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Insulin
resistance: 5 Abstracts
Eur J Clin Nutr 2002 Mar;56 Suppl 1:S30-5
The 'carnivore connection'--evolutionary aspects
of insulin resistance. |
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Colagiuri
S, Brand Miller J.
Department of Endocrinology, Diabetes and Metabolism, Prince of Wales Hospital,
Sydney, Australia. colagiuris@sesahs.nsw.gov.au |
| Insulin
resistance is common and is determined by physiological (aging,
physical fitness), pathological (obesity) and genetic factors.
The metabolic compensatory response to insulin resistance is hyperinsulinaemia,
the primary purpose of which is to maintain normal glucose tolerance.
The 'carnivore connection' postulates a critical role for the quantity
of dietary protein and carbohydrate and the change in the glycaemic
index of dietary carbohydrate in the evolution of insulin resistance
and hyperinsulinaemia. Insulin resistance offered survival and
reproductive advantages during the Ice Ages which dominated human
evolution, during which a high-protein low-carbohydrate diet was
consumed. Following the end of the last Ice Age and the advent
of agriculture, dietary carbohydrate increased. Although this resulted
in a sharp increase in the quantity of carbohydrate consumed, these
traditional carbohydrate foods had a low glycaemic index and produced
only modest increases in plasma insulin. The industrial revolution
changed the quality of dietary carbohydrate. The milling of cereals
made starch more digestible and postprandial glycaemic and insulin
responses increased 2-3 fold compared with coarsely ground flour
or whole grains. This combination of insulin resistance and hyperinsulinaemia
is a common feature of many modern day diseases. Over the last
50 y the explosion of convenience and takeaway 'fast foods' has
exposed most populations to caloric intakes far in excess of daily
energy requirements and the resulting obesity has been a major
factor in increasing the prevalence of insulin resistance. |
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| PMID:
11965520 [PubMed - indexed for MEDLINE] |
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J
Am Coll Nutr 1998 Dec;17(6):595-600
Utility of a short-term 25% carbohydrate diet on improving glycemic
control in type 2 diabetes mellitus.
Gutierrez M, Akhavan M, Jovanovic L, Peterson CM.
Sansum Medical Research Foundation, Santa Barbara, California 93105, USA.
OBJECTIVE: To determine if introduction of a low carbohydrate diet might be a
useful option for type 2 diabetic patients who do not achieve glucose target
levels despite conventional treatment. METHODS: Subjects with type 2 diabetes,
either treated with diet alone (n=9) or second generation sulfonylurea agents
(n= 19), which were discontinued, were placed on a diet based on ideal body weight
and comprised of 25% carbohydrate. After a mean of 8 weeks, they were then switched
to a caloricly equivalent diet, but composed of 55% carbohydrate. RESULTS: Compared
to baseline diet, after 8 weeks of a 25% diet, subjects showed significantly
improved glycemia as evidenced by fasting blood glucose values (p<0.005) and
hemoglobin A1c levels (p<0.05). Those previously treated with oral hypoglycemic
agents showed, in addition, a significant decrease in weight and diastolic blood
pressure despite the discontinuation of the oral agent. When then placed on a
55% carbohydrate diet, the hemoglobin A1c rose significantly over the ensuing
next 12 weeks (p<0.05). CONCLUSION: A low carbohydrate, caloricly-restricted
diet has beneficial short-term effects in subjects with type 2 who have failed
either diet or sulfonylurea therapy and may obviate the necessity for insulin.
Our study also affirms the need for reassessing the role of diet whenever type
2 diabetic patients manifests hyperglycemia, despite conventional oral treatment
or diet management.
PMID: 9853539 [PubMed - indexed for MEDLINE] |
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Diabetologia
1994 Dec;37(12):1280-6
The carnivore connection: dietary carbohydrate in the evolution
of NIDDM.
Miller JC, Colagiuri S.
Department of Biochemistry, University of Sydney, Australia.
We postulate a critical role for the quantity and quality of dietary carbohydrate
in the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM). Our primate
ancestors ate a high-carbohydrate diet and the brain and reproductive tissues
evolved a specific requirement for glucose as a source of fuel. But the Ice Ages
which dominated the last two million years of human evolution brought a low-carbohydrate,
high-protein diet. Certain metabolic adaptations were therefore necessary to
accommodate the low glucose intake. Studies in both humans and experimental animals
indicate that the adaptive (phenotypic) response to low-carbohydrate intake is
insulin resistance. This provides the clue that insulin resistance is the mechanism
for coping with a shortage of dietary glucose. We propose that the low-carbohydrate
carnivorous diet would have disadvantaged reproduction in insulin-sensitive individuals
and positively selected for individuals with insulin resistance. Natural selection
would therefore result in a high proportion of people with genetically-determined
insulin resistance. Other factors, such as geographic isolation, have contributed
to further increases in the prevalence of the genotype in some population groups.
Europeans may have a low incidence of diabetes because they were among the first
to adopt agriculture and their diet has been high in carbohydrate for 10,000
years. The selection pressure for insulin resistance (i.e., a low- carbohydrate
diet) was therefore relaxed much sooner in Caucasians than in other populations.
Hence the prevalence of genes producing insulin resistance should be lower in
the European population and any other group exposed to high-carbohydrate intake
for a sufficiently long period of time.
PMID: 7895958 [PubMed - indexed for MEDLINE] |
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Diabetes
1992 Oct;41(10):1278-85
Comparison of effects of high and low carbohydrate diets on plasma
lipoproteins and insulin sensitivity in patients with mild NIDDM.
Garg A, Grundy SM, Unger RH.
Veterans Affairs Medical Center, University of Texas Southwestern Medical Center,
Dallas 75235-9052.
Previous studies indicate that diets rich in digestible carbohydrates improve
glucose tolerance in nondiabetic individuals, but may worsen glycemic control
in NIDDM patients with moderately severe hyperglycemia. The effects of such high-carbohydrate
diets on glucose metabolism in patients with mild NIDDM have not been studied
adequately. This study compares responses to an isocaloric high-carbohydrate
diet (60% of total energy from carbohydrates) and a low-carbohydrate diet (35%
of total energy from carbohydrates) in 8 men with mild NIDDM. Both diets were
low in saturated fatty acids, whereas the low-carbohydrate diet was rich in monounsaturated
fatty acids. The two diets were matched for dietary fiber content (25 g/day).
All patients were randomly assigned to receive first one and then the other diet,
each for a period of 21 days, in a metabolic ward. Compared with the low-carbohydrate
diet, the high-carbohydrate diet caused a 27.5% increase in plasma triglycerides
and a similar increase in VLDL- cholesterol levels; it also reduced levels of
HDL cholesterol by 11%. Plasma glucose and insulin responses to identical standard
breakfast meals were studied on days 4 and 21 of each period, and these did not
differ significantly between the two diets. At the end of each period, a euglycemic
hyperinsulinemic glucose clamp study with simultaneous infusion of [3-3H]glucose
revealed no significant changes in hepatic insulin sensitivity; and peripheral
insulin-mediated glucose disposal remained unchanged (14.7 +/- 1.4 vs. 16.5 +/-
2.3 microM.kg-1.min-1 on the high-carbohydrate and low-carbohydrate diets, respectively).(ABSTRACT
TRUNCATED AT 250 WORDS)
PMID: 1397701 [PubMed - indexed for MEDLINE] |
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J
Am Coll Nutr 1985;4(4):451-9
Effect of low-carbohydrate diets high in either fat or protein
on thyroid function, plasma insulin, glucose, and triglycerides in
healthy young adults.
Ullrich IH, Peters PJ, Albrink MJ.
A low-carbohydrate diet, frequently used for treatment of reactive hypoglycemia,
hypertriglyceridemia, and obesity may affect thyroid function. We studied the
effects of replacing the deleted carbohydrate with either fat or protein in seven
healthy young adults. Subjects were randomly assigned to receive seven days of
each of two isocaloric liquid- formula, low-carbohydrate diets consecutively.
One diet was high in polyunsaturated fat (HF), with 10%, 55%, and 35% of total
calories derived from protein, fat, and carbohydrate, respectively. The other
was high in protein (HP) with 35%, 30%, and 35% of total calories derived from
protein, fat, and carbohydrate. Fasting blood samples were obtained at baseline
and on day 8 of each diet. A meal tolerance test representative of each diet
was given on day 7. The triiodothyronine (T3) declined more (P less than .05)
following the HF diet than the HP diet (baseline 198 micrograms/dl, HP 138, HF
113). Thyroxine (T4) and reverse T3 (rT3) did not change significantly. Thyroid-stimulating
hormone (TSH) declined equally after both diets. The insulin level was significantly
higher 30 minutes after the HP meal (148 microU/ml) than after the HF meal (90
microU/ ml). The two-hour glucose level for the HP meal was less, 85 mg/dl, than
after the HF meal (103 mg/dl). Serum triglycerides decreased more after the HF
diet (HF 52 mg/dl, HP 67 mg/dl). Apparent benefits of replacing carbohydrate
with polyunsaturated fat rather than protein are less insulin response and less
postpeak decrease in blood glucose and lower triglycerides. The significance
of the lower T3 level is unknown.
Publication Types:
Clinical Trial
Randomized Controlled Trial
PMID: 3900181 [PubMed - indexed for MEDLINE] |
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