January Research Highlights

American Journal Clinical Nutrition

• Insulin Resistant subjects with the metabolic syndrome have a blunted sympathetic neural response to oral glucose compared with insulin sensitive subjects with the metabolic syndrome, which is related to central adiposity.

• Iron supplements do not inhibit the absorption of zinc or copper in healthy breastfed infants at 6–9 mo of age. In addition, researchers found no age-related changes in zinc or copper absorption between 6 and 9 mo of age.

• Prematurity is associated with protracted oxidative stress, and human milk is partially protective.

• Mediterranean diets supplemented with virgin olive oil or nuts down-regulate cellular and circulating inflammatory biomarkers related to atherogenesis in subjects at high risk of CVD. The results support the recommendation of the Med-Diet as a useful tool against CVD.

• Few studies have investigated the association of dietary carbohydrate and fiber intake with breast cancer risk in women in China, where carbohydrate intake is traditionally high. The objective was to prospectively evaluate the association of dietary carbohydrates, glycemic index, glycemic load, and dietary fiber with breast cancer risk and to determine whether the effect of these dietary intakes is modified by age and selected insulin- or estrogen-related risk factors. A total of 74,942 women aged 40–70 y were recruited into the Shanghai Women's Health Study, a population-based cohort study. Our data suggest that a high carbohydrate intake and a diet with a high glycemic load may be associated with breast cancer risk in premenopausal women or women <50>

• The objective was to evaluate the relation between total vitamin A and retinol intakes and the risk of incident total and hip fracture in postmenopausal women. A total of 75,747 women from the Women's Health Initiative Observational Study participated. No association between vitamin A or retinol intake and the risk of hip or total fractures was observed in postmenopausal women. Only a modest increase in total fracture risk with high vitamin A and retinol intakes was observed in the low vitamin D–intake group. Bonnie - can we start to put to rest the supposed link between vitamin A and bone loss, PLEASE.

• Few studies have examined the association between carotenoid intake (other than β-carotene) and bone mineral density (BMD). We evaluated associations between total and individual carotenoid intake (-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein+zeaxanthin) with BMD at the hip, spine, and radial shaft and the 4-y change in BMD. Both cross-sectional and longitudinal analyses were conducted in 334 men and 540 women (mean ± SD age: 75 ± 5 y) in the Framingham Osteoporosis Study. Energy-adjusted carotenoid intakes were estimated from the Willett food-frequency questionnaire. Carotenoids showed protective associations against 4-y loss in trochanter BMD in men and in lumbar spine in women. No significant associations were observed at other bone sites. Although not consistent across all BMD sites examined, these results support a protective role of carotenoids for BMD in older men and women.

• Metabolic abnormalities and targeted treatment trials have been reported for several neurobehavioral disorders but are relatively understudied in autism. The objective of this study was to determine whether or not treatment with the metabolic precursors, methylcobalamin and folinic acid, would improve plasma concentrations of transmethylation/transsulfuration metabolites and glutathione redox status in autistic children. In an open-label trial, 40 autistic children were treated with 75 µg/kg methylcobalamin (2 times/wk) and 400 µg folinic acid (2 times/d) for 3 mo. Metabolites in the transmethylation/transsulfuration pathway were measured before and after treatment and compared with values measured in age-matched control children. The significant improvements observed in transmethylation metabolites and glutathione redox status after treatment suggest that targeted nutritional intervention with methylcobalamin and folinic acid may be of clinical benefit in some children who have autism. Bonnie - this should be very interesting information for some, reassuring for others who have already implemented these nutrient therapies.

Journal Nutrition

• Taken together, these data suggest that naturally occurring dietary compounds such as 3'-diindolylmethane (DIM), a condensation product of indol-3-carbinol found in Brassica vegetables, and the phytoalexin resveratrol (RES), may be effective agents for dietary strategies against epigenetic activation of COX-2 expression by AhR agonists (xenobiotic environmental compounds such as grilling/charred residues). Bonnie - in short, Brassica vegetable consumption impedes inflammation and the overpopulation of cancer-causing xenobiotics.

• In a cross-sectional study, we examined the relation between intake of 3 common foodstuffs that contain flavonoids (chocolate, wine, and tea) and cognitive performance. 2031 participants (70–74 y, 55% women) recruited from the population-based Hordaland Health Study in Norway underwent cognitive testing. Participants who consumed chocolate, wine, or tea had significantly better mean test scores and lower prevalence of poor cognitive performance than those who did not. Participants who consumed all 3 studied items had the best test scores and the lowest risks for poor test performance. The associations between intake of these foodstuffs and cognition were dose dependent, with maximum effect at intakes of 10 g/d for chocolate and 75–100 mL/d for wine, but approximately linear for tea. Thus, in the elderly, a diet high in some flavonoid-rich foods is associated with better performance in several cognitive abilities in a dose-dependent manner. Bonnie - this is why they are considered superfoods.

Journal of the American Dietetic Association

• Substantial differences in total antioxidant content of different sweeteners were found. Refined sugar, corn syrup, and agave nectar contained minimal antioxidant activity; raw cane sugar had a higher FRAP. Dark and blackstrap molasses had the highest FRAP, while maple syrup, brown sugar, and honey showed intermediate antioxidant capacity.

• A majority of young adults reported they enjoy and value eating with others, but 35% of males and 42% of females reported lacking time to sit down and eat a meal. Eating dinner with others was significantly associated with several markers of better dietary intake, including higher intakes of fruit, vegetables, and dark-green and orange vegetables. Eating on the run was significantly associated with higher intakes of soft drinks, fast food, total fat and saturated fat, and lower intake of several healthful foods. Findings suggest that health services and programs for young adults should encourage taking the time to sit down for meals and to share meals with others.

American Journal Preventive Medicine

• Automated telephone counseling can support the parents of overweight children to reduce the extent to which their children are overweight.

• Neighborhood disparities in access to food are of great concern because of their potential to influence dietary intake and obesity. Additional research is needed to address various limitations of current studies, identify effective policy actions, and evaluate intervention strategies designed to promote more equitable access to healthy foods.

• Policymakers must be able to calculate the comparative effectiveness of interventions to control heart disease if they are to optimize the population impact of programmatic initiatives. A model was created to calculate the number of deaths that would be prevented or postponed if perfect care for heart disease prevention and treatment were achieved—that is, the elimination of risk factors and the prescription of all effective medications before and between acute events, and the delivery of all effective therapies to individuals suffering an acute heart disease event. In this subject group, 44% of all deaths were due to heart disease. Perfect care before the first heart disease event would prevent or postpone 33% of all deaths. Perfect care between acute events would prevent or postpone 23% of all deaths. Perfect care during acute events would prevent or postpone 8% of all deaths. This direct comparison of heart disease prevention and treatment strategies indicates that nearly 90% of the impact from perfect care for heart disease would accrue from interventions before and between acute events. The impact of risk-factor interventions before or between events is amplified by the fact that these interventions also reduce the risk of death from other chronic diseases. Bonnie - once again, the P word, prevention, looms large.

New England Journal Medicine

• We examined 51 bone-biopsy specimens obtained after a 3-year, double-blind, randomized, placebo-controlled, dose-ranging trial of oral alendronate to prevent bone resorption among healthy postmenopausal women 40 through 59 years of age. The patients were assigned to one of five groups: those receiving placebo for 3 years; alendronate at a dose of 1, 5, or 10 mg per day for 3 years; or alendronate at a dose of 20 mg per day for 2 years, followed by placebo for 1 year. The number of osteoclasts was increased by a factor of 2.6 in patients receiving 10 mg of alendronate per day for 3 years as compared with the placebo group. Moreover, the number of osteoclasts increased as the cumulative dose of the drug increased. Long-term alendronate treatment is associated with an increase in the number of osteoclasts, which include distinctive giant, hypernucleated, detached osteoclasts that are undergoing protracted apoptosis. Bonnie - note that osteoclasts take bone away or resorb bone. This is not what one would expect when taking bisphosphonates, considering they are supposed to do the opposite.
  

Journal Allergy and Clinical Immunology

• Asthma is a complex disease, and its incidence is determined by an intricate interplay of genetic and environmental factors. The identification of novel genes for asthma suggests that many genes with small effects rather than few genes with strong effects contribute to the development of asthma. There is thus substantial need to develop better tools for individual exposure assessment in all relevant environmental fields.
  
  
• Glutathione (GSH) is an important antioxidant in the epithelial lining fluid (ELF). We hypothesized that airway GSH homeostasis was altered in children with severe asthma and was characterized by decreased GSH and increased glutathione disulfide (GSSG) concentrations. Compared with controls, subjects in this study with severe asthma indeed had lower airway GSH and increases GSSG. Bonnie - it is apparent that increasing Glutathione levels through supplementation and/or improvement of methylating pathways is crucial.
  
  
• Five-grass-pollen sublingual immunotherapy tablets reduced both symptom scores 39.3% and rescue medication use in children and adolescents with grass pollen–related rhinoconjunctivitis. Adverse events were generally mild or moderate in intensity and expected. No serious side effects were reported.
  
  
• Fenugreek seed powder, an ingredient in spiced foods, contains several potential allergens. There is evidence for a high rate of cross-reactivity to peanut.
  
  
• Staphylococcus aureus–derived enterotoxins, a common cause of food contamination, are associated with antigen responses in atopic dermatitis. Researchers demonstrated in a recent mouse study that S. aureus indeed impairs oral tolerance and permits allergic responses.