Contents:

• Executive summary
• What is diabetes?
• Type 1 diabetes
• Type 2 diabetes
• Gestational diabetes
• Metabolic syndrome
• Pre-diabetes
• Common health complications
• Why do people become diabetic?
• Genetics
• Lifestyle and environmental factors
• Life with diabetes
• Classical approach to treatment
• Medication
• Type 1 diabetes
• Type 2 diabetes
• Diet
• How well does it work?
• The D-Diet
• Basic principles of the D-Diet
• Why and how it works
• The D-Diet nutrition basics
• Conclusion
• References

The D-Diet

Those with either type of diabetes will benefit from this approach but unlike type 2 diabetics, those with type 1 will always need to take insulin. Nevertheless, type 1 diabetics can use the D-Diet to keep insulin doses to a minimum and markedly reduce their risk of further health complications.

This approach is based on what you eat, not on counting how much you eat because, perhaps surprisingly, what you eat actually regulates how much you eat (see page 20).

Research has shown that with the right diet it is possible to decrease blood sugar, limit medication, cut the risk of complications and even reverse type 2 diabetes.

One of the first studies to test the effects of a plant-based, low-fat diet and exercise on a
group of 40 type 2 diabetic patients, had outstanding results – 36 of the patients were able to
discontinue all medication after only 26 days (Barnard et al., 1982). The same research group later demonstrated that the benefits of this diet are long-term and last for years, if the diet is adhered to (Barnard et al., 1983).

In one of the groundbreaking studies that followed, researchers employed a combination of
diet change and exercise (Barnard et al., 1994). The subjects were 197 men with type 2 diabetes and after just three weeks, 140 of them were able to discontinue their medication. A further study, conducted around the same time, involved 21 diabetics with diabetic neuropathy (characterised by numbness and shooting or burning pains in the lower limbs), who volunteered to follow a vegan, whole food diet and exercise programme for 25 days. Within 16 days, 17 of the patients reported that the neuropathic pain had been completely alleviated. Although the numbness persisted, it was noticeably improved within the 25 days of the programme (Crane and Sample, 1994).

A 2006 study, conducted by the Physicians Committee for Responsible Medicine with the George Washington University and the University of Toronto, tested health benefits of a low-fat vegan diet emphasising foods with a low glycemic index value and excluding all animal products on people with type 2 diabetes. It was compared to a diet based on the American
Diabetes Association (ADA) guidelines which restricted calorie intake and limited carbohydrates (Barnard et al., 2006). Portions of vegetables, grains, fruits and pulses were unlimited.

Over the 22-week study, 43 per cent of the vegan group and 26 per cent of the ADA group reduced their diabetes medications. Furthermore, the vegan group lost an average of almost one stone (13 pounds), compared with just over half a stone (9 pounds) in the ADA group.

Overall quality of this vegan diet was compared to the ADA diet on the basis of the Alternate Healthy Eating Index (AHEI), which is used to estimate the risk of chronic diseases (Turner-McGrievy et al., 2008). It employs a scoring system which assesses several dietary behaviours and rates food and nutrient intakes. The vegan group improved in every AHEI food category (vegetables, fruit, nuts and soya protein, ratio of white to red meat, cereal fibre, trans fat, polyunsaturated to saturated fat ratio) and significantly improved the overall AHEI score. The ADA group improved in only two categories (nuts and soya protein, polyunsaturated to saturated fat ratio) and did not improve the overall AHEI score of the
group. An increase in AHEI score was also associated with decreases in HbA1c value (which measures blood sugar levels over time) and weight.

Following the success of the previous studies, a 74- week clinical trial using a low-fat vegan diet was conducted (Barnard et al., 2009a). Participants were type 2 diabetics and they were randomly assigned a low-fat vegan diet or a diet following ADA guidelines. HbA1c changes from the beginning of the study to 74 weeks, or to the last available value before any medication adjustment, were -0.40 points for the vegan group and +0.01points for the conventional diet group. In patients whose medication did not need to be adjusted, HbA1c fell 1.23 points over the initial 22 weeks, compared to 0.38 points in the ADA group. Glycemic control, therefore, improved more in the vegan group.

The reduction in triglycerides (fats in blood) in the vegan group was also remarkable as was the decrease in cholesterol levels (-20.4mg/dl in contrast to just -6.8mg/dl in the conventional group). Both groups managed to lose weight but unlike the vegan participants, volunteers on conventional (ADA) diet had restricted calorie intake whilst the vegan group did not.

Parallel to these intervention studies, another research group focused on analyzing dietary patterns of 2,875 volunteers without diabetes and determined their risk of diabetes by repeated measurements of basic indicators – blood glucose, insulin concentrations, cholesterol levels, and waist circumference (Liu et al., 2009). Their findings were clear: consumption of a diet based mainly on plant foods protects against insulin resistance, while refined grains, high-fat dairy, sweet baked foods, sweets and sugary soft drinks promote insulin resistance.

A similar study from 2011 (Rizzo et al., 2011) focused on the risk or presence of metabolic syndrome (which often precedes diabetes) and dietary patterns of middle aged and elderly people. The study concluded that vegetarians had significantly lower values for all risk factors apart from one (HDL cholesterol – which can be explained by the participants’ consumption of
dairy and eggs) and much lower occurrence of the metabolic syndrome than semi-vegetarians (eating meat occasionally) and meat-eaters.

Volunteers participating in some of the above studies preferred the vegan diet (Barnard, 2007) not only because it was effective but also because they found it better than the diet previously recommended. Participants in the 74-week study were repeatedly asked to rate the acceptability of their diets (Barnard et al., 2009b) and the results showed that patients initially felt more restricted by the ADA diet and at the end of the study reported that the vegan diet  was as acceptable as the conventional diet. These findings suggest that following a diet that reverses diabetes is no harder than following a conventionally recommended diet which produces only minor changes in metabolism.

The usefulness of vegan diets was eventually endorsed even by the American Diabetes Association when in 2010, their Clinical Practice Guidelines stated that plant-based diets had been shown to improve metabolic control in persons with diabetes (American Diabetes Association, 2010).