Find the podcast at the origin of this transcription in Science or Fiction. © Futura You may have guessed it: these beliefs around food and the sex of the baby go back to ancient times. Times when science did not exist to explain the mysteries of conception.The history of a link between diet and the sex of the childMany cultures have attempted to establish a link between what a pregnant woman eats and the sex of their child, based on empirical observations or coincidences. In the second case, we call it apophenia, the tendency to create causal links between two things that, in reality, are not interdependent. Like: “My wife played ping pong during her pregnancy and gave birth to a boy, so ping pong makes you have boys. »This is how we established a strange link between eating sardines and giving birth to a little girl. It is said that since sardines are rich in omega-3 and other beneficial nutrients, it would promote the birth of a girl. This idea could come from popular beliefs according to which light foods rich in so-called “feminine” nutrients increase the probability of having a girl. Feminine nutrients? What does that mean? Well, not much actually. In fact, in these beliefs, foods that are light or rich in calcium, such as dairy products or fish like sardines, are deemed “feminine,” while saltier or protein foods may be associated with “masculine” attributes. So, let me clarify, I am only explaining the belief to you, there is no scientific or nutritional basis behind all this. In any case, other fatty fish, such as salmon, are also sometimes cited in this context. Yet, as you might expect, no scientific study has been able to establish a direct link between the consumption of specific fish and sex determination. And is it the same for boys and eating salty? This is one of the most common beliefs, indeed. It is said that eating salty foods would encourage the conception of a boy, and sometimes we also hear that sweet foods would encourage the birth of a girl. This theory comes from the idea that diet could alter the pH, therefore the acidity of the body or the vaginal environment. Apparently, this would create conditions more favorable to sperm carrying a Y chromosome (i.e. boy) in the first case or X (i.e. girl) in the second case. But once again, and I’ve looked, there is no scientific data that supports this idea. Above all, I think that we had deeply rooted (and somewhat sexist) beliefs, and that when science arrived, we tried to use them as best we could to justify them. It wouldn’t be the first time…A variation of this myth also suggests that a more acidic vaginal environment would favor girls, while a more alkaline environment would be favorable to boys. So in this case, certainly, specific diets are sometimes recommended to modify the body’s pH, but again, there is no tangible evidence. In addition to dietary theories, many people refer to methods such as the Chinese conception calendar, which claims to predict the sex of the baby based on the mother’s age and the month of conception. There are also beliefs that certain positions during sexual intercourse influence the sex of the future child. Like dietary theories, these methods are largely unproven. There is no way to influence the sex of the baby. This is all based on biological principles. © Any Grant, Adobe StockGenetics to explain sex determinationAnd besides, how do we determine the sex of a baby? It comes down to one word: genetics! And not diet, timing, position or whatever else. Determining the sex of a child is a purely genetic process, which occurs at the time of conception. As a quick reminder: we have 23 pairs of chromosomes, including a pair of sex chromosomes: XX in women and XY in men. It is in fact the father’s sperm that will determine the sex of the child, since they contain either an X chromosome or a Y chromosome. But what does that change? Well, the mother’s egg is always X. So if a Y sperm meets it, it will be a boy, since we will then have a pair of XY chromosomes. On the other hand, if it is an X sperm that meets the egg, we will give birth to a little girl since we will have an XX pair of sex chromosomes. Afterwards, that is the case in the majority of cases. We can also have variations in sexual development in intersex people, with a single X chromosome, an XXY combination, mosaicism, the absence of certain enzymes, etc. In short, that’s not the subject of this episode, but it’s still important to mention that there are not just girls and boys, even if we’re talking from a purely biological point of view. Foods to avoidBut here it is, to put it simply: the sex of the child is determined solely by genetic mechanisms, and no serious scientific study has proven that diet or other environmental factors could influence this process.C It’s super interesting to see that even the boy-girl concept is in much richer than that! But then, would there still be dietary recommendations for pregnant people? To stay healthy, not to influence sex. Indeed, despite what we have just said, diet still plays a crucial role in the smooth progress of pregnancy and in the development of the fetus. Obviously, the best is to discuss it with a health professional, but it is always good to consume foods containing calcium, iron, and omega-3. This is good for both the future parent and the child. And of course, among the foods to ban: alcohol, but this is nothing new. I would still like to point this out because, according to the Ministry of Health, 40% of pregnant people continue to drink after announcing their pregnancy. Not great… As a reminder, alcohol consumption during this period is toxic to the fetus and can lead to serious developmental disorders. Also be careful with raw or poorly cooked products: meats, eggs, unpasteurized cheeses, fish or seafood for example. It is better to avoid them to reduce the risk of toxoplasmosis and listeriosis, serious diseases that could impact the baby’s development. Finally, be careful of excess caffeine, it can increase the risk of miscarriage. In short, eating sardines or salty foods has no effect on the sex of the future child, it is genetics that will do its job, but that does not prevent you from adopting a balanced diet rich in nutrients, essential for health!
