From Joy Pape, RN BSN CDE WOCN
Certified Diabetes Nurse Educator
Numbers Don't Lie — My New Mantra
I must have had my head in the sand, just woke up last January, or have been working in
the office with real people too long. This "sugar alcohol, other carbohydrates and net
carb" thing wasn't a huge issue until the low carb lifestyle got so poplular and it seems
everybody wanted a piece of the pie, minus the sugar... I mean table sugar.
I've been working with people who have diabetes and related issues in the low carb field
for almost ten years. I always did and will continue to teach people to eat real food
and check their numbers. Not the net carb numbers on packages that one has to go through
hoola hoops to figure out, but numbers on the scale, numbers on their blood glucose meters,
Hemoglobin A1c, blood pressure, lipids, etc. These numbers don't lie.
As for diabetes, my patients tell me the numbers concocted to come up with net carbs do
not correlate with their post meal blood glucose levels.
If you have diabetes and want to check out how a certain food affects you, check your
blood glucose right before eating, then one hour, ninety minutes and or two hours after
the first bite of that food. It will be very revealing. For those of you who take
insulin and count carbs, you can try adjusting your insulin to the net carb value, and
check your blood glucose as mentioned above. Again it will be revealing.
There's one thing for sure, no two people who have diabetes will respond exactly the same.
Another thing to remember is every food is different as are the manufacturers and testing,
not to mention the other variables involved in blood glucose control like premeal glucose,
medications, activity, stress... on and on.
My last word on this... my patients are confused and so am I. Checking your numbers will
help you figure it out. Don't forget, this whole movement started by choosing real food
and avoiding junk foods. Are we just replacing junk foods with other junk foods?
I don't get it.
From Gil Wilshire, M.D., FACOG
President and Chief Scientific Officer,
The difficulty of assessing the impact of sugar alcohols on metabolism with
regard to adipolysis (fat burning) revolves around several issues:
- What is the full impact of colonic absorption of short-chain fatty
acids and other fermentation byproducts on adipocyte metabolism?
- What are the implications of mixed-meal scenarios? Does the
concurrent intake of fat, protein, or typical carbohydrates modify the
sugar alcohol's digestion or breakdown?
- Are there significant phenotypic differences in metabolism?
Are they widespread? What is the magnitude of the differences?
- What are the differences between the various polyols?
With regard to the first point, there should be no doubt that colonic-derived
calories certainly add to the total energy balance. The impact of these
calories on adipolysis in the context of ongoing ketosis is not clear.
The mixed meal scenario is also not well understood. At least one published
study on the Atkins Advantage Bar (Hertzler SR, Med Sci Monit, 2003; 9(2): CR 84-90)
has demonstrated a higher-than-expected rise in serum insulin levels (with respect
to "net carbs" claims) after ingestion. This study was confounded by the presence
of glycerol in the product, so the data does not clarify the situation very much.
Regarding the third point, I am aware of a lot of anecdotal evidence of sugar
alcohols throwing off blood sugar control in insulin-dependent diabetics. More
to the point, I have just been made privy to some late-breaking human data being
generated by the Glycemic Research Institute and the University of Florida at
Tampa. They appear to be seeing a wide variation of blood sugar responses between
subjects after polyol consumption. Whether this represents differences in peoples'
resident colonic flora, or inherent differences in actual "hard wired" metabolic
pathways is not clear at the moment.
With respect to the last point, it is well-documented that glycerol cannot be
deducted from total glycemic loads. On the other hand, erythritol, with its
rapid renal excretion, probably counts very little in its metabolic impact. The
middle-of-the-road, common polyols (e.g. maltitol, sorbitol, xylitol), however,
are generating much of the uncertainty. As we have been learning from the study
of fructose, the metabolic impact of a dietary ingredient can be only partly
understood by its effects on blood glucose and insulin levels. Effects on blood
lipids, anabolic hormones (which are pulsatile), 11-beta-hydroxy-steroids, and
lipoprotein lipase all need to be measured before any substance can be called
a "low impact" ingredient. Much of what happens in digestive metabolism also
remains hidden in the (generally) inaccessible reaches of blood flow within
the portal and splanchnic circulations. (These are the blood flow systems
between the gut, liver, and inner abdominal fat that are not accurately
reflected by the blood that is drawn from the arm.) Perhaps data may eventually
be generated from primate research models; but this will take considerable
time and money.
In summary, anecdotal evidence and early human research data suggests that - in
at least some individuals - sugar alcohols are not inert metabolic bystanders.
Until more is learned, caveat emptor, should be the motto of anyone who is
diabetic or losing weight with a ketogenic strategy. Buyer beware if sugar
alcohol consumption is throwing off blood sugars or is associated with stalls
in weight loss.
From Jonny Bowden, MA, CN, CNS
Nutrition and Fitness Expert and Author
I think I'm at a bit of a disadvantage here coming to the party after an extremely
thorough introduction by Lora and an incisive commentary by Dr. Fineman, with whom
I agree almost entirely.
I think it's useful to point out that there is some research showing that one sugar
alcohol in particular, Xyltiol, actually has health benefits. It appears to prevent
bacteria adhesion which is why it is so useful in preventing tooth decay, and may
even be useful in preventing or modulating bacterial infections elsewhere. That's
why I use it as my sweetener of choice and sell it on my website. However, it's
not used a lot in low-carb products.
When we come to the products, we have a whole different set of problems. Right
now I think it's fair to say that the collective wisdom is that sugar alcohols
do not pose the same problems that sugars do as far as blood glucose and insulin
are concerned. However, Dr. Fineman is entirely right that the response is going
to be individual. Why? Because there are psychological factors involved as well
as metabolic ones. Does the taste of sweetness perpetuate or contribute to sugar
addiction? Can people consume these products the way they were intended to be
used as treats and occasional supplements to the diet, or are they downing
them like candy bars and thus derailing their potential positive effects?
We just don't know yet.
Obviously, in the best of all possible worlds, everyone would eat organically
grown and raised food, and the control of insulin and sugar would be the natural
outcome of eating some variation on a hunter-gatherer diet. But this is the real
The best companies that are making these products, are making the judgment call
that there needs to be some compromise with the reality of everyday life in the
fast lane. They're offering people useful and convenient products that can be
integrated into a controlled-carb eating plan without creating havoc with
No dietary regimen is any good if people don't stay on it, so to the degree that
these products allow you to remain on track, they are a good thing. These products
serve a very important purpose for people with active lifestyles who can't always
stop and prepare food, or for people who want the occasional taste of something
sweet and don't have a problem with binging. But we also have to acknowledge that we
can't say with certainty that they're going to work for every person on the
planet with either a metabolic anomaly or a psychological tendency to be
addicted to sweets. That's something we're just going to have to watch unfold
as our clinical experience with them, and the research that's bound to come
in the next few years, unfolds.