T2D is one of the modern-day major public health issues. If there are persistent excessive levels of sugar in the blood (glucose) eventually the pancreas becomes exhausted and therefore cannot produce sufficient insulin to prevent the sugar increasing to toxic levels. There is now reliable evidence to demonstrate that those who develop T2D are at increased risk of a range of other diseases/conditions including obesity, hypertension, heart disease, blindness and Alzheimer’s Disease(AD).
When T2D is diagnosed it is common practice for drugs to be prescribed, with the object of controlling the sugar levels in the blood. These may well include insulin. Because diabetics are at an increased risk of developing heart disease they are likely to be advised to reduce their consumption of fat, especially saturated fat and to increase the intake of the complex carbohydrates (eg. bread, potatoes, rice and pasta).
Prior to all the concern about fat, it was the accepted practice to recommend that diabetics should reduce their intake of carbohydrates. Therefore it is highly relevant that there have been a number of research projects which have been based on this approach.
In Sweden, 16 patients who had T2D and a BMI >30 were placed on a diet with low carbohydrate (LCD)which had 20%E as carbohydrate and compared with a similar control group of 15, which had a diet containing 60%E as carbohydrate. Of the LCD group 11 were being treated with insulin, 15 with metformin and 5 with sulfoaylurea(SU).
As a result of the LCD, the 11 insulin-treated patients were able to reduce the insulin dose from an average of 60 IU/day to 39 IU/day within one week. After 24 weeks 3 patients were able to discontinue the insulin treatment completely and the average dose for the remainder was 18 IU/day. One of the patients was a bus driver who had been disqualified from holding a passenger service vehicle licence in accordance with the Swedish regulations. Because the LCD enabled him to discontinue the insulin treatment he licence was restored and he resumed his job as a bus driver. It was also found that those on the LCD had reduced their body weight from an average of 100.6 kg to an average of 89.5 kg. This was maintained for 6 months after the end of the trial(1).
A further report provided information obtained over the subsequent 38 months during which time the participants were not subject to detailed guidance and were essentially left to their own devices. Although there was some regression to the original values, nevertheless there was still a significant reduction in body weight of 7.5 kg. The concentration of glucose on the haemoglobin, HbA1c, is a measure of the blood glucose level over the previous several months and is therefore used as an indicator of the presence of T2D and a measure of the degree of severity. Initially this value was 8.0% but by the end of the period it had fallen to 6.8%. at the end of the initial 6-month period 10 of the controls switched to the low carbohydrate diet. Two of them successfully lost 20 kg and effectively controlled their blood sugar so that they no longer needed any medication(2).
In another study 10 obese patients with T2D were placed a diet which had only 21 g of carbohydrate for 14 days and as a result the fasting blood glucose decreased from 7.5 mmol/L to 6.3 mmol/L , which enabled the insulin doses to be reduced. A survey of the participants that there were no differences between the low carbohydrate diet and the usual diet with respect to feelings of hunger, satisfaction with the diets and feelings of comfort or discomfort(3).
The studies which have been cited here provide a convincing case for anyone who is diagnosed with T2D or at risk of developing T2D that a strategy to lower the intake of carbohydrates is likely to alleviate the causes of the condition and will also contribute to the loss of body weight. While it may be necessary to resort to the use of medication it is highly likely that a low carbohydrate diet will lower the amount required and may even eliminate the need for it entirely. The conventional recommendations to reduce the intake of fat and to increase the intake of the complex carbohydrates will probably not be effective. It would be much better to revert to the original advice and reduce carbohydrates which is what was done before all the alleged dangers of fat have arisen.
- J V Nielsen et al (2005) Uppsala Journal of Medical Science 1 (10) pp69-74
- J V Nielsen & Eva A Joensson(2008) Nutrition and Metabolism 5 (May) 14-20
- G Boden et al (2005) Annals of Internal Medicine 142 (6) pp 403-411.