At the start of March, the WHO has released a new guidance around sugar intake. We asked Dr Nita Forouhi from the Medical Research Council Epidemiology Unit at the University of Cambridge for her insight on the guidance, whether it comes too late and the impact it could have on diabetes prevalence.
You were quoted by the BBC as saying the WHO guidance is "ambitious and challenging". Could you explain this further?
The WHO guidance is timely amid the accumulating evidence for the potential adverse health effects of the consumption of free sugars. It is indeed very welcome that the WHO has made two strong recommendations – (1) to reduce intake of free sugars throughout the life course, and (2) that the intake of free sugars should not exceed 10% of the total energy intake. This is based on the totality of evidence regarding the relationship between free sugars intake and body weight and dental caries.
They also have made a conditional recommendation (awaiting public consultation), suggesting that further reduction of free sugars intake to below 5% of total energy would have additional benefits. This is ambitious, in a positive sense, because particularly for minimising the lifelong risk of dental caries, the lower the intake the better.
However, this is also challenging, because:
- Lowering a dietary recommendation does not automatically drive the changes in actual intake, which depend both on how people might change their dietary behaviours, and how the foods and drinks available to them help them achieve these goals.
- Shifting population intakes is a difficult task. For instance, current mean intakes of free sugars are over 10% of total energy in all age groups in the UK (over 15% in those aged 11-18 years).
- People can easily over-consume sugars without realising it, due to added and hidden sugars present in foods and drinks in our ubiquitously sweetened food environment.
- We have to provide information on healthy replacement foods when people cut down on foods/drinks with free sugars.
There are many possible solutions. A three-pronged approach involving people, products and places will help.
- People need more information and health education
- Products need to be low in added and hidden sugars – our entire food environment is sweetened
Places that sell food and drinks need to provide access to lower or no free sugars versions and healthier op
Do you agree that the WHO has been slow to change its advice on sugar?
The recommendations are timely and welcome now. Recognising the challenges and the opportunities, the focus should be on what the implementation of a lower target would mean in practice for people, and for all agencies associated with food manufacture, supply, sale, safety, security and health. International co-operation is needed from key players to move from recommendations to practical solutions for lowering free sugars intakes around the world.
How clear is the link between sugar intake and the risk of developing type 2 diabetes?
The link between sugar intake per se and the risk of developing type 2 diabetes is not well established. In fact the WHO report appraised associations only with body weight and with dental caries, not with cardio metabolic disease.
There is however substantial credible evidence for an association between sugar sweetened beverage (SSB, a major contributor to sugar intake) consumption and increased type 2 diabetes risk. The evidence is robust and includes a published meta-analysis of nine studies, and separately also evidence from the European Prospective Investigation into Cancer (EPIC)-InterAct study funded by the European Union, which included eight European countries, across 26 research centres. Consumption of SSBs allows for rapid consumption of large quantities of sugar in liquid form, which can be less satiating than in solid form, and may promote passive overconsumption.
The evidence for the risk of type 2 diabetes is based on observational epidemiological data. Some might criticise this as being suboptimal, demanding evidence from clinical trials, on the basis that observational evidence has limitations that do not permit a cause-and-effect relationship to be established. However, we must accept that clinical trial evidence for dietary factors (unlike for pharmaceutical products) and chronic conditions are generally not feasible, for logistical reasons, and in the case of SSB are also probably unethical, given existing knowledge.
In summary, based on high quality observational evidence, we can be confident of the adverse association of SSB consumption with type 2 diabetes risk. SSB contribute substantially to total free sugars intake, and form a tangible message and an “easy win” to target for sugars intake reduction.
What could be the impact on rates of diabetes around the world if the WHO sugar guideline was adopted by governments? What could be the results for healthcare systems as well as people with the disease and those at risk?
Potentially reducing sugar intake should be a “win, win” situation. It would have many health benefits, including preventing and reducing dental caries, levels of obesity, preventing weight gain, and contributing to the prevention of type 2 diabetes. It is also likely to have beneficial effects for coronary heart disease.
But, we should remember that to consider sugar alone is reductionist. Reducing sugar intake is important to tackle, but we must place it in context that it is one component of the overall risk for developing type 2 diabetes. Increasing age, family history, ethnicity, body weight and obesity, levels of physical activity, socio-economic factors and overall diet are all factors that will impact on the risk of diabetes.
To achieve reductions in free sugars intakes across the population, concerted efforts are needed from all agencies including the people (consumers), food manufacturers and other agencies involved in food production through to food sales (food and drink products), and policy makers and governments (agreements with the food and beverage industry; legislation).