Learning to Like Vegetables While Breastfeeding

Learning to Like Vegetables While Breastfeeding

The Study:

A study was reported in the July issue of the  American Journal of Clinical Nutrition entitled “Learning to like vegetables during breastfeeding: a randomized clinical trial of lactating mothers and infants.”  They conducted a randomized controlled study of 97 mother-infant pairs.  The mothers drank vegetable, beet, celery, and carrot juices for 1 month, beginning at 0.5, 1.5, or 2.5 months after their baby’s birth or for 3 months beginning at 0.5 months after the birth of their baby.

The control group drank equal volumes of water but avoided drinking the juices.

Mothers rated the tastes of the juices and their self-reported juice intakes were recorded at monthly visits.

After weaning, at 7.9 months of age, the infants were given 3 different tasting cereals, and their acceptance of them was recorded:

• plain cereal
• carrot-flavored (exposed flavor) cereal
• broccoli-flavored (non-exposed) cereal

Each was tested on a separate day.

Results:

• A one month exposure of an infant to drinking breast milk while his/her mother was drinking carrot juice, beginning at 0.5 months postpartum was sufficient to alter the taste preference of the infant.
• One month of exposure had a greater effect than 3 months of exposure or no exposure
• The mothers liked the taste of the vegetable juices more, over time, but did not increase their intake of them

Discussion:

The authors concluded “Early life may be an optimum time for both infants and their mothers to learn to like the taste of health foods”.  They also stated more research is needed in this area.

I don’t understand why 1 month of exposure would have more effect than 3 months.

I tried to do online medical research of controlled studies documenting exactly what types of food can enter into human milk and affect its taste.  I couldn’t find any other formal controlled studies.  If you do a google search, you can find a long list of foods that “shouldn’t be eaten” while  breast feeding because of problems they may create.  I would have liked to see more actual studies, like the one above.  There is a lot of research on which drugs ingested by mothers can enter milk and whether they do so in a quantity that may be potentially harmful.  We also know that certain allergens, eg. cow’s milk protein, can enter the breast milk of a mother who is drinking cows milk, and set off severe allergic reactions in their infant  if their infant is sufficiently allergic to it.

We also know that taste preferences are variable, person to person, and even in the same person at different times.  Some people, including newborns/infants, are more particular/fussy/demanding  than others.  It is not unusual for an infant who is on formula to refuse all formulas except one.  Chemically, it only takes trace amounts of some substances to be detected by taste and/or smell, so theoretically, the results of the above study should not be completely surprising.

It also makes me wonder about analogous effects about other maternal environmental exposures.  If this works for carrot juice, what about ethanol, cocaine, marijuana, air & water pollution,  etc. ?