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Soft drink industry and research bias
Does the over-consumption of sugar-sweetened beverages contribute to tooth decay, type 2 diabetes, cardiovascular disease, and obesity?
Evidence is strengthening to say yes. Despite best efforts by the sugar-sweetened beverage (SSB) industry to have us believe otherwise.
Unveiling the research
A paper recently published in Annals of Internal Medicine describes the analysis of 60 studies considered fairly rigorous in design, published between 2001-2016, pertaining to the connection between SSB and obesity and type 2 diabetes.1
The researchers from UCSF ascertained that nearly ALL the evidence – that is 26 of the 60 papers analysed – refuting the link had been funded by the ‘big soda’ industry.
The other 34 studies did find associations between the drinks and those health outcomes, including one that was industry-funded.
Such a finding certainly weakens the argument by the SSB industry that correlation is based on opinion, not science.
“If it were truly controversial, you would expect some of the independently funded studies would not find associations,” said Dean Schillinger, lead author of the analysis. “Yet there are pockets of society that believe that they don’t cause these diseases because of the controversy that industry has created.”
And such influence is not new. Following the recent discovery of a cache of sugar industry documents, it was found an industry-sponsored research program in the 1960s and 1970s successfully cast doubt about the hazards of too much sugar while promoting dietary fat as the bad guy causing coronary heart disease.2
The documents showed that as early as 1954 a sugar industry trade organization recognized that if Americans ate low-fat diets, then per-capita consumption of sucrose would increase by more than one-third. That is big money for big sugar!
Simultaneously, evidence emerged downplaying the concerns of high sugar consumption and its relationship with high blood cholesterol and triglycerides, instead focusing on reducing intake of dietary cholesterol and fat (particularly saturated fat), claiming this to be the only food-based intervention required to minimise risk heart disease.
“(This) helped shape not only public opinion on what causes heart problems but also the scientific community’s view of how to evaluate dietary risk factors for heart disease,” lead author Cristin Kearns says.
At a similar time, the relationship between tooth decay and sugar was also downplayed through sugar industry influence over the National Institute of Dental Research in the U.S.
This is the stuff that has shaped the focus of research for decades, and caused us to be down right confused! What the general public receives is mixed messages about what may be harmful to health or not.
The fog is lifting
Slowly public policy is beginning to recognise the deleterious effect of excess added sugar consumption, increasing risk for tooth decay, obesity, type 2 diabetes, cardiovascular and non-alcoholic fatty liver disease.
These conditions are prevalent, and it is not surprising. If we removed all products in the supermarket that contained the 60-plus variants of added sugar, 80% of the shelves would be empty. We consume on average 60g a day, when the WHO recommends* limiting to 25g – that is 6 teaspoons – for health benefits.3
In Australia, it is now recommended to limit the intake of added sugars from confectionary, sugar-sweetened soft drinks and cordials, fruit drinks, vitamin waters, energy and sports drinks, owing to strengthening evidence linking, in particular, SSB consumption and dental caries and excessive weight gain. And a close look at the latest dietary guidelines reveals cereals comprised of heavily refined grains and added sugars should be considered discretionary foods.
But the guidelines do not highlight the prevalence of added sugars in so-called ‘healthy’ packaged foods. Something we hope will change in the future.
Moving forward
If the non-industry funded evidence is finding a correlation between negative health effects and drinking the sugary stuff, should manufacturers shoulder some responsibility to accept and acknowledge such science, and do something about it?
Some of the big guys say they are. Pepsi aims to reduce sugar content in 2/3 of their drinks to less than 100 calories for a 12oz serve by 2025. And despite past attempts at diverting attention away from SSB consumption and toward physical activity in the fight against obesity, Coke hopes to reduce sugar content too.
What they substitute the sugar with, however, may open a can of health-effecting worms.
So, how might we tackle this from a public health perspective?
There is talk in Australia of a sugary drink tax. And what about adding warning labels to packaging?
The City of San Francisco advertised on billboards warnings of health impacts by SSB, much to the disgruntlement of the soft drink industry, who retaliated saying “it is unconstitutional for commercial speech to be infringed or “chilled” by compelled, noncommercial speech (eg, a warning), particularly when the compelled speech is misleading, false, or a subject of scientific controversy.”4-5 Such claims of misleading the public were dismissed by a U.S. District Court Judge in July 2016.
They believe warnings like this are common sense and educate all people – including those of lower socio-economic status who tend to consume more, and could benefit from such warnings as has worked with tobacco in the past – on the possible health risks associated with SSB consumption, including tooth decay, type 2 diabetes, and obesity.5
To inform the individual on responsible consumption and provide a clear, consistent message about the impact on health from too much SSB and added sugar, it will take combined action from industry and public health. And the research must be honest and unbiased.
“The scientific endeavor combines unbiased experimentation with objective observations of the natural world to accumulate knowledge so as to approximate truth. In misappropriating scientific methods to reject science, the SSB industry, whose objectives are to sell products (even if those products, in the amounts consumed by millions of Americans, could promote illness), demonstrated the vulnerabilities to which science can be subjected.”4
Well said.
By Angela Johnson (BHSc Nut. Med.)
*The WHO recommends limiting free, or added, sugar intake to 10% of total daily energy with the ideal amount limited to only 5% of total daily energy intake (WHO), for health benefits.
The energy needs of an individual will vary depending on their age, sex and levels of activity. Based on the assumption that an average adult intake of energy is approximately 8700 kJ, we should limit intake of added/free sugar to 870 kJ, or 435 kJ. That is approximately 50g / 12 teaspoons, or half that for health benefits.
References:
- Schillinger D, Tran J, Mangurian C, Kearns C 2016, ‘Do Sugar-Sweetened Beverages Cause Obesity and Diabetes? Industry and the Manufacture of Scientific Controversy’, Annals of Internal Medicine, vol. 165, no. 9.
- Kearns CE, Schmidt LA, Glantz SA. 2016, ‘Sugar Industry and Coronary Heart Disease Research: A Historical Analysis of Internal Industry Documents’. JAMA Intern Medicine, 176, no. 11, pp. 1680-1685.
- ABS 2016, Australian Health Survey: Consumption of Added Sugar 2011-12, viewed 1 December 2016, <http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/4364.0.55.011main+features12011-12>
- Schillinger, D, & Jacobson, MF 2016, ‘Science and Public Health on Trial: Warning Notices on Advertisements for Sugary Drinks’, JAMA.
- City Attorney of San Francisco 2016, Big soda falls flat, viewed 1 December 2016, <http://www.sfcityattorney.org/2016/05/17/big-soda-falls-flat/>.
