Friday, August 25, 2006

Evidence-Based Guidelines Needed for Diabetes Diet

Monday I featured an online segment of dLife TV that highlighted the two sides of the debate about which type of dietary recommendation someone diagnosed with type II diabetes should receive. On one side we have those who feel recommending a low-carb diet, and thus advising a radical dietary modification, is an exercise in futility - either because the patient cannot or will not limit carbohydrate to control their disease; on the other side we have researchers publishing study after study with statistically significant improvements and physicians and healthcare professionals already making the recommendation to use a low-carb diet, who insist that when patients "see the pay off they stick with it."

In the comments, Kevin Dill, who follows a low-carb diet himself, asked a good question:

I guess my only question is which definition of a low carb diet are we going to use?? While Dr Atkins has provided the most popluar version, is it any better than Protein Power, South Beach, the Zone, or any of the other of myriad interpretations of low carb when it comes to controlling blood sugar?. IS Ketosis necessary? or is simply reducing the carbs below a certain level, (what ever that may be), sufficient? IF low carb is the one true answer, then why has DEAN ORNISH also been successful?? The real culprit is not just the carbs, its the constant state of over consumption, compounded by a sedentary lifestyle. While I agree that a low/reduced/controlled carb diet should be offered as an option, its only opening up a whole new can of worms. If the low carb community can't agree amongst itself which plan is "right", how would you expect people who aren't overly fond of the idea of reduced carbs to fair? But then again, they may do a better job with it as they do not have the emotional attachment that so many low carbers have to their chosen plan.

First some clarification - again - low-carb may not be the "one true answer" for every person diagnosed with type II diabetes. I've stated this previously and most recently on August 18th, "I don't think that only a low-carb diet should be recommended, nor do I think that initiating a drug at diagnosis is necessarily a bad idea."

My view is simply this - a low-carb diet has sufficient, credible and compelling data published at this point. Enough that it should be reviewed, an appropriate approach to low-carb eating defined, and then it offered as an option to anyone diagnosed with type II diabetes if they prefer to try to control their blood sugars with this alternative dietary approach. What we lack is a good, working definition of a low-carb (or controlled-carb, or carbohydrate restricted) diet and a clinical practice guideline. As pointed out above, which plan out there should be advocated as an appropriate diet for those diagnosed with type II diabetes?

From my perspective, the question shouldn't be "which popular diet to recommend," but "what does the data tell us is a level of carbohydrate that results in statistically significant improvement?"

The only approach here, in my mind, is a strict evidence-based approach which demands we set aside opinions, beliefs, anecdotes and assumptions and carefully review the hard data as the basis of our first step to definition for clinical application.

As it is now, we have two camps in the diet debate: those who advocate the carb-rich diet, with 45-55% of calories from carbohydrate, espoused by the leading organizations and government, countered by an assortment of various approaches to carbohydrate restriction with limited definition for practical use with patients. The carbohydrate intake of the various published carbohydrate restricted diets out there is all over the place - some recommending as little as 20g net carbohydrate per day to start and maxing out at about 100g net a day, some more moderate levels ranging from 72g to 150g a day, and others allowing up to 40% of calories from carbohydrate.

The current recommendations are available almost everywhere you turn - in print, the internet & media and hand-outs in the doctors office; the carbohydrate restricted diets are often designed by trial-and-error by the patient advised to reduce carbohydrate with little practical advice about how to do that. While some physicians have created patient hand-outs, many will not due to a fear of what may happen for making a recommendation contrary to the established guidelines.

We know the diet promoted these days may slow progression in some, but has yet to halt progression or reverse the condition over the long-term; we know the low-carb diet - in dietary trials - reverses the condition in some, returning blood sugars, cholesterol, insulin, weight and blood pressure to normal levels and also reduces or eliminates the need for medication; but, in an on-your-own approach, undertaken without clinical guidelines based on evidence, carbohydrate restriction may or may not have the same beneficial effect.

Without a practical, clinical guideline, physicians and other healthcare professionals advising a low-carb diet are left to design what they think a carbohydrate restricted diet is, which may or may not translate to the actual type of diet designed in clinical trials that resulted in statistically significant improvements; and the oft-vague advice to reduce carbohydrate without specifics leaves too much room for error by the patient due to a lack of evidence-based information to use in their daily menu planning.If we maintain the status quo, that is each side in the debate remaining in their comfort zone surrounded by like-minded folks, unwilling to engage with the other, nothing will change. I've watched as opportunity after opportunity was lost the last four years to find common ground and agreement, all in the name of each side insisting they know better than the other, believing the other is too entrenched in their beliefs to even sit and review the evidence.

So while this status-quo approach has maintained each view within its own cocoon of knowledge, it's established a precedent to dismiss, ignore and ridicule the other with little more than a belief that one side is right and one side is wrong.

If only it were that simple. If only things in this world were always black and white.

The only way to hammer out a definition and clinical guideline is to engage both sides and insist each side bring to the table their knowledge, understanding and evidence, review the evidence from the other side, and work together to improve the dietary recommendations for those diagnosed with type II diabetes.

This is no longer a matter of one side being right and the other wrong. We are in the middle of an alarming epidemic in the United States and can no longer afford to have either side sit on their laurels, basking in the belief they're right, damn the torpedoes.

Evidence-based medicine demands we sit together, review the evidence and use that data to establish truly evidence based guidelines. It demands we take the findings and use them not only because we've taken the time and resources to search for greater understanding, but because the data is what it is and not simply an opinion or belief.

Evidence-based medicine demands we do this even when we do not like or agree with the weight of the evidence available.

At the present, all of the popular, published diets work, yet each has a particular spin to differentiate it from the others. Some are very low-carbohydrate initially and ramp carbohydrate back up to low- to-moderate levels, yet still strictly reduced levels over time; some reduce carbohydrate significantly and maintain that low level of carbohydrate for the long-term ; and some simply reduce carbohydrate to a moderate level and ask those following to maintain that reduced, moderate level over time.

Recently a "next generation" of carbohydrate restricted approaches has cropped up - glycemic index and glycemic load; banning the white stuff; consuming whole foods only; or limiting sugar in the diet. While these are not promoted as "low-carb," they're based on the functional understanding of carbohydrate and sugar in the metabolism.

Each of the above popular diet plans is designed mostly for those seeking to lose and maintain their weight. With few exceptions, they're not specifically designed for those actively seeking to control their diabetes. While a number of these plans work well for those with type II diabetes, a person with type II diabetes is often left with too little information to make a decision from based on their current health status.

A clinical guideline, developed from the available data, in an evidence-based approach would enable a physician or healthcare professional to work with their patient to make a good decision about which dietary level of carbohydrate to use as a means of glycemic control.

The longer the established dogma remains and the longer those advancing carbohydrate restriction continue to differentiate and try to gain a some kind of recognition from the establishment by crafting "politically correct" diets, the more consumers will be confused and the less likely they'll be to get it right on their own or with their physician.

The time is now to take the leap from talking the talk of evidence-based medicine, to walking the walk and practicing what we preach - an actual review the data and then following the principle of evidence-based medicine to establish an evidence-based clinical guideline for dietary recommendations for those diagnosed with type II diabetes.

It will be a start, it will enable those diagnosed to decide if such a dietary approach is something they're willing to try, it will open the door to new avenues of research and it will potentially allow us to reverse the trend of increasing incidence of diabetes that, if we do nothing, promises to destroy our future.

The question really is, are the powers that be up to the task of a truly evidence-based approach? If they are, we can look forward to an evidence-based clinical guideline; if not, don't expect much to change anytime soon.

No comments:

Post a Comment