Letter about dental decay, obesity shows that sugar industry is not to be trusted

The South African Sugar Association (SASA) tries to trash our scientific arguments about the association of sugars with dental decay, obesity and diabetes ( "Sugar leaves a bitter taste" Cape Times August 18th) in their letter , "Confronting some fallacies of SA's sugar consumption with scientific facts", Cape Times, August 19.

But the science that we report is the most up to date consensus of the leading expert committees

The weakness of SASA's arguments and their misquoting the conclusions of expert committees is disconcerting. If they fudge even the fact that sugars cause tooth decay, how then can their views be trusted on other diseases?

First, the most extensive in-depth systematic review on sugars and tooth decay, written for the World Health Organisation's (WHO) expert committee on sugars, states unequivocally that decay is proportionate to the consumption of sugars, even at low levels ( and not proportionate to other carbohydrates, as SASA claims).

Second, SASA maintains that several studies show that prevention of dental decay should focus on oral hygiene and fluoride use.

That is false.

As a leading nutritionist says in the WHO Bulletin, "fluoride has not eliminated dental caries and many communities are not exposed to optimal quantities of fluoride. Controlling the intake of sugars therefore remains important for caries prevention."

Third, SASA misquotes WHO as stating that the link between sugar and body weight is due to overconsumption of calories and not specific to sugars.

However, here is WHO's categorical statement: "Increasing or decreasing dietary sugars is associated with parallel changes in body weight."

Fourth, SASA says that eating sugar does not cause diabetes. But drinking sugar sweetened beverages does.

The UK Scientific Advisory Committee on Nutrition (SACN) concludes that sugars sweetened beverages, a common source of sugars, are associated with a higher risk of Type 2 diabetes mellitus and obesity.

Finally, SASA states that "South Africans consume 9.7 percent of their calories from sugar" and that this is within WHO recommendations.

But 9.7 percent is the average for the entire population: many people eat far more than that. And, as the 2014 report of SACN concludes,:"in order for an individual to achieve a recommendation to consume less than 10 percent of dietary energy from free sugars, the population average needs to be less than this figure".

On that basis, the population average of South Africans needs to be reduced to five percent-about five teaspoons of free sugars a day.

The public and policy makers deserve to be provided with the best scientific evidence on what is good for health. We thus agree with SASA that "custodians of nutrition information " should provide accurate information.

Their letter demonstrates that the sugar industry should not be trusted as custodians.

Prof Sudeshni Naidoo

Specialist in Dental Public Health and Deputy Dean for Research, Faculty of Dentistry, University of the Western Cape.

Emeritus Prof Aubrey Sheiham, University College, London.