TI&M - Breastfeeding Briefs

Breastfeeding Briefs

December 1994
no. 20

Hypo...what?

For more than 50 years infants who are not breastfed and who are allergic to cow's milk protein have been fed with semi-elemental formulae. The foreign cow protein in these formulae is broken down into very short chains of amino acids so that the infant immune system does not react against it. These formulae are very expensive and have a disagreeable flavor. Fortunately cow's milk allergy is rare (approx. 3-7%) so only a very few infants need these breast milk substitutes.

Several years ago European baby milk manufacturers began to put new formulae on the market which they named "hypoallergenic". The manufacturers claim that the these formulae can prevent the development of allergies, hence the name "hypoallergenic". In these formulae the cow protein is not broken down as much as in the semi-elemental formulae and so children who are allergic to cow's milk will usually react against these formulae. In fact there have been several cases of infants going into life- threatening anaphylactic shock following drinking a "hypoallergenic" formula whith had entered the American market. As a result the American Federal Drug Administrahon made the Carnahon milk company remove the term "hypoallergenic" from its baby milk labels. At the present time the European Society of Pediatric Allergy and Clinical Immunology recommends removing these terms from labels in Europe as has been done in the USA.(1)

In the meanhme many European baby milk companies have entered the market, each with their own "hypoallergenic" or "hypoantigenic" milk, knowing that the public will not understand the difference between the terms. These companies make claims which are not backed up by independent, non-industry research.

In reviewing studies carried out by independent researchers several important conclusions can be drawn: 1) allergy prevention is not proven, 2) some of the formulae are nutrtionally inadequate, and 3) the infants fed these formulae show some abnormal amino acids blood profiles. Practically all of the studies conclude that the formulae need further study, some even suggest that they should not be on the market (see Rigo et al). Many of the studies are carried out by the baby milk industry, presented in industry sponsored symposia and then used in product promohon. Very often the research data used in this promotion have been reworked to give a false impression of the effectiveness of the formulae in preventing allergy or milk intolerance.

Several researchers socializing in immunology are highly critical of the claim of allergy prevention made by manufacturers of these formulae. Dr. Robert Schwartz of the American Academy of Allergy and Immunology has stated that hypoallergenic "is a sales term, it's misused and it can be dangerous for that reason."(2)

The best way to prevent allergies is exclusive breastfeeding for about six months, avoidance of passive smoking and late introduction of solid foods. Breast milk is nature's true hypoallergenic food.

HIGHLIGHTS

Varendi H, Porter RH, Winberg J. Does the newborn find the nipple by smell? The Lancet, 344:989-990, 1994.

In a study in Sweden one breast of 30 newly delivered women was washed with an oderless soap. 22 of their babies spontaneously chose and latched on to the unwashed nipples. "Unnecessary rouhne washing may interfere with... the infant's access to biologically relevant chemical signal".

Hilder AS. Short birth intervals: the experience of Bangladeshi immigrants to the United Kingdom, l974 through l984, Ethnicity & Disease, 3: 138-144, l993.

The birth interval of newly arrived Bangladeshi women was half that of women in Bangladesh between 1974 and 1984.. The reason for this reduchon is thought to be their use of artificial infant feeding in the LIK rather than the hadihonal breastfeeding.

(1) Pediatric Allergy and Immunology, 4: 101 -111, 1993.
(2) The Medical Post, May 14, 1991.

Breastfeeding, why...

Ford RPK, Taylor BJ, Mitchell EA, Entight SA, Stewart AW, Becmft DM0, Scragg R, Hassall IB, Barry DMJ, Allen EM, Roberts AP. Breastfeeding and the risk of sudden infant death syndrome, International Journal of Epidemiology, 22(5): 885-890, 1993.

The New Zealand Cot Death Study was set up to idenhfy the risk factors associated with sudden infant death syndrome (SIDS). The study covered 78% of all births in New Zealand over the 3 year period, 1988-90. It analysed 356 cases of sudden infant death and 1529 healthy control infants. Breastfeeding was found to be associated with a lower risk of SIDS, and the length and extent of breastfeeding were also important.
92% of the control infants were breastfed at buth as compared with 86% of the SIDS cases, but as time went on the cases stopped breastfeeding sooner than control infants until at 6 months 58% of the controls were shll breastfeeding as compar with 36% of the cases. Comparing the rates of exclusive breastfeding, 60% of the controls were still exclusively breastfed at 16 weeks but only 25 % of the cases were. The reduction of risk remain when all the major confounding social, economic and demographic factors were taken into account.

The authors conclude that "added to a smoke-free pregnancy, and avoidance of the prone (face down) sleep position, mothers can now be given very positive advice on how to significantly reduce the risk of their baby succumbing to cot death".

Rigo J, Salle BL, Senterre J. Nutritional evaluation of various protein hydrolysate formulae in term infants during the first month of life, Acta Paediatrica Supplement 402: 100-104, 1994.

Researchers in Belgium compared infants fed on various partially hydrolysed protein formulae, commonly called "hypo-allergenic", with infants fed on breast milk. Growth, protein metabolism and blood amino acids were measured. Compared with the breastfed infants, infants fed some of the formulae showed impared growth and various biochemical abnormalities. Infants fed on the Gallia (France) formula showed growth reduction of 50% in weight and 30% in head circumference. The total protein concentration of blood was significantly reduced in infants fed 2 of the 5 formulae tested. Of the 23 amino acids measured in the blood of the formulae-fed infants, only one did not vary significandy from the amount found in breast milk-fed infants. The authors conclude that "further extensive nutritional studies on growth, biochemical indices of protein metabolism and metabolic balance, including minerals and trace elements, appear to be necessary before maintaining and promoting the use of such formulae..".

Cousens S, Nacro B, Curtis V, Kanki B, Tall F, Traore E Diallo, I, Mertens T. Prolonged breast-feeding: no association with increase risk of clinical malnutrition in young children in Burkina Faso. Bulletin of the World Health Organization 71(6): 713-722, 1993.

52 children aged 12-36 months who were admitted to hospital with a diagnosis of malnutrition were compared to healthy controls with regard to method of feeding. In Burkina Faso all children are breastfed at birth with over 90% shll breastfeeding at 12 months and 3/4 of the children are weaned by 24 months. Result show that after adjusting for confounding factors children receiving solid food had a 3-fold higher risk of malnutrition if they received no breast milk.

The authors offer three possible explanations for these results. One, the nutritional content of breast milk may help protect children from malnutrition in settings where weaning foods are of low nutritional value; two, the protective value of breast milk against disease may protect children from becoming ill which negatively affects their nutritional status; and three, ill children may continue to accept breast milk while rejecting weaning foods, thereby helping to maintain adequate nutrihonal status during illness.

Freudenheim JL, Marshall JR, Graham S, Laughlin R Vena JE, Bandera E, Muti P, Swanson, Nemoto T. Exposure to breastmilk in infancy and the risk of breast cancer, Epidemiology, 5 : 324-331, 1994.

Evidence is accumulating which shows that breastfeeding reduces a woman's chances of being a victim of breast cancer. A study done in the USA and Italy presnts evidence that women also run a reduced risk for breast cancer if they had been breastfed as babies. 528 women with confirmed diagnosis of breast cancer were compared with 602 healthy women. Results showed that the risk of breast cancer in those that had been breastfed was reduced to 0.7 for both pre-and post menopausal women. The effect of being breastfed remained when various compounding factors such as age at menarche and number of pregnancies was controlled for.

Pollack JI. Long-term associations with infant feeding in a clinically advantaged population of babies, Developmental Medicine and Child Neurology, 36 : 429- 440, 1994.

Researchers are increasingly studying long term effect of infant feeding methods. A study in the United Kingdom of 7800 children at 5 and 10 years of age was carried out to determine the effect of breast or artificial feeding. After controlling for confounding factors, results showed that at 5 years of age children who had ben exclusively breastfed for more than 3 months scored significantly higher in verbal tests. At 10 years of age these children scored significantly higher in language tests, reasoning and percephon skills. The author speculates that the reason for this difference is "that levels of micronutrients in formula milk are subophmal at a crihcal period of growth and differentiation of nerve tissue".

Victora CG, Fuchs SC, Flores AJC, Fonseca W, Kirkwood B. Risk factors for pneumonia among children in a Brazilian metropolitan area, Pediatrics, 93(6): 977-985, 1994.

In Porto Alegre, Brazil, the main infectious cause of infant mortality is respiratory tract infection. 510 children with diagnosed pneumonia were compared with 510 healthy controls regarding various factors such as home environment, parents education, and feeding method. Results showed that children receiving only artificial milk had a 3 times greater risk of contracting pneumonia than those receiving breast milk. Both cow milk and artifical formula showed that same 3-fold risk.

Breastfeeding, how...

Blomquist HK, Jonsbo F, Persson LA. Supplementary feeding in the maternity ward shortens the duration of breast feeding, Acta Paediatrica, 83: 1122-1126, 1994.

The UNlCEF/WHO "Baby Friendly Hospital Initiative" is based on the "10 Steps for Successful Breastfeeding". Step 6 states that new- borns should receive no food or drink other than breast milk, unless medically indicated. The breastfeeding patterns of 521 Swedish infants were studied to determine what factors played a role in determining breastfeeding duration. After controlling for various confounding factors it was found that infants who had received supplements, either breast milk or formula, during their hospital stay were 3.9 times more likely not to be breastfed at 3 months than infants who received no supplements. 25% of the total population of infants received supplements in hospital for reasons including weight loss of more than 10%, maternal diabetes, fussiness, and for no specific reasons, sometimes indicated as "insufficient amounts of milk". Interestingly, infants who received supplements because of maternal diabetes" did not show a shortened duration. It might be that supplementation of the newborn on strict 'medical' grounds does not disturb ... maternal confidence as it does when supplement are given because of 'insufficient amount of milk and fussiness."

Howard CR, Howard FM, Weitzman ML. Infant formula distribution and adverhsing in pregnancy: A hospital survey, Birth 21 (I) : l4-19, 1994.

Advertising through the health care system is a common and very efficient means of promoting breast milk substitutes. A survey carried out in the USA highlighted the extent of this practice. 136 women were questioned regarding the primed information and formula samples they had received during their pregnancy. Half of the mothers had recived no counseling on infant feeding during pregnancy. However, 78% of the women received printed material published by a baby milk company. 90% of women who received free formula during pregnancy said that their health caregiver was the source. Of mothers who planned to breastfeed, 56% received free formula from a hospital, and 75% from private health care providers. Women who had planned to bottle feed were less likely to receive samples. The authors believe that "the continued participation of prenatal caregivers in promotion efforts of formula companies provides a negative or mixed message about the importance of breastfeeding and may be a barrier to its success".

Fleischer Michaelson K, Sauer Larsen P, Lykke Thomsen B, Samuelson G. The Copenhagen cohort study on infant nutrihon and growth: breast milk intake, human milk macronutrientscontent, and influencing factors, American Journal of Clinical Nutrition, 59: 600- 611, 1994.

The human milk intake of 91 healthy breastfed infants was measured at 2,4 and 9 months. In the exclusively breastfed infants the average 24 hr. intake at 2 months was 781 ml, and 855 at 4 months. 82% of the infants received supplements during their stay in hospital. The volume of breast milk intake was negatively associated with the amount of supplements received. 150 ml total supplement resulted in a 5% reduction in volume at 2 months and a 9% reduction at 4 months.
Protein concentration was about 8% higher for first births. Milk with the highest fat content came from mothers who had gained the most weight during pregancy. Total energy intake was lower than current recommendations.

Ueda T, Yokoyama Y, Irahara M, Aono T. Influence of psychological shess on suckling-induced pulsatile oxytocin release, Obstetrics and Gynecology, 84 (2): 259 - 262.

Oxytocin is the hormone responsible for the milk let-down reflex during breasfeeding. It is relesed in short pulses in response to suckling. It is known that stress plays a role in inhibiting milk let-down. Researchers in Japan studied the oxytocin response in the blood of 22 mothers during breastfeeding when the mothers were put under stress. One third of the mothers did difficult verbal calculation, one third were subjcted to building construction noise, and the rest acted as controls. In the control group the response to suckling was rapid, but in the two stress groups, response was delayed. Also the number of release pulses were fewer (2.25 pulses per 20 minutes in controls vs 1.21 puls per 20 minutes in the stressed groups).

Hill-Bonczyk SG, Avery MD, Savik K, Potter S. Women's experiences with combining breast-feeding and employment, Journal of Nurse-Midwifery 38l5): 257-266, 1993.

Researchers in Minnesota (USA) studied 619 first time mothers regarding their work and breastfeeding experienses. 80% of the 619 women returned to work by 12 weeks after birth, 48% of whom continued to breastfeed. Women who continued to breatfeed after returning to work were significantly older, had more education, worked fewer hours per week and returned to work sooner than women who did not continue breastfeeding aftet returning work. Of the 288 women who combined breastfeeding and work, 103 continued to provide exclusive breast milk feeds for an average of 8 weeks after returning to work. "An overwhelming majority of the mothers felt that [breastfeeding] was worth the trouble, that they would recommend it to others, and that they had done something special for their infant that no one else could do."

Segura-Millan S, Dewey KG, Perez-Escamilla R. Factors associated with perceived insufficient milk in a low- income urban population in Mexico, Journal of Nutrition, 124: 220-212, 1994.

Not having enough milk is the most widely cited reason for mothers to abandon breastfeeding prematurely. To study this phenomenon researchers in Mexico questioned 165 mother regarding planned and actual infant feeding methods. 80% of the mothers reported having perceived insufficient milk (PlM) sometime during the 4 month study period. 7-37% of mothers exclusively breastfeeding reported PIM and 63-73% of mothers using breast milk substitutes reported PIM. 47% of the women interviewed in the hospital intended to introduce formula during the first week and half of these women mentioned concern about their milk supply as the reason. 61 % of the mothers who reported PIM did so during the first week. When the mothers were asked why they thought they suffered from not having enough milk, 64-86% cited infant crying, empty or soft breast (23-28%), and infant sucked its fist (6-14%). Only 7-12% of the mothers reported increasing their breastfeeding frequency to overcome PIM. Interestingly, PIM was never reported based on the mother's perception of infant weight gain, but rather on misinterpretation of normal infant behavior.

Heinig MJ, Nommsen LA, Peerson JM, Lonnerdal B Dewey K. Intake and growth of breast-fed and formula- f infants in relation to the timing of introduction of complementary foods: the DARLING study, Acta PaediaMca, 82: 999-1006, 1993.

Researchers in California studied the food intake of breastfed(BF) and formula fed(FF) infants. Among breastfed infants they also studied differences between infants who started solid food before 6 months (early starters) and those who started solid foods after six months (late starters). Mothers measured all foods and fluids for 4 days at 3, 6, 9, l2, and 18 months. The reasons for starting solids were "infant interest" (53% BF, 29% FF), "appropriate age" (47% BF, 44% FF), "hunger" (37% BF, 40% FF), and "doctor's advice" (15% BF, 36% FF). There was no significant difference in breast milk intake between early and late starters at 3 months, but at 6 and 9 months the early starters consumed less breast milk than the late starters. Weight, length and weight-for-length did not differ between early and late starting BF infants.
Early starter breastfed infants reached developmental milestones 5-8 weeks earlier than late starters perhaps because infant showing interest and developmental readiness, may have ben more likely to receive solids earlier. Among formula-fed infants, timing of introduction of solid food did not affect intake, growth, or achvity. The authors conclude that solid foods given before 6 months generally replace breastmilk among breastfed, but not formula among formula-fed infants.

Prepared by GIFA-The Geneva Infant Feeding Association member of the International Baby Food Achon Network-lBFAN

Copies of Breastfeedin Briefs sent upon request to GIFA, Box l57, 1211 Geneva 19, Switzerland or to UNICEF country offices. Available also in French, Spanish and Portuguese