Dr David Cavan: Reversing type 2 diabetes in the real world
Dr David Cavan is a diabetes physician with a special interest in self-management of the disease. He was previously a Consultant Physician at the Bournemouth Diabetes and Endocrine Centre for 17 years, where he oversaw the development of education programmes for people with both type 1 (BERTIE) and type 2 (Focus) diabetes and also helped to develop an approach for people starting insulin pump therapy. He was also Director of Policy and Programmes at the International Diabetes Foundation (IDF). Dr Cavan has released a number of books, in partnership with Diabetes.co.uk, regarding the reversal of type 2 and control of type 1 diabetes. This talk was given at the Public Health Collaboration conference 2018 at the Royal College of General Practitioners in London.
Dr Cavan begins the talk by recalling his personal journey. He remembers, years ago, getting excited about the introduction of new diabetes drugs that he was told by the representatives were effective and could fix the diabetes epidemic. When this didn’t happen, Dr Cavan says he became disillusioned and tried another approach; he started asking people what they were eating and tried to figure out how best to modify this. He quickly realised that carbohydrate restriction was effective in controlling diabetes and began to advise low carb diets to his patients. He remarks that when he started doing this, it was unheard of and he could not believe that one of his first patients (a type 2 diabetic) was able to come off insulin. Now, these sorts of stories are commonplace in the context of carbohydrate restriction.
Following some brilliant results with his patients, Dr Cavan wrote a book, based on low carb advice, on how to control and possibly reverse type 2 diabetes. He puts emphasis on the importance of making the possibility of type 2 diabetes reversal known to the public, as he believes it’s key to providing motivation and hope. This was followed by two other books – a recipe book to complement the first book and another on taking control of type 1 diabetes. Dr Cavan says that he’s been contacted by many of his readers who have seen amazing results.
Dr Cavan emphasises that type 2 diabetes is an ‘insulin problem’ rather than a glucose problem. In other words, high insulin levels and insulin resistance are the problems at the heart of type 2 diabetes, and high glucose levels are just a symptom. With type 2 diabetes rates exploding since the 1960s, evidence suggesting that lifestyle factors are key in its development are ever-increasing. Dr Cavan explains that, for a long time, prediabetes and type 2 diabetes were thought to be a one-way street. It is now known that these diseases can very much be prevented and even reversed with a healthy lifestyle, involving a healthy diet and physical activity.
It was evidence, first from bariatric surgery and then from the Counterpoint study (which led to the DiRECT study), Dr Cavan says, that showed type 2 diabetes to be reversible. He presents what he calls “the diabetes disease process” and shows again how high insulin levels and insulin resistance are the root cause of type 2 diabetes, but also, are problems that are fed by high carbohydrate diets which are the standard intervention for diabetics. To reverse the diabetes disease process then, it makes sense that the opposite of this (a low carbohydrate intake) is key.
Dr Cavan highlights that there are a number of interventions that can reverse type 2 diabetes. He notes that while a very low calorie diet (800 kcal / day) is able to reverse type 2 diabetes in the short-term, it is not sustainable in the long-term and may not be well tolerated. In contrast, Dr Cavan says that a ketogenic diet is also capable of reversing type 2 diabetes and is maintainable in the long-term if the restrictions are considered manageable by the individual. As these two approaches are not for everyone, Dr Cavan generally recommends a diet with 50-100 grams of carbs per day if asked. He also notes that various types of intermittent fasting may be effective methods for some people.
Dr Cavan recounts how he was asked to move to and work in Bermuda for six months. He says it was the most diabetogenic (diabetes-causing) environment he has ever seen, with a large intake of sugar-sweetened beverages, cheap sugary snacks and high carbohydrate meals. On top of this, most people drive to get around and very few people walk. In an effort to combat this, Dr Cavan put together a diabetes reversal program, incorporating both carbohydrate restriction and physical activity. He shares the data from 30 participants that completed a 12 month follow-up, showing many favourable results including nearly two thirds reducing or eliminating their medication.
There are a number of challenges when rolling out a low carb intervention, not least of which is the social pressure and isolation that can come with eating different things to your friends, family and colleagues. In order to overcome these challenges, Dr Cavan says, the environment needs to be changed. In the case of Bermuda, the government has announced a sugar tax (much like the one now active in the UK) and has reduced taxes on imported fruit and vegetables. Progress can also be made in the availability of sugary food and beverages, for example in canteens. Dr Cavan finishes by stressing that reversing diabetes on a large scale will require modification of the diabetogenic environment.