Livestock keeping can positively influence the nutritional status of populations and households through increased consumption of animal-source foods (ASF) and other indirect pathways, but can also adversely affect health by increasing the risk of diseases. We conducted a systematic review synthesising the current state of knowledge on the associations among livestock keeping, infectious disease and the nutritional status of children under 5 years and women of reproductive age in low- and lower–middle-income countries (LMICs). A comprehensive search of 12 electronic databases and grey literature sources published from 1991 to the end of December 2020 was conducted. Investigations exploring relationships between livestock keeping and risk of infectious disease transmission and nutritional status were selected using pre-defined inclusion criteria. After screening and filtering of 34,402 unique references, 176 references were included in the final synthesis. Most (160/176, 90.1%) of the references included in the final synthesis were from sub-Saharan Africa (SSA) and Asia. About two out of every five (42%) studies reviewed showed that livestock production is associated with improved height-for-age Z scores (HAZ) and weight-for-length/height Z scores (WHZ), while close to a third (30.7%) with improved weight-for-age Z scores (WAZ). Similarly, livestock production showed a positive or neutral relationship with women’s nutritional status in almost all the references that reported on the topic. Conversely, four-fifths (66/81, 79.5%) of the references reporting on infection and morbidity outcomes indicated that livestock keeping is linked to a wide range of infectious disease outcomes, which are spread primarily through water, food and insects. In conclusion, in many LMIC settings, livestock production is associated with better nutritional outcomes but also a higher risk of disease transmission or morbidity among women and children.

This review was prospectively registered on PROSPERO 2020 [CRD42020193622]

Epidemiological studies have reported inverse associations between various single healthy diet indices and lower levels of systemic inflammation, but rarely are they examined in the same sample. The aim of the present study was to investigate the potential relationships between biomarkers of systemic inflammation (C-reactive protein (CRP) and fibrinogen) and overall foods (dietary patterns), single foods (fruits and vegetables), and specific nutritive (antioxidants) and non-nutritive (flavonoids) food components in the same narrow-age cohort of older adults. The dietary intake of 792 participants aged 70 years from the Lothian Birth Cohort 1936 was assessed using a 168-item FFQ. Models were adjusted for age, sex, childhood cognitive ability, lifestyle factors and history of disease. Using logistic regression analyses, CRP (normal v. elevated) was favourably associated (at P< 0·05) with the ‘health-aware’ (low-fat) dietary pattern (unstandardised β = (0·200, OR 0·82, 95 % CI 0·68, 0·99) and fruit intake (unstandardised β = (0·100, OR 0·91, 95 % CI 0·82, 0·99), including flavonoid-rich apples (unstandardised β = (0·456, OR 0·63, 95 % CI 0·439, 0·946). Using linear regression analyses, fibrinogen (continuous) was inversely associated (at P< 0·05) with the Mediterranean dietary pattern (standardised β = (0·100), fruit intake (standardised β = (0·083), and combined fruit and vegetable intake (standardised β = (0·084). We observed no association between food components (antioxidant nutrients or specific flavonoid subclasses) and inflammatory markers. In the present cross-sectional study, nutrient-dense dietary patterns were associated with lower levels of systemic inflammation in older people. The results are consistent with dietary guidelines that promote a balanced diet based on a variety of plant-based foods.

Maternal nutritional status during pregnancy has been reported to be associated with childhood asthma and atopic disease. The Avon Longitudinal Study of Parents and Children has reported associations between reduced umbilical cord Fe status and childhood wheeze and eczema; however, follow-up was short and lung function was not measured. In the present study, the associations between maternal Fe status during pregnancy and childhood outcomes in the first 10 years of life were investigated in a subgroup of 157 mother–child pairs from a birth cohort with complete maternal, fetal ultrasound, blood and child follow-up data. Maternal Fe intake was assessed using FFQ at 32 weeks of gestation and Hb concentrations and serum Fe status (ferritin, soluble transferrin receptor and TfR-F (transferrin receptor:ferritin) index) were measured at 11 weeks of gestation and at delivery. Maternal Fe intake, Hb concentrations and serum Fe status were found to be not associated with fetal or birth measurements. Unit increases in first-trimester maternal serum TfR concentrations (OR 1·44, 95 % CI 1·05, 1·99) and TfR-F index (OR 1·42, 95 % CI 1·10, 1·82) (i.e. decreasing Fe status) were found to be associated with an increased risk of wheeze, while unit increases in serum ferritin concentrations (i.e. increasing Fe status) were found to be associated with increases in standardised mean peak expiratory flow (PEF) (β 0·25, 95 % CI 0·09, 0·42) and forced expiratory volume in the first second (FEV1) (β 0·20, 95 % CI 0·08, 0·32) up to 10 years of age. Increasing maternal serum TfR-F index at delivery was found to be associated with an increased risk of atopic sensitisation (OR 1·35, 95 % CI 1·02, 1·79). The results of the present study suggest that reduced maternal Fe status during pregnancy is adversely associated with childhood wheeze, lung function and atopic sensitisation, justifying further studies on maternal Fe status and childhood asthma and atopic disease.

The aims of the present study were to determine compliance with current advice on vitamin D and to assess the influence of season, dietary intake, supplement use and deprivation on vitamin D status in pregnant mothers and newborns in the north of Scotland where sunlight exposure is low. Pregnant women (n 1205) and their singleton newborns were studied in the Aberdeen Maternity Hospital (latitude 57°N) between 2000 and 2006. Plasma 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 were measured at 19 weeks of gestation in mothers and at delivery in newborns. During pregnancy, 21·0 (95 % CI 18·5, 23·5) % of women took vitamin D supplements. The median intake was 5 μg/d and only 0·6 (95 % CI 0·1, 1·0) % took the recommended 10 μg/d. Supplement use, adjusted for season, dietary intake and deprivation, significantly increased maternal 25-hydroxyvitamin D (25(OH)D) by 10·5 (95 % CI 5·7, 15·2) nmol/l (P< 0·001); however, there was no significant effect on cord 25(OH)D (1·4 (95 % CI − 1·8, 4·5) nmol/l). The biggest influence on both maternal and cord 25(OH)D was season of birth (P< 0·001). Compared with the least deprived women (top three deciles), the most deprived pregnancies (bottom three deciles) were characterised by a significantly lower seasonally adjusted 25(OH)D ( − 11·6 (95 % CI − 7·5, − 15·7) nmol/l in the mother and − 5·8 (95 % CI − 2·3, − 9·4) nmol/l in the cord), and a lower level of supplement use (10 (95 % CI 4, 17) v. 23 (95 % CI 20, 26) %). More should be done to promote vitamin D supplement use in pregnancy but the critical importance of endogenous vitamin D synthesis, and known adaptations of fat metabolism specific to pregnancy, suggest that safe sun advice may be a useful additional strategy, even at high latitude.

Studies in singletons have found an association between birthweight and Type 2 diabetes in adult life. The aim of this study was to investigate whether this association could also be seen in twins. 59 monozygotic (MZ) and 69 dizygotic (DZ) same-sex twin pairs aged 19–50 years and 89 singleton controls matched for age, gestational age, gender, maternal age and parity were recruited from a local obstetric database. Associations between adult glucose, HbA1C and insulin levels and insulin resistance and birthweight were assessed by linear regression with adjustment for confounding variables. Twins were significantly lighter at birth than singleton controls, but there were no significant differences in adult weight, glucose, HbA1C and insulin levels or insulin resistance between twins and controls. The relationship between birthweight and fasting glucose and insulin levels, and insulin resistance was not significantly different from zero in either twins or controls, but birthweight was significantly negatively associated with HbA1C only in controls. There was no evidence of a difference between MZ and DZ twins in unpaired or within-pair analysis. These results provide little evidence that low birthweight in twins increases the risk of impaired glucose-insulin metabolism in young adults or that genetic factors can account for the association observed in singletons.