Dr David Unwin: Low carb is not just about diabetes
Dr David Unwin, of Norwood Surgery in Southport, is a strong advocate of lifestyle medicine. He is the RCGP National Champion for Collaborative Care and Support Planning in Obesity and Diabetes and a RCGP Clinical Expert in Diabetes. In 2016, he won the NHS Innovator of the Year Award. His work has been published in multiple journals and featured on television. Recently, Dr Unwin released an online RCGP course for healthcare professionals, exploring low GI diets in type 2 diabetes, which has received much positive feedback. This talk was given at the Public Health Collaboration conference 2018 at the Royal College of General Practitioners in London.
Part 1 – Recapping low carb and type 2 diabetes
Dr Unwin begins the talk by recounting how he discovered the power of a low carbohydrate lifestyle in placing type 2 diabetes, a disease once thought to be chronic, progressive and irreversible, into remission. He notes that the fastest case of remission he has seen in his practice is just 38 days. The implementation of the low carb approach has seen his practice’s diabetes control rocket from last place to first place, compared to that of averages across the country, all while spending the least on diabetes drugs. Dr Unwin opines that the obesity and diabetes epidemics are mostly due to diet, not genetics, and that we can fight against poor health rather than just accepting it. Astoundingly, 50% of Dr Unwin’s research cohort have achieved remission of their type 2 diabetes, without drugs, at an average of 21 months.
One of the things Dr Unwin teaches his patients is that starch, the carbohydrate present in foods such as bread, rice, pasta and potatoes, is actually concentrated chains of glucose, the sugar in our blood. He notes that, in his experience, many young doctors have not even known this off the top of their head. Proper education around diet and lifestyle is therefore extremely important in treating diabetes and other health conditions. On a related note, Dr Unwin produced a paper and a series of charts that make the glycaemic index (GI) and glycaemic load (GL) of foods easy to understand for both healthcare professionals and patients alike, by presenting GL in terms of teaspoons of sugar. Using these charts, he also opines that not all fruit and vegetables should be promoted equally, as different ones can impact the blood sugars of someone with diabetes very differently.
Dr Unwin explains that there has been great progress in the guidelines recently, regarding low carb diets. For example, both the Scottish Intercollegiate Guidelines Network (SIGN) and Diabetes UK guidelines now list low carb as an option for people with type 2 diabetes, however both express concerns over the long-term effects of such a lifestyle. Dr Unwin notes however that Diabetes UK could not back up their mention of ‘concerns’ with a reference.
Part 2 – Low carb and non-alcoholic fatty liver disease (NAFLD)
Interestingly, Dr Unwin has found that liver function, measured via a liver damage marker called GGT, improved rapidly and remarkably in his patients that saw success with the low carb lifestyle. The decrease in GGT actually preceded things like weight loss and HbA1c reduction and so improvements in GGT could predict patients’ success.
Dr Unwin shows that over an average of 21 months, the patients in his cohort dropped their GGT by 39%. Considering that NAFLD disease affects 20% of the developed world, he wonders why this problem is not discussed more often. He quotes Professor Roy Taylor who said “before diagnosis of Type 2 diabetes, there is a long silent scream from the liver”. Not only does NAFLD predict type 2 diabetes, but it can predict other conditions as well. Data from the Framingham study (which primarily focuses on cholesterol) show that the 25% of people with the highest GGT levels had a 67% higher cardiovascular risk.
So how does NAFLD come about? Dr Unwin delves into the underlying physiology, starting with the hormone insulin. He explains that insulin pushes excess glucose into abdominal fat and liver fat which, as you can imagine, can explain the development of fatty liver. In addition, Dr Unwin reiterates that triglycerides (formed from excess glucose) drop on a low carb diet. Because insulin also causes sodium (salt) to be retained by the kidneys, this explains the drop in blood pressure that is normally seen after going low carb too.
The aforementioned Prof Roy Taylor believes that type 2 diabetes results from the accumulation of fat in the liver and pancreas by increasing insulin resistance and reducing beta cell (insulin-producing cells) activity, respectively. Therefore, by halting the accumulation of new fat, and pulling existing fat out of these organs, it stands to reason that type 2 diabetes can be put into remission or reversed, as shown in the study. A way of achieving these outcomes, and so reversing the development of NAFLD and diabetes, Dr Unwin explains, is to reduce insulin levels by reducing carbohydrate intake. In one of his studies, Dr Unwin found that there was not a correlation between weight loss and GGT levels. He explains that this shows both improvements in liver function and diabetes remission can be independent of weight loss and that the improvements seen in the liver can come long before the others.
Looking at the results another group of Dr Unwin’s patients with type 2 diabetes, these ones on a low carb lifestyle for an average of 26 months, we see long-term marked improvements across the board. 50% of the group achieved remission of their diabetes and there were large improvements in HbA1c, total cholesterol, HDL cholesterol, cholesterol ratio, triglycerides, weight, blood pressure and GGT. Again, Dr Unwin reiterates, these results do not support the concerns some people express over cardiovascular risks with a low carb, real food lifestyle. Indeed, putting his group’s average values before and after the intervention into the JBS3 heart age calculator, Dr Unwin found that the calculated heart age dropped from 77 to 68 (bearing in mind the patients would also have been 2 years older after the intervention). In addition, the drops in HbA1c alone seen in Dr Unwin’s patients are suggestive of a significant reduction in cardiovascular risk.
To round off the talk, Dr Unwin reiterates that low carb is not just about diabetes and the research is backing this up. It has applications in many other areas, including NAFLD, cardiovascular health, hunger, obesity and even cognitive impairment and Alzheimer’s disease. A low carb approach can not only save the NHS money on drugs, but can also empower patients, giving them back hope for and control over their health.
If you would like to view Dr Unwin’s Public Health Collaboration talk from the previous year, click here.