Fish consumption, n-3 fatty acids, and colorectal cancer: a meta-analysis of prospective cohort studies.

Animal studies show favorable effects of n-3 fatty acids on inflammation and cancer, but results from epidemiologic studies appear to be inconsistent. The authors conducted meta-analyses of prospective cohort studies that evaluated the association between fish consumption or n-3 fatty acids and colorectal cancer incidence or mortality. Random-effects models were used, and heterogeneity between study results was explored through stratified analyses. The pooled relative risks for the highest compared with the lowest fish consumption category were 0.88 (95% confidence interval: 0.78, 1.00) for colorectal cancer incidence (14 studies) and 1.02 (95% confidence interval: 0.90, 1.16) for colorectal cancer mortality (four studies). The pooled relative risks for colorectal cancer incidence were 0.96 (95% confidence interval: 0.92, 1.00) for each extra occurrence of fish consumption per week (seven studies) and 0.97 (95% confidence interval: 0.92, 1.03) for each extra 100 g of fish consumed per week (four studies). Stratified analysis showed that the pooled relative risk for colorectal cancer incidence was more pronounced for women and in studies with a large exposure contrast. In cohort studies, fish consumption was shown to slightly reduce colorectal cancer risk. Existing evidence that n-3 fatty acids inhibit colorectal carcinogenesis is in line with these results, but few data are available addressing this association.

The effect of iron fortification and de-worming on anaemia and iron status of Vietnamese schoolchildren.

Previous data from Vietnam show that anaemia is highly prevalent among schoolchildren, who are considered not to be iron deficient. Trichuris infection doubled the risk of anaemia. The present study aimed to evaluate the hypothesis that de-worming is more effective than iron fortification in an anaemic, infection-prone population. In a trial with a 2 x 2 factorial design, 425 anaemic children aged 6-8 years were randomly assigned to receive either iron-fortified noodles or placebo, and mebendazole or placebo. Outcomes considered were change in haematological indicators of iron status (Hb, serum ferritin (SF), serum transferrin receptor (TfR) and haemoglobinopathies analysis); inflammations (C-reactive protein (CRP)); parasite infection status (hookworm, Trichuris and Ascaris infection); and IgE. ANOVA and logistic regression were used to assess the effects of iron fortification and de-worming on Hb, SF, TfR, body iron and anaemia. Hb improved in all groups after 6 months of intervention. Iron fortification significantly improved Hb, SF and body iron (2.6 g/l, 16.3 microg/l and 1 mg/kg, respectively). Prevalence of elevated IgE was very high at baseline (99%) and significantly reduced to about 75% in all groups after intervention. De-worming unexpectedly showed no effect on Hb, iron status and IgE level. It is concluded that iron fortification slightly improved anaemia and iron status in anaemic schoolchildren in rural Vietnam that were not considered iron deficient. Chronic infection or other unidentified factors may play an important role in the seasonal reduction of anaemia seen in all treatment groups.

Efficacy of iron fortification compared to iron supplementation among Vietnamese schoolchildren.

The effect of iron fortification is generally assumed to be less than iron supplementation; however, the magnitude of difference in effects is not known. The present study aims to compare the efficacy of these two strategies on anaemia and iron status. After screening on low Hb, 425 anaemic children in six primary schools in Tam Nong district of Phu Tho province were included in a randomized, placebo-controlled trial comparing two groups receiving iron fortified instant noodles or iron supplementation for 6 months and a control group, with children in all groups having been dewormed. Blood samples were collected before and after intervention for haemoglobin, serum ferritin (SF), serum transferrin receptor (TfR), C-reactive protein (CRP), and haemoglobinopathies analysis. Regression analysis was used to assess the effect of iron fortification and iron supplementation on haemoglobin concentration, SF, TfR, body iron, and anaemic status as outcome variables. The improvement of haemoglobin, SF, and body iron level in the group receiving iron fortification was 42% (2.6 g/L versus 6.2 g/L), 20% (23.5 microg/L versus 117.3 microg/L), and 31.3% (1.4 mg/kg versus 4.4 mg/kg) of that in the iron supplementation group. The prevalence of anaemia dropped to 15.1% in the control group, with an additional reduction of anaemia of 8.5% in the iron supplementation group. The additional reduction due to iron fortification was 5.4%, which amounts to well over 50% of the impact of supplementation. In conclusion, the efficacy of iron fortification based on reduction of prevalence of anaemia, and on the change in haemoglobin level, is about half of the maximum impact of supplementation in case of optimal compliance. Thus, in a population of anaemic children with mild iron deficiency, iron fortification should be the preferred strategy to combat anaemia.

The intraclass correlation coefficient applied for evaluation of data correction, labeling methods, and rectal biopsy sampling in DNA microarray experiments.

We show that the intraclass correlation coefficient (ICC) can be used as a relatively simple statistical measure to assess methodological and biological variation in DNA microarray analysis. The ICC is a measure that determines the reproducibility of a variable, which can easily be calculated from an ANOVA table. It is based on the assessment of both systematic deviation and random variation, and it facilitates comparison of multiple samples at once. We used the ICC first to optimize our microarray data normalization method and found that the use of median values instead of mean values improves data correction. Then the reproducibility of different labeling methods was evaluated, and labeling by indirect fluorescent dye incorporation appeared to be more reproducible than direct labeling. Finally, we determined optimal biopsy sampling by analyzing overall variation in gene expression. The variation in gene expression of rectal biopsies within persons decreased when two biopsies were taken instead of one, but it did not considerably improve when more than two biopsies were taken from one person, indicating that it is sufficient to use two biopsies per person for DNA microarray analysis under our experimental conditions. To optimize the accuracy of the microarray data, biopsies from at least six different persons should be used per group.

Dietary quality and lifestyle factors in relation to 10-year mortality in older Europeans: the SENECA study.

The single and combined effects of three healthy lifestyle behaviors-nonsmoking, being physically active, and having a high-quality diet-on survival were investigated among older people in the SENECA Study. This European longitudinal study started with baseline measurements in 1988-1989 and lasted until April 30, 1999. The study population consisted of 631 men and 650 women aged 70-75 years from Belgium, Denmark, Italy, The Netherlands, Portugal, Spain, and Switzerland. A lifestyle score was calculated by adding the scores of the lifestyle factors physical activity, dietary quality, and smoking habits. The single lifestyle factors and the lifestyle score were related to mortality. Even at ages 70-75 years, the unhealthy lifestyle behaviors smoking, having a low-quality diet, and being physically inactive were singly related to an increased mortality risk (hazard ratios ranged from 1.2 to 2.1). The risk of death was further increased for all combinations of two unhealthy lifestyle behaviors. Finally, men and women with all three unhealthy lifestyle behaviors had a three- to fourfold increase in mortality risk. These results underscore the importance of a healthy lifestyle, including multiple lifestyle factors, and the maintenance of it with advancing age.