Coenzyme Q10, Alpha-Lipoic Acid, and Vitamin E May Benefit Diabetics With Chronic Complications

Supplementation With Coenzyme Q10, Alpha-Lipoic Acid, and Vitamin E May Benefit Diabetics With Chronic Complications

http://www.vitasearch.com/CP/weeklyupdates/

Reference: “Complementary therapy in diabetic patients with chronic complications: a pilot study,” Palacka P, Gvozdjakova A, et al, Bratisl Lek Listy, 2010; 111(4): 205-11. (Address: Comenius University, Medical Faculty, Pharmacobiochemical Laboratory of 3rd Medical Clinic, Bratislava, Slovakia. E-mail: pal_patrick@yahoo.com ).

Summary: In a pilot study involving 59 diabetic patients with chronic complications, results indicate that combined supplementation with coenzyme Q10, alpha-lipoic acid and vitamin E, along with polarized light (PL) therapy may exert beneficial effects. The patients were randomized to 1 of 3 groups for 3 months – 1) PL group (n = 19): PL was applied to neuropathic ulcers of diabetic foot twice daily; 2) Antioxidant group (n=20): received daily supplementation with 60 mg of hydrosoluble CoQ10, 100 mg of alpha-lipoic acid (ALA) and 200 mg of vitamin E; 3) PL+Antioxidant (n=20): received both PL and antioxidants.

At intervention end, decrease in lactate dehydrogenase (LDH) activity was found in the PL group, improvement in echocardiographic parameters was found in the antioxidant group, and decrease in LDH activity and improvement in heart left ventricular function was observed in the PL+antioxidant group. Thus, the authors of this study conclude, “Thus the data show that support ive therapy with PL along with the antioxidants hydrosoluble CoQ10, alpha-lipoic acid and vitamin E is an effective way of controlling the complications of type 2 diabetes.”

Supplementation With Grape Seed Extract May Benefit Patients With Nonalcoholic Fatty Liver Disease

Supplementation With Grape Seed Extract May Benefit Patients With Nonalcoholic Fatty Liver Disease

http://www.vitasearch.com/CP/weeklyupdates/

Reference: “Grape seed extract to improve liver function in patients with nonalcoholic fatty liver change,” Khoshbaten M, Najafipoor F, et al, Saudi J Gastroenterol, 2010; 16(3): 194-7. (Address: Department of Drug Applied Research Center, Tabriz University of Medical Sciences, Iran).

Summary: In a controlled study involving 30 patients with nonalcoholic fatty liver disease (NAFLD), results indicate that supplementation with grape seed extract may exert beneficial effects. The patients were randomized to grape seed extract or vitamin C (1000 mg / 12 hours) for 3 months. At intervention end, serum levels of ALT (alanine aminotransferase) decreased significantly in patients treated with GSE when compared to controls (vitamin C group). Additionally, grape seed extract supplementation significantly improved grade of steatosis. Thus, the authors conclude, “This study describes the beneficial effect of using grape seed extract for three months in patients with nonalcoholic fatty liver disease. These results may improve with a longer period of follow-up.”

Calcium Supplementation May Improve Body Composition in Postmenopausal Women

Calcium Supplementation May Improve Body Composition in Postmenopausal Women

http://www.vitasearch.com/CP/weeklyupdates/

Reference: “The effect of calcium and vitamin D supplementation on obesity in postmenopausal women: secondary analysis for a large-scale, placebo controlled, double-blind, 4-year longitudinal clinical trial,” Zhou J, Lappe JM, et al, Nutr Metab (Lond), 2010; 7(1): 62. (Address: 601 North 30th Street, Omaha, NE 68131, USA. E-mail: lanjuanzhao@creighton.edu ).

Summary: In a population-based, double-blind, placebo-controlled, randomized study involving 870 postmenopausal women, results indicate that long-term calcium supplementation may exert a beneficial effect on body composition. The women were randomized to one of three groups for a period of 4 years: 1) Ca-group: received calcium supplementation (1400 mg/d or 1500 mg/d) + vitamin D placebo; 2) Ca+D group: received supplementation with calcium (1400 mg/d or 1500 mg/d) plus vitamin D (1100 IU/d); 3) placebo group: received two placebos. At intervention end, the calcium supplemented groups showed less gain in trunk fat and more trunk lean compared with the placebo group. Thus, the authors of this study conclude, “Calcium supplementation over four years has a beneficial effect on body composition in postmenopausal women.”

Plant compound resveratrol shown to suppresses inflammation, free radicals in humans

Plant compound resveratrol shown to suppresses inflammation, free radicals in humans

BUFFALO, N.Y. — Resveratrol, a popular plant extract shown to prolong life in yeast and lower animals due to its anti-inflammatory and antioxidant properties, appears also to suppress inflammation in humans, based on results from the first prospective human trial of the extract conducted by University at Buffalo endocrinologists.

Results of the study appear as a rapid electronic publication on the Journal of Clinical Endocrinology & Metabolism website and will be published in an upcoming print issue of the journal.

The paper also has been selected for inclusion in Translational Research in Endocrinology & Metabolism, a new online anthology that highlights the latest clinical applications of cutting-edge research from the journals of the Endocrine Society.

Resveratrol is a compound produced naturally by several plants when under attack by pathogens such as bacteria or fungi, and is found in the skin of red grapes and red wine. It also is produced by chemical synthesis derived primarily from Japanese knotweed and is sold as a nutritional supplement.

Husam Ghanim, PhD, UB research assistant professor of medicine and first author on the study, notes that resveratrol has been shown to prolong life and to reduce the rate of aging in yeast, roundworms and fruit flies, actions thought to be affected by increased expression of a particular gene associated with longevity.

The compound also is thought to play a role in insulin resistance as well, a condition related to oxidative stress, which has a significant detrimental effect on overall health.

“Since there are no data demonstrating the effect of resveratrol on oxidative and inflammatory stress in humans,” says Paresh Dandona, MD, PhD, UB distinguished professor of medicine and senior author on the study, “we decided to determine if the compound reduces the level of oxidative and inflammatory stress in humans.

“Several of the key mediators of insulin resistance also are pro-inflammatory, so we investigated the effect of resveratrol on their expression as well.”

The study was conducted at Kaleida Health’s Diabetes-Endocrinology Center of Western New York, which Dandona directs.

A nutritional supplement containing 40 milligrams of resveratrol was used as the active product. Twenty participants were randomized into two groups of 10: one group received the supplement, while the other group received an identical pill containing no active ingredient. Participants took the pill once a day for six weeks. Fasting blood samples were collected as the start of the trial and at weeks one, three and six.

Results showed that resveratrol suppressed the generation of free radicals, or reactive oxygen species, unstable molecules known to cause oxidative stress and release proinflammatory factors into the blood stream, resulting in damage to the blood vessel lining.

Blood samples from persons taking resveratrol also showed suppression of the inflammatory protein tumor necrosis factor (TNF) and other similar compounds that increase inflammation in blood vessels and interfere with insulin action, causing insulin resistance and the risk of developing diabetes.

These inflammatory factors, in the long term, have an impact on the development of type 2 diabetes, aging, heart disease and stroke, noted Dandona.

Blood samples from the participants who received the placebo showed no change in these pro-inflammatory markers.

While these results are promising, Dandona added a caveat: The study didn’t eliminate the possibility that something in the extract other than resveratrol was responsible for the anti-inflammatory effects.

“The product we used has only 20 percent resveratrol, so it is possible that something else in the preparation is responsible for the positive effects. These agents could be even more potent than resveratrol. Purer preparations now are available and we intend to test those.”

Additional contributors to the study, all from Dandona’s laboratory, are Chang Ling Sia, Sanaa Abuaysheh, Kelly Korzeniewski, Priyanka Patniak, MD, Anuritha Marumganti, MD, and Ajay Chaudhuri, MD.

The study was supported in part by grants to Dandona from the National Institutes of Health and the American Diabetes Association.

http://www.eurekalert.org/pub_releases/2010-07/uab-pcr072910.php

Microbes in Our Gut Regulate Genes That Control Obesity and Inflammation

ScienceDaily (Jan. 14, 2011) — If you are looking to lose weight in the coming year, you may need help from an unexpected place: the bacteria in your gut. That’s because scientists have discovered that the bacteria living in your intestines may play a far more significant role in weight loss and gastrointestinal problems than ever imagined.

In a new research report published online in The FASEB Journal, researchers show that a deficiency of Toll-like receptor 2 (Tlr2) — used by mammals (including humans) to recognize resident microbes in the intestines — leads to changes in gut bacteria that resemble those of lean animals and humans. This discovery builds on previous research demonstrating that a deficiency of TLR2 protects against obesity, while at the same time promoting gastrointestinal problems like excessive inflammation. It also shows that genes controlling TLR2 expression play a very important role in one’s gastrointestinal health and weight management.

“Our work highlights the remarkable capacity for an orchestrated reprogramming of the intestinal inflammatory network to overcome significant genetic challenges in the mammalian bowel,” said Richard Kellermayer, Ph.D., a researcher involved in the work from the Section of Pediatric Gastroenterology, Hepatology and Nutrition at Baylor College of Medicine in Houston. “The appropriate exploitation of this remarkable capacity may provide means for the prevention and optimized treatment of common metabolic (such as obesity and diabetes) and gastrointestinal disorders.”

To make this discovery, Kellermayer and colleagues studied normal mice and mice deficient in TLR2 using the large intestinal lining of these mice. They compared the TLR2-deficient ones to the normal group, as well as the bacteria, the epigenome (more specifically DNA methylation, a molecular change in the DNA associated with decreased gene expression), and the gene expression of the animals. The researchers found that the absence of TLR2 leads to microbial changes in the gut that resemble lean animals and humans, as well as immunologic changes similar to those observed in ulcerative colitis.

“Every New Year, a significant percentage of us resolve ourselves to lose weight,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, “but national statistics on obesity show that we’re failing fast. This research linking gut bacteria to TLR2 expression opens entirely new doors for weight control solutions, first by cementing TLR2 as a drug target for obesity, and second by providing further evidence that managing gut bacteria may be an important and effective way to control weight. The challenge, of course, is to find a way to tip the scales just enough to keep weight under control without causing serious gastrointestinal problems.”

Beyond Brain Health by Chris D. Meletis, ND

Turmeric (Curcuma longa) is a popular spice that has been used for centuries in Southeastern Asia and India; curcumin, the main constituent of turmeric, is the main flavoring agent in curry dishes. Turmeric and curcumin have been studied extensively for their antioxidant and anti-inflammatory effects in a variety of health concerns.

It is important for any natural health-promoting substance to have the ability to transit through the digestive process and arrive intact in clinically meaningful levels in the blood, where the substance carries out its effects in the body. Researchers from UCLA have been able to resolve this challenge by increasing the bioavailability of curcumin in a unique form known as Longvida®. As was mentioned in the November issue of Vitamin Research News, in clinical studies, Longvida shows demonstrably increased levels achieved in the blood stream, and perhaps even more important is the ability of this breakthrough form of curcumin to cross the blood-brain barrier.1 (The blood-brain barrier is composed of a specialized layer of cells that restricts the passage of many substances from the general circulation into the brain. It presents a challenge in the treatment of brain conditions as it limits the ability of many therapeutic agents to enter the brain.)

This ability to optimize the absorption of curcumin is important in that curcumin’s benefits are multifactorial, and it may perhaps be one of the most scientifically researched natural compounds as literally thousands of studies investigating its effects have been carried out. This article will serve as a review of some of curcumin’s most promising qualities,2 several of which will be highlighted below.

Neurological Health

Curcumin’s influence on the brain is mainly attributed to its anti-inflammatory and antioxidative effects; however, other mechanisms are apparent as well.3 In animal models of cognitive dysfunction, curcumin administration lowered amyloid beta (Abeta) (the principle component of senile plaques that are the driving pathology in brain disorders) by slowing the production of amyloid-beta precursor protein (APP).4 Curcumin will also bind to the Abeta fibrils and aggregates5 where it may have a direct effect on decreasing amyloid pathology.6 The anti-inflammatory, antioxidant and anti-amyloid activity of curcumin in cognitive health makes it a promising area of research.7

In mood balancing, curcumin is thought to have potential clinical usefulness because of its ability to 1) Inhibit monoamine oxidase and thereby enhance the release of serotonin and dopamine and 2) Enhance neurogenesis, namely in the frontal cortex and hippocampus.8-9 Several animal studies highlight the benefits of curcumin in improving mood; curcumin boosted monoamine oxidase inhibition, enhanced serotonin and dopamine levels and reversed stress-related behaviors.10-12 Additional animal studies show a protective effect of curcumin against seizures as well; the neuroprotective and antioxidative effects are thought to be responsible.13-15

Anti-Inflammatory Effects

Inflammation is widely used as a term to loosely define pathological immunologic effects. Overexpression of inflammatory pathways is undoubtedly associated with many disease processes. Curcumin exhibits a number of anti-inflammatory effects, and it has been studied in lung health and immune challenges. Controlling inflammation occurs at numerous levels; a number of studies have elucidated key areas where curcumin has an effective role in thwarting specific inflammatory processes thereby resulting in positive clinical outcomes.

Lung Health

In asthmatic mouse models, curcumin decreased the total number of leukocytes (white blood cells, a component of inflammation) and eosinophils (additional allergy-mediating cells) in lung fluid. Additionally, other inflammatory cells and mucus occlusion in lung tissues were decreased as well as IgE (a primary immunological mediator of allergy) in the lung fluid. Investigators of this study conclude that curcumin produced these positive effects through inhibition of NF-kappaB.16

Curcumin’s potent anti-inflammatory effects stem from its ability to modulate T and B cells, macrophages, neutrophils, dendritic and natural killer cells. It also down regulates the expression of pro-inflammatory cytokines such as tumor necrosis factor (TNF), interleukins 1, 2, 6, 7 and 12, and NF-kappaB as previously mentioned.17

Curcumin is a direct free radical scavenger in the lung tissue (and elsewhere), and can down regulate other pro-inflammatory mediators including matrix metalloproteinase, adhesion molecules and growth factor receptor genes, thereby exerting antioxidative and anti-inflammatory effects in the lungs.18

As an adjunctive therapy to standard corticosteroid treatment in asthma and chronic obstructive pulmonary disease (COPD), curcumin shows promise as well. Histone deacetylase 2 (HDAC-2) is an enzyme that plays a major role in how corticosteroids work; its function is decreased in circumstances of steroid insensitivity, and oxidative stress further compromises its function. Curcumin improves HDAC activity and thereby restores corticosteroid function.19

Joint Function

Curcumin also shows benefit in joint health. Animals with arthritis who were given curcumin experienced a dose-related suppression in arthritic signs and symptoms; markers such as infiltration of immune cells, synovial hyperplasia (thickening of inner joint tissue), destruction of cartilage and bone erosion were all halted by curcumin.20 Additionally, matrix metalloproteinases 1 and 3 (MMP-1, MMP-3) and tumor necrosis factor-alpha (TNF-alpha)-stimulated chondrocytes and fibroblasts (diseased joint cells) were also inhibited by curcumin in a dose dependent manner.

Furthermore, in an animal model of osteoarthritis, curcumin significantly decreased interleukin-1beta stimulated release of glycosaminoglycans (GAGS) with increasing doses to pre-experimental levels.21 In a similarly designed study using human chondrocytes (cartilage cells found in joints), curcumin inhibited several inflammatory markers including nitric oxide, prostaglandin E2, interleukins 6 and 8 and MMP-3 all in direct relationship to the dose used.22 Curcumin’s potent anti-inflammatory effects on chondrocytes support its use in joint health.

Specific Organ Health

Curcumin and its metabolites offer protection for a variety of conditions and organ systems. At the root of curcumin’s efficacy in these areas are its anti-inflammatory and antioxidative effects, as previously discussed. The following are a few brief areas where curcumin research has provided some valuable insight into its protective effects.

Kidney and Liver

Tetrahydrocurcumin (THU1) is one of curcumin’s major metabolites and shows some of the highest antioxidative activity. THU1 has been shown to improve 2 major kidney functions, creatinine and urea clearance; it is also supportive in kidney health after kidney transplants. In the liver, previous studies have shown reduced liver damage from iron, aflatoxin- and benzo[a]pyrene- induced mutagenicity.23

Cardiovascular System

The effects of curcumin have been widely researched in the cardiovascular system. Benefits of curcumin here include diminished cardiotoxicity from Adriamycin (a chemotherapeutic drug) and supporting a healthy heart in diabetic patients. Curcumin’s anti-thrombotic (anti-clotting), anti-inflammatory and anti-proliferative effects may also protect the health of the arteries and heart. Other effects include lessening the development of cardiac hypertrophy (enlargement) and heart failure in animals, and supporting healthy atrial and ventricular heart rhythm.24

Through other avenues of effect, curcumin may preserve heart muscle function after ischemic (lack of oxygen) or biochemical damage to the heart. Also, curcumin decreases the extent of cardiovascular remodeling in experimental models of pressure overload (when the pressure from the circulation is excessive on the heart it damages the muscle).25

Conclusion

The medical literature contains thousands of studies investigating the role of curcumin in health. Curcumin’s health benefits are wide ranging, and this brief review only provides a fraction of the data concerning curcumin.

References

1. Frautschy SA et al. Efficacy of curcumin formulations in relation to systemic availability in the brain and different blood compartments in neuroinflammatory and AD models at the 39th Annual Meeting of the Society of Neuroscience, Chicago, October 2009.

2. Srivastava RM, Singh S, Dubey SK, et al. Immunomodulatory and therapeutic activity of curcumin. Int Immunopharmacol. 2010 Sep 8. [Epub ahead of print]

3. Kulkarni SK, Dhir A. An overview of curcumin in neurological disorders. Indian J Pharm Sci. 2010 Mar;72(2):149-54.

4. Zhang C, Browne A, Child D, Tanzi RE. Curcumin decreases amyloid-beta peptide levels by attenuating the maturation of amyloid-beta precursor protein. J Biol Chem. 2010 Sep 10;285(37):28472-80. Epub 2010 Jul 9.

5. Yanagisawa D, Shirai N, Amatsubo T, et al. Relationship between the tautomeric structures of curcumin derivatives and their Abeta-binding activities in the context of therapies for Alzheimer’s disease. Biomaterials. 2010 May;31(14):4179-85.

6. Ringman JM, Frautschy SA, Cole GM, et al. A potential role of the curry spice curcumin in Alzheimer’s disease. Curr Alzheimer Res. 2005 Apr;2(2):131-6.

7. Frautschy SA, Cole GM. Why pleiotropic interventions are needed for Alzheimer’s disease. Mol Neurobiol. 2010 Jun;41(2-3):392-409. Epub 2010 May 2.

8. Kulkarni S, Dhir A, Akula KK. Potentials of curcumin as an antidepressant. ScientificWorld Journal. 2009 Nov 1;9:1233-41.

9. Xu Y, Ku B, Cui L, et al Curcumin reverses impaired hippocampal neurogenesis and increases serotonin receptor 1A mRNA and brain-derived neurotrophic factor expression in chronically stressed rats. Brain Res. 2007 Aug 8;1162:9-18. Epub 2007 Jun 21.

10. Bhutani MK, Bishnoi M, Kulkarni SK. Anti-depressant like effect of curcumin and its combination with piperine in unpredictable chronic stress-induced behavioral, biochemical and neurochemical changes. Pharmacol Biochem Behav. 2009 Mar;92(1):39-43. Epub 2008 Oct 25.

11. Wang R, Xu Y, Wu HL, et al. The antidepressant effects of curcumin in the forced swimming test involve 5-HT1 and 5-HT2 receptors. Eur J Pharmacol. 2008 Jan 6;578(1):43-50. Epub 2007 Sep 19.

12. Xu Y, Ku BS, Yao HY, et al. The effects of curcumin on depressive-like behaviors in mice. Eur J Pharma col. 2005 Jul 25;518(1):40-6.

13. Bharal N, Sahaya K, Jain S, et al. Curcumin has anticonvulsant activity on increasing current electroshock seizures in mice. Phytother Res. 2008 Dec;22(12):1660-4.

14. Jyoti A, Sethi P, Sharma D. Curcumin protects against electrobehavioral progression of seizures in the iron-induced experimental model of epileptogenesis. Epilepsy Behav. 2009 Feb;14(2):300-8. Epub 2008 Dec 17.

15. Sumanont Y, Murakami Y, Tohda M, et al. Prevention of kainic acid-induced changes in nitric oxide level and neuronal cell damage in the rat hippocampus by manganese complexes of curcumin and diacetylcurcumin. Life Sci. 2006 Mar 13;78(16):1884-91. Epub 2005 Nov 2.

16. Oh SW, Cha JY, Jung JE, et al. Curcumin attenuates allergic airway inflammation and hyper-responsiveness in mice through NF-kappaB inhibition J Ethnopharmacol. 2010 Jul 17. [Epub ahead of print]

17. Jagetia GC, Aggarwal BB. “Spicing up” of the immune system by curcumin. J Clin Immunol. 2007 Jan;27(1):19-35. Epub 2007 Jan 9.

18. Biswas S, Rahman I. Modulation of steroid activity in chronic inflammation: a novel anti-inflammatory role for curcumin. Mol Nutr Food Res. 2008 Sep;52(9):987-94.

19. Marwick JA, Ito K, Adcock IM, Kirkham PA. Oxidative stress and steroid resistance in asthma and COPD: pharmacological manipulation of HDAC-2 as a therapeutic strategy. Expert Opin Ther Targets. 2007 Jun;11(6):745-55.

20. Mun SH, Kim HS, Kim JW, et al. Oral administration of curcumin suppresses production of matrix metalloproteinase (MMP)-1 and MMP-3 to ameliorate collagen-induced arthritis: inhibition of the PKCdelta/JNK/c-Jun pathway. J Pharmacol Sci. 2009 Sep;111(1):13-21.

21. Clutterbuck AL, Mobasheri A, Shakibaei M, et al. Interleukin-1beta-induced extracellular matrix degradation and glycosaminoglycan release is inhibited by curcumin in an explant model of cartilage inflammation. Ann N Y Acad Sci. 2009 Aug;1171:428-35.

22. Mathy-Hartert M, Jacquemond-Collet I, Priem F, et al. Curcumin inhibits pro-inflammatory mediators and metalloproteinase-3 production by chondrocytes. Inflamm Res. 2009 Dec;58(12):899-908. Epub 2009 Jul 5.

23. Osawa T. Nephroprotective and hepatoprotective effects of curcuminoids. Adv Exp Med Biol. 2007;595:407-23.

24. Wongcharoen W, Phrommintikul A. The protective role of curcumin in cardiovascular diseases. Int J Cardiol. 2009 Apr 3;133(2):145-51. Epub 2009 Feb 23.

25. Srivastava G, Mehta JL. Currying the heart: curcumin and cardioprotection. J Cardiovasc Pharmacol Ther. 2009 Mar;14(1):22-7. Epub 2009 Jan 18.

Consumption of Green Tea May Help Prevent Obesity

Grove KA, Lambert JD. Laboratory, epidemiological, and human intervention studies show that tea (Camellia sinensis) may be useful in the prevention of obesity. J Nutr. 2010;140: 446-453.

Green tea (Camellia sinensis), a popular beverage worldwide, contains large amounts of polyphenols known as catechins: (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin-3-gallate (ECG), and (-)-epigallocatechin-3-gallate (EGCG). A cup of brewed green tea contains 240-320 mg of catechins, with EGCG accounting for 30% to 50% of that amount. Green tea also contains the xanthines: caffeine, theophylline, and theobromine. It has been studied for its potential health benefits and its effects on certain chronic diseases. Obesity, which affects about 20% of U.S. adults, is a risk factor for chronic diseases (e.g., diabetes, cardiovascular diseases, and cancer). These authors summarize the literature on the potential efficacy of tea to prevent obesity.

In their review of laboratory studies, the authors focus on mechanistic data from animal model studies that have examined the effects of tea on obesity and related pathologies, including diabetes, hypercholesterolemia, and fatty liver disease. Most studies have used green tea, green tea extract (GTE), or pure EGCG in both genetic and dietary models of obesity.

One cited study reported that treatment with 7.0 µmol/g dietary EGCG for 15 weeks reduced body weight gain in male mice fed a high-fat diet compared with control mice. The treated mice had significantly lower adipose tissue weight, fasting blood glucose, fasting plasma cholesterol, and plasma alanine aminotransferase levels. The same investigators reported that short-term dietary EGCG treatment of obese mice tended to reduce body weight gain compared with high-fat-fed controls. “This treatment regimen represents a more realistic obesity-related application of EGCG or green tea supplementation, because the most likely consumers of these products would have a preexisting weight problem,” state the authors. Other cited studies, as well as one including rats fed a normal-fat diet, support these findings.

Regarding tea and genetic animal models of obesity, the authors cite a study of the efficacy of GTE in obese, leptin-deficient mice, in which there was no significant effect on body weight. The study did, however, report higher plasma high-density lipoprotein cholesterol and lower hepatic triglyceride levels in the GTE-treated mice.

Few studies have examined the interaction between tea polyphenols and exercise; however, the animal studies cited by these authors support the benefits of tea polyphenols plus exercise in reducing body weight gain.

According to the authors, the “in vivo effects of EGCG may be explained by underlying mechanisms suggested by in vitro studies of de novo lipogenesis, lipid absorption, and carbohydrate absorption and utilization.” Several studies have begun to examine the effects of tea polyphenols on fatty acid synthase. Two studies have reported that EGCG can inhibit pancreatic lipase activity, but the effective concentrations in these studies varied.

The authors cite several studies in dietary models of obesity that have examined the role of green tea-mediated modulation of glucose uptake and disposition in obesity prevention. The findings from two studies indicate that treatment with green tea can increase carbohydrate catabolism. In vitro studies have suggested that EGCG and ECG play a role in inhibiting glucose uptake in the gut.

Most studies of animal models of obesity and tea have found no significant effect of tea or tea components on energy intake. The exceptions are two studies cited by these authors: one reported a significant decrease in food intake by mice treated with Oolong tea extract compared with untreated mice, and the other study reported that 0.5% tea catechins reduced energy intake by 5.6% (the trend was not significant, however).

Regarding human studies, the authors note that there are few epidemiological studies examining the impact of tea on body weight and other obesity-related markers. More interventional studies have been conducted. In one study of healthy Japanese men, the participants consuming high-catechin tea for 12 weeks had lower body weight, waist circumference, and body fat mass compared with baseline values. In a follow-up study by the same investigators, 240 obese subjects were treated with a catechin-enriched green tea beverage or a control green tea beverage for 12 weeks. Those in the high-catechin beverage group had a significant decrease in body weight, total fat area, and visceral fat compared with baseline values. These decreases were greater than those in the low-catechin control group. The authors note that the results of studies on tea and body weight and body fat have not been “universally positive,” citing some studies that reported no significant effects of green tea consumption on body weight.

The authors further cite a study that reported a beneficial effect on weight loss and weight maintenance following weight loss with green tea consumption and a study that showed a trend toward a greater decrease in body weight with green tea and exercise, compared with exercise only. “Further studies on the interaction between tea and exercise in humans are warranted,” say the authors.

U.S. sales of green tea-based dietary supplements are increasing, partly because of the number of reports describing the potential antiobesity and other beneficial effects of tea and tea polyphenols. Green tea-based dietary supplements can potentially deliver a much higher dose of catechins than do green tea beverages. Since 1999, say the authors, 34 case studies have linked the consumption of green tea-based supplements to hepatotoxicity. Laboratory studies in animals have generally supported the supplements’ potential toxicity at high doses. “These findings suggest that caution should be exercised in the use of green tea-based dietary supplements and that further studies are needed to determine the upper limit of safety for bolus dosing with tea polyphenols as well as the underlying mechanisms of toxicity.”

The authors conclude that “laboratory studies in animals, a limited number of epidemiological studies, and small-scale human intervention studies support the hypothesis that tea and tea polyphenols have beneficial effects on weight gain, weight loss, and prevention of obesity.”

—Shari Henson

DNA robots get sophisticated by Jef Akst

Scientists are one step closer to creating molecular robots that may eventually perform complex tasks, such as building nanomolecules or delivering drugs to target tissues.

They have constructed DNA-based robots that can walk along a specific path unaided or collect various nanoparticles along an assembly line, according to two studies published this week in Nature.

“This has the feel to me of the beginning of a technology revolution,” said Andrew Ellington, an evolutionary engineer at the University of Texas at Austin and the vice president of the International Society for Nanoscale Science, Computation and Engineering, who was not involved in the research. “This work will absolutely pave the way for how you build molecular robots.”

The robots built in one study are a type of DNA walker, called a molecular “spider.” They are minute, mobile molecules that move along a flat surface made out of folded DNA, known as DNA origami, binding to and unbinding from the surface as they go.

The movement of these spiders is largely random, however, said biochemist and study co-author Milan Stojanovic of Columbia University. But together with several other big players in the nanotechnology and DNA computing fields, including Nils Walter of the University of Michigan, Erik Winfree of the California Institute of Technology, and Hao Yan of Arizona State University, Stojanovic designed a DNA origami surface that directed the DNA spider down a specified path (see video).

“You just have to start it, and it walks the path,” said chemist Kurt Gothelf, director of Centre for DNA Nanotechnology at Aarhus University in Denmark, who was not involved in the research.

The spider is fueled by the chemical interactions its single-stranded DNA “legs” have with the origami surface. In order to take a “step,” the legs first cleave a DNA strand on the surface, weakening its interaction with that part of the origami surface. This encourages the spider to move forward, pulled towards the intact surface, where its interactions are stronger. When the spider binds to a part of the surface that it is unable to cleave, it stops.

In essence, the researchers created a DNA spider that can “sense the environment,” Stojanovic said — “molecules that respond [to environmental] cues and behave [in] certain programmable ways on their own.” The next step, he added, is to increase the complexity of movements performed by such autonomous robots by compiling “a collection of rules [of] interactions between molecules and between molecules and environment.”

A fluorescence video microscopy-generated animation of a DNA spider moving along the designated path from the green-labeled start site towards the red-labeled goal. Each colored dot represents its position at a given time over the 40-minute observation period (see legend).

Credit: Nils Walter, Anthony Manzo, Nicole Michelotti and Alexander Johnson-Buck, University of Michigan

Meanwhile, Nadrian Seeman of New York University and his colleagues have designed another type of DNA walker that can collect nano-sized “cargo” as it moves. Unlike the autonomous spider, the cargo-collecting walker is controlled by single strands of DNA added by the researchers to direct the robot. These strands instruct the robot to move past an “assembly line” of three small loading devices, also made out of DNA, each containing a gold nanoparticle. Each loading device can be programmed to either donate its cargo to the passing walker, or keep it, such that the walker can receive anywhere from zero to three particles along its short (less than 200 nanometers) journey.

It’s “like an automobile assembly line,” Seeman said. “We have the option to either add or not add various components to [the walker] depending on how the devices are programmed.”

One possibility for future experiments will be to combine the advances of each of the two papers into one complex, autonomous DNA robot, said Lloyd Smith of the University of Wisconsin, who wrote an accompanying review in Nature. “It’s going to take more work to take it to that next level, [but] bringing those two things together is going to be the next step towards” a fully autonomous, functional nano-sized robot.

Another future direction, the researchers agree, would be to scale up the length of the pathways and the complexity of the behaviors. But even once greater levels of complexity are achieved, what can actually be done with the little robots is still up for debate. “This whole field,” which is still in its early stages, Smith said, “hasn’t really found the application yet.” DNA robots have thus far proven to be capable of fairly sophisticated manipulation at the nanoscale, but the practical uses of this novel technology are still a little unclear.

One popular idea is to use cargo-collecting robots to construct nanomolecules that would be difficult to make using traditional methods, because of the control they offer researchers at such a tiny scale. “The ability to hold a molecule in a particular position and hold another molecule in a defined position could open up possibilities in organic synthesis,” said Smith. Another possibility is their use in drug delivery, said biochemist William Shih of Harvard University, who did not participate in the studies. “Having a very smart robotic delivery system could do a lot better job of killing the disease tissue and do far less damage to our otherwise healthy tissue,” he explained.

But most agree that these potential applications are yet to be realized; the current work merely shows “proof of principle” that such complex behavior might one day be achieved using this technology, Seeman said.

“I think these are both really, really significant papers, not because of what we can do with [these robots] now, but because of what we can do with them in the future,” said Ellington. They are “paving the way to a future where we can do practical DNA technology.”

H. Gu, et al., “A proximity-based programmable DNA nanoscale assembly line,” Nature, 465:202-5, 2010.

K. Lund, et al., “Molecular robots guided by prescriptive landscapes,” Nature, 465:206-10, 2010

Read more: DNA robots get sophisticated – The Scientist – Magazine of the Life Sciences http://www.the-scientist.com/blog/display/57400/#ixzz0oz3tm7it

Supplements Better Than Nothing By Sheah Rarback

srarback@hotmail.com

It would be a healthier world if everyone enjoyed fruits and vegetables, but unfortunately, that is not the case. Most Americans are not eating the recommended minimum of five servings a day, and for kids the most commonly consumed “vegetable” continues to be potatoes — as in French fried.

At least once a month someone sits down with me and starts our counseling conversation with, “I don’t like vegetables and I don’t want to be told to eat them.” It is challenging. Research demonstrates a reduced risk of chronic disease with a plentiful intake of produce, so sometimes an alternative is required for the vegetable-resistant.

One option is a powdered fruit and vegetable supplement. These supplements are made by juicing and then drying fruits and veggies at low temperatures, removing water, sugar and fiber.

The companies that produce the supplements fund academic research that is published in peer-reviewed journals. The most recent was in the April 2010 online edition of Molecular Nutrition and Food Research. This double-blind study of 117 healthy men and women measured changes in inflammatory blood markers after subjects consumed either placebo or two different powdered fruit and vegetable supplements. The goal is to have low levels of inflammatory markers, since inflammation increases risk for heart disease, diabetes and cancer.

After 60 days, the subjects receiving the fruit and vegetable supplements had lower levels of inflammatory markers, as well as higher blood levels of antioxidant vitamins, when compared to the group receiving placebo.

These findings are consistent with most previous research. Similar findings have been reported for people eating fruit and vegetables or enjoying a Mediterranean vegetable soup. These results show changes in blood levels — though not less disease — in people taking supplements. Long-term studies are needed to demonstrate disease changes.

For optimal nutrition, food is always the first choice.

Any whole food pill or powdered drink is meant to be a supplement to a varied food intake. But it’s good to know there are tested alternatives available if you are not getting your five servings a day.

Sheah Rarback is a registered dietitian and on the faculty of the University of Miami Leonard M. Miller School of Medicine. Her column runs every other week.

Read more: http://www.miamiherald.com/2010/05/18/1634231/supplements-better-than-nothing.html#ixzz0oZ02TFHA

The Chicago Blackhawks are the first vitamin D team in modern professional sports history.

According to my sources, the Chicago Blackhawk team physicians began diagnosing and treating vitamin D deficiency in all Blackhawk players about 18 months ago. Apparently, most players are on 5,000 IU per day.

After many losing seasons, last year the Blackhawks came out of nowhere to get to the Western conference finals. This year they are playing even better.

According to my sources, improved athletic performance is only one of the benefits for the Blackhawk players. The other is a reduction in the number and severity of colds and flu and a reduction in the number and severity of repetitive use injuries.

Six months ago, Runner’s World published a story on vitamin D and physical performance.

Asp K. Running on D: The “sun vitamin” may boost performance, but you probably aren’t getting enough. Runners World, December 2009.

A year ago, the flagship journal of the American College of Sports Medicine was the first journal to publish the theory that vitamin D would improve athletic performance.

Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ.  Athletic performance and vitamin D. Med Sci Sports Exerc. 2009 May;41(5):1102-10.

However, readers of this newsletter first learned about it in 2007:

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