Wednesday, January 3, 2018

A little bit of sugar may (or may not) make the weight go down.

The statistics do not support the view that there are big differences in sugar consumption between the fat and the thin.  We need to define our enemy clearly in the battle against obesity.

The Sydney Morning Herald has announced a war on sugar. Its rationale is that we need to combat obesity with all its attendant ills.  Good thinking.  Sugar might appear to be easy pickings. Beware.
It is important that individual sugar consumption not be cast as the behaviour that we must attack with all our might. That will be a waste of energy – no pun intended – and leave the real changes essential for reversing our current trend to a fatter, less healthy community untouched.
Just how crucial is sugar to obesity?  A study of 132 479 individuals in the UK, published in the International Journal of Epidemiology* in 2016, analysed their consumption of macronutrients – fat, protein, carbohydrate and sugar – and compared how much energy in the diet of obese versus non-obese individuals came from these food categories.  This group was assembled for the UK Biobank genetic study and the current study made use of the comprehensive health data collected on all participants.
Anderson and Pell, the lead authors of the study from the University of Glasgow, made the point that in this study ‘dietary intake was self-reported outside the clinic, which may encourage more truthful reporting, and was collected using a 24 hour recall questionnaire which produce more accurate results than a food frequency questionnaire (the usual approach adopted in large-scale studies)’.  Their general conclusion was ‘66.3% of men and 51.8% of women were overweight/obese.’
Anderson et al wrote: "Compared with [those participants with] normal BMI, obese participants had 11.5% higher total energy intake and 14.6%, 13.8%, 9.5% and 4.7% higher intake from fat, protein, starch and sugar, respectively." So while the fat folk were consuming more energy than the thin, the excess due to sugar intake between the two groups was quite small. ‘There is only a weak correlation between absolute energy derived from sugar and from fat. Therefore, targeting high sugar consumers will not necessarily target high consumers of fat and overall energy.’
They concluded "fat is the largest contributor to overall energy. The proportion of energy from fat in the diet, but not sugar, is higher among overweight/obese individuals. Focusing public health messages on sugar may mislead on the need to reduce fat and overall energy consumption."
Do these observations mean that we should not include sugar as needing attention in our approach to obesity?  It cannot be said to be the main game. Unlike tobacco – a single and inessential commodity – there is no case to ban it completely, nor is such an approach desirable. A sugar tax would make all sugar-containing foods and drinks more expensive and hence less accessible to less affluent consumers and needs careful calibration against the criterion of equity. Also, Anderson et al warn of the tendency to substitute one source of energy for another and if this substitute is fat, then we are no further ahead.
The power of the sugar industry – cane, corn and beet – is immense and it is far from squeaky clean when it comes to promoting a healthy diet.  It is at the level of production and marketing that our attention needs to focus in encouraging a healthier approach to sugar.
Encouraging individuals to lobby for less sugar in processed foods and drinks will not be easy and blood will be spilt as that battle plays out.  But it is there – and not by beating up individuals to reduce their individual consumption of sugar (desirable but neither necessary nor sufficient) – where our efforts should be applied.
It is interesting that, in an international comparison of cost-effective ways of reducing obesity, McKinsey and Co, a consultancy, nominated reducing portion size as the best.  Given the nearly 12% difference in total energy intake between the obese and non-obese participants in this study, reducing the size of meals we eat by 10% would seem a wise recommendation – without worrying too much about macronutrients such as sugar.

Monday, January 1, 2018

SOCIAL CAUSES OF ILLNESS ARE NOT IMMUTABLE: THEY ARE AMENABLE TO CHANGE

Modifying our own behaviour in health promoting directions is sensible but for sustainable, nation-wide change we need to take action of a different kind.

Far from being a cause for despair, the insight that a lot of illness in our society derives from the environment we have created should give us enthusiasm to use the New Year to achieve better health generally.  As John Kennedy stated, “Our problems are man-made; therefore they may be solved by man”.  Or woman.

Discounting for Kennedy’s hyperbole, social determinants of illness are within our power to modify to our advantage. And while changing individual behaviour (less sugar, less salt, more exercise etc) is commendable, there are things that we can do in the community to make those individual behaviour changes easier for everyone and more likely to be sustained.

An interesting comparison between our globalised and immensely successful society and that of the Roman Empire is drawn by Kyle Harper, vice-president of the University of Oklahoma in a recent essay entitled How climate change and disease helped the fall of Rome. https://aeon.co/ideas/how-climate-change-and-disease-helped-the-fall-of-rome.  He wrote:

The decisive factor in Rome’s biological history was the arrival of new germs capable of causing pandemic events.

The empire was rocked by three such intercontinental disease events. The Antonine plague coincided with the end of the optimal climate regime, and was probably the global debut of the smallpox virus. The empire recovered, but never regained its previous commanding dominance. Then, in the mid-third century, a mysterious affliction of unknown origin called the Plague of Cyprian sent the empire into a tailspin. Though it rebounded, the empire was profoundly altered – with a new kind of emperor, a new kind of money, a new kind of society, and soon a new religion known as Christianity. Most dramatically, in the sixth century a resurgent empire led by Justinian faced a pandemic of bubonic plague, a prelude to the medieval Black Death. The toll was unfathomable – maybe half the population was felled.

He points to the critical role of infectious disease and natural changes in climate in weakening the Roman Empire to near collapse. Plague, especially, was brought by rats from the east in boats carrying trading goods to Roman ports. But the authorities and population were ignorant of the causes of these afflictions and powerless to control them.  And the effects of infectious disease more generally and endemically in the crowded cities of the Empire as urban migration surged diminished the productivity of the nation.  The average life expectancy of a Roman citizen was in the 20s.

An immense difference exists between the knowledge possessed by our technologically advanced societies and the Roman Empire. We have knowledge that enables prevention and therapy for many of our health problems.  Our success, through sanitation, immunisation and vastly improved nutrition as well as an impressive armamentarium of medical and surgical therapies means that our life expectancy is four times that of Rome. 

But clearly we are not problem-free and we are left with a hefty rump of problems, the major degenerative disorders of diabetes, heart disease and stroke, cancer, physical trauma, musculoskeletal disorders and drug and mental illness that are deeply troubling.  But unlike the epidemics of Rome, where nothing was known about their origin, we know a vast amount about the causes of these ailments.  And the causes, while often complex and shrouded in the economics and behaviour of our society, are as Kennedy suggests, soluble by humans. Three courses of action command our attention.

First, to move the settings on the dials that govern the way we live, the population needs to be convinced that the move has merit.  For this to happen in relation health the community needs first to be clear that proposed changes in our national diet and exercise patterns, for example, make sense and are potentially beneficial. 

Health messaging is needed that moves beyond recommending individual behaviour change and instead points to how such things as sugar taxes, if lobbied for effectively, will enable many people to lower their sugar consumption.  The paradox is this: if lots of people decrease their consumption of alcohol, tobacco or sugar just a bit, the likely benefits are greater than if a few people go to extremes.  Advertising agencies could assist in marketing that insight.

Second, there is a place for political leadership rather than followship.  By this I mean the kind of ‘out there’ behaviour that we saw from John Howard in relation to gun control and from Neal Blewett in regard to HIV/AIDS – pushing the agenda for change.  Politicians can only go as far as the community will permit and so this point is heavily dependent on the first. 

Third, the industrial and commercial interests that dominate our economic environment should be commended when they make moves to reduce the hazards in our environment – by offering food choices in our markets that are less injurious, cutting down on portion sizes in restaurants, and attending to equity of access to fresh food in rural, remote and Aboriginal communities.

Simply because disease is socially determined we are not rendered impotent in dealing with it.  If we take the correct messages from this insight and contribute to the large social changes needed for effective prevention, then 2018 will be an important year in preserving the health of our nation.