Virtually shopping to test food taxes

Health researchers from New Zealand, Melbourne and the Netherlands have provided further evidence that food taxes and subsidies can improve people’s diets. The world-first study used a virtual supermarket to test consumers’ responses to different kinds of food taxes and subsidies. Results published in The Lancet Public Health confirmed that taxes targeting individual food types reduce the amount of that food bought, but also result in substitution effects. This suggests, the researchers reason, that combining several taxes into a broader suite – dubbed a “junk food tax” – could lead to a greater improvement in the overall healthiness of all food purchased. The study’s 1038 participants were able to virtually “walk around” and select items from the shelves of a 3D computer simulation based on images from a real New Zealand supermarket. They each completed up to five shops – 4258 in all. Food prices across the board were randomly varied from shop to shop, so researchers could gather as much information as possible about how people respond to price fluctuations. On top of these random tweaks, researchers added bigger price changes to simulate five different policies: a fruit and vegetable subsidy (20%), sweetened beverage tax (20% or 40%), saturated fat tax ($2 or $4 per 100 g saturated fat), a salt tax (2 cents or 4 cents per 100 mg sodium), sugar tax (40 cents or 80 cents per 100 g sugar). A control condition had no tax or subsidy. Using established criteria, researchers classified each food item as “healthy” or “unhealthy” and then analysed the healthiness of the shopping baskets. With no taxes or subsidies, 68% of food purchases were classified as healthy. Taxes on food high in saturated fat, sugar and salt led to shoppers buying markedly less of the taxed nutrients (132 g less saturated fat, 119 g or about 28 teaspoons of sugar, and 11 g salt, respectively). These three taxes also improved the healthiness of the overall shopping basket by 1.8%, 1.1% and 1.3%, respectively. The sweetened beverage taxes did not significantly improve overall healthiness, possibly because sugary drinks make up only a small fraction of people’s diet. But the most comprehensive version tested, which included sweetened beverages, energy drinks and fruit juices, resulted in shoppers buying 170 mL per week less of those drinks. Researchers also identified some intriguing substitution effects. Both saturated fat and salt taxes resulted in people buying more fruit and vegetables (as a percentage by weight of all food purchases) and more sugar as a percentage of total energy. People bought more fruit and vegetable when produce was subsidised (a third of a kilogram per week); however, the healthiness of their overall baskets was unchanged.

Strong evidence for causal link between obesity and multiple diseases

Research from the University of South Australia presents further evidence of a causal relationship between obesity and a wide range of serious conditions, including cardiovascular disease, diabetes, cancer and neurological, musculoskeletal and respiratory afflictions. Published in Lancet Digital Health, the study draws data from the UK Biobank – a research database holding health and genetic information from half a million volunteers – to analyse associations between body mass index (BMI) and a range of disease outcomes in 337 536 people. The researchers developed a multidimensional analysis in which genetic data were subjected to a suite of stringent examinations in order to deliver high confidence of causality. They compared evidence from five different statistical approaches to establish how strong the evidence for causal effect actually was. Fully consistent evidence across all approaches was seen for 14 different diseases, and for 26 different diseases, evidence was obtained for at least four of the five methods used. What increases the confidence that these associations are largely reflective of real effects is the fact that those effects which came across with consistent evidence are also ones for which we have previous clinical evidence. One key finding from the study was the extent to which it confirms existing concerns over the link between obesity and diabetes, with many of the diseases identified as related to high BMI known to be commonly associated with poorly controlled diabetes. The researchers saw evidence for effects on peripheral nerve disorders, chronic leg and foot ulcers, and even gangrene and kidney failure, which are all known to be diabetic complications. This suggests a key aspect to reduce comorbidity risk in obesity is careful monitoring of blood sugar and effective control of diabetes and its complications.

New president, and charity status, for neuromodulation peak body

Melbourne-based pain specialist and anaesthetist, Dr Nick Christelis has been named as the new president of the Neuromodulation Society of Australia and New Zealand (NSANZ), the peak body supporting the estimated one-in-five Australians and New Zealanders living with chronic pain. Neuromodulation, also known as Spinal Cord Stimulation (SCS), is a minimally invasive and reversible therapy that may prove an effective, additional or alternative option for those who have tried, and failed, conservative pain management treatments. SCS works by intercepting pain signals as they travel along nerve fibres through the spinal cord before they reach the brain. The Australian Charities and Not-for-Profits Commission recently awarded NSANZ charity status. “[That] will allow us to perform three major functions – fund and promote further research in the neuromodulation field; educate doctors training in this medical field; and establish a neuromodulation device registry,” said Dr Christelis. “We are currently drafting policy documents and guidelines outlining standards for safe and effective neuromodulation practices, encompassing device-related education, training, implantation techniques and management. We are also planning to perform a local audit to determine the need for establishing a national neuromodulation device registry, which will be the first of its kind in Australia and New Zealand, similar to the national joint replacement registry.” According to a Deloitte Access Economics report released by Pain Australia earlier this year, the 2018 estimated total financial cost of chronic pain in Australia was $73.2 billion, comprising $12.2 billion in health system costs, $48.3 billion in productivity losses, and $12.7 billion in other financial costs.

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