Why aren’t low-carb diets prescribed for all people with diabetes? A new paper by more than 25 leading doctors and researchers argues that such diets should be the first treatment for Type 2.
Published in the January 2015 issue of the journal Nutrition, the paper is called “Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base.” It looks at nearly 100 studies. It concludes that the science supporting low-carb approaches to diabetes is extremely strong. Traditional low-fat recommendations, on the other hand, have no evidence to support them.
As a reminder, carbohydrates (“carbs”) are fibers, starches, sugars. They are plant foods that are good for energy but, with the exception of fiber, otherwise don’t have much nutritional value.
Here are the main points the researchers found:
• Low-carb diets reliably reduce high blood glucose, the main feature of diabetes.
• Glucose reduction benefits do not require weight loss, though weight loss is often a side effect.
• Carb restriction often reduces or eliminates the need for medication.
• There are no side effects comparable to those seen with drug treatment.
• Low-carb diets are relatively easy to stick to, because calories are not limited and people don’t feel hungry or deprived.
• Fat intake, including saturated fat intake, has NOT been shown to increase the risk of heart disease. High fat levels in the blood are a risk factor, but they are not generally related to dietary fat intake.
The whole paper is at this link and is well worth reading.
Some history, as given in the paper: For decades, the American Diabetes Association (ADA) recommended a low-fat, relatively high-carb diet. After years of criticism and many new studies, the policy has changed to be more like “Different diets are better for different people.” This is an improvement, but doctors trained in the old approach often advise patients against low-carb eating. The diabetes establishment still pushes people toward a diet that will probably make them sicker.
Before the discovery of insulin, low-carbohydrate and sometimes very-low-calorie diets were the only treatment for diabetes. People would live on cream and butter and some meat if they could get it. They didn’t live long, but it was the only way they could go on at all. If they ate any carbs, their sugars would soar and they would die.
Even after insulin became available, this high-fat diet was the main treatment. After a while, with new drugs and better insulins, medicine started to loosen up on this very-low-carb approach.
Then came the 50s, and the scientific “discovery” that high-fat diets cause heart disease. This finding has since been discredited, but by then fat had become the enemy. Since a low-carb diet necessarily involves eating more fat, the ADA decided more carbs was better than more fat.
This decision has been a disaster for people with diabetes, the new paper argues. The authors point out that there is virtually no evidence that fat harms people with diabetes. High glucose levels are the main problem in the disease.
Carbs are the foods that turn into glucose in the blood, so the more carbs you eat, the higher your glucose is likely to go. This isn’t exactly rocket science. The authors cite numerous studies to back up their conclusion.
For my book Diabetes: Sugar-Coated Crisis, I interviewed ADA’s then scientific director, Richard Kahn. I asked him why their outdated advice hadn’t changed. He told me, “We need more studies, particularly long-term studies in patients who are really randomized…in the real world, people don’t know exactly what they’re eating… It’s such a difficult topic to study. ”
But here’s the thing. If we don’t have any good studies, what is the old advice based on? And if it’s so hard to do good studies, how will that unsupported advice ever change? In my book, low-carb guru Dr. Richard Bernstein told me he didn’t think the advice would change until all the people who originally proposed it had died. The new paper, which Bernstein cowrote, hopes to change that.
What’s included and not included
The paper defines what is meant by very-low-carbohydrate (10% of calories), low- (less than 26%), and moderate- (26% to 45%) carb diets. It doesn’t say whether starches or sugars are worse. It doesn’t say whether protein or fat is healthier, although they suggest fat as a better source of energy for most people.
They say the risks of low-carb eating are mainly from glucose going too low because of medicines. Diabetic drugs will need to be reduced or eliminated for most people, although they suggest metformin may be continued in many people.
They say the answers to questions like “starch versus sugar” or “protein versus fat” aren’t known yet. They advise, “Eat to the meter,” meaning check your blood glucose levels and eat what keeps your sugars lowest and makes you feel best.
Their concluding advice to doctors is, “Given the superior outcomes of carbohydrate-restricted diets, patients should not be discouraged from adhering to them as is frequently observed. They should, in fact, be encouraged to follow this approach.”
For people with diabetes, though, the huge missing piece is, “Well, what should I eat then?” Is it all animal products? Because that is not a sustainable or an affordable diet. Some vegetarian populations have low rates of diabetes, and they eat a lot of carbs.
Should you go low-carb, and what’s the best way to do it? This has been written about many times, but we’ll have another go at it next week.
Coming up on his 20-year anniversary with diabetes, Scott Coulter shares some of what he has learned. Bookmark DiabetesSelfManagement.com and tune in tomorrow to hear his insights!