Hydration as a limiting factor in lactation

Abstract

A relatively untapped area of research concerning lactation and hydration exists for bioanthropologists interested in the ecology of breastfeeding. This review details current limited knowledge on the topic with recommendations about relevant research questions for human biologists. On average, lactating mothers produce >750 ml/day milk for their infants. Breastfeeding thus promotes a powerful thirst stimulus in the lactating mother, resulting in a 12–16% increase in fluid intake among Western women. Thirst during lactation may be mediated by oxytocin release, since this hormone is structurally similar to the antidiuretic hormone, vasopressin. Prolactin also may be involved. A few studies among Western women concluded that moderate dehydration does not affect milk production, but it is not known how lactating women in hot and/or dry climates respond to chronically limited water supplies. Lactating women in such environments may use both physiological and behavioral adaptations to conserve fluid requirements, such as reducing activities during breastfeeding and carrying extra fluid supplies while travelling. Given the limited state of knowledge on lactation and hydration, future field studies should incorporate research to determine the importance of adequate fluids in maintaining milk production and the health of both mothers and infants. Am. J. Hum. Biol. 10:151–161, 1998. © 1998 Wiley‐Liss, Inc.

Maternal Knowledge and Use of Galactagogues in Andean Communities of Cusco, Peru

“…Despite this divergence with public health policy, increased liquid consumption during breastfeeding may have a health promotion role in the Andean communities. It is recommended that water intake increases from 2.7 to 3.8 liters per day while breastfeeding (Bentley 1998;IOM 2004). Complying with water intake recommendations may have implications for people living in environments where safe drinking water is scarce.…”

“If there is no water, we cannot feed our children”: The far‐reaching consequences of water insecurity on infant feeding practices and infant health across 16 low‐ and middle‐income countries

“…Lactating women in the hot‐humid Amazon are more likely to be dehydrated compared with non‐lactating women (Rosinger, ), even when typical water consumption exceeds recommendations (Rosinger & Tanner, ). Simultaneously quantifying water insecurity, maternal hydration, and milk production would help to evaluate this relationship, and answer the call laid out by Bentley () in understanding how hydration affects human milk production and feeding.…”

Biobehavioral variation in human water needs: How adaptations, early life environments, and the life course affect body water homeostasis

“…Women who are lactating have higher physiological water needs as intake recommendations are a liter higher for lactating women compared to nonlactating women (Food and Nutrition Board and Institute of Medicine, ). While thirst cues reportedly increase among Western lactating women resulting in increased water intake (Bentley, ), it remains unclear if these thirst cues are universal among all populations, particularly ones with lifetime exposures to higher water needs.…”

“…Changes in hydration status and higher water needs have the possibility to affect breast milk production and potentially breast milk composition (Bentley, ). One direct mechanism for newborns not consuming enough breast milk may be through inadequate milk transfer.…”

“…Physiological dilution of breast milk has been reported in cows subjected to heat stress and water restriction (Kadzere, Murphy, Silanikove, & Maltz, ). However, little data exist among humans regarding concurrent changes in water intake or hydration status and changes in breast milk composition (Bentley, ). One study among Bedouin women examined changes in breast milk composition between winter and summer months when the temperatures are substantially elevated.…”