I guess if anything was going to drag me out of semi-retirement on my little vineyard in Orange it would be yet another highly misleading story about sugar on the ABC, in this instance the Lateline program on Tuesday night. Why the ABC, my preferred source of news and current affairs, bothered to essentially repeat the same biased story about sugar it ran two years ago on Radio National is beyond me.
Again, the focus of the ABC story was a former economist who gave up sugar and lost weight. Yes, I know, anecdotal evidence. And yes, if he had given up fat he would have lost weight too, or starch or alcohol. Cutting down on calories does induce weight loss. However, the man’s personal experience was with sugar and having been enlightened he apparently embarked on a mission to rid the Australian diet of the root of all evil.
But he had a problem: Australia’s leading expert on carbohydrates and health, Professor Jennie Brand-Miller from the University of Sydney, was not overly concerned about sugar. Her view was that health effects of carbohydrate-rich foods were related to their blood sugar-raising potential or glycaemic index. Viewed through this perspective, foods rich in refined starch, which strongly raise blood glucose, may be just as bad, or even worse, than foods rich in sugar. Despite considerable scientific support such permissive views on sugar could not be tolerated so a kind of fatwa was issued: Brand-Miller had to be beheaded, in a profession sense. And the ABC and the economist have been after her ever since.
In the movie That Sugar Film Damon Gameau set about testing the effects of a high sugar diet on his healthy body. He increased his sugar intake to 40 teaspoons a day on the basis that this was ‘just slightly more than that of the average teenager worldwide’.
That’s an interesting claim but is it true?
Actually, it’s a strange measure to have chosen as it is almost impossible to verify. Most countries in the world simply don’t have good dietary data on teenagers, or adults for that matter. Let’s look at the available data and consider whether the claim is close to being right.
Any global average for sugar intake will be greatly influenced by typical intakes in populous countries such as China, India and Indonesia. Yet sugar intakes in these countries are very low – of the order of 20 grams per day or less, which equates to a miserly 4 teaspoons of sugar per day.
Thank goodness for the World Health Organization’s new report ‘Sugars intake for adults and children’. Now, at last, we have some actual science to go on.
WHO’s record on sugar
The World Health Organization (WHO) is a leading global health agency with a proud history of sound dietary advice, including advice about sugar. In a 1990 report, WHO recommended a limit on intake of ‘free sugars’ of no more than 10% of daily calories, which is about the current average intake of Australian adults. Free sugars means all sugars added to foods by the manufacturer, cook or consumer, plus sugars in honey, fruit juices and syrups.
WHO’s rationale for limiting sugar intake was to lower the risk for tooth decay. No lower limit on intake of free sugars was recommended.
Thirteen years later WHO again looked at the science of sugar and health and found ‘convincing’ evidence that both the amount of free sugars and the frequency of sugar consumption increased the risk for tooth decay. And again WHO recommended a limit of 10% of daily calories.
The 2015 WHO report
In its latest report WHO found … wait for it … that eating too much sugar causes tooth decay and that the intake of free sugars should be limited to … wait for it … less than 10% of daily calories.
As new scientific evidence has emerged the low fat diet has slowly fallen from favour. But the myth-makers are suggesting the whole thing was a con, born out of fraud and carried along by a conspiracy.
The origins of the low fat diet
The low fat diet had its origins in 1980 with the publication of the first Dietary Guidelines for Americans. The recommendation to ‘Avoid too much fat, saturated fat and cholesterol’ was intended to lower blood cholesterol and reduce the risk for heart disease. Although the focus was really on lowering saturated fat, it was thought that lowering total fat intake may help prevent some cancers and obesity.
In Australia, the simpler guideline ‘Avoid eating too much fat’ was adopted to aid its communication.
Keys versus Yudkin
The low fat diet had a low key launch. Yet these humble origins are now being re-imagined as the disastrous consequences of a fight to the (professional) death of two of the great nutritionists their era – Ancel Keys and John Yudkin. As an epidemic of heart disease raged in the post-war years Yudkin pointed his finger at sugar. But Keys argued that the effect of different fats on blood cholesterol was the key mechanism affecting heart disease risk, and he won the day.
Over the last year or so two senior Australian nutritionists have been subjected to a sustained social media campaign to denigrate them and their research. Their alleged crime? Daring to say what they believed to be true.
In 2011, Professor Jennie Brand-Miller from the University of Sydney and Dr Alan Barclay, Chief Scientific Officer at the Glycaemic Index Foundation and Head of Research at the Australian Diabetes Council published a paper on the Australian Paradox – the apparent fall in sugar consumption that occurred over a period when rates of obesity in this country increased. The paper was obviously intended to stir the pot a little.
The narrative in the United States at the time was that the increase in obesity prevalence in that country had coincided with increasing sugar intake, so perhaps sugar was a causative factor. In their paper Barclay and Brand-Miller pointed out that while that may well be the case in the United States, sugar intakes had remained fairly constant in the United Kingdom over the same period and had actually fallen by 16 per cent in Australia. However, both countries had experienced an increase in rates of obesity, hence the Australian Paradox.
Under normal circumstances this simple paper may have dissolved away into the vast ocean of scientific literature and never been heard of again. However, a member of the public took exception to the finding that sugar intakes in Australia were falling. Despite not having any qualifications in nutrition or science he had formed a view that sugar intakes in Australia were in fact rising. A social media campaign was initiated to attack the nutrition researchers and their findings and a formal complaint was lodged with the University of Sydney.
Following the publication of the latest national dietary survey it is clear that sugar intake has fallen since 1995. But mere facts are unlikely shake the resolve of the non-nutritionists driving the lucrative sugar scare.
The trend in sugar consumption in Australia has been a contentious issue in recent years, especially as nutritionists and lay people have sought dietary explanations for the obesity epidemic. On one side of the argument is the view that the intake of sugar, or perhaps fructose, has increased in recent decades and that this has been the driving force behind the epidemic. This argument emerged in the United States where sugar intakes are undoubtedly high.
In the Australian context it has been argued that sugar intake hasn’t increased at all and is actually in steady decline. Proponents of this argument include Dr Alan Barclay and Professor Jennie Brand-Miller who published an assessment of trends in intakes of sugars and obesity rates in Australia, the United Kingdom and the United States between 1980 and 2003. In this paper the authors identified an ‘Australian Paradox’ – increased rates of obesity despite an apparent fall in sugar intake.
The recent publication of new data from the Australian Health Survey (AHS) has provided some clarity on this issue.
Sugar data from the Australian Health Survey
The AHS was conducted by the Australian Bureau of Statistics, which also conducted Australia’s last national dietary survey of adults and children in 1995, so now we have insights into how the diet of Australians has changed over the intervening period of approximately 16 years. Here are some of the top-line results relating to sugar.
• Intake of total sugars has fallen in men, women and children.
• The percentage of dietary energy from total sugars has also fallen.
• Carbohydrate intake has fallen, both in absolute terms and as a percentage of energy. Total energy intake has also fallen.
Addressing the obesity epidemic by taxing sugary soft drinks sounds good in theory but it appears to fall down in practice. How could a taxation strategy be made to work?
Obesity is proving to be an intractable public health problem demanding innovative solutions and one idea that is attracting attention is the taxation of sugar-sweetened beverages. The theory is simple enough. Basic economics tells us that if the price of sugary soft drinks were to rise, their consumption would fall; lower intake should mean lower calorie intake which would lead to lower body weights. But would it work in practice?
The Ohio experience
A recent research study conducted in the United States provided some interesting insights. Taxing soft drinks has a long history in the US and occurs in many states today, though historically the rates have been low and the purpose has been to raise revenue. But there was an interesting exception. In 1992, the state of Ohio introduced high taxation of sugary soft drinks which was then repealed at the end of 1994. This provided an opportunity to test the effect of taxation of soft drinks on body weights over a period of two years. The researchers compared changes in body weights in Ohio over this period to (1) all other states that had no increased taxation and (2) a bundle of states with the same mean BMI as Ohio. The researchers found:
… very little evidence that the large tax imposed in Ohio had any detectable effect on population weight … our results cast serious doubt on the assumptions that proponents of large soda taxes make on its likely impacts on population weight.
How come? Why didn’t quite high taxation of sugary soft drinks affect body weights?
Sugar-sweetened beverages are in the sights of public health nutritionists, especially in relation to obesity. But there is some good news: a fundamental shift from sugar-sweetened to non-sugar soft drinks is underway and the amount of sugar entering the national diet from these beverages is in long-term decline.
Despite all the interest in sugar in recent years Australian nutritionists don’t really know for sure whether sugar intake in Australia is going up, going down or staying the same. Unlike American nutritionists who have the findings from the ongoing NHANES series of nutrition surveys to go on, we have been hamstrung by the poor quality of our nutrition data. There are few national nutrition surveys to guide us.
In 2011, Dr Alan Barclay and Professor Jennie Brand-Miller collated the available Australian data and concluded that per capita consumption of sugar had decreased by 16% in Australia between 1980 and 2003. Their work was attacked with uncommon vigour. Apparently, this was not a message that some people wanted to hear. One concern expressed about their work was that Barclay and Brand-Miller had partly relied on ‘apparent consumption’ data, which the Australian Bureau of Statistics ceased publishing in 1998/99.
In a subsequent analysis by the commodity firm Green Pool, the apparent consumption data were updated and analysed, and again suggested a long-term fall in sugar consumption in Australia was underway. There were more howls of protest. Unfortunately, when the quality of the available data is ordinary this sort of debate ensues and we end up with lots of heat but little light.
Fructose has been accused of being the root of all dietary evil but at a symposium in Sydney this week Canadian researcher John Sievenpiper argued that fructose has been misjudged.
John Sievenpiper knows a fair bit about dietary carbohydrates and health. His team in Toronto recently conducted systematic reviews and meta-analyses evaluating the effects of fructose on body weight, blood pressure and glycemic control in humans. He discussed some of the findings at the ‘Sweet Symposium’ on 2 December.
The fructose-centric view
Sievenpiper reviewed the rapid evolution of what he called the ‘fructose-centric view’ in modern nutrition, which positions fructose as a central driver of the obesity epidemic and cardiometabolic risk. Certainly several lines of evidence had raised suspicions about fructose – apparent increases in fructose consumption were associated with increases in obesity in population studies; animal studies showed fructose had adverse metabolic effects; there were similar findings in some human studies; and an articulate anti-fructose champion, Robert Lustig, emerged and took his simple ‘fructose is toxic’ message to the general public. And the media loved it – even the ABC’s ‘science’ program Catalyst jumped on the bandwagon and pushed the idea around. In less than a decade the fructose hypothesis became an anti-fructose doctrine with a chanting chorus of true believers.
Following the failure of the ‘eat less fat’ strategy for addressing the obesity epidemic the focus has shifted to sugar-sweetened beverages. Will this approach be more fruitful? Is sugar the problem, or is it liquid calories? Or are we missing something obvious?
Two new studies recently published in the New England Journal of Medicine have shed further light on the issue of soft drinks and weight gain.
Two new soft drink studies
Ebbeling and colleagues studied 224 overweight and obese adolescents who regularly consumed sugar-sweetened soft drinks. Half the subjects participated in a 1-year program designed to decrease consumption of these beverages. Both this intervention group and a control group were followed up for a further year after the intervention was complete. After one year the mean body weight of those in the intervention group was significantly lower (1.9kg) than that of the control group, though significance was lost at two years. So the program worked while underway but its effects did not persist.