decrease in diabetes risk.
All in all, this study adds substantial evidence in support of the World Health Organization recommendation to limit the intake of free sugars in our diet.
^ Laura O’Connor, Fumiaki Imamura, Marleen A. H. Lentjes, Kay-Tee Khaw, Nicholas J. Wareham, Nita G. Forouhi. Prospective associations and population impact of sweet beverage intake and type 2 diabetes, and effects of substitutions with alternative beverages. Diabetologia May 2015 DOI: 10.1007/s00125-015-3572-1