Diabetes reversal, not just treatment, should be a goal in the management of type 2 diabetes. Type 2 diabetes can be reversed not only with an extremely low calorie diet, but it can also be reversed with an extremely healthy diet. Could it be because an extremely healthy diet is also low in calories?
Study subjects lost as much weight on a green, leafy vegetable-packed plant-based diet as those who were on a semi-starvation diet based on liquid meal replacements. So, does it matter what we’re eating as long as we’re eating few enough calories to lose 15 pounds a month?
Even if diabetes reversal is just about calorie restriction, instead of subsisting off largely sugar, powdered milk, corn syrup, and oil, common ingredients in some liquid diet drinks, on the plant-based diet at least one can eat real food—infact, as many low-cal veggies as desired. So, even if it only works because it’s just another type of calorie-restricted diet, it’s certainly a healthier version. But, even participants in the study who did not lose weight—or even gained weight eating enormous quantities of whole healthy plant foods—appeared to improve their diabetes. Thus, the beneficial effects of this kind of diet appear to extend beyond weight loss.
The successful treatment of type 2 diabetes with a plant-based diet goes back to the 1930s, providing “incontestable evidence” that a diet centered around vegetables, fruits, grains, and beans was more effective in controlling diabetes than any other dietary treatment. In a randomized controlled trial, insulin needs were cut in half and a quarter of the subjects ended up off insulin altogether. But, again, this was a low-calorie diet.
Walter Kempner at Duke University School of Medicine reported similar results 20 years later with his rice and fruit diet studies, showing for the first time documented reversal of diabetic retinopathy in a quarter of his patients, something never even thought possible. One patient, for example, was a 60-year-old diabetic woman already blind in one eye and who could only see contours of large objects with the other. Five years later, while on the diet, instead of her vision getting worse, it got better. She “could make out faces and read signs and large newspaper print,” and got off insulin, had normal blood sugars, and had a 100-point drop in her cholesterol. Another patient went from only being able to read big headlines to being able to read newsprint four months later.
What was behind these remarkable reversals? Was it because the diet was extremely low-fat or because there was no animal protein or animal fat? Or, was it because the diet was so restrictive and monotonous that the patients lost weight and improved their diabetes that way?
To tease this out, we needed a study where researchers switched people to a healthy diet, but forced them to eat so much they didn’t lose any weight. Then, we could see if a plant-based diet has unique benefits independent of all the weight loss. For that, we had to wait another 20 years until the study was done in the 1970s. In it, diets were designed to be weight-maintaining. Participants were weighed every day, and, if they started losing weight, the researchers made them eat more food—in fact, so much food that some of the participants had trouble eating it all, but they eventually adapted. Thus, there were no significant alterations in body weight despite restrictions of meat, dairy, eggs and processed junk, and there were enough whole plant foods—whole grains, beans, vegetables, and fruit—to provide 65 grams of fiber a day, four times what the Standard American Diet provides.
The control diet they used was the conventional diabetic diet, which actually had nearly twice the fiber content of the Standard American Diet, so it was probably healthier than what they had been used to eating. So, how did they do? With zero weight loss, did the dietary intervention still help? The study compared the number of units of insulin with which subjects had to inject themselves daily before and after going on the plant-based diet. Overall, despite no change in weight, insulin requirements were cut about 60 percent, and half were able to get off insulin altogether. Was this after five years or after seven months as had been the case in the other studies discussed above? No.
It was after 16 days.
To be clear, we’re talking about diabetics who had had diabetes as long as 20 years, injecting 20 units of insulin a day, getting off insulin altogether in as few as 13 days, thanks to less than two weeks on a plant-based diet. Patient 15, for example, had injected 32 units of insulin while on the control diet, and then, 18 days later, none. Lower blood sugars on 32 units less insulin.
That’s the power of plants.
As a bonus, their cholesterol dropped like a rock to under 150 on average in 16 days, making them nearly heart attack proof as well. Just as “moderate changes in diet usually result in only modest reductions” in cholesterol, asking people with diabetes to make moderate changes often achieves equally moderate results, which is one possible reason why most end up on drugs, injections, or both. Everything in moderation may be a truer statement than people realize. Moderate changes in diet can leave one with moderate blindness, moderate kidney failure, moderate amputations. Moderation in all things is not necessarily a good thing.
The more we, as physicians, ask from our patients, the more we—and they—get. The old adage, “shoot for the moon,” seems to apply. It “may be more effective than limiting patients to small steps that may sound more manageable but are not sufficient to actually prevent disease progression.”
Michael Greger, M.D.
PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations—2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not to Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.