Can a mother’s diet influence the food preferences of her child

What a pregnant woman can and cannot eat is one of the most controversial topics in pregnancy.

A woman will be bombarded by a list of rules as soon as a couple announces the impending birth of their child.

Don’t eat soft cheeses or cold meats. Avoid salads and unwashed vegetables. Yeah, right.

The flavor of food is a question that has always fascinated me. As a mother and her developing fetus have such a close relationship, it is intriguing to ask if the food choices made by a pregnant woman can affect what their child will like to eat once they are born.

What science is there?

Strange-smelling newborns

Hospital reports of babies born with distinct smells were the first scientific indication that certain elements in a mother’s food may affect a developing baby.

An Israeli team published a series of case studies. They described four babies with a distinctive smell that resembled a meal eaten just before giving birth.

Two mothers from this case study had babies with a cumin-like smell. The mothers admitted to the researchers, after a short quiz, that they both had eaten Middle-Eastern “schug” in the days before delivery. This is a hot sauce made with cumin, garlic, and other ingredients. A newborn baby of a different woman had an odor that was strongly reminiscent of fenugreek. Fenugreek is a leguminous seed plant with a sweet and nutty taste. A similar questioning revealed that the mother had consumed a large amount of “high,” a Yemenite dish made from fenugreek, shortly before giving birth.

These case studies provide the first evidence that the old wives tale is indeed true. The mother’s eating habits may affect her child for a lifetime.

Next, we will explore the biological mechanisms that may be involved.

Amniotic fluid flavouring

Our stomach and intestines break down food and drinks into small molecules, which are then absorbed by the bloodstream. The placenta, umbilical cord, and even molecules that produce an odor in the mother can pass to the bloodstream of the fetus during pregnancy.

The fetus is enclosed in a membrane called the amniotic sac, which contains a mucous fluid. The amniotic liquid is filled with mucous-like fluid (amniotic) that the developing baby can urinate in. This means that a portion of odorous molecules from the mother’s placenta or umbilical cord will be transferred to the child and end up there. It is not surprising that a fetus who has been bathing in an amniotic sac for 40 weeks would have a little pong.

Julie Mennella from the United States and her colleagues were the first to show experimentally how a woman’s dietary habits can affect the odor in the amniotic liquid. Researchers identified ten women about to undergo routine amniocentesis. Amniocentesis involves the removal of a small amount of amniotic liquid from the amniotic sac using a large needle for medical testing. The women were all in their second trimester.

Five women were given a garlic capsule 45 minutes prior to their amniocentesis. The other five women received a milk capsule. Researchers then assembled an “odour-panel” of 13 adults who were given samples of amniotic liquid from two women: one who had consumed a pill of garlic and another who had taken a pill of milk. The panel did not know which sample came from which woman. Their job was to decide which piece smelled more like garlic.

The results were unambiguous. The judging panel almost unanimously chose samples of amniotic liquid from women who had eaten garlic capsules to smell more garlic. Garlic extract taken by the women before the amniocentesis gave their amniotic liquid that garlic-like smell.

It is important to know that the amniotic liquid can be “flavoured” because, by the second quarter of pregnancy, a fetus will be able to swallow it. Near-term fetuses can consume up to 1000ml of fluid a day. This is approximately 50% of the fluid volume in the amniotic sac. This swallowing helps to regulate the fluid level in the amniotic pouch and can also help with the development of a baby’s digestive system and respiratory system.

Can babies develop a taste for certain flavors by consuming flavored amniotic liquid in the womb?

Test your sense of smell.

Our sense of smell is just as important to our taste perception as our senses of taste.

This means that the odorous molecules of the amniotic liquid can reach the olfactory receptors (smell) in the nose. Is it possible that infants exposed to these “smells” in utero, are more attracted to them after birth?

A French research team examined this idea. The preference of two groups of pregnant women for the flavour of aniseed was used to select them. Twelve women from the first group were regular consumers of aniseed-flavoured foods and drinks. In comparison, twelve women in the second group had never eaten or drunk anything with this flavor. The first group was given aniseed cookies, lollies, and drinks in the last two weeks of their pregnancy to ensure that they consumed enough of the taste.