Literature review & commentary.
|Author:||Gaby, Alan R.|
|Publication:||Name: Townsend Letter Publisher: The Townsend Letter Group Audience: General; Professional Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2011 The Townsend Letter Group ISSN: 1940-5464|
|Issue:||Date: June, 2011 Source Issue: 335|
Nutritional Supplement Improves Stress and Mental Function
Two hundred fifteen healthy males (mean age, 39 years) were randomly assigned to receive, in double-blind fashion, a multivitamin-multimineral supplement or placebo daily for 33 days. The supplement provided daily 15 mg each of thiamine and riboflavin, 50 mg of niacinamide, 23 mg of pantothenic acid, 10 mg of vitamin B6, 400 mcg of folic acid, 10 mcg of vitamin B12, 150 mcg of biotin, 500 mg of vitamin C, 100 mg each of calcium and magnesium, and 10 mg of zinc. Compared with placebo, active treatment was associated with significant improvements on the Perceived Stress Scale, the General Health Questionnaire (a measure of general mental health), the serial subtractions test (a measure of cognitive function), and the vigor subscale of the Profile of Mood States (p [less than] 0.05 for each comparison).
Comment: Many people take vitamins and minerals because they perceive that taking them improves various factors such as tolerance to stress, mental health, energy level, and cognitive function. However, despite the fact that the typical Western diet is marginal or low in a wide range of nutrients (including B vitamins, calcium, magnesium, and zinc), there has been little scientific research investigating whether taking nutritional supplements can make apparently healthy people "feel better." This new study provides scientific documentation for what many of us have known for a long time. The study might also help convince those skeptics who continue to believe that the only thing nutritional supplements can give you is expensive urine.
Kennedy DO et al. Effects of high-dose B vitamin complex with vitamin C and minerals on subjective mood and performance in healthy males. Psychopharmacology. 2010;211:55-68.
Probiotic Improves Functional Abdominal Pain ...
One hundred forty-one children (mean age, 6.4 years) with functional abdominal pain or recurrent abdominal pain due to irritable bowel syndrome were randomly assigned to receive, in double-blind fashion, Lactobacillus rhamnosus GG (LGG; 3 x [10.sup.9] cfu twice a day) or placebo for 8 weeks, and were then followed for an additional 8 weeks. Compared with baseline, LGG, but not placebo, significantly reduced both the frequency (p [less than] 0.01) and severity (p [less than] 0.01) of abdominal pain. At week 12, the proportion of patients who had at least a 50% reduction in the frequency and intensity of pain was significantly greater in the active-treatment group than in the placebo group (72% vs. 53%; p [less than] 003). At the end of the follow-up period, these percentages were 79% and 62%, respectively (p [less than] 0.03). At entry, 59% of the children had abnormal intestinal permeability. At 12 weeks, the proportion of children with abnormal intestinal permeability was significantly lower in the active-treatment group than in the placebo group.
Comment: In the present study, LGG reduced the frequency and severity of abdominal pain in children with functional abdominal pain or irritable bowel syndrome. There are several possible mechanisms to explain the beneficial effect of LGG. First, probiotic organisms may reduce the number of pathogenic intestinal flora, thereby decreasing the production of various symptom-evoking bacterial metabolites. Second, some probiotics contain disaccharidase enzymes and might therefore improve the digestion of lactose and fructose (malabsorption of these sugars is a common cause of abdominal pain). Third, a decrease in intestinal permeability (as demonstrated in this study) could reduce food allergies by decreasing the absorption of allergenic macromolecules.
francavilla R et al. A randomized controlled trial of Lactobacillus GG in children with functional abdominal pain. Pediatrics. 2010;126:e1445--e1452.
... and Also Helps Prevent Infections in Children
Two hundred eight-one children (mean age, 4.4 years) attending daycare centers were randomly assigned to receive, in double-blind fashion, Lactobacillus GG (LGG; 109 cfu in 100 ml of a fermented milk product) or placebo (the same pasteurized fermented milk product without LGG) daily for 3 months. The incidence of upper respiratory tract infections was significantly lower by 34%, the incidence of lower respiratory tract infections was nonsignificantly lower by 18%, and the incidence of gastrointestinal infections was nonsignificantly lower by 37% in the active-treatment group than in the placebo group.
Comment: In this study, daily administration of LGG to preschool children for 3 months reduced the incidence of upper respiratory tract infections and possibly other types of infections as well. Probiotic organisms have been shown to enhance immune function, which is the presumed mechanism
Hojsak I et al. Lactobacillus GG in the prevention of gastrointestinal and respiratory tract infections in children who attend day care centers: a randomized, double-blind, placebo-controlled trial. Clin Nutr. 2010;29:312-316.
Topical Manuka Honey for MRSA and Other Wound Infections
In a previous study, daily topical application of manuka honey improved skin ulcers contaminated with methicillinresistant Staphylococcus aureus (MRSA). In the present study, S. aureus bacteria were exposed to sublethal concentrations of manuka honey, both continuously and in progressively increasing concentrations (long-term stepwise resistance training). Reduced susceptibilities to manuka honey were found during long-term stepwise resistance training, but these changes were not permanent, and honey-resistant mutants were not detected.
Comment: The use of honey for the treatment of wounds has increased in Europe and North America since licensed wound care products became available in 2004 and 2007, respectively. The effectiveness of honey against MRSA is noteworthy, considering that this infection is difficult to treat. The results of the present study provide reassurance that MRSA organisms are unlikely to develop resistance to manuka honey if the bacteria are exposed to high concentrations of honey.
Cooper RA et al. Absence of bacterial resistance to medical-grade manuka honey. Eur Clin Microbiol Infect Dis. 2010;29:1237-1241.
Cinnamon Improves Glycemic Control in Type 2 Diabetes
Fifty-eight patients with type 2 diabetes who were being treated only with hypoglycemic agents and who had an HbA1c level greater than 7% were randomly assigned to receive, in double-blind fashion, 2 g per day of cinnamon (500 mg at breakfast, 1 g at lunch, 500 mg at dinner) or placebo for 12 weeks. The mean HbA1 c level decreased in the cinnamon group from 8.22% to 7.86% (p [less than] 0.005 compared with the change in the placebo group). Mean systolic and diastolic blood pressure also decreased significantly in the cinnamon group compared with the change in the placebo group.
Comment: Extracts of cinnamon have been shown to increase glucose uptake in vitro. In addition, cinnamon may enhance insulin release. A few earlier studies have demonstrated an improvement in glycemic control among type 2 diabetics treated with cinnamon; however, cinnamon was of no benefit in other studies. The results of the present study suggest that cinnamon produces a modest improvement in blood glucose control in type 2 diabetics. Cinnamon has been found to be ineffective in people with type 1 diabetes.
Akilen R et al. Glycated haemoglobin and blood pressure-lowering effect of cinnamon in multi-ethnic Type 2 diabetic patients in the UK: a randomized, placebo-controlled, double-blind clinical trial. Diabet Med. 2010;27:1159-1167.
Do Pesticides Cause ADHD?
In a cross-sectional study of 1139 children (aged 8-15 years) participating in the National Health and Nutrition Examination Survey (2000-2004), children with higher urinary concentrations of dialkyl phosphate metabolites of organophosphate pesticides (especially dimethyl alkylphosphate [DMAP]) were more likely to be diagnosed with attention deficit/hyperactivity disorder (ADHD). A 10-fold increase in DMAP concentration was associated with a 55% increase in ADHD prevalence, after adjustment for potential confounding variables. For the most commonly detected DMAP metabolite, dimethyl thiophosphate, children with levels higher than the median of detectable concentrations had a 93% increase in ADHD prevalence, compared with children with undetectable levels.
Comment: When I was in elementary school in the 1950s, virtually no one suffered from ADHD. Today this condition is epidemic. Environmental factors that might be contributing to the high prevalence of ADHD include exposure to neurotoxic chemicals (such as pesticides), increased prenatal use of ultrasound, less time outdoors in the sun, greater exposure to low-level radiation (e.g., computers, televisions, clocks), and increased use of food additives. The results of the present study support the possibility that pesticides contribute to the development of ADHD.
Bouchard MF et al. Attention-deficit/hyperactivity disorder and urinary metabolites of organophosphate pesticides. Pediatrics. 2010;125:e1270--e1277.
Does Cow's Milk Cause Type 1 Diabetes?
Two hundred thirty infants with HLA-conferred susceptibility to type 1 diabetes and at least one family member with type 1 diabetes were randomly assigned to receive, in double-blind fashion, a casein hydrolysate formula or a conventional cow's milk-based formula (control) whenever breast milk was not available during the first 6 to 8 months of life. The children were then observed for a mean of 7.5 years. The risk of having one or more autoantibodies indicative of islet cell autoimmunity was 46% lower in the casein hydrolysate group than in the control group.
Comment: Observational studies have found a positive association between cow's milk consumption and incidence of type 1 diabetes. If consumption of cow's milk plays a causal role in the development of type 1 diabetes, it may do so by provoking an autoimmune reaction against pancreatic beta cells in susceptible individuals. Antigenic proteins that may be involved include bovine insulin, serum albumin, beta-lactoglobulin, and beta-casein. The results of the present study suggest that avoidance of cow's milk proteins during infancy has a long-lasting beneficial effect on markers of beta-cell autoimmunity, an effect that would be expected to reduce the incidence of type 1 diabetes.
Knip M et al. Dietary intervention in infancy and later signs of beta-cell autoimmunity. N Engl J Med. 2010;363:1900-1908.
Calcium Supplementation and Cardiovascular Disease
Some 1460 Australian women (mean age, 75 years) were randomly assigned to receive, in double-blind fashion, 1200 mg per day of calcium (as calcium carbonate) or placebo for 5 years, and the women were then followed for an additional 4.5 years. The study was originally designed to determine the effect of calcium supplementation on fracture risk. During the 5-year treatment period, the incidence of the combined endpoint of cardiovascular disease-related death or first-time hospitalization for atherosclerotic vascular disease (including ischemic heart disease, arrhythmia, heart failure, cerebrovascular disease, and peripheral arterial disease) was nonsignificantly lower by 6% in the calcium group than in the placebo group. During the full 9.5 years of observation, the incidence of the combined endpoint was nonsignificantly lower by 8% in the calcium group than in the placebo group.
Comment: A recent meta-analysis of 15 randomized controlled trials found that participants who received supplemental calcium without any other nutrients had a statistically significant (p [less than] 0.04) 30% increase in the incidence of myocardial infarction. However, the data were derived from post hoc analyses of studies that were not designed to test the effect of calcium on heart disease risk. Findings of borderline statistical significance from post hoc analyses are more likely to be due to chance than are findings of borderline statistical significance from primary analyses. While the present study found that calcium supplementation did not increase the risk of atherosclerotic vascular disease in elderly Australian women, it does not invalidate the results from previous studies. If calcium supplementation does increase heart disease risk, the most likely explanation is an interaction with the cardioprotective nutrient magnesium. Calcium supplementation has been shown to deplete magnesium in animals, and possibly in humans as well. Magnesium status in Western populations is generally low, and is even lower in people who have or are at risk of developing heart disease. Furthermore, magnesium deficiency appears to play a role in the pathogenesis of heart disease. Thus, it would be reasonable to expect that any deleterious effect of calcium supplementation on heart disease risk would be prevented by coadministration of magnesium.
Lewis JR et al. Calcium supplementation and the risks of atherosclerotic vascular disease in older women: results of a 5-year RCT and a 4.5-year follow-up. I Bone Miner Res. 2011;26:35-41.
By Alan R.Gaby, MD
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