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Biomedical subjects

J A Mennella

Publications and source records attributed to J A Mennella.

At least 19 recordsLinked to original sources
PubMed2001

Flavor variety enhances food acceptance in formula-fed infants.

BACKGROUND: Research in humans and animal models suggests that acceptance of solid foods by infants during weaning is enhanced by early experiences with flavor variety. OBJECTIVE: We tested the hypotheses that the acceptance of novel foods by formula-fed infants could be facilitated by providing the infants with a variety of flavors at the time when beikost is first introduced and that, contrary to medical lore, infants who had previously consumed fruit would be less likely to reject vegetables when first introduced than would infants without such an experience. DESIGN: The infants' acceptance of a novel vegetable (puréed carrot) and a novel meat (puréed chicken) was evaluated after a 9-d exposure period in 3 groups of infants, some of whom had previously consumed fruit. During the home-exposure period, one group was fed only carrots, the target vegetable; a second group was fed only potatoes, a vegetable that differed in flavor from carrots; and a third group was fed a variety of vegetables that did not include carrots. RESULTS: Infants fed either carrots or a variety of vegetables, but not those fed potatoes, ate significantly more of the carrots after the exposure period. Exposure to a variety of vegetables also facilitated the acceptance of the novel food, puréed chicken, and daily experience with fruit enhanced the infants' initial acceptance of carrots. CONCLUSION: These findings are the first experimental evidence to indicate that exposure to a variety of flavors enhances acceptance of novel foods in human infants.

Adult↗
PubMed2001

Prenatal and postnatal flavor learning by human infants.

BACKGROUND: Flavors from the mother's diet during pregnancy are transmitted to amniotic fluid and swallowed by the fetus. Consequently, the types of food eaten by women during pregnancy and, hence, the flavor principles of their culture may be experienced by the infants before their first exposure to solid foods. Some of these same flavors will later be experienced by infants in breast milk, a liquid that, like amniotic fluid, comprises flavors that directly reflect the foods, spices, and beverages eaten by the mother. The present study tested the hypothesis that experience with a flavor in amniotic fluid or breast milk modifies the infants' acceptance and enjoyment of similarly flavored foods at weaning. METHODS: Pregnant women who planned on breastfeeding their infants were randomly assigned to 1 of 3 groups. The women consumed either 300 mL of carrot juice or water for 4 days per week for 3 consecutive weeks during the last trimester of pregnancy and then again during the first 2 months of lactation. The mothers in 1 group drank carrot juice during pregnancy and water during lactation; mothers in a second group drank water during pregnancy and carrot juice during lactation, whereas those in the control group drank water during both pregnancy and lactation. Approximately 4 weeks after the mothers began complementing their infants' diet with cereal and before the infants had ever been fed foods or juices containing the flavor of carrots, the infants were videotaped as they fed, in counterbalanced order, cereal prepared with water during 1 test session and cereal prepared with carrot juice during another. Immediately after each session, the mothers rated their infants' enjoyment of the food on a 9-point scale. RESULTS: The results demonstrated that the infants who had exposure to the flavor of carrots in either amniotic fluid or breast milk behaved differently in response to that flavor in a food base than did nonexposed control infants. Specifically, previously exposed infants exhibited fewer negative facial expressions while feeding the carrot-flavored cereal compared with the plain cereal, whereas control infants whose mothers drank water during pregnancy and lactation exhibited no such difference. Moreover, those infants who were exposed to carrots prenatally were perceived by their mothers as enjoying the carrot-flavored cereal more compared with the plain cereal. Although these same tendencies were observed for the amount of cereal consumed and the length of the feeds, these findings were not statistically significant. CONCLUSIONS: Prenatal and early postnatal exposure to a flavor enhanced the infants' enjoyment of that flavor in solid foods during weaning. These very early flavor experiences may provide the foundation for cultural and ethnic differences in cuisine.

Amniotic Fluid↗
PubMed2001

Regulation of milk intake after exposure to alcohol in mothers' milk.

OBJECTIVE: Contrary to the folklore which claims that drinking alcohol during lactation benefits both mother and infant, previous research in our laboratory revealed that breastfed infants consumed significantly less milk during the immediate hours after their mothers' consumption of an alcoholic beverage. Because breastfed infants are clearly capable of regulating milk intake, the present study tested the hypothesis that infants would compensate for the diminished milk intake if their mothers then refrained from drinking alcohol. METHODS: A within-subjects design that controlled for time of day was implemented because of the great individual and daily variation in both milk composition and intake. To this end, 12 exclusively breastfed infants and their mothers were tested on 2 days separated by 1 week. Each woman drank a 0.3 g/kg dose of alcohol in orange juice on one testing day and orange juice alone on the other; the order was counterbalanced. The infants' behaviors were monitored for the next 16 hr, the first 4 hr of monitoring on each test day occurred at the Monell Center. The infants fed on demand and immediately before and after each feeding, infants were weighed without a change in clothing. RESULTS: Consistent with previous findings, infants consumed significantly less milk during the 4 hr immediately after exposure to alcohol in mothers' milk compared with the control condition. Compensatory increases in intake were then observed during the 8 to 16 hr after exposure when mothers refrained from drinking alcohol. CONCLUSIONS: These findings demonstrate that short-term exposure to small amounts of alcohol in mothers' milk produces distinctive changes in the infants' patterns of feeding.

Adult↗
PubMed2000

Short-term influence of breastfeeding on the infants' interaction with the environment.

The present study tested the hypothesis that around the age of weaning, human infants are more interactive with their environment immediately after breastfeeding. To this aim, we assessed 4- to 6-month-old infants' responsiveness to a rotating, musical mobile before breastfeeding on one test day, and after breastfeeding on another. Thirteen infants, fitted with miniature movement detectors on both their left leg and wrist, were videotaped for 4 consecutive min during which the mobile was alternately switched on and off in 1-min intervals. Although the infants showed no significant differences in limb activity as a function of the timing of a breastfeed, they looked at the mobile significantly longer when tested after breastfeeding. This finding suggests that breastfeeding has a substantial effect on 4- to 6-month-old infants' attentiveness to and interaction with their environment.

Attention↗
PubMed2000

Children's hedonic response to the smell of alcohol: effects of parental drinking habits.

BACKGROUND: Previous research in our laboratory revealed that during the first year of life, infants who had more exposure to alcohol, as inferred from questionnaires about parental alcoholism and alcohol intake, mouthed an ethanol-scented toy more compared with less exposed infants. The present study focused on older children (3.8-6.0 years) to determine whether their hedonic response to the odor of alcohol was related to the drinking habits of their parents. METHODS: Age-appropriate, game-like tasks that were fun for children and minimized the impact of language development were used to examine their preferences and identification of a variety of odors, one of which was beer. RESULTS: The children's preference for the odor of beer varied as a function of the escape drinking of their mothers alone or both parents. That is, children who lived in a household in which one or both parents drank alcohol to escape were significantly more likely to dislike the odor bottle that contained alcohol when compared with children whose parents did not drink to escape. This difference between the groups was odor specific. Additional analyses also revealed that the fathers of children who rejected the beer odor reported drinking significantly more than the fathers of those who liked the odor. CONCLUSIONS: These findings suggest that some early learning about alcohol is based on sensory experiences and anchor it to children's experiences at home and the emotional context in which their parents experience alcohol.

Alcohol Drinking↗
PubMed1999

Experience with a flavor in mother's milk modifies the infant's acceptance of flavored cereal.

The present series of studies aimed to investigate whether experience with a flavor in mothers' milk modifies the infants' acceptance of similarly flavored foods at weaning. First, we established, using methods developed in our laboratory, that the ingestion of carrot juice by lactating women produced a sensory change in their milk approximately 2 to 3 hr after the ingestion of the beverage. Second, we randomly formed two groups of breast-fed infants who had been fed cereal for a few weeks but had only experienced cereal prepared with water. Their mothers were asked to consume one of two types of beverages (i.e., carrot juice, water) during the exposure period. Each mother was observed feeding her infant cereal during four test sessions. The first two sessions occurred during the 2 days before the exposure period; in counterbalanced order, infants were fed cereal prepared with water on 1 testing day and cereal prepared with carrot juice on the other. These two test sessions were then repeated following the exposure period. The results demonstrated that the infants who had exposure to the flavor of carrots in their mothers' milk during the exposure period consumed less of the carrot-flavored cereal and spent less time feeding when compared to the control infants whose mothers consumed the water. This may be a form of sensory-specific satiety such that the infants become less responsive to a flavor that they have been extensively exposed to in the very recent past.

Adult↗
PubMed1998

Infants' exploration of scented toys: effects of prior experiences.

To evaluate breastfed infants' responses to scented objects, we videotaped the facial and bodily reactions of sixty-three infants as they explored, in succession, three toys that were identical in appearance but different in their characteristic odor. Two of the toys were scented with odorants previously shown to be transmitted to human milk, one with ethanol and the other with vanilla, whereas the third toy was unscented. Each videotape was subjected to frame-by-frame analysis to measure a variety of behaviors that are considered either to be exploratory in nature in that they lead to perceptual information about the object or to reflect the infants' hedonic reaction. Analyses of these behaviors revealed that the infants looked more and vocalized less in the presence of the vanilla-scented toy and spent less time manipulating the ethanol-scented toy when compared with the unscented toy. Moreover, differential exposure to the odors of ethanol and vanilla, as indicated by differential consumption of alcohol by a parent or use of vanilla-scented product by the mother, was related to differential responses to these odors. These findings suggest that human infants are able to detect and retain information about the chemical features of their environment.

Ethanol↗
PubMed1998

Short-term effects of maternal alcohol consumption on lactational performance.

Previous research demonstrated that breast-feeding infants consumed significantly less milk during the immediate hours after their mothers consumed an acute dose of alcohol when compared with a nonalcoholic beverage. The present study tested the hypothesis that maternal alcohol consumption decreases the amount of milk available to the infant and alters milk composition in the short term. To this aim, 22 lactating women were tested on 2 days separated by 1 week; the women reported that they drank very little during pregnancy, but significantly increased alcohol intake during lactation. Each woman drank a 0.3 g/kg dose of alcohol in orange juice on one testing day and orange juice alone on the other; the order was counterbalanced. Immediately before drinking the beverage (baseline) and 2 hr after (postconsumption), women expressed their milk by using an electric breast pump until no milk had been secreted from either breast for 5 min. Although there was no difference in the energy content of the milk, maternal alcohol consumption slightly, but significantly, reduced the amount of milk produced by the lactating mother. These findings underscore the importance of determining whether and when infants compensate for the reductions in intake experienced at the breast following maternal alcohol consumption and how such changes impact on mother-infant interaction.

Adult↗
PubMed1998

Early flavor experiences: research update.

Anyone who has observed infants for any period of time can testify to the intense activity occurring in and around their mouths--the primary site for learning in the first few months of life. Before they are even able to crawl, infants have learned much about their new sensory world. Though recent research we have begun to explore the impact of these early experiences on infants' acceptance of solid foods and how they explore objects in their environment. We have also begun to focus on the sensory experiences of the formula-fed infant, in particular, how their responses to particular formulas, which are extremely unpalatable to older children and adults, change during infancy. This is a relatively new and exciting area of study, with much research yet to be done. It is clear, however, that infants are not passive receptacles for flavored foods. Parents who offer a variety of foods will provide both a nutritious, well-balanced diet, as well as an opportunity for their children's own personal preferences to develop.

Alcohol Drinking↗
PubMed1998

Effects of exposure to alcohol in mother's milk on infant sleep.

OBJECTIVE: To test the hypothesis that exposure to alcohol in breast milk affects infants' sleep and activity levels in the short term. METHODS: Thirteen lactating women and their infants were tested on 2 days, separated by an interval of 1 week. On each testing day, the mother expressed 100 mL of milk, while a small, computerized movement detector called an actigraph was placed on the infant's left leg to monitor sleep and activity patterning. After the actigraph had been in place for approximately 15 minutes, the infants ingested their mother's breast milk flavored with alcohol (32 mg) on one testing day and breast milk alone on the other. The infants' behaviors were monitored for the next 3.5 hours. RESULTS: The infants spent significantly less time sleeping during the 3.5 hours after consuming the alcohol-flavored milk (78.2 minutes compared with 56.8 minutes after feeding alcohol in breast milk). This reduction was apparently attributable to a shortening in the longest sleeping bout (34.5 compared with 56.7 minutes for sleeping after breast milk alone) and the amount of time spent in active sleep (25.8 minutes compared with 44.2 minutes after breast milk alone); the decrease in active sleep was observed in all but 2 of the 13 infants tested. CONCLUSIONS: Although the mechanisms underlying the reduction in sleep remain to be elucidated, this study shows that short-term exposure to small amounts of alcohol in breast milk produces distinctive changes in the infant's sleep-wake patterning.

Adult↗
PubMed1997

Mothers' milk enhances the acceptance of cereal during weaning.

Although baby food manufacturers and child care manuals often advise parents to prepare their infant's cereal with water or either mother's milk or formula, depending on the feeding regimen of the infant, little is known about the infant's acceptance of differently flavored cereals. The present study demonstrates that breast-fed infants, who had been fed cereal for approximately 2 wk but had experienced cereal prepared only with water, consumed more of the cereal-mother's milk mixture compared with cereal water mixture and displayed a series of behaviors signaling their preferences for the former. Moreover, the infants' willingness to accept the flavored cereal is correlated with their mothers' reported willingness to try novel foods and flavors.

Adult↗
PubMed1997

Infants' suckling responses to the flavor of alcohol in mothers' milk.

Contrary to medical folklore, previous research has demonstrated that alcohol consumption by lactating women diminished milk intake by their infants during breast feeding. To determine whether this decrease in milk consumption was due to the infants responding to the altered flavor of the milk that also resulted, we evaluated the infants' intake and sucking responses to alcohol-flavored human milk outside of the context of breast feeding, thereby separating the changes due to the infants response to the flavor from any other changes that could also result from acute maternal alcohol consumption such as alterations in milk ejection or the composition of milk. The testing procedure consisted of a two-bottle preference test that was composed of four, 60-sec trials in which the mother's milk flavored with alcohol was alternated with the mother's milk alone in an ABBA or BAAB design. Attached to the nipple of each bottle was a transducer that responded to pressure changes produced by the infants' suckling. There was no suppression of sucking or intake in response to the ethanol-flavored milk. Rather, the infants consumed significantly more and sucked more frequently when drinking the alcohol-flavored milk compared with the unaltered milk. That experience with the flavor of alcohol in mothers' milk modified the infants' responses to alcohol flavor is suggested by the relationship between the reported frequency of mothers' drinking during lactation and the infants' rhythm and frequency of sucking when feeding the alcohol-flavored milk. These findings indicate that infants can readily detect the flavor of alcohol in mother's milk but that the decrease in consumption at the breast after maternal alcohol consumption is apparently not due to the infants rejecting the flavor of alcohol in their mothers' milk.

Adult↗
PubMed1996

Developmental changes in the acceptance of protein hydrolysate formula.

To investigate the age-related changes in the acceptance of a protein hydrolysate formula, Nutramigen, and to determine whether infants' response to a novel formula is related to their mothers' willingness to try novel foods, healthy infants, who were either 1 to 2 (Group 1) or 7 to 8 (Group 1 retested and Group 2) months of age, were fed their familiar brand of milk- or soy-based formula on one testing day and a casein hydrolysate formula, Nutramigen, on another. The data revealed that infants younger than 2 months detected the difference between Nutramigen and their regular formulas as evidenced by a slight, relative depression in intakes (p = .04). However, these infants drank substantial amounts of the Nutramigen and satiated while feeding it. In marked contrast, virtually all of the 7- to 8-month-old infants rejected the Nutramigen (p = .000002), and this was evident within the 1st minute of the feed. Finally, there was a significant correlation between the mothers' eating habits as determined by the questionnaires and the 1- to 2-month-old infants' response to Nutramigen. Mothers who exhibited a greater willingness to consume novel foods (p = .003) or less food neophobia (p = .04) had infants who consumed relatively more of the Nutramigen.

Child Development↗
PubMed1995

Evidence suggesting that the odortypes of pregnant women are a compound of maternal and fetal odortypes.

Odortypes--namely, body odors that distinguish one individual from another on the basis of genetic polymorphism at the major histocompatibility complex and other loci--are a fundamental element in the social life and reproductive behavior of the mouse, including familial imprinting, mate choice, and control of early pregnancy. Odortypes are strongly represented in urine. During mouse pregnancy, an outcrossed mother's urine acquires fetal major histocompatibility complex odortypes of paternal origin, an observation that we took as the focus of a search for odortypes in humans, using a fully automated computer-programmed olfactometer in which trained rats are known to distinguish precisely the odortypes of another species. Five women provided urine samples before and after birth, which in each case appropriately trained rats were found to distinguish in the olfactometer. Whether this olfactory distinction of mothers' urine before and after birth reflects in part the odortype and hence genotype of the fetus, and not just the state of pregnancy per se, was tested in a second study in which each mother's postpartum urine was mixed either with urine from her own infant or with urine of a different, same-aged infant. Responses of trained rats were more positive with respect to the former (congruous) mixtures than to the latter (incongruous) mixtures, implying that, as in the mouse, human fetal odortypes of paternal genomic origin are represented in the odortype of the mother, doubtless by circulatory transfer of the pertinent odorants.

Animals↗
PubMed1995

Garlic ingestion by pregnant women alters the odor of amniotic fluid.

Amniotic fluid samples were obtained from 10 pregnant women undergoing routine amniocentesis procedure. Approximately 45 min prior to the procedure, five of the women ingested placebo capsules, whereas the remaining five ingested capsules containing the essential oil of garlic. Randomly selected pairs of samples, one from a woman who ingested garlic and the other from a woman who ingested placebo capsules, were then evaluated by a sensory panel of adults. The odor of the amniotic fluid obtained from four of the five women who had ingested the garlic capsules was judged to be stronger or more like garlic than the paired samples collected from the women consuming placebo capsules. Thus, garlic ingestion by pregnant women significantly alters the odor of their amniotic fluid.

Adult↗
PubMed1995

Mother's milk: a medium for early flavor experiences.

For centuries, many believed that the lactating woman's diet could influence the composition and flavor of her milk and that substances in human milk could be transmitted from the wet nurse or mother and have long-lasting effects on the child. The research described herein focuses on mother's milk as a medium of early sensory experiences for the human infant and establishes several points. First, human milk is not a food of invariant flavor. Rather, like the milk of other mammals, human milk is flavored by ingested compounds such as garlic, mint, vanilla, and alcohol and provides the potential for a rich source of varying chemosensory experiences to the infant. Second, the infants' response to a particular flavor in milk may depend upon the recency and duration of past exposures. That is, the prior diet of mothers, and consequently their infants, may modify the infants' responses to these flavors during breastfeeding.

Animals↗
PubMed1994

Infant salt taste: developmental, methodological, and contextual factors.

Two studies investigated the human infant's response to salt during development. In the first study, measures of intake and sucking were obtained from two groups of infants, newborns and 4- to 8-month-olds, in response to brief presentations of two concentrations of salt (0.2 or 0.4 M) and water. For several measures of sucking and for intake, there were significant age and concentration effects. Generally, newborn infants tended to reject saline relative to water more than did 4- to 8-month-old infants. This result, consistent with previously published research, suggests a developmental change in salt acceptability and, probably, sensitivity in the human infant. In the second longitudinal study, the response to salted (0.15 M) versus unsalted formulas was evaluated monthly in infants 2 to 7 months of age. Again, a developmental change was observed: Based on some sucking measures, younger infants appeared to be indifferent to the salted formula relative to the unsalted formula whereas older infants tended to reject the salted formula, presumably because either it was less sweet than the unsalted formulas or because it was novel. These data are consistent with the hypothesis developed from animal model studies that during early human postnatal development, transductive elements sensitive to saltiness mature.

Dose-Response Relationship, Drug↗