Broccoli sprouts may boost antioxidant defenses in people with diabetes....
According to findings, a daily dose of five or 10 grams of the broccoli sprout powder was associated with an increase in the total antioxidant capacity of the blood, and reductions in malondialdehyde (MDA), a reactive carbonyl compound and a well-established marker of oxidative stress. The study adds to the growing body of science supporting the potential health benefits of broccoli and broccoli sprouts, most often touted for their potential anti-cancer activity.
The tissue of cruciferous vegetables, like broccoli, cauliflower, cabbage and Brussels sprouts, contain high levels of the active plant chemicals glucosinolates. These are metabolized by the body into isothiocyanates, which are known to be antioxidants and powerful anti-carcinogens. The main isothiocyanate from broccoli is sulphoraphane.
The new study employed a broccoli sprout powder that provided a dose of sulphoraphane isothiocyanates of 22.5 micromoles per gram, and looked at the potential antioxidant activity of broccoli sprout powder to counter oxidative stress in diabetics.
Oxygen-breathing organisms naturally produce reactive oxygen species (ROS), which play an important role in a range of functions, including cell signaling. However, over production of these ROS from smoking, pollution, sunlight, high intensity exercise, or simply ageing, may overwhelm the body's antioxidant defenses and lead to oxidative stress.
Oxidative stress has been linked to an increased risk of various diseases including cancer, Alzheimer's, and cardiovascular disease.
Researchers also note that oxidative stress is a key driver in the onset of insulin resistance, which ultimately leads to diabetes. Diabetes itself is associated with increased levels of oxidative stress, and this can promote the development of diabetes-related complications
Researchers from the National Nutrition and Food Technology Research Institute at the Shahid Beheshti University of Medical Sciences in Tehran, Iran, recruited 81 diabetics to participate in their double-blind, placebo-controlled, randomized clinical trial.
Participants were randomly assigned to receive either five or 10 grams per day of the broccoli sprout powder, or placebo, for four weeks.
Results showed that both broccoli groups experienced significant decreases in MDA, a well-established marker of oxidative stress, as well as reductions in levels of oxidized LDL cholesterol, another oxidative stress marker.
The doses used in this study provided 225 micromoles and 112 micromoles sulforaphane isothiocyanates daily per 10 g and 5 g broccoli sprout doses, respectively.
European Journal of Clinical Nutrition; "Broccoli sprouts reduce oxidative stress in type 2 diabetes: a randomized double-blind clinical trial" Z Bahadoran, P Mirmira, et al
Showing posts with label diabetes and control. Show all posts
Showing posts with label diabetes and control. Show all posts
Sunday, June 12, 2011
Wednesday, June 1, 2011
Preventing Type 2 Diabetes with Early Pharmacological Intervention
According to Ralph DeFronzo, it is never too early to prevent diabetes....
In the U.S., 26 million individuals have type 2 diabetes, and twice as many have impaired glucose tolerance (IGT). Approximately 40-50% of individuals with IGT will progress to type 2 diabetes over their lifetime. Therefore, treatment of high-risk individuals with IGT to prevent type 2 diabetes has important medical, economic, social, and human implications.
Weight loss, although effective in reducing the conversion of IGT to type 2 diabetes, is difficult to achieve and maintain. Moreover, 40-50% of IGT subjects progress to type 2 diabetes despite successful weight reduction. In contrast, pharmacological treatment of IGT with oral antidiabetic agents that improve insulin sensitivity and preserve β-cell function -- the characteristic pathophysiological abnormalities present in IGT and type 2 diabetes -- uniformly have been shown to prevent progression of IGT to type 2 diabetes.
The most consistent results have been observed with the thiazolidinediones (Troglitazone in the Prevention of Diabetes [TRIPOD], Pioglitazone in the Prevention of Diabetes [PIPOD], Diabetes Reduction Assessment with Ramipril and Rosiglitazone Medication [DREAM], and Actos Now for the Prevention of Diabetes [ACT NOW]), with a 50-70% reduction in IGT conversion to diabetes. Metformin in the U.S. Diabetes Prevention Program (DPP) reduced the development of type 2 diabetes by 31% and has been recommended by the American Diabetes Association (ADA) for treating high-risk individuals with IGT. The glucagon-like peptide-1 analogs, which augment insulin secretion, preserve β-cell function, and promote weight loss, also would be expected to be efficacious in preventing the progression of IGT to type 2 diabetes. Because individuals in the upper tertile of IGT are maximally/near-maximally insulin resistant, have lost 70-80% of their β-cell function, and have an ∼ 10% incidence of diabetic retinopathy, pharmacological intervention, in combination with diet plus exercise, should be instituted.
Type 2 diabetes can be prevented with early pharmacological intervention; DeFronzo RA, Abdul-Ghani M; Diabetes Care 34 Suppl 2 S202-9 (May 2011)
In the U.S., 26 million individuals have type 2 diabetes, and twice as many have impaired glucose tolerance (IGT). Approximately 40-50% of individuals with IGT will progress to type 2 diabetes over their lifetime. Therefore, treatment of high-risk individuals with IGT to prevent type 2 diabetes has important medical, economic, social, and human implications.
Weight loss, although effective in reducing the conversion of IGT to type 2 diabetes, is difficult to achieve and maintain. Moreover, 40-50% of IGT subjects progress to type 2 diabetes despite successful weight reduction. In contrast, pharmacological treatment of IGT with oral antidiabetic agents that improve insulin sensitivity and preserve β-cell function -- the characteristic pathophysiological abnormalities present in IGT and type 2 diabetes -- uniformly have been shown to prevent progression of IGT to type 2 diabetes.
The most consistent results have been observed with the thiazolidinediones (Troglitazone in the Prevention of Diabetes [TRIPOD], Pioglitazone in the Prevention of Diabetes [PIPOD], Diabetes Reduction Assessment with Ramipril and Rosiglitazone Medication [DREAM], and Actos Now for the Prevention of Diabetes [ACT NOW]), with a 50-70% reduction in IGT conversion to diabetes. Metformin in the U.S. Diabetes Prevention Program (DPP) reduced the development of type 2 diabetes by 31% and has been recommended by the American Diabetes Association (ADA) for treating high-risk individuals with IGT. The glucagon-like peptide-1 analogs, which augment insulin secretion, preserve β-cell function, and promote weight loss, also would be expected to be efficacious in preventing the progression of IGT to type 2 diabetes. Because individuals in the upper tertile of IGT are maximally/near-maximally insulin resistant, have lost 70-80% of their β-cell function, and have an ∼ 10% incidence of diabetic retinopathy, pharmacological intervention, in combination with diet plus exercise, should be instituted.
Type 2 diabetes can be prevented with early pharmacological intervention; DeFronzo RA, Abdul-Ghani M; Diabetes Care 34 Suppl 2 S202-9 (May 2011)
Thursday, April 7, 2011
Diabetes Tied to Poor Impulse Control
Patients with newly diagnosed Type 2 diabetes were significantly more likely to show poor impulse control in psychological testing than healthy people....
In the standard Go/NoGo test of impulse control, newly diagnosed diabetics made about 50% more errors of commission than normal controls, regardless of whether they were overweight.
The differences were not attributable to cognitive impairment, the researchers concluded, because diabetic patients performed as well as controls on the Wisconsin Card Sorting Test of executive function.
"Our results showed that middle-aged, newly diagnosed, and medication-free patients with Type 2 diabetes have a particular neuropsychological deficit in inhibitory control of impulsive response, which is an independent effect of diabetes apart from being overweight," Yasuhiko Iwamoto, MD, of Tokyo Women's Medical University in Japan, and colleagues wrote.
They suggested the findings could help explain why diabetic patients find it difficult to make the recommended lifestyle adjustments such as avoiding high-fat foods and maintaining daily exercise.
The researchers explained that decision-making about daily activities relies on brain functions in different cerebral regions, mixing predictions of future rewards and punishments, inhibition of impulsive responses, and executive functions.
Overeating, they explained, occurs when the prospect of immediate reward overwhelms inhibitions that derive from awareness of negative consequences. "In such conditions, rapid reward prediction or impulsive response to environmental stimuli prevails over the preparations by executive function," Iwamoto and colleagues asserted.
Earlier studies had indicated that reward predictions by overweight individuals tend to be higher than those of normal weight people, and their impulse control was generally lower. Consequently, the Japanese researchers sought to test diabetic patients for performance on psychological tests that measure these functions.
The Go/NoGo test for impulse control involved showing participants one of two letters, N or H, with instructions to press a button when they saw the N but not H. Pressing the button in response to H was an error of commission, and failing to press it when shown the N was an error of omission. The test also measured reaction times, including slowed responses that sometimes followed errors.
Prediction of future rewards was evaluated with so-called reversal and extinction tasks.
In the former, participants won points for correctly switching images on a computer screen that randomly replaced each other. The extinction task was structured the same way, except that participants stopped winning points for executing the reversal after nine correct responses; at that point, they received points for not responding to the stimulus.
As on a TV game show, correct responses were signaled with a pleasant chime sound, whereas errors were announced with a buzzer. Participants were also assessed for clinical depression and for standard laboratory measures of glycemia and insulin resistance. A total of 27 newly diagnosed Type 2 diabetic patients and 27 non-diabetic controls participated. All participants in both groups were men, and none of the diabetic patients were taking medications for diabetes. The diabetic group included 16 who were overweight (mean BMI 29.8). There were 11 overweight controls (mean BMI 27.6).
Response inhibition in the Go/NoGo test was significantly decreased in the diabetic patients, the researchers reported. In a combined measure of commission and omission errors, labeled d', diabetic patients had a mean value of 2.55 compared with 3.22 for controls (P=0.001).
The difference was most pronounced for errors of commission, with a mean of 10 for patients versus about 6 for controls (P=0.002).
The researchers found a significant interaction between Go/NoGo performance and glycated hemoglobin levels, with an r2 value of 0.287 for d' versus HbA1c (P=0.024). Scores did not differ significantly by weight, although there was a trend toward reduced impulse control in overweight participants. Diabetes did not affect reaction times, overall or after errors, but weight did affect them, with faster reaction times in overweight participants.
Iwamoto and colleagues also found that diabetes status did not affect scores on the reversal and extinction tests. Overweight participants made about 40% more errors on the extinction test compared with normal-weight individuals (P=0.029) but not on the reversal test.
Achievement scores on the Wisconsin Card Sorting Test were similar in all patient groups stratified by weight and diabetes status.
So-called perseverative errors (involving continuous repetition of a response) appeared more common in normal-weight diabetic participants, but rates of these errors varied widely among individuals and the group difference was not statistically significant.
"Our study included only newly diagnosed patients with Type 2 diabetes, suggesting the possibility that the neuropsychological deficits in response inhibition may contribute to the behavioral problems leading to chronic lifestyle-related diseases, such as Type 2 diabetes," they wrote.
However, they acknowledged that the causal arrow could point in the other direction -- that "metabolic changes with diabetes affect brain functions and cause neuropsychological deficits."
Indeed, the researchers observed, some earlier studies have found that metabolic improvements in diabetic patients lead to improved cognitive performance.
"Further longitudinal studies will be useful to detect progression or improvement of neuropsychological deficits associated with metabolic change," Iwamoto and colleagues wrote.
They also recommended more studies into the potential causal role of impulsivity in development of Type 2 diabetes. If confirmed, psychobehavioral interventions aimed at improving impulse control could be beneficial in preventing or treating the disease
In the standard Go/NoGo test of impulse control, newly diagnosed diabetics made about 50% more errors of commission than normal controls, regardless of whether they were overweight.
The differences were not attributable to cognitive impairment, the researchers concluded, because diabetic patients performed as well as controls on the Wisconsin Card Sorting Test of executive function.
"Our results showed that middle-aged, newly diagnosed, and medication-free patients with Type 2 diabetes have a particular neuropsychological deficit in inhibitory control of impulsive response, which is an independent effect of diabetes apart from being overweight," Yasuhiko Iwamoto, MD, of Tokyo Women's Medical University in Japan, and colleagues wrote.
They suggested the findings could help explain why diabetic patients find it difficult to make the recommended lifestyle adjustments such as avoiding high-fat foods and maintaining daily exercise.
The researchers explained that decision-making about daily activities relies on brain functions in different cerebral regions, mixing predictions of future rewards and punishments, inhibition of impulsive responses, and executive functions.
Overeating, they explained, occurs when the prospect of immediate reward overwhelms inhibitions that derive from awareness of negative consequences. "In such conditions, rapid reward prediction or impulsive response to environmental stimuli prevails over the preparations by executive function," Iwamoto and colleagues asserted.
Earlier studies had indicated that reward predictions by overweight individuals tend to be higher than those of normal weight people, and their impulse control was generally lower. Consequently, the Japanese researchers sought to test diabetic patients for performance on psychological tests that measure these functions.
The Go/NoGo test for impulse control involved showing participants one of two letters, N or H, with instructions to press a button when they saw the N but not H. Pressing the button in response to H was an error of commission, and failing to press it when shown the N was an error of omission. The test also measured reaction times, including slowed responses that sometimes followed errors.
Prediction of future rewards was evaluated with so-called reversal and extinction tasks.
In the former, participants won points for correctly switching images on a computer screen that randomly replaced each other. The extinction task was structured the same way, except that participants stopped winning points for executing the reversal after nine correct responses; at that point, they received points for not responding to the stimulus.
As on a TV game show, correct responses were signaled with a pleasant chime sound, whereas errors were announced with a buzzer. Participants were also assessed for clinical depression and for standard laboratory measures of glycemia and insulin resistance. A total of 27 newly diagnosed Type 2 diabetic patients and 27 non-diabetic controls participated. All participants in both groups were men, and none of the diabetic patients were taking medications for diabetes. The diabetic group included 16 who were overweight (mean BMI 29.8). There were 11 overweight controls (mean BMI 27.6).
Response inhibition in the Go/NoGo test was significantly decreased in the diabetic patients, the researchers reported. In a combined measure of commission and omission errors, labeled d', diabetic patients had a mean value of 2.55 compared with 3.22 for controls (P=0.001).
The difference was most pronounced for errors of commission, with a mean of 10 for patients versus about 6 for controls (P=0.002).
The researchers found a significant interaction between Go/NoGo performance and glycated hemoglobin levels, with an r2 value of 0.287 for d' versus HbA1c (P=0.024). Scores did not differ significantly by weight, although there was a trend toward reduced impulse control in overweight participants. Diabetes did not affect reaction times, overall or after errors, but weight did affect them, with faster reaction times in overweight participants.
Iwamoto and colleagues also found that diabetes status did not affect scores on the reversal and extinction tests. Overweight participants made about 40% more errors on the extinction test compared with normal-weight individuals (P=0.029) but not on the reversal test.
Achievement scores on the Wisconsin Card Sorting Test were similar in all patient groups stratified by weight and diabetes status.
So-called perseverative errors (involving continuous repetition of a response) appeared more common in normal-weight diabetic participants, but rates of these errors varied widely among individuals and the group difference was not statistically significant.
"Our study included only newly diagnosed patients with Type 2 diabetes, suggesting the possibility that the neuropsychological deficits in response inhibition may contribute to the behavioral problems leading to chronic lifestyle-related diseases, such as Type 2 diabetes," they wrote.
However, they acknowledged that the causal arrow could point in the other direction -- that "metabolic changes with diabetes affect brain functions and cause neuropsychological deficits."
Indeed, the researchers observed, some earlier studies have found that metabolic improvements in diabetic patients lead to improved cognitive performance.
"Further longitudinal studies will be useful to detect progression or improvement of neuropsychological deficits associated with metabolic change," Iwamoto and colleagues wrote.
They also recommended more studies into the potential causal role of impulsivity in development of Type 2 diabetes. If confirmed, psychobehavioral interventions aimed at improving impulse control could be beneficial in preventing or treating the disease
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