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Low-carb diet is the way forward in diabetes

Dr Katharine Morrison's article was judged 'highly commended' in our clinical writing competition.

In the UK, babies born to women with diabetes have four times the background abnormality rate of those born to women without diabetes.

In Professor Lois Jovanovich's clinic in Santa Barbara in the US, the rate for babies of mothers with diabetes is the same as in the general population. She encourages patients to eat a restricted carbohydrate diet of 90-135g a day. She uses this and other techniques to maintain blood sugars as normal as possible in pre-pregnancy and pregnancy. You would think that pregnancy centres in the UK would be keen to try this out – but they aren't.

The complications of diabetes exact a terrible toll on patients with type 1 and type 2 diabetes. The landmark Diabetes Control and Complications Trial (DCCT)1 showed the higher the blood sugars, the faster complications develop.

High post-prandial blood sugars not only cause glycaemic-related damage, but set off an inflammatory cascade that causes endothelial damage and cancer. Post-meal blood sugars can be reduced if a restricted carbohydrate diet is adopted. Long-term adherence and prevention of complications can be achieved. Some complications can even be reversed. So why don't diabetes clinics throughout the UK promote the restricted-carb diet for their patients?

The DCCT trial showed adolescent patients with type 1 diabetes had three times as many hypos as adult patients, despite having an average HbA1c of 8% compared with the adult group average of 7%. Some US endocrinologists encourage their adolescent patients to follow a restricted-carb diet so that they can safely reduce their blood sugar. So why aren't adolescent diabetes clinics in the UK exploring this option with their patients?

The current high carb/low fat diet started off in the 1970s in the US, when Senator George McGovern brought in dietary guidelines to limit fat in the diet for the first time. He was strongly influenced by people who genuinely believed that fat, particularly saturated fat, was a major cause of arteriosclerosis. Scientists of the time pleaded for time, aware there was no evidence to support the claims. Senator McGovern famously said: ‘We don't have time to wait for evidence. We have to do something now.'

We are still waiting for evidence that saturated fat causes heart disease. But as the fat content of our diets has decreased over the last 20 years, the carbohydrate intake has zoomed, and we have seen a massive rise in obesity and its related illnesses.

Every day we hear how the NHS is in financial crisis. A patient with diabetes who has complications costs the NHS nine times more than a well-controlled patient without complications. All the features of metabolic syndrome can be reversed by a low carb/high fat/moderate protein diet. This saves money on drugs and other treatments too. What are the economic and personal costs of failing to give women with diabetes the dietary information to reduce their risk of having a deformed or dead baby?

If any one macronutrient deserves the blame for the obesity crisis and poor diabetic control, it is surely carbohydrates rather than fats. Sugars and starch all end up raising the blood sugar pretty quickly after a meal. Although patients with diabetes are advised to reduce sugars to some extent, the same advice is not given to restrict starch. Diabetes UK tells patients to base every meal around starch. In the patient's interest? I don't think so.

Dr Katharine Morrison is a GP in Mauchline, Ayrshire


1 The Diabetes Control and Complications Trial research group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Eng J Med 1993;329:977-86