Breastfeeding protects against current asthma up to 6 years of age.

OBJECTIVE: To investigate the effects of breastfeeding on wheezing and current asthma in children 2 to 6 years of age. STUDY DESIGN: Infants (n=1105) were enrolled in a prospective birth cohort in New Zealand. Detailed information about infant feeding was collected using questionnaires administered at birth and at 3, 6, and 15 months. From this, durations of exclusive and any breastfeeding were calculated. Information about wheezing and current asthma was collected at 2, 3, 4, 5, and 6 years. Logistic regression was used to model associations between breastfeeding and outcomes with and without adjustment for confounders. RESULTS: After adjustment for confounders, each month of exclusive breastfeeding was associated with significant reductions in current asthma from 2 to 6 years (all, P<.03). Current asthma at 2, 3, and 4 years was also reduced by each month of any breastfeeding (all, P<.005). In atopic children, exclusive breastfeeding for ≥ 3 months reduced current asthma at ages 4, 5, and 6 by 62%, 55%, and 59%, respectively. CONCLUSION: Breastfeeding, particularly exclusive breastfeeding, protects against current asthma up to 6 years. Although exclusive breastfeeding reduced risk of current asthma in all children to age 6, the degree of protection beyond 3 years was more pronounced in atopic children.

Vitamin D status of newborns in New Zealand.

Recognition of the important non-skeletal health effects of vitamin D has focused attention on the vitamin D status of individuals across the lifespan. To examine the vitamin D status of newborns, we measured serum levels of 25-hydroxyvitamin D (25(OH)D) in the cord blood of 929 apparently healthy newborns in a population-based study in New Zealand, a country at 41 °S latitude, with strong anti-skin cancer (sun avoidance) campaigns and without vitamin D food fortification. Randomly selected midwives in two regions recruited children. The median cord blood level of 25(OH)D was 44 nmol/l (interquartile range, 29-78 nmol/l). Overall, 19 % of newborns had 25(OH)D levels < 25 nmol/l and 57 % had levels < 50 nmol/l; only 27 % had levels of 75 nmol/l or higher, which are levels associated with optimal health in older children and adults. A multivariable ordinal logistic regression model showed that the strongest determinants of low vitamin D status were winter month of birth and non-European ethnicity. Other determinants of low cord blood 25(OH)D included longer gestational age, younger maternal age and a parental history of asthma. In summary, low levels of vitamin D are common among apparently healthy New Zealand newborns, and are independently associated with several easily identified factors. Although the optimal timing and dosage of vitamin D supplementation require further study, our findings may assist future efforts to correct low levels of 25(OH)D among New Zealand mothers and their newborn children.

Effects of moderate-dose omega-3 fish oil on cardiovascular risk factors and mood after ischemic stroke: a randomized, controlled trial.

BACKGROUND AND PURPOSE: Fish-derived omega-3 fatty acids have long been associated with cardiovascular protection. In this trial, we assessed whether treatment with a guideline-recommended moderate-dose fish oil supplement could improve cardiovascular biomarkers, mood- and health-related quality of life in patients with ischemic stroke. METHODS: Patients with CT-confirmed stroke were randomized to 3 g/day encapsulated fish oil containing approximately 1.2 g total omega-3 (0.7 g docosahexaenoic acid; 0.3 g eicosapentaenoic acid) or placebo oil (combination palm and soy) taken daily over 12 weeks. Serum triglycerides, total cholesterol and associated lipoproteins, selected inflammatory and hemostatic markers, mood, and health-related quality of life were assessed at baseline and follow-up. The primary outcome was change in triglycerides. Compliance was assessed by capsule count and serum phospholipid omega-3 levels (Australian Clinical Trials Registration: ACTRN12605000207617). RESULTS: One hundred two patients were randomized to fish oil or placebo. Intention-to-treat and per-protocol (>85% compliance) analyses showed no significant effect of fish oil treatment on any lipid, inflammatory, hemostatic, or composite mood parameters measured. Adherence to treatment based on pill count was good (89%) reflected by increased serum docosahexanoic acid (P<0.001) and eicosapentaenoic acid (P=0.0006) in the fish oil group. Analysis of oil composition, however, showed some degradation and potentially adverse oxidation products at the end of the study. CONCLUSIONS: There was no effect of 12 weeks of treatment with moderate-dose fish oil supplements on cardiovascular biomarkers or mood in patients with ischemic stroke. It is possible that insufficient dose, short duration of treatment, and/or oxidation of the fish oils may have influenced these outcomes.

Breastfeeding protects against adverse respiratory outcomes at 15 months of age.

The relationship between breastfeeding, respiratory and other allergic disorders has been controversial. Our aim was to investigate the relationships between breastfeeding, respiratory outcomes, eczema and atopy at 15 months of age in a prospective birth cohort in New Zealand. A total of 1105 children were enrolled at birth, and 1011 (91.2%) were followed up at 15 months. Logistic regression was used to model associations between breastfeeding duration and respiratory outcomes, eczema and atopy after adjusting for relevant confounding variables: ethnicity, socio-economic status, parity, body mass index, smoking in pregnancy, gender and respiratory infections in the first 3 months of life. Breastfeeding was associated with a significant reduction in the risk of adverse respiratory outcomes at 15 months. After adjustment for confounders, each month of exclusive breastfeeding reduced the risk of doctor-diagnosed asthma by 20% (odds ratio 0.80, 95% confidence interval 0.71 to 0.90), wheezing by 12% (0.88, 0.82 to 0.94) and inhaler use by 14% (0.86, 0.78 to 0.93). Associations for both exclusive and additional breastfeeding durations, and respiratory outcomes remained independently significant when modelled simultaneously. Although independently associated with all respiratory outcomes, adjusting for parental history of allergic disease or maternal history of asthma did not alter our findings. Breastfeeding was not associated with eczema or atopy at 15 months. In conclusion, there was a significant protective effect of breastfeeding on infant wheezing and other adverse respiratory outcomes that may be early indicators of asthma in New Zealand children.

Hair nicotine at 15 months old, tobacco exposure and wheeze or asthma from 15 months to 6 years old.

OBJECTIVE: To investigate the relationship between hair nicotine levels at 15 months of age and prior parent-reported smoking exposure, and the risk of wheezing and current asthma from 15 months to 6 years of age. STUDY DESIGN: We measured hair nicotine levels at 15 months of age in 376 of 535 infants enrolled in a prospective birth cohort in Christchurch, New Zealand. We obtained detailed information from parents about smoking exposure during pregnancy and in the home at 3 and 15 months of age. Data for demographics, wheezing, and asthma were obtained from yearly questionnaires up to age 6 years. We assessed hair nicotine levels in relation to reported smoke exposure in pregnancy and up to age 15 months, and the association between high levels of hair nicotine and annual reports of current wheeze and current asthma using multiple logistic regression. RESULTS: Hair nicotine increased with numbers of smokers and daily cigarettes smoked at home, and was also strongly associated with smoking in pregnancy. High level of hair nicotine was associated with increased risk of wheeze (Odds ratio 2.30, P = 0.001) and, though not significant, of current asthma (Odds ratio 2.02, P = 0.056) at 15 months of age, after controlling for socio-economic status, ethnicity, body mass index, respiratory infections in the first 3 months of life, and duration of exclusive breastfeeding. At older ages the associations were non-significant. CONCLUSION: In children aged 15 months hair nicotine level was related to smoking exposure, and was associated with increased risk of wheeze and asthma.

Fish consumption in pregnancy and omega-3 status after birth are not associated with postnatal depression.

BACKGROUND: Research to date suggests a relationship between fish consumption, omega-3 polyunsaturated fatty acids, and depression. However, interpretation of this research is difficult due to methodological limitations. Postpartum women provide an excellent opportunity to examine these relationships because omega-3s are transferred from mother to fetus during pregnancy and from mother to child after birth through breast milk. Hence new mothers are more likely to be depleted in omega-3s. Our aim was to determine whether prenatal fish consumption and omega-3 status after birth were associated with postnatal depression. METHODS: Eighty first-time mothers were recruited; 41 who scored on or over the cut-off on one of two depression-screening instruments, and 39 in the control group. Depression was diagnosed using the Composite International Diagnostic Interview. Fish consumption was measured during pregnancy, and depression and omega-3 status were determined postnatally. Logistic regression and t-tests were used to examine relationships between fish consumption, omega-3 status, and postnatal depression, while controlling for known covariates. RESULTS: Prenatal fish consumption was not predictive of postnatal depression, and postnatal omega-3 status was not associated with postnatal depression. However, prenatal fish consumption did predict omega-3 status after birth. LIMITATIONS: Prenatal fish consumption was measured using only a food frequency questionnaire, and no participants consumed oily fish (rich in omega-3s) regularly. CONCLUSIONS: There was no association between postnatal depression and either fish consumption in early pregnancy, or omega-3 status after birth. Our findings make it difficult to justify trials of omega-3 polyunsaturated fatty acids in the treatment of postnatal depression.

Are the health benefits of fish oils limited by products of oxidation?

Human clinical trials have shown that fish oils reduce the risk of a variety of disorders including CVD. Despite this, results have been inconsistent. Fish oils are easily oxidised and some fish oils contain higher than recommended levels of oxidised products, but their effects have not been investigated. Recent evidence indicates that dietary oxidised fats can contribute to the development of atherosclerosis and thrombosis. This review summarises findings from cellular, animal and human trials that have examined the effects of oxidised lipids and their potential to affect health outcomes, and proposes that oxidised products in fish oils may attenuate their beneficial effects. More research is required to determine the magnitude of negative effects of fish oil on health outcomes in clinical trials.

Randomised double-blind placebo-controlled trial of fish oil in the treatment of depression.

Converging evidence suggests that omega-3 polyunsaturated fatty acids have aetiological importance in depression. To determine the effect of adding fish oil to existing therapy in participants who were being treated for depression in a community setting, 77 participants were randomly assigned to receive 8 g of either fish or olive oil per day in addition to their existing therapy. Fifty-nine (77%) participants completed 12 weeks of treatment. Dietary, biochemical and lifestyle factors were measured throughout the study. Mood was assessed using the Short Form Hamilton Depression Rating Scale (HDRS-SF) and the Beck Depression Inventory II. Sample size calculations were based on the HDRS-SF. Intention-to-treat and per protocol analyses were carried out using residual maximum likelihood. There was no evidence that fish oil improved mood when compared to the placebo oil, despite an increase in circulating omega-3 polyunsaturated fatty acids. However, mood improved significantly in both groups within the first 2 weeks of the study (P<0.001) and this improvement was sustained throughout. In conclusion, fish oil was no more effective than the control as an add-on therapy for depression in this setting.

Cord-blood 25-hydroxyvitamin D levels and risk of respiratory infection, wheezing, and asthma.

OBJECTIVE: Higher maternal intake of vitamin D during pregnancy is associated with a lower risk of wheezing in offspring. The relationship between cord-blood levels of 25-hydroxyvitamin D (25[OH]D) and childhood wheezing is unknown. We hypothesized that cord-blood levels would be inversely associated with risk of respiratory infection, wheezing, and asthma. PATIENTS AND METHODS: Cord blood from 922 newborns was tested for 25(OH)D. Parents were asked if their child had a history of respiratory infection at 3 months of age or a history of wheezing at 15 months of age and then annually thereafter. Incident asthma was defined as doctor-diagnosed asthma by the time the child was 5 years old and reported inhaler use or wheezing since the age of 4 years. RESULTS: The median cord-blood level of 25(OH)D was 44 nmol/L (interquartile range: 29-78). Follow-up was 89% at the age of 5 years. Adjusting for the season of birth, 25(OH)D had an inverse association with risk of respiratory infection by 3 months of age (odds ratio: 1.00 [reference] for ≥75 nmol/L, 1.39 for 25-74 nmol/L, and 2.16 [95% confidence interval: 1.35-3.46] for <25 nmol/L). Likewise, cord-blood 25(OH)D levels were inversely associated with risk of wheezing by 15 months, 3 years, and 5 years of age (all P < .05). Additional adjustment for more than 12 potential confounders did not materially change these results. In contrast, we found no association between 25(OH)D levels and incident asthma by the age of 5 years. CONCLUSIONS: Cord-blood levels of 25(OH)D had inverse associations with risk of respiratory infection and childhood wheezing but no association with incident asthma.

Dietary supplement use in people being treated for depression.

The use of dietary supplements has increased over the past 10 years, with up to 50% of adults being reported to have taken dietary supplements. The types of supplements taken are often related to physical morbidities. However, information about their use in combination with prescription drugs is lacking. In particular, there is little information on the use of supplements by people with depression. Our aim was to examine the use of dietary supplements by people being treated for depression. Seventy-two participants who were being treated for depression in the community were recruited for a clinical trial to determine the effect of fish oil on mood in the treatment of depression. The results of the primary analysis are reported elsewhere. Exclusion criteria included any co-existing psychiatric disorder (except anxiety disorders), blood clotting disorders, unstable medical conditions, and those taking fish oil supplements. Demographic information, details about the participants' depression and current therapies, use of dietary and herbal supplements in the previous 12 months, and physical activity data were collected at baseline. Characteristics of supplement users were compared with those of non-users using either chi-square or Mann-Whitney U tests. Forty-five (63%) of 72 participants who provided dietary supplement information had taken at least one dietary supplement within the previous 12 months. On average, supplement users were found to have taken 2.8 (SD=1.56) dietary supplements during the assessment period. Women were more likely to be taking supplements than men (P<0.001). In conclusion, the use of dietary supplements is common among people being treated for depression. This has important implications for clinical practice as little is known about supplement-drug interactions.

Fish consumption and self-reported physical and mental health status.

OBJECTIVE: The aim of this study was to assess whether self-reported mental health status, measured using the SF-36 questionnaire, was associated with fish consumption, assessed using a food-frequency questionnaire. DESIGN: The cross-national data were collected in the 1996/97 New Zealand Health Survey and 1997 Nutrition Survey, which were conducted using the same sampling frame. Survey respondents were categorised into those who consumed no fish of any kind and those who consumed some kind of fish, at any frequency. Data were adjusted for age, household income, eating patterns, alcohol use and smoking. Other demographic variables and potential confounding nutrients were included in the preliminary analyses but were not found to have a significant relationship with fish consumption. SUBJECTS: Data from a nationally representative sample of 4644 New Zealand adults aged 15 years and over were used in this analysis. RESULTS: Fish consumption was significantly associated with higher self-reported mental health status, even after adjustment for possible confounders. Differences between the mean scores for fish eaters and those who never eat fish were 8.2 for the Mental Health scale and 7.5 for the Mental Component score. Conversely, the association between fish consumption and physical functioning was in the opposite direction. CONCLUSIONS: This is the first cross-sectional survey to demonstrate a significant relationship between fish intake and higher self-reported mental health status, therefore offering indirect support for the hypothesis that omega-3 polyunsaturated fatty acids may act as mood stabilisers.