A comment published in this week's edition of The Lancet reports that nutrition experts have expressed their astonishment over the involvement of Sweden in a debate concerning support of low carbohydrate high fat (LCHF) diets in the country. The comment is the work of Dr Jim Mann and Dr Edwin R Nye, University of Otago, Dunedin, New Zealand.

Many 'fad' diets have been promoted in recent years, such as the ultra-low carbohydrate Atkins diet. Other similar LCHF diets have also been credited with considerable weight loss without apparent adverse effects. The authors explain: "Most authorities have argued against prescription of LCHF diets and such messages have not been incorporated into dietary guidelines for populations and people with diabetes. However, recent experiences in Sweden show the potential of committed adherents, supported by a potentially misguided mass media, to influence officialdom to an extent that might adversely influence national public health and the health of individuals."

In 2007, the controversy began when two dieticians pointed out to Sweden's National Board of Health and Welfare that LCHF dietary advice recommended to diabetic patients by general practitioner Dr Annika Dahlqvist was not compatible with either scientific evidence or conventional practice. However, following a report by diabetologist Dr Christian Berne, Dahlqvist was cleared. The report said there was some scientific basis for offering LCHF diets but with a number of warnings, such as the absence of long-term studies and the need for patient monitoring (including measurement of lipids). Dahlqvist's justification resulted in headlines suggesting a shift by the Board. Dahlqvist herself indicated that her diet was suitable not only for diabetics but also for the general population for better health and weight control.

Soon, another aspect of the story surfaced. A group of experts which is a branch of the Board was scheduled to publish a report on nutritional recommendations for people with diabetes. However two of the experts on the panel were withdrawn by the newly appointed Director-General. He considered that their links to the food industry via the Swedish Nutrition Foundation might represent a conflict of interest. The Foundation receives food industry funding. It also provides independent advice to the industry through expert scientists. The two scientists involved (Bengt Vessby and Nils-Georg Asp) are internationally respected. Their dismissal caused outrage in the rest of the Board and the scientific community. The expert group began work in September 2008. But in the meantime the authors say that 'misguided enthusiasm and reporting appear to have triumphed over expert opinion'. Aftonbladet, the country's largest newspaper, has published details of high fat/low carbohydrate principle. An anonymous letter, quoting Dahlqvist's blogs, has been sent to all schools, preschools, and day-care centres in the country, advocating this dietary approach to 'save our children's brains'. The authors explain: "Despite the National Food Administration of Sweden having published a list of 72 articles which suggest that high fat diets are detrimental compared with eight articles suggesting that they are not, enthusiasm for high-fat diets persists. One of Dahlqvist's popular books on the subject of high-fat diets has been number one on the non-fiction bestseller list in Sweden."

The authors assume the Swedish public will deduce that the sequence of events is another example of experts failing to agree. Furthermore, they will conclude there is no point in making dietary changes associated with clinical and public health benefit, such as to lower-fat diets. They explain: "It is also ironic that this debate should have occurred in a country which helped to pioneer cardiac rehabilitation and preventive cardiology, and one of the few to report a decline in the rates of childhood obesity."

They write in closing: "There are some lessons here for international agencies, professional organisations, and governmental and regulatory bodies. Perhaps one of the most important is the need for internationally accepted criteria for evidence-based nutrition guidelines as there are for evidence-based medicine."

"Fad diets in Sweden, of all places"
Dr Jim Mann, Dr Edwin R Nye
The Lancet

Written by Stephanie Brunner (B.A.)