Alan S. Ryan

Lower Breastfeeding Rates Persist Among the Special Supplemental Nutrition Program for Women, Infants, and Children Participants, 1978–2003

OBJECTIVE. 2005-1555 2006 by the American Academy of PediatricsWe set out to compare rates of breastfeeding between women who participated in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) with those of non-WIC mothers from 1978 to 2003. METHODS. The Ross Laboratories Mothers Survey is a national survey designed to determine patterns of milk feeding during infancy. Mothers were asked to recall the type of milk fed to their infant in the hospital and during each month of age. Rates of breastfeeding in the hospital and at 6 months of age were evaluated. Logistic regression analyses identified significant predictors of breastfeeding in 2003. RESULTS. From 1978 through 2003, rates for the initiation of breastfeeding among WIC participants lagged behind those of non-WIC mothers by an average of 23.6 ± 4.4 percentage points. At 6 months of age, the gap between WIC participants and non-WIC mothers (mean: 16.3 ± 3.1 percentage points) steadily increased from 1978 through 2003 and exceeded 20% by 1999. Demographic factors that were significant and positive predictors of breastfeeding initiation in 2003 included some college education, living in the western region of the United States, not participating in the WIC program, having an infant of normal birth weight, primipary, and not working outside the home. For mothers of infants 6 months of age, WIC status was the strongest determinant of breastfeeding: mothers who were not enrolled in the WIC program were more than twice as likely to breastfeed at 6 months of age than mothers who participated in the WIC program. CONCLUSIONS. Breastfeeding rates among WIC participants have lagged behind those of non-WIC mothers for the last 25 years. The Healthy People 2010 goals for breastfeeding will not be reached without intervention. Food package and programmatic changes are needed to make the incentives for breastfeeding greater for WIC participants.

Sexual dimorphism and human tooth size differences

Abstract Current male/female differences in tooth size are due to the male/female differences in body bulk that exist in any given human population. These differences are residues of the sexual dimorphism that was maintained for adaptive reasons during the Middle Pleistocene. Late in the Pleistocene the development of food processing techniques led to the reduction of both male and female dental dimensions. Dental sexual dimorphism, however, was maintained until the very end of the Pleistocene when the hunting of large game animals by crude techniques was replaced by a focus on great numbers of small game caught by more sophisticated means and by an increasing utilization of plant foods. The subsequent reduction in dimorphism represents the actions of the Probable Mutation Effect operating under conditions of relaxed selection. The conclusion offered is that the smallest degree of sexual dimorphism visible in the modern world is to be found among those populations that are separated by the greatest interval of time from precursors who depended for their survival on a Pleistocene big game hunting mode of subsistence.

Dental and cranial variation in living Indriidae

Four species of Indriidae are extant in Madagascar. We have studied large samples of each of these to characterize dental and cranial variation, and to estimate the degree of sexual dimorphism in the dentition and cranium. Two dental fields are apparent, characterized by reduced variability: (1) a canine field centered on the upper canine and occluding caniniform lower premolar, and (2) a cheek tooth field centered on the second molars. No consistent pattern of sexual dimorphism was found in dental or cranial dimensions, and we conclude that none of the four species is sexually dimorphic. This lack of dental and cranial dimorphism is unusual in primates, and probably reflects the relatively limited aggressive behavior and the lack of male dominance in Indriidae.

Anterior Dental Microwear and Its Relationship to Diet and Feeding Behavior in Three African Primates (Pan troglodytes troglodytes, Gorilla gorilla gorilla and Papio hamadryas)

Anterior dental microwear is shown to be related to diet and to feeding habits in three groups of extant African primates includingPan troglodytes troglodytes, Gorilla gorilla gorilla andPapio hamadryas. Five distinct types of incisal microwear are found in these groups. These include: fine wear striae, polish, small pits, large pits and microflakes. It is demonstrated that each species exhibits a different set of microwear types. Chimpanzees exhibit extensive pitting, mesiodistally oriented fine wear striae and small areas of polish, features of microwear that are probably related to the husking of hard fruit skins and the occasional stripping of leaves. Gorillas show large areas of polish, small pits and labiolingually oriented wear striae, a combination of features that may be associated with the stripping of leaves and pith. Baboons show extensive edge damage involving clusters of large pits and microflakes; this set of microwear types may be related to the initial chewing of gravel-laden seeds, roots and rhizomes. Microwear found on the canine/premolar complex of all three groups corresponds to the puncture-crushing and to the slicing of food.

Iron-deficiency anemia in infant development: Implications for growth, cognitive development, resistance to infection, and iron supplementation

Iron plays an important role in many metabolic processes, including oxygen transport, oxidative metabolism, and cellular growth. During infancy, inadequate supply of iron resulting in iron-deficiency anemia is associated with morbidity, impaired growth, and decreased behavior and psychomotor development. Although iron requirements during infancy have become better defined, iron-deficiency anemia persists as one of the most common health problems worldwide, a condition that affects approximately 20–25% of the worlds infants. Today, much attention is being given to not only preventing iron-deficiency anemia but also to avoiding excessive iron supplementation. There is concern that excessive and widespread iron supplementation could lead to decreased resistance to infection and promotion of gastrointestinal illnesses. However, the literature on the relationship between iron status and chronic infection and disease contains conflicting viewpoints. Some investigators contend that mild iron-deficiency is beneficial for immunity whereas others argue that any deficits in iron status are detrimental. Iron absorption and metabolism are influenced by interactions between iron and other dietary nutrients. Many components of the diet act to inhibit or enhance iron absorption; this information is critical for food fortification programs designed to prevent iron-deficiency anemia worldwide. This paper reviews some of the biological characteristics of iron metabolism and absorption, iron needs during infancy, interactions of iron with other nutrients, methods for hematological assessment, iron-deficiency anemia and growth, the relationship between iron-deficiency anemia and infant psychomotor development, and the impact that iron supplementation has on resistance to infection and gastrointestinal illnesses. The serious consequences of iron-deficiency anemia for infant health, behavior and development, and the widespread prevalence of this disorder are reasons for its prevention. The benefits of oral supplementation of iron appear to outweigh the possibility of iron excess during infancy, a period of rapid growth and development characterized by a marginal dietary supply of iron. Yrbk Phys Anthropol 40:25–62, 1997.

A Preliminary Scanning Electron Microscope Examination of Wear Striation Direction on Primate Teeth

Wear striations experimentally produced on initially unworn teeth were examined at high magnification using a scanning electron microscope. Certain characteristics of individual wear striations on these teeth indicate the direction of motion that produced them. Other striations on worn teeth of American Indians and the Paleocene primate Phenocolemur show similar characteristics and correspond to mandibular movement during mastication.

Regional and Sociodemographic Variation of Breastfeeding in the United States, 2002

With use of data from the Ross Mothers Survey (RMS), rates for breastfeeding in the hospital and at 6 months of age were evaluated within 4 geographical regions of the United States. Odds ratios for determinants of breastfeeding were also calculated. Regardless of sociodemographic characteristics, breastfeeding in the hospital and at 6 months of age was most common in the West and least common in the South. College education and not participating in the Women, Infants, and Children (WIC) program were the strongest predictors of breastfeeding in the hospital. Not working outside the home and not participating in WIC were the strongest predictors of continued breastfeeding to 6 months of age. Region of residence is important in considering how to develop programs targeted to populations with lower breastfeeding rates.

Duration of Breast-feeding Patterns Established in the Hospital Influencing Factors Results from a National Survey

Data from a national survey of new mothers were analyzed to determine the effect that demographic characteristics, breast-feeding instructions, and infant formula discharge kits had on breast-feeding patterns established in the hospital. Results indicated that mothers who exclusively breast-fed their infant were more likely to be affluent, college educated, and not working outside the home. Mothers who exclusively breast-fed their infants in the hospital and subsequently practiced partial breast-feeding or formula, or cows milk feeding were more likely to return to the work force within the first 6 postpartum months. Mothers who partially breast-fed their infants in the hospital were more likely to have a low-birth-weight neonate. Stepwise logistic regression analysis indicated that greater total family income, a better education, and having more than one child had positive significant effects on exclusive breast-feeding by the first and fourth month. Women who received a formula discharge kit compared with those who did not had a slightly higher probability of initiating partial breast-feeding (10 vs. 7% by the first month; 27 vs. 25% by the fourth month). Maternal employment had a large impact on duration of exclusive breast-feeding. By the fourth month, mothers who were employed had a higher probability of initiating partial breast-feeding (43 vs. 19%) compared with mothers who were not in the work force.

Weight, stature, and body mass index data for Mexican Americans from the third national health and nutrition examination survey (NHANES III, 1988–1994)

Selected age‐ and sex‐specific percentiles are presented for 4,054 Mexican American children ages 1–18 years who were included in the third National Health and Nutrition Examination Survey (NHANES III, 1988–1994). These percentile values are compared with corresponding percentiles for Mexican Americans from the Hispanic Health and Nutrition Examination Survey (HHANES, 1982–1984). In each sex, the weight and weight/stature2 percentiles from NHANES III were significantly larger than those from HHANES. For weight, the NHANES III values tended to be clearly larger after 11 years in males and females, and they were larger for weight/stature2 at the 50th and 90th percentiles in each sex after 6 years. For stature, the NHANES III values were significantly larger at the 90th percentile among females, but the differences were not significant for any other percentiles among females or males. In comparison with non‐Hispanic White children, Mexican American children tend to be shorter and heavier, especially after the preschool period. The similarity of the findings for stature from NHANES III and HHANES indicates that the shorter statures of Mexican Americans are not cohort‐specific. The tendency to larger values for weight/stature2 in Mexican Americans has important public heath implications since this ratio tends to track after early childhood, and high ratios in adulthood constitute an important risk factor for common diseases such as diabetes mellitus and coronary heart disease. Am. J. Hum. Biol. 11:673–686, 1999.

Fatness‐dependence and utility of the subscapular/triceps ratio

As shown in 1257 children (aged 6–10 years) and in 4065 adults (aged 20–50 years), the subscapular/triceps ratio is fatness dependent. Over a 20 mm range of the iliac skinfold (20–40 mm) the subscapular/triceps ratio increases by approximately 0.01 per mm of iliac fat in women and in children of both sexes and at a slightly lower rate in males. Over the entire range of iliac fatness (through 65 mm) fatness‐related differences in the subscapular/triceps ratio may be as much as 0.60. Though the subscapular/triceps ratio is also an individual characteristic, the fatness‐dependence of the ratio must be taken into consideration when comparing populations or in following individuals who are not fatness‐stable.