Does milk make children grow? Relationships between milk consumption and height in NHANES 1999-2002

Determinant of under nutrition among under five children in Ambo town during covid 19 pandemic in 2020. A community-based cross-sectional study

BACKGROUND

About 8 to 44% of all child mortality in Africa is associated with undernutrition. To alleviate this problem, it is necessary to determine the magnitude and determinants of undernutrition during Covid 19 pandemic. However, there is scarce evidence in an urban setting like Ambo town. Therefore, this study assessed the magnitude and factors associated with undernutrition among under-five children in Ambo town, west Ethiopia.

METHODS AND PATIENTS

A community-based cross-sectional study was conducted in Ambo town from March 01-30, 2020. The child and mother/caregiver socio-demographic characteristics, child illness and health care utilization, and child feeding practice-related data were collected using the standardized tool adopted from similar studies conducted in Ethiopia. Anthropometric measurements of the child were made using a calibrated scale. A systematic sampling technique was employed to select 363 mothers/caregivers of the child as a source of data. Nutritional status indices were generated using ENASMART software. After testing for collinearity, variables with a p-value < 0.25 in binary logistic regression were interred to backward multiple logistic regressions at a level of significance of p < 0.05.

RESULTS

A total of 363 participants were included in this study providing a 100% response rate and providing the following result. The mean (+ SD) age of children was 28.85 (+ 14.17) months and that of mothers/caregivers was 28.12 + 48 years. This study found 16.00%, 25.30%, and 19.00% of the study participants were underweight, wasted, and stunted respectively. Decisions making on major food purchases, who usually care for the child, the age at which the child starts complimentary food, late introduction of complementary food were positively associated with wasting. Diarrhea, birth weight, child age, age at which the child starts complimentary food, consumption of milk and milk product, and who usually care for the child were significantly associated with being underweight. Consumption of milk and milk products, household food security level, and birth weight were independent determinants of stunting.

CONCLUSION

This study identified a high prevalence of undernutrition, especially wasting. Childbirth weight, age, diarrhea, feeding practice, household (HH) food security, Decision making on major food purchases, late introduction of complementary food were found to be the potential determinants of undernutrition. Thus there should be an effort to improve the nutritional status of children in the study area by focusing on these factors.

What can Mendelian randomization contribute to biological anthropology?

Uncovering causal relationships between exposures and outcomes can be difficult in observational studies because of the potential for confounding and reverse causation to produce biased estimates. Conversely, randomized controlled trials (RCTs) provide the strongest evidence for causality but they are not always feasible. Mendelian randomization (MR) is a method that aims to strengthen causal inference using genetic variants as proxies or instrumental variables (IVs) for exposures, to overcome the above-mentioned biases. Since allele segregation occurs at random from parents to offspring, and alleles for a trait assort independently from those for other traits, MR studies have frequently been compared to "natural" RCTs. In biological anthropology (BA) relationships between variables of interest are usually evaluated using observational data, often remaining descriptive, and other approaches to causal inference have seldom been implemented. Here, we propose the use of MR to investigate cause and effect relationships in BA studies and provide examples to show how that can be done across areas of BA relevance, such as adaptation to the environment, nutrition and life history theory. While we consider MR a useful addition to the biological anthropologist's toolbox, we advocate the adoption of a wide range of methods, affected by different types of biases, in order to better answer the important causal questions for the discipline.

The Role of Cow's Milk Consumption in Breast Cancer Initiation and Progression

PURPOSE OF REVIEW

This review evaluates cow milk's impact on breast carcinogenesis by linking recent epidemiological evidence and new insights into the molecular signaling of milk and its constituents in breast cancer (BCa) pathogenesis.

RECENT FINDINGS

Recent prospective cohort studies support the association between cow's milk consumption and the risk of estrogen receptor-α-positive (ER⁺) BCa. Milk is a complex biological fluid that increases systemic insulin-like growth factor 1 (IGF-1), insulin and estrogen signaling, and interacting hormonal promoters of BCa. Further potential oncogenic components of commercial milk include exosomal microRNAs (miR-148a-3p, miR-21-5p), bovine meat and milk factors, aflatoxin M1, bisphenol A, pesticides, and micro- and nanoplastics. Individuals with BRCA1 loss-of-function mutations and FTO and IGF1 gain-of-function polymorphisms enhancing IGF-1/mTORC1 signaling may be at increased risk for milk-induced ER⁺ BCa. Recent prospective epidemiological and pathobiochemical studies identify commercial milk consumption as a critical risk factor of ER⁺ BCa. Large meta-analyses gathering individuals of different ethnic origins with milk derived from dairy cows of varying genetic backgrounds and diverse feeding procedures as well as missing data on thermal processing of milk (pasteurization versus ultra-heat treatment) make multi-national meta-analyses unsuitable for BCa risk estimations in susceptible populations. Future studies are required that consider all vulnerable periods of breast carcinogenesis to cow's milk exposure, beginning during the perinatal period and puberty, since these are the most critical periods of mammary gland morphogenesis. Notwithstanding the need for better studies including detailed information on milk processing and vulnerable periods of human breast carcinogenesis, the available evidence suggests that dietary guidelines on milk consumption may have to be reconsidered.

Standard vs. Nutrient-Enriched Cow's Milk and Its Impacts on Child Growth: A Systematic Review and Meta-Analysis

Stunting among children indicates malnutrition or undernutrition, hindering their growth and development. This will have negative effects on the overall health of children. This review investigates the effects of different types of cow's milk and their impacts on children's growth. A web-based search of Cochrane, Web of Science, SAGE, and Prospero was carried out using predetermined search/MESH phrases and keywords. The data extraction and analysis were carried out independently by two reviewers, who then double-checked, revised, and discussed any disagreements with a third reviewer. Eight studies met the inclusion criteria and were rated as good (N = 5) and fair quality (N = 3), which were included in the final analysis. The results illustrated that standard cow's milk has more consistent findings than nutrient-enriched cow's milk potentially in assisting children's growth. However, studies on standard cow's milk and child's growth are still lacking for this age group. In addition, there are inconsistent findings between nutrient-enriched cow's milk and children's growth. It is crucial to ensure milk is included in children's diets as per recommended nutrient intake.

Total Usual Nutrient Intakes and Nutritional Status of United Arab Emirates Children (<4 Years): Findings from the Feeding Infants and Toddlers Study (FITS) 2021

Background

The transition from a predominantly milk-based diet to a diverse family diet is a window of opportunity for optimal child growth and development.

Objectives

The study aims to examine the nutritional status and food-consumption patterns of children under 4 y of age in the United Arab Emirates (UAE) and their adherence to nutrient and dietary recommendations.

Methods

A population-based cross-sectional survey of 525 children aged 0-47.9 mo was conducted in 3 major emirates: Abu Dhabi, Dubai, and Sharjah. Anthropometric measurements were obtained, and dietary assessment was conducted using the 24-h dietary recall approach. Usual intakes of energy, macronutrient, and micronutrients, including from supplements, were assessed using PC-SIDE software. Adherence to food-group recommendations was evaluated based on the American Heart Association/American Academy of Pediatrics dietary guidelines.

Results

Among 0-4-y-old children, 10% were stunted, 6% were wasted, 17% were at risk of overweight, 5% were overweight, and 3% were obese. The contribution of sweets and sugar sweetened beverages to energy intake increased from 5% in 6-11.9-mo-old children to 17% in 36-47.9-mo-old children. Compared with dietary guidelines, the lowest adherence was for fruit (13-18%) and vegetables (7-12%), while protein was within the recommendations, and 92% and 89% of children (aged 24 to 35.9 mo and 36 to 47.9 mo, respectively) had high intakes of saturated fat. Almost all toddlers failed to meet the Adequate Intake for fiber. The proportions of children exceeding the free-sugar upper limit increased from 10.6% in infants (0-5.9 mo) to 56.7% in toddlers (12- 23.9 mo). Micronutrient inadequacies were observed, particularly for calcium, zinc, folate, and vitamins A and D.

Conclusions

This study suggests a triple burden of malnutrition among infants and young children in the UAE. Results call for national nutrition intervention strategies aimed at improving dietary quality in the pediatric population.

Association of cow's milk intake in early childhood with adiposity and cardiometabolic risk in early adolescence

BACKGROUND

Prior studies have provided conflicting evidence regarding associations of pediatric milk consumption with subsequent adiposity.

OBJECTIVES

We aimed to estimate associations of the consumption frequency and fat content of early childhood milk intake with early adolescent adiposity and cardiometabolic risk.

METHODS

We analyzed data collected prospectively from 796 children in Project Viva, a Boston-area prebirth cohort. Parents reported the frequency (times/day) and fat content [higher-fat: whole (3.25%) or 2% milk; lower-fat: 1% or skim milk] of cow's milk consumed in early childhood (mean, 3.2 years) via food-frequency questionnaires. We measured adiposity and cardiometabolic markers in early adolescence (mean, 13.2 years) and conducted multivariable regressions to assess associations adjusted for baseline parental and child sociodemographic, anthropometric, and dietary factors.

RESULTS

In early childhood, mean milk intake was 2.3 times/day (SD, 1.2 times/day), and 63% of children drank primarily higher-fat milk. The early childhood BMI z-score (BMIz) was inversely associated with the fat content of milk consumed in early childhood. After adjustment for baseline parent and child factors, early childhood intake of higher-fat compared with lower-fat milk was associated with lower adiposity; however, the 95% CIs for most adiposity outcomes-except for the odds of overweight or obesity (OR, 0.60; 95% CI, 0.38-0.93)-crossed the null after adjustment for the baseline child BMIz and BMIz change between ages 2 and 3 years. Early childhood consumption of higher-fat milk (compared with lower-fat milk) was not associated with adverse cardiometabolic outcomes. The frequency of cow's milk consumption in early childhood was not associated with adiposity or cardiometabolic risk in early adolescence.

CONCLUSIONS

Consumption of higher-fat cow's milk in early childhood was not associated with increased adiposity or adverse cardiometabolic health over a decade later. Our findings do not support current recommendations to consume lower-fat milk to reduce the risk of later obesity and adverse cardiometabolic outcomes. This trial was registered at clinicaltrials.gov as NCT02820402.

A critical biocultural approach to early growth in the United States

OBJECTIVES

A critical biocultural anthropology seeks to link perspectives from social theory and ethnography to human biology. In the United States (U.S.), multiple forms of structural inequalities affect early growth, including racism and poverty. The goal of this paper is to test the effects of social inequalities on birth weight and later height in the U.S. National Health and Nutrition Survey (NHANES), and to contextualize potential pathways of embodiment that link social structure and biology.

METHODS

This study used data from 8392 children ages 0-5 years from the 2005 to 2016 NHANES. Reported birth weight and measured length/height (converted to height-for-age z-scores) were used as outcome variables, while various measures of socioeconomic status and the NHANES-defined race and ethnicity categories were operationalized as social variables. Structural equation modeling (SEM) was chosen to represent the data.

RESULTS

The final model represented an excellent fit to the data. Higher birth weights were associated with higher height-for-age z-scores. The Black racial category was associated with lower birth weight and higher height-for-age z-score, while the "Other" racial category was also associated with lower birth weight. The socioeconomic status factor variable was significantly associated with birth weight and height-for-age z-scores. There were also multiple indirect effects of social variables on height-for-age z-scores mediated via their effects on birth weight.

CONCLUSIONS

Inequalities in race and socioeconomic status persist in birth weight and early childhood stature in the U.S. These findings can be contextualized by a critical biocultural anthropology that integrates lived experiences and pathways of embodiment.

Sugar-sweetened beverage consumption and overweight and obesity in adolescents in Ho Chi Minh City, Vietnam: a population-based analysis

BACKGROUND

The aim of this research was to describe the patterns of consumption of multiple sugar-sweetened beverages (including modern and traditional ones) among adolescents in Ho Chi Minh City and to identify a possible relationship between this consumption and overweight, obesity, and other factors.

METHODS

A secondary analysis from a cross-sectional study of 11-15-year-old students from 31 junior high schools across Ho Chi Minh City was used. We measured the students' anthropometric status and assessed beverage consumption using a validated Food Frequency Questionnaire. Multivariate logistic regression models were used to identify the association between the consumption of sugar-sweetened beverages, obesity and other factors.

RESULTS

The sugar-sweetened beverages (SSB) ranged widely from modern soft drinks and powdered drinks to traditional sugar-added fruit and leaf juices, and milk-based drinks. These beverages were very popular among 2,660 participants with 36% consuming at least one variety daily. Factors positively associated with sugar-sweetened beverage consumption included a higher level of physical activity, higher consumption of fast foods, and daily fruit and vegetable consumption. We found a negative association between milk-based SSBs and the overweight and obesity status of the students, i.e. every kcal more of fresh milk with sugar and condensed milk can reduce an obesity odd of 0.005 (95% CI [0.002-0.008], p < 0.001) and 0.004 (95% CI [0.002-0.010], p = 0.044) consecutively. None of the other SSBs was significantly related to adolescent overweight and obesity.

CONCLUSIONS

Milk-based drinks potentially protect adolescents against overweight and obesity. Further research to assess this protection is needed.

Gender Differences Between the Phenotype of Short Stature and the Risk of Diabetes Mellitus in Chinese Adults: A Population-Based Cohort Study

OBJECTIVE

Previous studies have shown that there are significant regional and gender differences in the association between the phenotype of short stature and diabetes mellitus (DM). The purpose of this study was to investigate the gender difference between the phenotype of short stature and the risk of DM in the Chinese population.

METHODS

The sample included 116,661 adults from 32 locations of 11 cities in China, of which the average height of men and women was 171.65 and 160.06 cm, respectively. Investigators retrospectively reviewed annual physical examination results for follow-up observations and set confirmed DM events as the outcome of interest. Multivariate Cox regression, restricted cubic spline, and piecewise regression models were used to check the association between height and DM risk.

RESULTS

During an average observation period of 3.1 years, there were 2,681 of 116,661 participants who developed new-onset DM, with a male to female ratio of 2.4 to 1. After full adjustment for confounders, we confirmed that there was a significant negative correlation between height and DM risk in Chinese women (HR per 10 cm increase: 0.85, 95% CI: 0.74-0.98), but not in men (HR per 10 cm increase: 1.16, 95% CI: 0.98-1.14). Additionally, through restricted cubic spline and piecewise regression analysis, we determined that the height of 157-158 cm may be the critical point for short stature used to assess the risk of DM in Chinese women.

CONCLUSIONS

In the Chinese population, female short stature phenotype is related to increased DM risk, among which 157-158 cm may be the saturation effect point of female short stature for predicting DM risk.

Double burden of malnutrition in ethnic minority school-aged children living in mountainous areas of Vietnam and its association with nutritional behavior

BACKGROUND/OBJECTIVES

Although children of ethnic minority groups are experiencing a transition from a predominance of undernutrition to overnutrition, there is little evidence of a dual-malnutrition burden. Therefore, this study examined the double burden of malnutrition among school-aged ethnic minority children living in mountainous areas and its association with their diets.

SUBJECTS/METHODS

A cross-sectional study was conducted from September 2019 to March 2020 in 3 mountainous areas of Northern Vietnam among 1,556 ethnic minority school-aged children. The prevalence of under-nutrition (stunting and thinness) and over-nutrition (overweight and obesity) were measured using the WHO 2006 child growth standards (height-for-age and BMI-for-age Z-score). Nutritional practices were evaluated by the frequency of food consumption based on a 4-level scale.

RESULTS

The percentage of children with stunting and thinness were 14.0% and 5.4%, respectively, while the figure for overweight/obesity was 9.4%. The factors positively associated with stunting were living in a family with more than 2 children or being Muong/other ethnicities compared to the Tay ethnicity. Children who consumed fish/shrimps/crabs or milk weekly/daily were less likely to be undernourished compared to those who never consumed these foods. By contrast, children who never consumed foods rich in vitamin A precursors and vitamin A and fruit or consumed daily snacks/junk food were more likely to be overweight/obese.

CONCLUSIONS

Undernutrition remains a common issue among school-aged children and adolescents of ethnic minority groups, while over-nutrition exists simultaneously. Public health nutrition programs promoting adequate diets and positive lifestyle changes related to nutrition are essential to tackle the double burden of malnutrition among ethnic minority children.

Sugar Content of Market Beverages and Children's Sugar Intake from Beverages in Beijing, China

(1) Background: This study aims to find the sugar content of market beverages and estimate the sugar intake from beverages among students in Beijing. (2) Methods: Using snapshotting, we collected the sugar content of beverages through their packages or nutrition labels. Combined with the statistic of student beverage consumption, we estimated students' sugar intake. (3) Results: The median sugar content of total beverages was 9.0 g/100 mL, among which the fruits/vegetable juices and beverages had the highest sugar content (10.0 g/100 mL). Sugar content in most beverages in Beijing was generally higher than the recommendations, and fruit/vegetable juices and beverages exceeded the most. The median of sugar intake from beverages among students was 5.3 g/d, and the main sources were fruit/vegetable juices and beverages, protein beverages and carbonated beverages. Sugar intake from beverages differed according to gender, age and living area. Higher sugar intake was found among boys, older students and rural students. (4) Conclusions: Sugar content in market beverages in Beijing were high. Gender, age and residence were the influencing factors of sugar intake. Targeted measures should be taken to decrease the sugar content in beverages, especially the fruit/vegetable juices and beverages and the sugar intake among students.

Is High Milk Intake Good for Children's Health? A National Population-Based Observational Cohort Study

Milk is widely considered as a beneficial product for growing children. This study was designed to describe the milk consumption status of Korean children aged 30–36 months and to investigate its association with the risk of obesity and iron deficiency anemia (IDA). This nationwide administrative study used data from the Korean national health insurance system and child health screening examinations for children born in 2008 and 2009. In total, 425,583 children were included, and they were divided into three groups based on daily milk consumption: low milk group (do not drink or drink <200 mL milk per day, n = 139,659), reference group (drink 200–499 mL milk per day, n = 255,670), and high milk group (drink ≥500 mL milk per day, n = 30,254). After adjusting variable confounding factors, the consumption of a large amount of milk of ≥500 mL per day at the age of 30–36 months was associated with an increased risk of obesity at the age of 42–72 months and IDA after the age of 30 months. These results may provide partial evidence for dietary guidelines for milk consumption in children that are conducive to health.

Evolution of Lactase Persistence: Turbo-Charging Adaptation in Growth Under the Selective Pressure of Maternal Mortality?

The emergence of the capacity to digest milk in some populations represents a landmark in human evolution, linking genetic change with a component of niche construction, namely dairying. Alleles promoting continued activity of the enzyme lactase through the life-course (lactase persistence) evolved in several global regions within the last 7,000 years. In some European regions, these alleles underwent rapid selection and must have profoundly affected fertility or mortality. Elsewhere, alleles spread more locally. However, the functional benefits underlying the rapid spread of lactase persistence remain unclear. Here, we set out the hypothesis that lactase persistence promoted skeletal growth, thereby offering a generic rapid solution to childbirth complications arising from exposure to ecological change, or to new environments through migration. Since reduced maternal growth and greater neonatal size both increase the risk of obstructed labour, any ecological exposure impacting these traits may increase maternal mortality risk. Over many generations, maternal skeletal dimensions could adapt to new ecological conditions through genetic change. However, this adaptive strategy would fail if ecological change was rapid, including through migration into new niches. We propose that the combination of consuming milk and lactase persistence could have reduced maternal mortality by promoting growth of the pelvis after weaning, while high calcium intake would reduce risk of pelvic deformities. Our conceptual framework provides locally relevant hypotheses to explain selection for lactase persistence in different global regions. For any given diet and individual genotype, the combination of lactase persistence and milk consumption would divert more energy to skeletal growth, either increasing pelvic dimensions or buffering them from worsening ecological conditions. The emergence of lactase persistence among dairying populations could have helped early European farmers adapt rapidly to northern latitudes, East African pastoralists adapt to sudden climate shifts to drier environments, and Near Eastern populations counteract secular declines in height associated with early agriculture. In each case, we assume that lactase persistence accelerated the timescale over which maternal skeletal dimensions could change, thus promoting both maternal and offspring survival. Where lactase persistence did not emerge, birth weight was constrained at lower levels, and this contributes to contemporary variability in diabetes risk.

Nutritional intake and bone health

Osteoporotic or fragility fractures affect one in two women and one in five men who are older than 50. These events are associated with substantial morbidity, increased mortality, and an impaired quality of life. Recommended general measures for fragility fracture prevention include a balanced diet with an optimal protein and calcium intake and vitamin D sufficiency, together with regular weight-bearing physical exercise. In this narrative Review, we discuss the role of nutrients, foods, and dietary patterns in maintaining bone health. Much of this information comes from observational studies. Bone mineral density, microstructure-estimated bone strength, and trabecular and cortical microstructure are positively associated with total protein intake. Several studies indicate that fracture risk might be lower with a higher dietary protein intake, provided that the calcium supply is sufficient. Dairy products are a valuable source of these two nutrients. Hip fracture risk appears to be lower in consumers of dairy products, particularly fermented dairy products. Consuming less than five servings per day of fruit and vegetables is associated with a higher hip fracture risk. Adherence to a Mediterranean diet or to a prudent diet is associated with a lower fracture risk. These various nutrients and dietary patterns influence gut microbiota composition or function, or both. The conclusions of this Review emphasise the importance of a balanced diet including minerals, protein, and fruit and vegetables for bone health and in the prevention of fragility fractures.

Milk and dairy consumption is positively associated with height in adolescents: results from the Israeli National Youth Health and Nutrition Survey

PURPOSE

Milk consumption is associated with increased height primarily in early childhood. However, in adolescents, data are scarce with inconsistent results. Since height is a proxy for overall health and well-being, this study evaluated the association of dairy intake with height in adolescents.

METHODS

Students in 7th-12th grades, participating in the 2015-2016 Israeli Health and Nutrition Youth Survey, a school-based cross-sectional study, completed self-administered questionnaires, including a semi-quantitative food frequency questionnaire (n = 3529, 48% males, 15.2 ± 1.6 years). Anthropometric measurements were also performed. Dairy servings were calculated as the calcium equivalent of 1 cup of milk, and consumption was divided into four categories from very low (< 1 serving/day) to high (3 + servings/day). BMI- and Height-for-age z scores (HAZs) were calculated according to WHO growth standard; relatively short stature (RSS) was defined as HAZ < - 0.7 SD (< 25th percentile). Multivariable linear and logistic regression analyses were performed to evaluate the association of dairy intake with HAZ and prevalence of RSS, respectively.

RESULTS

Median consumption of dairy products was 2 servings/day, 1.4 from unsweetened products (milk, cheese and yogurt). Controlling for age, sex, BMI-z-score and socioeconomic status, each increment of unsweetened dairy intake was associated with on average 0.04 higher HAZ (equivalent to 0.3-0.4 cm, p < 0.05), and with reduced risk for RSS: OR 0.90, 95%CI: 0.84, 0.97, p < 0.01. No such associations were found with sweetened dairy products.

CONCLUSION

Consumption of unsweetened dairy products (3-4 servings/day) appears to contribute to achieving growth potential in adolescents. Intervention studies are necessary to determine the causal relationship between dairy intake and linear growth.

Longitudinal Associations between Intake of Fruit and Vegetables and Height Attainment from Preschool to School Entry

To examine associations between fruit and vegetable intake in young childhood and height attainment during preschool and at school entry. Data for this study was based on "The Healthy Start" primary intervention study, which included 635 obesity-prone children, (58% boys), from the greater Copenhagen area, with a mean (SD) age of 4.0 (1.1) years (age range 2-6 years) at baseline. In the current study, 553 children (57% boys) were included with information on dietary intake at baseline and height measured at baseline (preschool age), and 511 children (56.8% boys) with the height measured at school entry (~6 years old). Height was measured by trained health professionals during the intervention and by school nurses at school entry. Information on intakes of fruit and vegetables, separately and combined, was gathered with four-day dietary records reported by parents. Participants were grouped into tertiles for their intakes at baseline. Compared to boys with low consumption, those with a moderate and high intakes of fruit and vegetables (F&V) had a greater attained height at preschool of 1.3 cm (95% confidence interval (CI): 0.3; 2.3) and at school entry of 2.4 cm (95% CI: 0.8; 3.9) and 1.8 cm (95% CI: 0.2; 3.4), respectively, also after adjustment for differences in age, body mass index (BMI), and total energy intake. Additional adjustment for mid-parental height and parents' education did not alter the significant associations between moderate consumption of F&V and attained height at preschool and school entry. There was no association among girls. Our results showed that a moderate consumption of F&V was directly associated with higher attainment in height at preschool and school entry in boys. From a public health perspective, it should be prioritized to continue developing intervention programs to improve fruit and vegetable intake.

Improvement in appetite among stunted children receiving nutritional intervention in Bangladesh: results from a community-based study

Background/objectives

Stunted children often have poor appetite, which may limit their response to nutritional interventions. We investigated the effect of a nutritional intervention on the appetite status of stunted children.

Methods

A longitudinal prospective intervention study was conducted with 50 stunted (length for age; LAZ < −2) (age and sex matched) aged 12–18 months and their mothers in Bauniabadh slum of Dhaka city. The stunted children received the following intervention package: one boiled egg and 150 ml milk daily 6 days a week for 3 months; psychosocial stimulation including structured play activities and parental counseling for 6 months; routine clinical care. Appetite status was measured using an interview-based tool “Early Childhood Appetite and Satiety Tool.”

Results

Over the period of nutritional intervention, the mean appetite score increased from 49 to 60 in the stunted children and was associated with increased food consumption. Over the intervention period, both egg and milk consumption increased (40.3–49.6 g and 83.8–138.5 ml, respectively).

Conclusions

Assessment of appetite status using EACST appears to be a useful tool for monitoring a nutritional intervention in stunted children. This tool may be useful for programs in managing child stunting in low-income countries and an important way to assess the efficacy of a nutritional intervention in these children.

Milk and Dairy Products: Good or Bad for Human Bone? Practical Dietary Recommendations for the Prevention and Management of Osteoporosis

Osteoporosis affects women twice as often as men. Additionally, it is estimated that 0.3 million and 1.7 million people have hip fractures in the USA and Europe, respectively. Having a proper peak bone mass and keeping it as long as possible is especially important for osteoporosis prevention. One of the most important calcium sources is milk and dairy products. Breast milk is the best infant food, but milk should not be avoided later in life to prevent losing bone mass. On the other hand, more and more people limit their milk consumption and consume other dairy or non-dairy products. For example, they are usually replaced with plant beverages, which should be consumed carefully in several age groups. Additionally, an important element of milk and dairy products, as well as plant beverages, are probiotics and prebiotics, which may modulate bone turnover. Dietary recommendations focused on milk, and dairy products are an important element for the prevention of osteoporosis.

Lifetime Impact of Cow's Milk on Overactivation of mTORC1: From Fetal to Childhood Overgrowth, Acne, Diabetes, Cancers, and Neurodegeneration

The consumption of cow's milk is a part of the basic nutritional habits of Western industrialized countries. Recent epidemiological studies associate the intake of cow's milk with an increased risk of diseases, which are associated with overactivated mechanistic target of rapamycin complex 1 (mTORC1) signaling. This review presents current epidemiological and translational evidence linking milk consumption to the regulation of mTORC1, the master-switch for eukaryotic cell growth. Epidemiological studies confirm a correlation between cow's milk consumption and birthweight, body mass index, onset of menarche, linear growth during childhood, acne vulgaris, type 2 diabetes mellitus, prostate cancer, breast cancer, hepatocellular carcinoma, diffuse large B-cell lymphoma, neurodegenerative diseases, and all-cause mortality. Thus, long-term persistent consumption of cow's milk increases the risk of mTORC1-driven diseases of civilization. Milk is a highly conserved, lactation genome-controlled signaling system that functions as a maternal-neonatal relay for optimized species-specific activation of mTORC1, the nexus for regulation of eukaryotic cell growth, and control of autophagy. A deeper understanding of milk´s impact on mTORC1 signaling is of critical importance for the prevention of common diseases of civilization.

Adolescent dairy product and calcium intake in relation to later prostate cancer risk and mortality in the NIH-AARP Diet and Health Study

PURPOSE

Although a growing body of evidence supports an early-life contribution to prostate cancer (PCa) development, few studies have investigated early-life diet, and only three have examined early-life dairy product intake, a promising candidate risk factor because of its known/suspected influence on insulin-like growth factor levels and height.

METHODS

We used recalled dietary data from 162,816 participants in the NIH-AARP Diet and Health Study to investigate associations for milk, cheese, ice cream, total dairy, and calcium intake at ages 12-13 years with incident total (n = 17,729), advanced (n = 2,348), and fatal PCa (n = 827) over 14 years of follow-up. We calculated relative risks (RRs) and 95% confidence intervals (CIs) by Cox proportional hazards regression.

RESULTS

We observed suggestive positive trends for milk, dairy, and calcium intake with total and/or advanced PCa (p-trends = 0.016-0.148). These trends attenuated after adjustment for additional components of adolescent diet, particularly red meat and vegetables/potatoes. In contrast, suggestive inverse trends were observed for cheese and ice cream intake with total and/or advanced PCa (p-trends = 0.043-0.153), and for milk, dairy, and calcium intake with fatal PCa (p-trend = 0.045-0.117).

CONCLUSION

Although these findings provide some support for a role of adolescent diet in increasing PCa risk, particularly for correlates of milk intake or overall dietary patterns, our protective findings for cheese and ice cream intake with PCa risk and mortality, and for all dairy products with PCa mortality, suggest alternative explanations, such as the influence of early-life socioeconomic status, and increased PCa screening, earlier detection, and better PCa care.

Association between milk intake and childhood growth: results from a nationwide cross-sectional survey

PURPOSE

The literature is inconsistent regarding milk intake and physical growth. This study aims to evaluate the association of milk intake with body height and weight in a nationally representative sample of Chinese children.

METHODS

A total of 41,439 children ages 6-17 were recruited from 30 provinces in mainland China in 2013-2016 using a multistage stratified cluster sampling approach. Milk intake information was collected using a questionnaire aided with standard containers. Weight and height were measured using a standard physician beam scale with a height rod. Milk intake was categorized into no-, low-, and high-intake groups based on the intake rate, and weight status into normal, overweight, and obese groups based on the body-mass-index (BMI). Associations between height/weight status and milk intake were evaluated using multivariate weighted linear and logistic regression models.

RESULTS

Chinese children had low milk intake: 1/5 of children did not drink milk, and those drinking milk had a median intake of 100 ml/month. The low- and high-intake groups were 0.83 cm (95% confidence interval: 0.00, 1.68 cm) and 1.26 cm (0.34, 2.19 cm) taller than the no-intake group for girls, respectively, after adjusting for confounding factors. Boys with high milk intake had lower BMI (-0.56, 95% CI: -1.00, -0.12 kg/m²) and risk of obesity (OR = 0.67, 95% CI: 0.46, 0.97) than those without milk intake.

CONCLUSIONS

This study revealed the association of increased milk intake with increased body height and lowered obesity risk among Chinese children. Given the cross-sectional nature of the study and the possibility of residual confounding, further research is warranted to uncover the role of milk intake in promoting children's growth.

Association between milk consumption and child growth for children aged 6-59 months

Apart from high levels of energy, proteins, micro- and macronutrients, milk contains calcium and the insulin-like growth factor-1 that are of major relevance for children’s development and growth. Using Demographic and Health Survey data between 1990 and 2017 with information on milk consumption and anthropometric measurements from all low- and middle-income countries available, we investigate whether milk consumption in childhood is associated with stunting, wasting, and underweight. We specify logistic regression models and adjust for a range of covariates and fixed effects on the primary sampling unit level. We analyze heterogeneity in the association by wealth quintiles and age groups and present country-specific estimates. The final samples for wasting, underweight and stunting include 668.463, 693.376, and 673.177 observations of children aged 6 to 59 months, respectively. Our results suggest that milk consumption is associated with a reduced probability of being underweight of 1.4 percentage points (95% confidence interval −0.02, −0.01) and a reduced probability of being stunted of 1.9 percentage points (95% confidence interval −0.02, −0.01). The association for wasting is not robust. The association is stronger for children from wealthier households, which might indicate that milk consumption is a proxy for better overall nutrition or socio-economic status.

Diet and Lifestyle in Prostate Cancer

A variety of diet and lifestyle factors have been studied with respect to prostate cancer risk in large, prospective cohort studies. In spite of this work, and in contrast to other common cancers, few modifiable risk factors have been firmly established as playing a role in prostate cancer. There are several possible explanations for the lack of well-established risk factors. First, prostate cancer has among the highest heritability of all common cancers; second, early life exposures may play an important role in risk, rather than mid- and later-life exposures assessed in most epidemiological studies. Finally, prostate-specific antigen (PSA) screening plays a critical role in prostate cancer detection and incidence rates, which has important implications for epidemiological studies.Among modifiable risk factors, smoking and obesity are consistently associated with higher risk specifically of advanced prostate cancer. There is also considerable evidence for a positive association between dairy intake and overall prostate cancer risk, and an inverse association between cooked tomato/lycopene intake and risk of advanced disease. Several other dietary factors consistently associated with risk in observational studies, including selenium and vitamin E, have been cast into doubt by results from clinical trials. Results for other well-studied dietary factors, including fat intake, red meat, fish, vitamin D, soy and phytoestrogens are mixed.In practical terms, men concerned with prostate cancer risk should be encouraged to stop smoking, be as physically active as possible, and achieve or maintain a healthy weight. These recommendations also have the advantage of having a positive impact on risk of type 2 diabetes, cardiovascular disease, and other chronic diseases. Reducing dairy intake while increasing consumption of fish and tomato products is also reasonable advice.

Secondary data analysis to answer questions in human biology

Despite a growing number of publicly available datasets, the use of these datasets for secondary analyses in human biology is less common compared with other fields. Secondary analysis of existing data offers an opportunity for human biologists to ask unique questions through an evolutionary and biocultural lens, allowing for an analysis of cultural and structural nuances that affect health. Leveraging publicly available datasets for human biology research is a way for students and established researchers to complement their data collection, use existing data for master's and doctoral theses, pilot test questions, and use existing data to answer interesting new questions or explore questions at the population level. Here we describe where publicly available data are stored, highlighting some data repositories and how to access them. We then discuss how to decide which dataset is right, depending on the research question. Next, we describe steps to construct datasets, analytical considerations and methodological challenges, best practices, and limitations depending on the structure of the study. We close by highlighting a number of publicly available datasets that have been used by human biologists and other datasets that may be of interest to the community, including research that has been conducted on some example datasets.

Household dairy production and child growth: Evidence from Bangladesh

Research from richer countries finds that dairy consumption has strong positive associations with linear growth in children, but surprisingly little evidence exists for developing countries where diets are far less diversified. One exception is a recent economics literature using the notion of incomplete markets to estimate the impacts of cattle ownership on children's milk consumption and growth outcomes in Eastern Africa. In addition to external validity concerns, an obvious internal validity concern is that dairy producers may systematically differ from non-dairy households, particularly in terms of latent wealth or nutritional knowledge. We re-examine these concerns by applying a novel double difference model to data from rural Bangladesh, a country with relatively low levels of milk consumption and high rates of stunting. We exploit the fact that a cow's lactation cycles provide an exogenous source of variation in household milk supply, which allows us to distinguish between a control group of households that do not own cows, a treatment group that own cows that have produced milk, and a placebo group of cow-owning households that have not produced milk in the past 12 months. We find that household dairy production increases height-for-age Z scores by 0.52 standard deviations in the critical 6-23 month growth window, though in the first year of life we find that household dairy supply is associated with a 21.7 point decline in the rate of breastfeeding. The results therefore suggest that increasing access to dairy products can be extremely beneficial to children's nutrition, but may need to be accompanied by efforts to improve nutritional knowledge and appropriate breastfeeding practices.

Childhood diet and growth in boys in relation to timing of puberty and adult height: the Longitudinal Studies of Child Health and Development

PURPOSE

To begin to explore the possible roles of childhood diet and growth in prostate cancer (PCa) development, we investigated these exposures in relation to two known/suspected PCa risk factors, earlier pubertal timing and greater attained height, in the Longitudinal Studies of Child Health and Development.

METHODS

We used biannual/annual height, weight, and dietary history data to investigate childhood diet, body mass index (BMI), birth length, and childhood height in relation to PCa risk factors (age at peak height velocity (APHV), height at age 13, and adult height) for 64 Caucasian American boys.

RESULTS

In adjusted models, childhood fat and animal protein intake was positively associated with height at age 13 and adult height (P < 0.05). A childhood diet high in fat and animal protein and low in vegetable protein was also associated with earlier APHV (P < 0.05), whereas no associations were observed for childhood energy intake or BMI. Birth length and childhood height were positively associated with height at age 13 and adult height, and childhood height was inversely associated with APHV (P < 0.05).

CONCLUSION

Our findings suggest that both childhood diet and growth potential/growth contribute to earlier pubertal timing and taller attained height in males, supporting roles of these factors in PCa development.

Milk Powder Added to a School Meal Increases Cognitive Test Scores in Ghanaian Children

Background

The inclusion of milk in school feeding is accepted as good nutritional practice, but specific benefits remain uncertain.

Objective

The objective was to determine whether consumption of 8.8 g milk protein/d given as milk powder with a multiple micronutrient-enriched porridge resulted in greater increases in linear growth and Cambridge Neuropsychological Test Automated Battery (CANTAB) scores in Ghanaian schoolchildren when compared with 1 of 3 control groups.

Methods

A randomized, double-blind, placebo-controlled clinical trial in healthy children aged 6-9 y was conducted comparing 8.8 g milk protein/d with 4.4 g milk protein/d or 4.4 g milk protein + 4.4 g rice protein/d (isonitrogenous, half of the protein from milk and half from rice) or a non-nitrogenous placebo. Primary outcomes were changes in length after 9 mo and CANTAB scores after 4.5 mo; secondary outcomes were body-composition measures. Supplements were added to porridge each school day and consumed for 9 mo. Anthropometric and body-composition measures and CANTAB tests were completed upon enrollment and after 4.5 and 9 mo. Group results were compared by using ANCOVA for anthropometric measures and the Kruskal-Wallis test for CANTAB scores.

Results

Children receiving 8.8 g milk protein/d showed greater increases on percentage correct in Pattern Recognition Memory (mean ± SD: 5.5% ± 16.8%; P < 0.05) and Intra/Extradimensional Set Shift completed stages compared with all other food groups (0.6 ± 2.3; P < 0.05). No differences were seen in linear growth between the groups. The children receiving either 4.4 or 8.8 g milk protein/d had a higher fat-free body mass index than those who received no milk, with an effect size of 0.34 kg/m2.

Conclusion

Among schoolchildren, the consumption of 8.8 g milk protein/d improved executive cognitive function compared with other supplements and led to the accretion of more lean body mass, but not more linear growth. This trial was registered at www.clinicaltrials.gov">www.clinicaltrials.gov as NCT02757508.

Assessment of Lactose-Free Diet on the Phalangeal Bone Mineral Status in Italian Adolescents Affected by Adult-Type Hypolactasia

Adult-type hypolactasia (ATH) is a clinical syndrome of primary lactase deficiency. A lactose-free diet is advisable to avoid the symptoms linked to the condition, but this potentially creates problems for optimal bone mineralization due to reduced calcium intake. To evaluate the effect of the lactose-free diet on the bone mineral status (BMS), we compared the phalangeal BMS of adolescents with ATH to that of peers on a normal diet. Also, we analyzed the correlations between BMS and dietary behavior, physical exercise, and calcium and vitamin D intake. A total of 102 cases and 102 healthy controls filled out a diet record and underwent phalangeal Quantitative Ultrasound (QUS). No difference in BMS was observed. The time spent on lactose-free diet (4.8 ± 3.1 years) was inversely correlated to the BMS. More than 98% of cases consumed lactose-free milk, but calcium and vitamin D intake were significantly lower. Calcium intake was correlated to physical exercise but not to BMS. Our results suggest that a lactose-free diet does not affect the phalangeal BMS of adolescents with primary lactase deficiency when their diet includes lactose-free cow’s milk. However, there is still a significantly lower calcium intake than in the population reference. The inverse correlation observed between the BMS and the time spent on a lactose-free diet suggests that a long-term follow-up is advisable.

Effects of Fermented Milk Products on Bone

Fermented milk products like yogurt or soft cheese provide calcium, phosphorus, and protein. All these nutrients influence bone growth and bone loss. In addition, fermented milk products may contain prebiotics like inulin which may be added to yogurt, and provide probiotics which are capable of modifying intestinal calcium absorption and/or bone metabolism. On the other hand, yogurt consumption may ensure a more regular ingestion of milk products and higher compliance, because of various flavors and sweetness. Bone mass accrual, bone homeostasis, and attenuation of sex hormone deficiency-induced bone loss seem to benefit from calcium, protein, pre-, or probiotics ingestion, which may modify gut microbiota composition and metabolism. Fermented milk products might also represent a marker of lifestyle promoting healthy bone health.

Association between noncow milk beverage consumption and childhood height

Background: Cow milk consumption in childhood has been associated with increased height, which is an important measure of children's growth and development. Many parents are choosing noncow milk beverages such as soy and almond milk because of perceived health benefits. However, noncow milk contains less protein and fat than cow milk and may not have the same effect on height.Objective: We sought to determine whether there is an association between noncow milk consumption and lower height in childhood and assess whether cow milk consumption mediates the relation between noncow milk consumption and height.Design: This was a cross-sectional study of 5034 healthy Canadian children aged 24-72 mo enrolled in the Applied Research Group for Kids cohort. The primary exposure was the volume of noncow milk consumption (number of 250-mL cups per day). The primary outcome was height, which was measured as height-for-age z score. Multivariable linear regression was used to determine the association between noncow milk consumption and height. A mediation analysis was conducted to explore whether cow milk consumption mediated the association between noncow milk consumption and height.Results: There was a dose-dependent association between higher noncow milk consumption and lower height (P < 0.0001). For each daily cup of noncow milk consumed, children were 0.4 cm (95% CI: 0.2, 0.8 cm) shorter. In the mediation analysis, lower cow milk consumption only partially mediated the association between noncow milk consumption and lower height. The height difference for a child aged 3 y consuming 3 cups noncow milk/d relative to 3 cups cow milk/d was 1.5 cm (95% CI: 0.8, 2.0 cm).Conclusions: Noncow milk consumption was associated with lower childhood height. Future research is needed to understand the causal relations between noncow milk consumption and height.

Nutrition, infection and stunting: the roles of deficiencies of individual nutrients and foods, and of inflammation, as determinants of reduced linear growth of children

The regulation of linear growth by nutritional and inflammatory influences is examined in terms of growth-plate endochondral ossification, in order to better understand stunted growth in children. Linear growth is controlled by complex genetic, physiological, and nutrient-sensitive endocrine/paracrine/autocrine mediated molecular signalling mechanisms, possibly including sleep adequacy through its influence on growth hormone secretion. Inflammation, which accompanies most infections and environmental enteric dysfunction, inhibits endochondral ossification through the action of mediators including proinflammatory cytokines, the activin A-follistatin system, glucocorticoids and fibroblast growth factor 21 (FGF21). In animal models linear growth is particularly sensitive to dietary protein as well as Zn intake, which act through insulin, insulin-like growth factor-1 (IGF-1) and its binding proteins, triiodothyronine, amino acids and Zn2+ to stimulate growth-plate protein and proteoglycan synthesis and cell cycle progression, actions which are blocked by corticosteroids and inflammatory cytokines. Observational human studies indicate stunting to be associated with nutritionally poor, mainly plant-based diets. Intervention studies provide some support for deficiencies of energy, protein, Zn and iodine and for multiple micronutrient deficiencies, at least during pregnancy. Of the animal-source foods, only milk has been specifically and repeatedly shown to exert an important influence on linear growth in both undernourished and well-nourished children. However, inflammation, caused by infections, environmental enteric dysfunction, which may be widespread in the absence of clean water, adequate sanitation and hygiene (WASH), and endogenous inflammation associated with excess adiposity, in each case contributes to stunting, and may explain why nutritional interventions are often unsuccessful. Current interventions to reduce stunting are targeting WASH as well as nutrition.

Associations between Consumption of Dairy Foods and Anthropometric Indicators of Health in Adolescents

Childhood obesity is associated with a greater chance of a lifetime of obesity. Evidence suggests dairy at recommended levels could be beneficial in maintaining normal weight and body composition. We assessed whether dairy consumption is associated with anthropometric indicators of health (z-scores for weight-for-age (WAZ); height-for-age (HAZ) and body mass index (BMIZ); waist-to-height ratio (WHtR); fat-free mass (FFM); and fat mass (FM)) in adolescents. In a cross-sectional study, 536 males and females ages 12–18 completed a 151-item semi-quantitative web-based food frequency questionnaire that included 34 dairy-containing foods. Dairy foods were categorized into milk, cheese, sweetened dairy, and total dairy. Anthropometrics were measured during school visits. Total dairy intake was associated with WAZ (β = 0.25 (95% CI: 0.01, 0.49), p = 0.045) and HAZ (β = 0.28 (95% CI: 0.04, 0.52), p = 0.021). In boys, total dairy was associated with WHtR (β = 0.02 (95% CI: 0.00, 0.04), p = 0.039), FFM (β = 4.83 (95% CI: 1.79, 7.87), p = 0.002), and FM (β = 3.89 (95% CI: 0.58, 7.21), p = 0.021), and cheese was associated with FFM (β = 4.22 (95% CI: 0.98, 7.47), p = 0.011). Dairy consumption seems to influence growth in both genders, and body composition and central obesity in boys. Prospective studies are needed to identify how types of dairy relate to growth, body composition, and central obesity of adolescents.

Adult height, nutrition, and population health

In this review, the potential causes and consequences of adult height, a measure of cumulative net nutrition, in modern populations are summarized. The mechanisms linking adult height and health are examined, with a focus on the role of potential confounders. Evidence across studies indicates that short adult height (reflecting growth retardation) in low- and middle-income countries is driven by environmental conditions, especially net nutrition during early years. Some of the associations of height with health and social outcomes potentially reflect the association between these environmental factors and such outcomes. These conditions are manifested in the substantial differences in adult height that exist between and within countries and over time. This review suggests that adult height is a useful marker of variation in cumulative net nutrition, biological deprivation, and standard of living between and within populations and should be routinely measured. Linkages between adult height and health, within and across generations, suggest that adult height may be a potential tool for monitoring health conditions and that programs focused on offspring outcomes may consider maternal height as a potentially important influence.

Effect of complementary feeding with lipid-based nutrient supplements and corn-soy blend on the incidence of stunting and linear growth among 6- to 18-month-old infants and children in rural Malawi

Low nutritional value of complementary foods is associated with high incidence of childhood growth stunting in low-income countries. This study was done to test a hypothesis that dietary complementation with lipid-based nutrient supplements (LNS) promotes linear growth and reduces the incidence of severe stunting among at-risk infants. A total of 840 6-month-old healthy infants in rural Malawi were enrolled to a randomised assessor-blinded trial. The participants received 12-month supplementation with nothing, milk-LNS, soy-LNS, or corn-soy blend (CSB). Supplements provided micronutrients and approximately 280 kcal energy per day. Outcomes were incidence of severe and very severe stunting [length-for-age z-score, (LAZ) < -3.00 and <-3.50, respectively], and change in LAZ. The incidence of severe stunting was 11.8%, 8.2%, 9.1% and 15.5% (P = 0.098) and that of very severe stunting 7.4%, 2.9%, 8.0% and 6.4% (P = 0.138) in control, milk-LNS, soy-LNS and CSB groups, respectively. Between 9 and 12 months of age, the mean change in LAZ was -0.15, -0.02, -0.12 and -0.18 (P = 0.045) for control, milk-LNS, soy-LNS and CSB groups, respectively. There was no significant between-group difference in linear growth during other age-intervals. Although participants who received milk-LNS had the lowest incidence of severe and very severe stunting, the differences between the groups were smaller than expected. Thus, the results do not provide conclusive evidence on a causal association between the LNS supplementation and the lower incidence of stunting. Exploratory analyses suggest that provision of milk-LNS, but not soy-LNS promotes linear growth among at-risk infants mainly between 9 and 12 months of age.

Biological Conditions and Economic Development: Nineteenth-Century Stature on the U.S. Great Plains

Average stature is now a well-accepted measure of material and economic well-being in development studies when traditional measures are sparse or unreliable, but little work has been done on the biological conditions for individuals on the nineteenth-century U.S. Great Plains. Records of 14,427 inmates from the Nebraska state prison are used to examine the relationship between stature and economic conditions. Statures of both black and white prisoners in Nebraska increased through time, indicating that biological conditions improved as Nebraska's output market and agricultural sectors developed. The effect of rural environments on stature is illustrated by the fact that farm laborers were taller than common laborers. Urbanization and industrialization had significant impacts on stature, and proximity to trade routes and waterways was inversely related to stature.

Milk intake, height and body mass index in preschool children

OBJECTIVES

To evaluate links between the volume of milk consumed and weight and height status in children aged 4 and 5 years.

DESIGN

We analysed data from 8950 children followed up as part of the Early Childhood Longitudinal Survey, Birth cohort, a nationally representative cohort of children. We used linear and logistic regression to assess associations of daily servings of milk intake at age 4 years with z-scores of body mass index (BMI), height and weight-for-height at 4 and 5 years, adjusted for sex, race/ethnicity, socioeconomic status and type of milk consumed.

RESULTS

Among children who drank milk at age 4 years, higher milk consumption was associated with higher z-scores of BMI, height and weight-for-height at 4 years (all p<0.05). This corresponded to differences between children drinking <1 and ≥4 milk servings daily of approximately 1 cm in height and 0.15 kg in weight. By age 5 years, only the association with height remained significant (p<0.001). At 4 years, children drinking ≥3 servings of milk daily were more likely to be overweight/obese (BMI≥85th percentile) than those drinking 0.5-2 servings of milk daily (adjusted OR 1.16 (95% CI 1.02 to 1.32) p=0.02).

CONCLUSIONS

In a cohort of children at age 4 years, the volume of milk consumed was associated with higher weight status and taller stature, while at 5 years, higher milk consumption continued to be associated with taller stature. Given higher odds of overweight/obesity with milk consumption ≥3 servings daily, this study supports current American Academy of Pediatrics recommendations that pre-school children consume two milk servings daily.

Nutritional aspects of bone health

Bone mass, geometry and microstructure, and bony tissue material level properties determine bone strength, hence the resistance to fracture. At a given age, all these variables are the consequence of the amount accumulated and of the structure developed during growth, up to the so-called peak bone mass, and of the bone loss and microstructure degradation occurring later in life. Genetic factors primarily contribute to the variance of the determinants of bone strength. Nutritional intakes are environmental factors that influence both processes, either directly by modifying modelling and remodelling, or indirectly through changes in calcitropic hormone secretion and action. Some effects of nutrition on the offspring bone could take place during foetal life. There are interplays between genetic factors, nutritional intakes and physical exercise. Among the nutrients, sufficient dietary intakes of calcium and protein are necessary for bone health in childhood and adolescence as well as later in life.

Translating human biology (introduction to special issue)

OBJECTIVES

Introducing a special issue on "Translating Human Biology," we pose two basic questions: Is human biology addressing the most critical challenges facing our species? How can the processes of translating our science be improved and innovated?

METHODS

We analyze articles published in American Journal of Human Biology from 2004-2013, and find there is very little human biological consideration of issues related to most of the core human challenges such as water, energy, environmental degradation, or conflict. There is some focus on disease, and considerable focus on food/nutrition. We then introduce this special volume with reference to the following articles that provide exemplars for the process of how translation and concern for broader context and impacts can be integrated into research.

CONCLUSIONS

Human biology has significant unmet potential to engage more fully in translation for the public good, through consideration of the topics we focus on, the processes of doing our science, and the way we present our domain expertise.

Effect of milk proteins on linear growth and IGF variables in overweight adolescents

OBJECTIVE

Milk may stimulate growth acting via insulin-like growth factor-I (IGF-I) secretion but the effect in adolescents is less examined. This study investigates the effect of milk proteins on linear growth, IGF-I, IGF binding protein-3 (IGFBP-3) and IGF-I/IGFBP-3 ratio in overweight adolescents.

DESIGN

The trial included 193 overweight adolescents aged 12-15 years. They were randomized to drink 1L/day of: skimmed milk, whey, casein or water for 12 weeks; all milk-based drinks contained 35 g protein/L. A subgroup of 32 adolescents was examined 12 weeks before they were randomized into the groups and started the intervention (pre-test control group). Examinations included anthropometry, diet registration and blood samples which were analyzed for IGF-I and IGFBP-3 by chemiluminescence methods. The effects of milk-based drinks on linear growth, IGF-I, IGFBP-3 and IGF-I availability, calculated as the IGF-I/IGFBP-3 ratio, were compared with baseline, the pre-test control group and water.

RESULTS

IGF-I increased with skimmed milk (P=0.015) and tended to increase with casein (P=0.075) compared to the pre-test control group. IGFBP-3 but not IGF-I increased with skimmed milk (P=0.006) and casein (P=0.001) compared to water. There was no difference in height or height Z-score for any of the milk-based test drink groups compared to water or compared to the pre-test control group. However, height Z-score decreased within the whey group.

CONCLUSIONS

Skimmed milk and casein may have a stimulating effect on the IGF-I system whereas there was no positive effect on height in overweight adolescents during this 12 week intervention.

Milk consumption during teenage years and risk of hip fractures in older adults

IMPORTANCE

Milk consumption during adolescence is recommended to promote peak bone mass and thereby reduce fracture risk in later life. However, its role in hip fracture prevention is not established and high consumption may adversely influence risk by increasing height.

OBJECTIVES

To determine whether milk consumption during teenage years influences risk of hip fracture in older adults and to investigate the role of attained height in this association.

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort study over 22 years of follow-up in more than 96,000 white postmenopausal women from the Nurses' Health Study and men aged 50 years and older from the Health Professionals Follow-up Study in the United States.

EXPOSURES

Frequency of consumption of milk and other foods during ages 13 to 18 years and attained height were reported at baseline. Current diet, weight, smoking, physical activity, medication use, and other risk factors for hip fractures were reported on biennial questionnaires.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards models were used to calculate relative risks (RRs) of first incidence of hip fracture from low-trauma events per glass (8 fl oz or 240 mL) of milk consumed per day during teenage years.

RESULTS

During follow-up, 1226 hip fractures were identified in women and 490 in men. After controlling for known risk factors and current milk consumption, each additional glass of milk per day during teenage years was associated with a significant 9% higher risk of hip fracture in men (RR = 1.09; 95% CI, 1.01-1.17). The association was attenuated when height was added to the model (RR = 1.06; 95% CI, 0.98-1.14). Teenage milk consumption was not associated with hip fractures in women (RR = 1.00 per glass per day; 95% CI, 0.95-1.05).

CONCLUSIONS AND RELEVANCE

Greater milk consumption during teenage years was not associated with a lower risk of hip fracture in older adults. The positive association observed in men was partially mediated through attained height.

Lactose intolerance: lack of evidence for short stature or vitamin D deficiency in prepubertal children

BACKGROUND

The health consequences of lactose intolerance (LI) are unclear.

AIMS

To investigate the effects of LI on stature and vitamin D status.

HYPOTHESES

LI subjects will have similar heights and vitamin D status as controls.

SUBJECTS AND METHODS

Prepubertal children of ages 3-12 years with LI (n=38, age 8.61 ± 3.08y, male/female 19/19) were compared to healthy, age- and gender-matched controls (n=49, age 7.95±2.64, male/female 28/21).

INCLUSION CRITERIA

prepubertal status (boys: testicular volume <3cc; girls: Tanner 1 breasts), diagnosis of LI by hydrogen breath test, and no history of calcium or vitamin D supplementation. Vitamin D deficiency was defined as 25-hydroxyvitamin D [25(OH)D] <50 nmol/L. Gender-adjusted midparental target height (MPTH) z-score was calculated using NCHS data for 18 year-old adults. Data were expressed as mean ± SD.

RESULTS

There was no significant difference in 25(OH)D between the LI and non-LI subjects (60.1±21.1, vs. 65.4 ± 26.1 nmol/L, p = 0.29). Upon stratification into normal weight (BMI <85(th) percentile) vs. overweight/obese (BMI ≥85(th) percentile), the normal weight controls had significantly higher 25(OH)D level than both the normal weight LI children (78.3 ± 32.6 vs. 62.9 ± 23.2, p = 0.025), and the overweight/obese LI children (78.3±32.6 vs. 55.3±16.5, p = 0.004). Secondly, there was no overall difference in height z-score between the LI children and controls. The normal weight LI patients had similar height as normal controls (-0.46 ± 0.89 vs. -0.71 ± 1.67, p = 0.53), while the overweight/obese LI group was taller than the normal weight controls (0.36 ± 1.41 vs. -0.71 ± 1.67, p = 0.049), and of similar height as the overweight/obese controls (0.36 ± 1.41 vs. 0.87 ± 1.45, p = 0.28). MPTH z-score was similar between the groups.

CONCLUSION

Short stature and vitamin D deficiency are not features of LI in prepubertal children.