How does weight-loss surgery reverse diabetes? Some experts believe remission occurs because the surgery affects gut hormones, which somehow impact pancreas function. This could be happening, but Dr. Taylor thinks the remission might actually occur because the surgery severely limits what people can eat. This hypothesis was the inspiration for his 600-calorie diet study. To date, no one knows what the exact mechanism is, but it is clear that bariatric surgery has let tens of thousands of people stop taking their diabetes medicines.
Bariatric surgery has significant side effects and risks, however, which may include digestive problems, nutrient deficiencies, and even death. Dr Iain Frame, director of research at Diabetes UK, which supported the 600-calorie diet study, noted that the study’s positive outcome “shows that Type 2 diabetes can be reversed [through diet] on a par with successful surgery without the side effects.”
What about complications?
Dr. Bernstein has found that when blood glucose levels are controlled, the body starts to heal itself and many complications improve. Most reversible seems to be neuropathy in the feet. Sexual dysfunction seems highly reversible as well, based on studies that have examined the topic. Retinopathy (eye disease) and nephropathy (kidney disease) also seem to improve when blood glucose levels come down.
Some complications, however, may be more difficult to reverse. A complication that has progressed beyond a certain point may persist even upon a return to normal blood glucose levels, since some tissue damage can be irreversible. If you are blind or experiencing kidney failure, it is highly unlikely that these problems will disappear entirely. It is always possible, though, that there will be noticeable improvement, no matter how “far along” your diabetes is.
Too good to be true?
The idea of reversing Type 2 diabetes is still considered somewhat extreme. Opposing voices raise several objections, such as the following:
No studies. The evidence of success is almost all anecdotal, critics say, so it can’t be given much credit. Actually, there are several studies, including the ones cited in this article, but they are small. There aren’t any large, well-controlled, multicenter studies on dietary approaches like those that exist for drugs.
There will probably never be any large studies on reversing Type 2 diabetes with food and exercise because they are too difficult to conduct, because most doctors currently don’t even accept the premise, and because there is no product to sell if an intervention is deemed successful. Richard Kahn, MD, former Chief Science and Medical Officer of the American Diabetes Association, said, “It’s very difficult to study long-term diet changes in the real world, where people often don’t know exactly what they’re eating.”
In Dr. Taylor’s 600-calorie-per-day study, all the meals were liquid and given to subjects by study administrators. Along with green, nonstarchy vegetables, this was all they could eat. To repeat these methods for a study of 10,000 people would be expensive and difficult.
The data say progression is inevitable. Maybe not, actually. True, most people with Type 2 diabetes do experience progression of the disease and complications. But reversal proponents say that this is because they stay on high-carbohydrate diets.
Jenny Ruhl points out that “although the UKPDS did show that even patients with good control deteriorated over time, ‘good control’ was defined to mean [HbA1c] test values near 7.0%. This is only mediocre control at best. It corresponds to an average blood sugar over 155 [mg/dl] and frequent spikes over 200.” Ruhl goes on to explain, “It is very likely that most UKPDS participants spent hours [after meals] with their blood sugars over 300 mg/dl…people who eat a lower-carbohydrate diet can keep their sugar below the 140 mg/dl level” where blood vessel damage is believed to start.