31 May, 2016
Low-carb diet helps to control diabetes
The biggest pilot study of a low-carbohydrate diet to treat type 2 diabetes has shown that it may successfully control the condition.
A review of more than 80,000 people who ditched their low-fat, high-carbohydrate diet found that their blood-glucose levels dropped after ten weeks. The results have led doctors to call for an overhaul of official dietary guidelines.
The study came about as a consequence of an online revolt by patients in which 120,000 people signed up to the “low-carb” diet plan launched by the forum diabetes.co.uk in a backlash against official advice.
By rejecting guidelines and eating a diet low in starchy foods but high in protein and “good” saturated fats, such as olive oil and nuts, more than 80 per cent of the patients said that they had lost weight, with 10 per cent shedding 9kg (20lb) or more.
More than 70 per cent of participants experienced improvements to blood glucose, and a fifth said at the end of the ten-week plan that they no longer needed drugs to regulate blood glucose.
About 2.7 million people in Britain have type 2 diabetes, a condition that goes hand in hand with obesity. A further 750,000 people are thought to have undiagnosed symptoms. Costing more than £8.8 billion directly and indirectly each year, it is a defining issue for public health.
Frustrated doctors, nutritionists and diabetes specialists called for the “absurdly simplistic” guidelines, promoted by Public Health and the national charity Diabetes UK, to be rewritten. The results of the study, however, have not yet been replicated in a controlled and peer-reviewed trial.
A report by Britain’s National Obesity Forum last week urged people to ignore public health advice and “eat fat to get thin”. The group was criticised for calling for people to reduce carbohydrates and stop counting calories.
The majority of the 120,000 people who have signed up to the low-carb diet plan since November suffer from weight-related type 2 diabetes. More research needs to be done into whether restricting carbohydrates in type 1 patients of normal weight has a significant effect on glycemic control.
“The results from the low-carb plan have been impressive and this is a solution that is clearly working for people with type 2 diabetes,” Arjun Panesar, chief executive officer of diabetes.org.uk, said.
David Unwin, a family doctor and clinical expert in diabetes, is one of a growing number of clinicians treating patients with this diet. “For many years I followed the advice given by PHE and Diabetes UK,” he said. “It didn’t go well. They really struggled to lose weight, their blood glucose remained high and many relied on medication.”
A recent study of 18 of Dr Unwin's patients resulted in an average weight loss of 8kg after cutting out carbohydrates; blood-glucose levels returned to “normal” in all but two.
“Many diabetics know not to put sugar in their tea but very few are aware that the toast they have at breakfast or rice at dinner may be wreaking havoc with their blood glucose. This is because when starchy carbohydrates like potato or pasta are broken down in the body by digestion the starch turns to sugar,” he said.
Some experts remain dubious about the direct link between carbohydrates and lower blood glucose.
“The robust evidence is that any diet which helps weight loss in diabetes will help improve patients metabolic levels since it is weight more than anything that drives diabetes development,” Naveed Sattar, professor of metabolic medicine at the University of Glasgow, said. “All diets work regardless of whether they are high-carbohydrate or low-carbohydrate, so long as folks stick to them.”
A spokeswoman from PHE said: “Our advice, agreed with Diabetes UK, is that people with diabetes should consume a diet consistent with the Eatwell Guide. The evidence considered by the Scientific Advisory Committee on Nutrition for its Carbohydrates and Health report does not support following a low-carbohydrate diet to prevent type 2 diabetes.”