Is sugar a “toxin? Should we tax fizzy drinks? Are the dangers of sugar exaggerated?
Sugar, obesity, the role of sugar-sweetened soft drinks — and what should be done about it — are in the spotlight ahead of an international symposium at the University Auckland next week.
The Science Media Centre has rounded up the following expert comments.
Feel free to use these quotes directly. If you would like assistance with contact details for these or other experts, contact the SMC (04 499 5476; smc@sciencemediacentre.co.nz).
Comments below are excerpts. Read full comments here.
Dr Caryn Zinn, Senior Lecturer, Dietitian, Sports Nutritionist, AUT University and Prof Grant Schofield, Director Human Potential Centre, AUT University comment:
“To the extent that sugary drinks contribute to the problem – removing just drinks won’t make a detectable difference – the problem is everywhere across most of the industrialized food supply.
“But may as well start somewhere and sugary drinks are a ‘nutrient free zone’ – in other words they offer little in the way of nutrients and cause some damage.
“We also need to understand that while sugar is especially disreputable, it is all insulin-raising processed carbohydrates, in the context of processed inflammatory oils, and low fibre that contribute to the problem. The more awareness, advocacy, and good ‘honest’ (non-industry lead) research the better. … Evidence for how to intervene with humans and how this would play out in a public health sense is in its infancy and much more data is needed.”
“Public health won’t improve and obesity won’t change unless the amount and variety of nutrient-poor processed foods decreases, (i.e. the opposite of what’s happened over the last 50 years). Price structures around these foods, compared to nutrient-rich whole foods, need to change as well as the predominant consumer purchasing strategy is driven by price.”
Dr Tony Merriman, Assoc Prof of Biochemistry, School of Medical Sciences, University of Otago comments:
“Sugar, when ingested in the dissolved form as present in sugary drinks does fit the definition of a toxin, ie a poisonous substance (a substance that causes illness and death). The more sugary drinks ingested the stronger the detrimental effects.”
“There are three important sources of evidence regarding the role of sugary drinks in obesity and other metabolic diseases and conditions (diabetes, kidney disease, heart disease, high blood pressure, obesity). Namely (1) our biochemical understanding of the processing of sugar in the body (particularly the liver), (2) epidemiological studies associating sugary drink consumption with metabolic disease, and (3) epidemiological research on interaction of sugary drinks with inherited genetic variants in determining metabolic disease.” …
“The evidence under one and two above is very robust, under three is emerging. What is needed are more intervention studies where matched groups of people are followed, with intervention in one group aimed at reducing/eliminating sugary drink consumption. Metabolic outcomes would be measured. If such intervention studies show an improvement in metabolic outcomes in the intervened groups this would prove the causality of sugary drinks in metabolic disease. These studies are difficult to do, as human behaviour is a significant variable, and few have been done. The most recent study of 224 adolescents showed a significant decrease in weight (1.9 kg) in the intervened group after 12 months, but at 24 months the decrease was less (0.8 kg) and not significantly different. More and larger intervention studies do need to be done.
“Despite the lack of robust evidence from intervention studies, the evidence under one and two above is very strong and does justify the proposed public health approaches aimed towards reduction in consumption of sugary drinks.
Prof Boyd Swinburn, School of Population Health, University of Auckland comments:
“The evidence is strengthening that increased energy intake is the main driver for the obesity epidemic. Within that, it is the increase in ultra-processed food as a greater proportion of the diet which is causing the problem. Within that, there are multiple factors (high palatability, cheap price, heavy marketing, ubiquitous availability, high convenience, long shelf life, energy density) which are behind the increase in intake of ultra processed foods. Within that, added sugar contributes to several components eg palatability, cheapness, shelf life). That is the view starting with the epidemic. Many people start with the biochemistry textbook and point to the pathways that sugar can take but I think a focus on nutrients and biochemistry is missing the bigger picture. The research which is needed is on solutions at the population level rather than causes at the individual level.
“The corporate behaviours of Big Tobacco and Big Food / Big Soda (and Big Alcohol, Big Carbon etc) are identical when faced with a conflict between public good and profits. The public health responses have many parallels (social marketing, regulation, taxation, leadership, clinical treatments etc).
“The products themselves have some comparability – both tobacco and junk food give people pleasure, are not essential for life, and cause long and short term harm. There have been some parallels between nicotine’s addictive properties and some ‘addiction-like’ patterns seen in some people with certain foods but this is less strong.”
Prof Elaine Rush, Professor of Nutrition, Faculty of Health and Environmental Science, AUT University comments:
“Sugar is not evil, but an excess of sugar is. i.e. it is the dose that counts and defines a toxin.
“It is not so much about what we are consuming — it is about what we are not eating! As a population we are overfed but undernourished! Eating and drinking is necessary for life – addictive by design – we need to consume every day and we tend to choose the same foods, over-consume the pleasant food and be creatures of habit. One size does not fit all.
“Some particular foods are over consumed by some people and do not belong in a healthy diet. If something should be removed from the diet, a clear target and example is sugary drinks. There is no need for sugar to be added to beverages and particularly for children there are huge problems with sweet drinks and tooth decay.
“The bottom line is: Water is the best drink.”
FULL COMMENTS
Dr Caryn Zinn, Senior Lecturer, Dietitian, Sports Nutritionist, AUT University and Prof Grant Schofield, Director Human Potential Centre, AUT University comment:
What emerging lines of evidence are leading health experts to focus on the role of sugar, specifically, in the obesity epidemic?
“Sugar and its links to insulin resistance and hyperinsulinaemia are now well known and the mechanisms well understood. The fructose component dysregulates some liver function, causes triglycerides increases and other low density lipoproteins, raises uric acid and causes (indirectly) insulin resistance. The glucose component raises blood glucose and insulin. This high insulin (hyperinsulinemia) is directly and indirectly causal for the major diseases in NZ – diabetes, cancer, cardiovascular disease and dementias. Sugar has been shown to be addictive by stimulating brain chemistry i.e. endorphin receptors and dopamine. These are the same pathways activated by drugs such as heroin or morphine. Sugar also has links with disrupting appetite control.”
How robust is this evidence so far? What kind of research is still needed?
“The mechanistic evidence is very strong. How to intervene with humans and how this would play out in a public health sense is in its infancy and much more data is needed.
“We need more Independent research – free from conflicts of interest – i.e. any links to food industry / sugar industry. This has been a real problem – see the breaking story in Australia with the “Australian Paradox” through Jenny Brand-Miller, Rory Robertson – available on ABC Background Briefing – this is a big story just breaking. As above the intervention research hasn’t been done yet.”
Are you convinced that sugar deserves special focus?
“Yes, sugar has both fructose and glucose — it does a double whammy on our metabolic (dys)regulation. And it has pervaded our food supply such that it hides in all sorts of processed foods. Unless you are an expert at reading labels (which the majority of our population aren’t) you would have has no idea about just how much sugar is added to foods, even in foods that you would never imagine (such as baked beans and peanut butter).”
Are there any particular advantages or risks to this approach?
“We need to move away from just demonizing fat to understanding the more nuanced effect of different foods on human metabolic function – sugar is important in this role. It’s not the only nutrient we should think about though.”
In your view, is calling sugar a “toxin” and drawing comparisons to tobacco or alcohol justified?
“Yes because sugar is known to have the same addictive properties in the human brain. Yes because it likely causes significant damage to the human body. No because it doesn’t have the same effects on judgement, violence, crime etc as these other substances.
Do you think these strategies are likely to help or hinder efforts to improve public health and reduce obesity?
“To the extent that sugary drinks contribute to the problem – removing just drinks won’t make a detectable difference – the problem is everywhere across most of the industrialized food supply. But may as well start somewhere and sugary drinks are a ‘nutrient free zone’ – in other words they offer little in the way of nutrients and cause some damage.
“We also need to understand that while sugar is especially disreputable, it is all insulin-raising processed carbohydrates, in the context of processed inflammatory oils, and low fibre that contribute to the problem. The more awareness, advocacy, and good ‘honest’ (non-industry lead) research the better. Public health won’t improve and obesity won’t change unless the amount and variety of nutrient-poor processed foods decreases, (i.e. the opposite of what’s happened over the last 50 years). Price structures around these foods, compared to nutrient-rich whole foods, need to change as well as the predominant consumer purchasing strategy is driven by price.”
Prof Boyd Swinburn, School of Population Health, University of Auckland comments:
What emerging lines of evidence are leading health experts to focus on the role of sugar, specifically, in the obesity epidemic?
“The evidence is strengthening that increased energy intake is the main driver for the obesity epidemic. Within that, it is the increase in ultra-processed food as a greater proportion of the diet which is causing the problem. Within that, there are multiple factors (high palatability, cheap price, heavy marketing, ubiquitous availability, high convenience, long shelf life, energy density) which are behind the increase in intake of ultra processed foods. Within that, added sugar contributes to several components eg palatability, cheapness, shelf life). That is the view starting with the epidemic. Many people start with the biochemistry textbook and point to the pathways that sugar can take but I think a focus on nutrients and biochemistry is missing the bigger picture.”
How robust is this evidence so far? What kind of research is still needed? Are there any studies underway whose results are highly-anticipated?
“Different levels of robustness for the different parts of the putative pathways. Evidence is more difficult to make robust when the drivers are multifactorial and global rather than single bullet and metabolic. The research which is needed is on solutions at the population level rather than causes at the individual level.”
Are you convinced that sugar deserves special focus? Are there any particular advantages or risks to this approach?
“Sugar-sweetened beverages deserve special focus because they are a very high source of empty calories, esp for kids, they are amenable to policy actions, they contribute nothing to nutrition, and there are good alternatives (tap water).”
In your view, is calling sugar a “toxin” and drawing comparisons to tobacco or alcohol justified? Do you think these strategies are likely to help or hinder efforts to improve public health and reduce obesity?
“There are strong analogies with tobacco. The corporate behaviours of Big Tobacco and Big Food / Big Soda (and Big Alcohol, Big Carbon etc) are identical when faced with a conflict between public good and profits. The public health responses have many parallels (social marketing, regulation, taxation, leadership, clinical treatments etc). The products themselves have some comparability – both tobacco and junk food give people pleasure, are not essential for life, and cause long and short term harm. There have been some parallels between nicotine’s addictive properties and some ‘addiction-like’ patterns seen in some people with certain foods but this is less strong.”
Prof Elaine Rush, Professor of Nutrition, Faculty of Health and Environmental Science, AUT University comments:
“Sugar is not evil , but an excess of sugar is. i.e. it is the dose that counts and defines a toxin.
“Fructose is naturally found in fruit and vegetables, which are essential for lifelong health. The problem is that many of the foods and drinks commonly consumed in New Zealand have added sugar and the main source of this refined/processed sugar is sugar cane. Processing and extraction processes reduce the nutritional quality of plants. Single nutrients, such as sugar, are not real foods.
“It is not so much about what we are consuming it is about what we are not eating! As a population we are overfed but under nourished! Eating and drinking is necessary for life – addictive by design- we need to consume every day and we tend to choose the same foods, over-consume the pleasant food and be creatures of habit. One size does not fit all.
“Some particular foods are over consumed by some people and do not belong in a healthy diet. If something should be removed from the diet, a clear target and example is sugary drinks. There is no need for sugar to be added to beverages and particularly for children there are huge problems with sweet drinks and tooth decay.
“It is not just a personal choice – the big problem is the environment that we are soaking in. In any environments, when thirsty, the available option is a vending machine. Part of the regulations for public venues and places food is consumed should be to provide easily accessible and free water- out of a tap! Fill your own drink bottle and reduce waste. It is common sense and evidence supports the powerful effects of location, marketing, price and taste.
“The bottom line is: Water is the best drink. Make half the bulk of your diet fruit and vegetables and every day have some lean meats, beans or eggs, low fat dairy products, and whole grains,. Treat foods are once a week. Hippocrates said ‘Let food be your medicine and medicine your food’ – every day! Eat real food, be active and have fun.”