Edgar Diabetes and Obesity Research Centre members have two letters published in the prestigious medical journal The Lancet this week, taking issue with several aspects of the PURE study, which was published in August 2017.
The International Prospective Urban Rural Epidemiology (PURE) study recorded the eating habits of 135,335 adults in 18 countries and followed the participants’ health for more than seven years. The authors concluded that a high carbohydrate intake was associated with higher risk of total mortality and they suggested that global dietary guidelines should be reconsidered in light of their findings.
EDOR members Professor Jim Mann, Dr Rachael McLean, and Dr Lisa Te Morenga, along with colleagues Joerg Meerpohl from Germany, and Chizuru Nishida from the World Health Organisation (WHO) in Geneva, have commented that guideline development is "informed by systematic reviews of bodies of evidence" rather than a single study. In addition, the increased risk of total mortality was only observed in people with an exceptionally high carbohydrate intake (more than 77% of total energy), which is higher than typically consumed and certainly exceeds the recommended intake for carbohydrate.
EDOR member Dr Andrew Reynolds commented in a separate letter that only total carbohydrate was considered in the PURE analysis. There was no distinction made between those carbohydrates that have been repeatedly shown to be detrimental to health - free sugars such as table sugar, refined grains - and those which have been clearly shown to have health benefits - fibre-rich wholegrains, legumes, vegetables and fruits.
Read more about carbohydrate
One study does not a dietary recommendation make, 30 August, 2017
Otago researcher investigating how grains may affect blood sugar and diabetes, 12 April, 2017
The highs and lows of carbohydrate, 30 September, 2016