Namanjeet Ahluwalia

Effects of long-term antioxidant supplementation and association of serum antioxidant concentrations with risk of metabolic syndrome in adults.

BACKGROUND Limited observational evidence suggests lower antioxidant concentrations in individuals with the metabolic syndrome (MetS); few randomized controlled trials have addressed the effect of multiple antioxidants on the risk of MetS. OBJECTIVE The objective was to examine the effect of antioxidant supplementation for 7.5 y on the incidence of MetS and the epidemiologic association between baseline serum antioxidant concentrations and the prospective risk of MetS. DESIGN Adults (n = 5220) participating in the SUpplementation en VItamines et Minéraux AntioXydants (SU.VI.MAX) primary prevention trial were randomly assigned to receive a supplement containing a combination of antioxidants (vitamins C and E, beta-carotene, zinc, and selenium) at nutritional doses or a placebo. Subjects were free of MetS at baseline and were followed for 7.5 y. RESULTS Antioxidant supplementation for 7.5 y did not affect the risk of MetS. Baseline serum antioxidant concentrations of beta-carotene and vitamin C, however, were negatively associated with the risk of MetS; the adjusted odds ratios (and 95% CIs) for the highest compared with the lowest tertile were 0.34 (0.21, 0.53; P for trend = 0.0002) and 0.53 (0.35, 0.80; P for trend = 0.01), respectively. Baseline serum zinc concentrations were positively associated with the risk of developing MetS; the adjusted odds ratio (and 95% CI) for the highest compared with the lowest tertile was 1.81 (1.20, 2.72; P for trend = 0.01). CONCLUSIONS The experimental finding of no beneficial effects of antioxidant supplementation in a generally well-nourished population is consistent with recent reports of a lack of efficacy of antioxidant supplements. However, the relations observed between the risk of MetS and baseline serum antioxidant concentrations, which probably reflect associations with overall dietary patterns, do support the current recommendations to consume antioxidant-rich foods. This trial was registered at clinicaltrials.gov as NCT00272428.

Cytokine production by stimulated mononuclear cells did not change with aging in apparently healthy, well-nourished women

Aging is often associated with a dysregulation of the immune system. We examined mitogen-stimulated production of interleukin (IL)-2 and proinflammatory cytokines, IL-1beta and IL-6, in apparently healthy and generally well-nourished old versus young women. Subjects were screened for health using the SENIEUR protocol and a panel of laboratory tests for inflammation, as well as for the adequacy of nutritional status using criteria related to undernutrition, and protein, iron, vitamin B(12), and folate status. Young (n=26, age: 20-40 years) and old (n=44, age: 62-88 years) cohorts did not differ on the number of circulating monocytes, granulocytes, B (CD19+) cells, and T (CD3+, CD4+, and CD8+) cells. No differences (P>0.10) were seen between the two age groups in IL-2, IL-1beta and IL-6 levels in whole blood cultures at 48 h after stimulation with PHA (5 mg/l). Furthermore, no age-related differences were noted in the absolute amounts (pg) of IL-1beta and IL-6 after normalizing for circulating monocytes, B cells, or T cells (P>0.10). Similarly, no age-related decline in absolute amount of IL-2 (pg) after normalizing for circulating T cells was noted (P>0.10). Thus, contrary to most previous reports, our results do not support an increase in the production of proinflammatory cytokines IL-1beta and IL-6, and a reduced production of IL-2 with aging when health and nutritional status are maintained. These findings support our previous results of no change in monocyte function and few alterations in acquired immune response in a carefully selected group of healthy and well-nourished elderly women.

Immune function did not decline with aging in apparently healthy, well-nourished women.

Nutrition plays a crucial role in immune function. Most studies on age-associated changes in immunocompetence in healthy adults did not examine the nutritional status of participants extensively. Inadequate nutritional status may confound the relationship of aging and immune response. The purpose of this study was to examine age-related changes in parameters of acquired and innate immunity in healthy and generally well-nourished older (62-88 years) versus younger (20-40 years) women. Subjects were screened for participation using the health criteria of the SENIEUR protocol as well as a number of nutrition criteria related to undernutrition, and protein, iron, vitamin B12, and folate status. Young and old women did not differ in total T (CD3+), T-helper (CD4+), or T-cytotoxic (CD8+) cell number. However, older women tended to have lower T-cell proliferation response to concanavalin A (P < 0.10) and significantly reduced response to phytohemagglutinin (P < 0.05). No age-related changes were noted in natural killer cell number or cytotoxicity. Phagocytosis and subsequent oxidative burst activity also did not differ between young and old women. Most immune parameters were not compromised with aging in this cohort of apparently healthy, well-nourished women. These findings highlight the importance of simultaneous examination of health and nutritional status in studies of immune function with aging.

Fruit and vegetable consumption trends among adolescents from 2002 to 2010 in 33 countries.

BACKGROUND Fruit and vegetable consumption is linked to many positive health outcomes, nevertheless many adolescents do not consume fruit and vegetables on a daily basis. METHODS Data of 488,951 adolescents, aged 11-, 13- and 15- years, from 33 mainly European and North American countries/regions participating in the cross-sectional Health Behaviour in School-aged Children surveys in 2002, 2006 and 2010, were used to investigate trends in daily fruit and vegetable consumption between 2002 and 2010. RESULTS Multilevel logistic regression analyses showed an increase in daily fruit and vegetable consumption between 2002 and 2010 in the majority of countries for both genders and all three age groups. A decrease in consumption was noticed in five countries for fruit and five countries for vegetables. CONCLUSION Overall, a positive trend was noticed, however increases in daily fruit and vegetable consumption are still indicated.

Caffeine intake in children in the United States and 10-y trends: 2001–2010

BACKGROUND Because of the increasing concern of the potential adverse effects of caffeine intake in children, recent estimates of caffeine consumption in a representative sample of children are needed. OBJECTIVES We provide estimates of caffeine intake in children in absolute amounts (mg) and in relation to body weight (mg/kg) to examine the association of caffeine consumption with sociodemographic factors and describe trends in caffeine intake in children in the United States. DESIGN We analyzed caffeine intake in 3280 children aged 2-19 y who participated in a 24-h dietary recall as part of the NHANES, which is a nationally representative survey of the US population with a cross-sectional design, in 2009-2010. Trends over time between 2001 and 2010 were examined in 2-19-y-old children (n = 18,530). Analyses were conducted for all children and repeated for caffeine consumers. RESULTS In 2009-2010, 71% of US children consumed caffeine on a given day. Median caffeine intakes for 2-5-, 6-11-, and 12-19-y olds were 1.3, 4.5, and 13.6 mg, respectively, and 4.7, 9.1, and 40.6 mg, respectively, in caffeine consumers. Non-Hispanic black children had lower caffeine intake than that of non-Hispanic white counterparts. Caffeine intake correlated positively with age; this association was independent of body weight. On a given day, 10% of 12-19-y-olds exceeded the suggested maximum caffeine intake of 2.5 mg/kg by Health Canada. A significant linear trend of decline in caffeine intake (in mg or mg/kg) was noted overall for children aged 2-19 y during 2001-2010. Specifically, caffeine intake declined by 3.0 and 4.6 mg in 2-5- and 6-11-y-old caffeine consumers, respectively; no change was noted in 12-19-y-olds. CONCLUSION A majority of US children including preschoolers consumed caffeine. Caffeine intake was highest in 12-19-y-olds and remained stable over the 10-y study period in this age group.

Intervention Strategies for Improving Iron Status of Young Children and Adolescents in India

Despite advances in scientific knowledge regarding multiple etiology, treatment, and potential strategies for combating iron deficiency and deficiencies of other micronutrients, iron deficiency anemia, vitamin A deficiency, and iodine deficiency remain significant public health challenges for growing children and adolescents. The short-term efficient supplementation approach, although technically feasible, has not been successful due to problems with delivery and compliance. Evidence is building that preventive supplementation coupled with nutrition education may be a more effective strategy associated with better compliance and improvement in iron status. Long-term, effective approaches include fortification, dietary modification, public health and disease control measures, and income generation programs. Food fortification can be a cost-effective intervention strategy if technologically feasible, nutritionally sound, culturally acceptable and economically viable food vehicle(s) and fortificant(s) can be identifed. Foods such as wheat, rice, and salt are commonly consumed in India; research is underway to evaluate various fortificants for these foods. Doubly fortified salt with iodine and iron may be particularly promising in the Indian situation as it is affordable, culturally acceptable, and may enhance iron absorption from Indian dietaries containing inhibitors of iron absorption. Feasibility studies are underway to evalute the stability and storage issues as well as bioavailability of fortificant iron. Dietary modification involves increased iron intake, by increasing total food intake and consumption of locally available iron-rich foods, and dietary practices favoring iron absorption. Blood loss associated with worm infestation can be controlled by periodic deworming and reducing reinfestation. Coordinating these major intervention approaches by building partnerships between the community, existing nutrition and health programs, government, industry, and academic institutions is critical for success of these programs. Nutrition education must be integral to all of these strategies discusssed. Primary health care system and school infrastructure and staff, along with school children and community members, can be powerful resources for addressing malnutrition in children and adolescents.

Day-to-Day Variation in Iron Status Indexes is Similar for Most Measures in Elderly Women With and Without Rheumatoid Arthritis

OBJECTIVE To determine the day-to-day variation in biochemical measures of iron status in a group of elderly women with rheumatoid arthritis compared with a group of healthy elderly women. DESIGN Venous blood samples were collected from each subject on 3 nonconsecutive days during a 2-week study period; subjects had fasted overnight. Variability in hemoglobin level, hematocrit value, serum iron concentration, total iron-binding capacity, transferrin saturation, serum ferritin concentration, and plasma transferrin receptor level was determined. SUBJECTS Two groups of women, one with rheumatoid arthritis (n=10) and another that was apparently healthy (n=10). STATISTICAL ANALYSES Variance component analysis was used to estimate the biological variation (sigma square day) and analytic variation (sigma square rep) for each iron index. The coefficient of variation (CV) for each variance component was calculated: coefficient of biological variation = CV day, coefficient of analytic variation = CV rep, and coefficient of a single future determination = CV fd. RESULTS The CV rep for all iron indexes was smaller than the CV day in both groups. The CV day was considerably higher for serum iron concentration and for transferrin saturation than for the other indexes in both groups (16.6% and 16.6% in healthy subjects and 33.6% and 28.2%, respectively, in subjects with rheumatoid arthritis). The higher CV day for serum iron concentration and transferrin saturation translated into a higher CV fd for these indexes. Because of the higher variance for these two indexes, more sampling days were required for reliable estimates. CV day and CV fd for plasma transferrin receptor level were relatively low. CONCLUSIONS These findings corroborate our previous finding that variation of serum ferritin concentration in the elderly is lower than that demonstrated in younger populations. This aging effect persists in the presence of rheumatoid arthritis. Fasting appeared to improve reliability in the determinations for serum iron concentration and transferrin saturation. Variability estimates for the indexes other than serum iron concentration and transferrin saturation were not altered by the inflammation of rheumatoid arthritis. Plasma transferrin receptor level is a reliable index for assessing iron status in populations with rheumatoid arthritis.

Trends from 2002 to 2010 in Daily Breakfast Consumption and its Socio-Demographic Correlates in Adolescents across 31 Countries Participating in the HBSC Study.

Breakfast is often considered the most important meal of the day and children and adolescents can benefit from breakfast consumption in several ways. The purpose of the present study was to describe trends in daily breakfast consumption (DBC) among adolescents across 31 countries participating in the HBSC survey between 2002 to 2010 and to identify socio-demographic (gender, family affluence and family structure) correlates of DBC. Cross-sectional surveys including nationally representative samples of 11–15 year olds (n = 455,391). Multilevel logistic regression analyses modeled DBC over time after adjusting for family affluence, family structure and year of survey. In all countries, children in two-parent families were more likely to report DBC compared to single parent families. In most countries (n = 19), DBC was associated with family affluence. Six countries showed an increase in DBC (Canada, Netherland, Macedonia, Scotland, Wales, England) from 2002. A significant decrease in DBC from 2002 was found in 11 countries (Belgium Fr, France, Germany, Croatia, Spain, Poland, Russian Federation, Ukraine, Latvia, Lithuania and Norway), while in 5 countries (Portugal, Denmark, Finland, Ireland, Sweden) no significant changes were seen. Frequency of DBC among adolescents in European countries and North America showed a more uniform pattern in 2010 as compared to patterns in 2002. DBC increased significantly in only six out of 19 countries from 2002 to 2010. There is need for continued education and campaigns to motivate adolescents to consume DBC. Comparing patterns across HBSC countries can make an important contribution to understanding regional /global trends and to monitoring strategies and development of health promotion programs.

Pre-diagnostic levels of adiponectin and soluble vascular cell adhesion molecule-1 are associated with colorectal cancer risk

AIM To examine the relationships between pre-diagnostic biomarkers and colorectal cancer risk and assess their relevance in predictive models. METHODS A nested case-control study was designed to include all first primary incident colorectal cancer cases diagnosed between inclusion in the SUpplémentation en VItamines et Minéraux AntioXydants cohort in 1994 and the end of follow-up in 2007. Cases (n = 50) were matched with two randomly selected controls (n = 100). Conditional logistic regression models were used to investigate the associations between pre-diagnostic levels of hs-CRP, adiponectin, leptin, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1, E-selectin, monocyte chemoattractant protein-1 and colorectal cancer risk. Area under the receiver operating curves (AUC) and relative integrated discrimination improvement (RIDI) statistics were used to assess the discriminatory potential of the models. RESULTS Plasma adiponectin level was associated with decreased colorectal cancer risk (P for linear trend = 0.03). Quartiles of sVCAM-1 were associated with increased colorectal cancer risk (P for linear trend = 0.02). No association was observed with any of the other biomarkers. Compared to standard models with known risk factors, those including both adiponectin and sVCAM-1 had substantially improved performance for colorectal cancer risk prediction (P for AUC improvement = 0.01, RIDI = 26.5%). CONCLUSION These results suggest that pre-diagnostic plasma adiponectin and sVCAM-1 levels are associated with decreased and increased colorectal cancer risk, respectively. These relationships must be confirmed in large validation studies.

Inter- and intra-individual variation in tests of cell-mediated immunity in young and old women

Exploring means to maintain or improve immunity in older persons has been receiving attention. To establish relationships between immune function and variables of interest, it is important to determine these variables accurately and precisely. Precision relates to the degree of variation in the laboratory test. The nature and magnitude of variability in tests of immune function has not been described extensively. We examined inter- and intra-individual variation in tests of cell-mediated immunity (CMI) in generally healthy and well-nourished young (20-40 years; n=15) and old (60-80 years; n=15) women. Subjects provided blood samples on 2 days within a week to determine leukocyte subsets, T-cell proliferation response to phytohemagglutinin A and concanavalin A, and interleukin (IL)-1beta, IL-2 and IL-6 production by stimulated mononuclear cells. Intra-individual variation was partitioned into day-to-day biological and analytical variation. Inter-individual variation was greater than intra-individual variability for most tests of CMI for both age groups. Furthermore, all CMI tests exhibited large day-to-day intra-individual variation (CV approximately 15% or greater) which was primarily due to biological rather than analytical sources, for both age groups. In conclusion, both age groups showed large between-person and considerable within-person variation in CMI tests. Therefore, assessment of CMI based on a single blood draw may not provide a reliable estimate of immune function.