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Among the
influential mainstream proponents of low-fat nutrition is the American
Diabetes Association who, for years, has recommended that diabetics
consume a high-carbohydrate diet.
Never mind that diabetes is an illness characterized by glucose
intolerance; that is, an inability to efficiently metabolize dietary
carbohydrates which, regardless of their source (complex, simple, high-glycemic,
low-glycemic, high-fiber, low-fiber) are ultimately broken down into
glucose inside the body. In healthy individuals with optimal glycemic
control, much of this glucose will be channeled into the muscles (and to
a lesser extent, the liver), where it will be stored as glycogen. This
stored glycogen can later be used as fuel for muscular effort.
In healthy
individuals, the transport of glucose from the blood into the muscles is
largely mediated by insulin, a hormone secreted by the pancreas. By
removing glucose from the bloodstream into muscles, insulin helps keep
blood sugar levels in a tightly-controlled range. This is important,
because both low and high blood sugar levels have a number of adverse
physiological consequences, and epidemiological studies have uncovered a
higher risk of cardiovascular and all-cause mortality for individuals
with hypoglycemia (low blood glucose) and hyperglycemia (high blood
glucose).(Bjornholt JV)(Wei M)
In full-blown
diabetics, a lack of sufficient insulin output by the pancreas leads to
chronically elevated high blood sugar levels. The resultant
hyperglycemia dramatically increases glycation, a process in which
protein and sugar molecules in the body "cross-link", forming
what are known as advanced glycation end-products (AGEs). Glycation is a
process to which none of us are immune, but it can be reduced by
avoiding high-glycemic load diets and by minimizing our intake of
overcooked, highly-browned foods.
Glycation
damages our organs and tissues and, along with free radical damage, is
considered a major contributor to the aging process. It is no
coincidence that diabetics typically have significantly-shortened
lifespans compared to non-diabetics, along with a far higher prevalence
of heart disease, cancer, kidney disease, amputation, and blindness.
Listen to the ADA -
and watch your blood sugar go up!
Recently, I
received a copy of a highly-informative and soon-to-be-published review
on popular low-carbohydrate diet books, which had kindly been forwarded
to me by its author. As I scanned through the review, my eyes nearly
popped out after reading the following quote, attributed to the American
Diabetes Association:
"The
message today: Eat more starches! It is healthiest for everyone to eat
more whole grains, beans, and starchy vegetables such as peas, corn,
potatoes and winter squash. Starches are good for you because they have
very little fat, saturated fat, or cholesterol. They are packed with
vitamins, minerals, and fiber. Yes, foods with carbohydrate -- starches,
vegetables, fruits, and dairy products -- will raise your blood glucose
more quickly than meats and fats, but they are the healthiest foods for
you. Your doctor may need to adjust your medications when you eat more
carbohydrates. You may need to increase your activity level or try
spacing carbohydrates throughout the day."
Reeling
in disbelief at the stupidity of such advice, I visited the ADA website
(March 28, 2004), and sure enough, in an article titled The
Diabetes Food Pyramid: Starches, were
the very words you see printed above.
The complete
lack of logic in the ADA's statement is absolutely mind-boggling. We are
simultaneously told that "Yes, foods with carbohydrate --
starches, vegetables, fruits, and dairy products -- will raise your
blood glucose more quickly than meats and fats" - a situation
to be avoided at all costs by diabetics - but that these
high-carbohydrate foods "are the healthiest" for
diabetics. How can that be?
The
consequences of the ADA's enthusiastic call to "Eat more
starches!" are alluded to in the sentence that states: "Your
doctor may need to adjust your medications when you eat more
carbohydrates." Yes, if your blood sugar rises from eating more
carbohydrates, your doctor will indeed need to adjust your diabetic
medication dosage - upwards!
The ADA
article also states that: "You may need to increase your
activity level or try spacing carbohydrates throughout the day",
further acknowledging the deleterious glycemic effects of increased
carbohydrate intake.
Why in blazes
is America's premier diabetes organization recommending a diet that will
raise blood sugar levels and necessitate increases in blood-sugar
lowering drugs? And, even worse, why are they actively discouraging
diabetics from trying the very diets that have been shown repeatedly to
improve glycemic control? I'm talking about carbohydrate-reduced diets.
Take the following quote:
"Currently
some controversy about carbohydrates is raging due to a few new diet
books. These books encourage a low carbohydrate, high protein and
moderate fat intake. These diets are not in synch with the American
Diabetes Association nutrition recommendations, which are based on years
of research and clinical experience."
The ADA is
100% correct that low-carb diets are not in synch with their own
recommendations; given the highly erroneous and counterproductive nature
of the ADA recommendations, this cannot be considered anything but a
virtue!
The ADA claims
that their nutrition recommendations "...are based on years of
research and clinical experience". If they are implying that
science supports their guidelines as being beneficial to diabetics,
nothing could be further from the truth. As we shall now discuss,
numerous studies show that high-carbohydrate diets can markedly worsen
glycemic control in both diabetic and even non-diabetic individuals.
Reduced-carbohydrate diets, on the other hand, can bring about dramatic
improvements in glycemic control.
What the Research
Shows
When Type 2
diabetics were placed on a low carbohydrate diet (25% carbohydrate) for
8 weeks, they experienced significant improvements in glycemic control,
as reflected by decreases in both fasting blood glucose and hemoglobin
A1c, a measurement that reflects the average blood sugar level over the
previous 3 months or so. Nineteen of the patients had been taking oral
diabetic drugs prior to the onset of the study; all were able to
discontinue the use of these drugs during the study. However, when the
patients were switched to a 55% carbohydrate diet - similar to that
recommended by the ADA - their blood glucose control and hemoglobin A1c
measurements significantly deteriorated. (Gutierrez et al. 1998)
Similar
results were noted in a 1987 study which also compared higher and lower
carbohydrate intakes in Type 2 diabetics. In this study, one of the
diets contained 20 percent protein, 20 percent fat, and 60 percent
carbohydrate, again similar to that recommended by the ADA. The other
contained 20 percent protein, 40 percent fat, and 40 percent
carbohydrate. Unfavorable glucose and insulin responses, and
significantly greater 24-hour urinary glucose excretion, were observed
when subjects followed the high carbohydrate diet. (Coulston et al.
1987)
A 1994 edition
of the Journal of the American Medical Association reported how
Type 2 diabetics consumed a 40% carbohydrate, 45% fat diet for 6-14
weeks, and a 55% carbohydrate, 30% fat diet for another 6-14 weeks in a
randomized crossover fashion. The high carbohydrate diet increased
daylong blood glucose and insulin values by 10%. (Garg et al. 1994)
Yet another
study with Type 2 diabetics showed that raising the dietary carbohydrate
content by a mere 10%, from 40% to 50%, resulted in a significant
increase in both post-meal blood glucose and insulin concentrations. (Sestoft
et al. 1985)
Finally,
researchers from the University of Minnesota recently found that Type 2
diabetics consuming a 30 percent protein, 30 percent fat, and 40 percent
carbohydrate diet (a macronutrient ratio similar to that prescribed in
Dr. Barry Sear's Zone Diet), showed significantly lower blood glucose
levels after meals and greater reductions in glycated hemoglobin levels
than those following a 15 percent protein, 30 percent fat, and 55
percent carbohydrate diet. (Gannon et al.)
Type 2
diabetics are not the only folks who experience improvements in blood
sugar metabolism when carbohydrate intake is restricted. A recent study
compared the effects of three different diets in healthy volunteers; 1)
zero fat, high carbohydrate, 2) moderate fat, moderate carbohydrate, and
3) high fat, low carbohydrate. Researchers observed significantly lower
insulin concentrations on the high fat, low carbohydrate diet. In
addition, those on the high fat, low carbohydrate diet burnt more fat
and less glucose for fuel. (Bisschop et al. 2001)
To be fair,
high carbohydrate diets can lead to improvements in blood sugar and
insulin function if caloric intake is restricted to the point
where fat loss occurs, but the ADA does not include this important
pre-requisite in their dietary guidelines.
Furthermore,
when calorie-reduced low-fat, high-carbohydrate regimens are directly
compared with similarly-restricted low carbohydrate diets, the latter
are still shown to be more effective in terms of glycemic control. (Baba
et al. 199)Brehm et al. 2003)(Lewis et al. 1977)(Volek et al.
2002)(Layman et al. 2003)(Farnsworth et al. 2003)(Heilbronn et al.
1999)(Jeppesen et al. 1997)(Gumbiner et al. 1996)(Golay et al.
1996)(Piatti et al. 1994)(Rabast et al. 1979)(Fujita et al. 1975)
Finally, while
calorie-restriction may help mitigate the harmful glycemic effects of
high carbohydrate diets, what happens when diabetic individuals
eventually return to maintenance-calorie intakes? If the studies
comparing maintenance-calorie high- and low-carb diets that we discussed
above are any indication, the result will be steadily deteriorating
glucose tolerance.
Conclusion
The
research leaves little doubt as to what diabetics can expect from the
American Diabetes Association's bizarre
"a-high-carbohydrate-diet-will-raise-your-blood
sugar-but-you-should-eat it-anyway" message: worsening glycemic
control! Because it is poor glycemic control that causes the health
problems that befall diabetics - not imaginary villains like saturated
fat or cholesterol - diabetics would be very wise to disregard the
contradictory, incoherent, and scientifically baseless recommendations
of the ADA.
References
Bjornholt JV, et al. Fasting
blood glucose: an underestimated risk factor for cardiovascular death.
Results from a 22-year follow-up of healthy nondiabetic men. Diabetes
Care, 1999; 22: 45-49.
Wei M, et al. Low Fasting
Plasma Glucose Level as a Predictor of Cardiovascular Disease and
All-Cause Mortality. Circulation, May, 2000; 101: 2047-2052.
Gutierrez M, et al. Utility of a Short-Term 25% Carbohydrate Diet on
Improving Glycemic Control in Type 2 Diabetes Mellitus. Journal of the
American College of Nutrition, 1998; 17 (6): 595-600.
Coulston AM, et al.
Deleterious metabolic effects of high-carbohydrate, sucrose-containing
diets in patients with non-insulin-dependent diabetes mellitus. American
Journal of Medicine, 1987 Feb; 82 (2): 213-20.
Garg A, et al. Effects of
varying carbohydrate content of diet in patients with
non-insulin-dependent diabetes mellitus. Journal of the American Medical
Association, 1994; 271: 1421-1428.
Sestoft L, et al.
High-carbohydrate, low-fat diet: effect on lipid and carbohydrate
metabolism, GIP and insulin secretion in diabetics. Danish Medical
Bulletin. 1985 Mar; 32 (1): 64-69.
Gannon MC, et al. An increase
in dietary protein improves the blood glucose response in persons with
type 2 diabetes. American Journal of Clinical Nutrition, 2003; 78:
734-741.
Bisschop PH, et al. Dietary
fat content alters insulin-mediated glucose metabolism in healthy men.
American Journal of Clinical Nutrition, 2001; 73: 554-559.
Baba NH, et al. High Protein
vs High Carbohydrate Hypoenergetic Diet for the Treatment of Obese
Hyperinsulinemic Subjects. International Journal of Obesity, 1999; 11:
1202-1206.
Brehm BJ, et al., A Randomized
Trial Comparing a Very Low Carbohydrate Diet and a Calorie-Restricted
Low Fat Diet on Body Weight and Cardiovascular Risk Factors in Healthy
Women. The Journal of Clinical Endocrinology and Metabolism, 2003; 88
(4): 1617-1623.
Lewis SB, et al. Effect of
Diet Composition on Metabolic Adaptations to Hypocaloric Nutrition:
Comparison of High Carbohydrate and High Fat Isocaloric Diets. The
American Journal of Clinical Nutrition, 1977; 30 (2): 160-170.
Volek JS, et al. Body
Composition and Hormonal responses to a Carbohydrate Restricted Diet.
Metabolism, 51(7), 2002, pages 864-870.
Layman DK, et al. Increased
Dietary Protein Modifies Glucose and Insulin Homeostasis in Adult Women
during Weight Loss. The Journal of Nutrition, 2003; 133 (2): 405-410.
Farnsworth E, et al. Effect of
a high-protein, energy-restricted diet on body composition, glycemic
control, and lipid concentrations in overweight and obese
hyperinsulinemic men and women. American Journal of Clinical Nutrition,
July 2003; 78: 31-39.
Heilbronn LK, et al. Effect of
Energy Restriction, Weight Loss, and Diet Composition on Plasma Lipids
and Glucose in Patients With Type 2 Diabetes. Diabetes Care, 1999; 22
(6): 889-895.
Jeppesen J, et al. Effects of
low-fat, high-carbohydrate diets on risk factors for ischemic heart
disease in postmenopausal women. The American Journal of Clinical
Nutrition, 1997; 65 : 1027-1033.
B Gumbiner, et al. Effects of
diet composition and ketosis on glycemia during very-low- energy-diet
therapy in obese patients with non-insulin-dependent diabetes mellitus.
The American Journal of Clinical Nutrition, 1996; 63: 110-115.
Golay A, et al. Similar weight
loss with low- or high-carbohydrate diets. The American Journal of
Clinical Nutrition, 1996; 63: 174-178.
Piatti PM, et al. Hypocaloric
high protein diet improves glucose oxidation and spares lean body mass.
Comparison to hypocaloric high-CHO diet. Metabolism, Dec. 1994; 43 (12):
1481-1487.
Rabast U, et al. Dietetic
treatment of obesity with low and high carbohydrate diets: Comparitive
studies and clinical results. International Journal of Obesity, 3 (3),
1979, pages 201-211.
Fujita Y, et al. Basal
and postprotein insulin and glucagon levels during a high and low
carbohydrate intake and their relationships to plasma triglycerides.
Diabetes, 1975; 24 (6): 552-558.
Anthony Colpo is an independent researcher and certified fitness
consultant with 20 years' experience in the physical conditioning arena.
To contact: contact@theomnivore.com
Disclaimer: This
article is presented for information purposes only and is not intended
as medical advice. Persons with medical conditions should institute
dietary changes whilst being monitored by a competent medical
practitioner.
© Anthony Colpo 2004. http://www.theomnivore.com
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