Much has been said over the years to tout the promised health benefits of soy. But, if you make soy a part of your regular diet, it might just be soy that is standing between you and getting pregnant.
A compound found in soy called genistein has been identified as a culprit in hindering sperm as they search for your non-fertilized egg. Mere traces of genistein can be sufficient to destroy sperm before they ever reach the fallopian tubes.
Surprisingly, it takes far lower doses of genistein to inhibit fertility in women than it does even in mice. Human sperm are particularly sensitive to the inhibiting qualities of genistein, at levels that are found in the blood of most people who consume soy as part of their diet.
Studies have shown that it is only fermented soy products—miso, soy sauce, tempeh and natto, for example—that provide significant health benefits, because the fermentation process decreases the levels of naturally occurring anti-nutrients such as phytic acid and makes otherwise difficult to digest nutrients in soy available.
Studies have shown that non-fermented products, which are far more widespread in the food supply (e.g., soy milk, yogurt and other non-dairy soy-based products), are arguably not the dramatically health-promoting food choices you’ve been led to believe.
It is important to note, however, that even fermented soy products can disrupt your ability to get pregnant. Genistein is one of the isoflavones whose absorption rate is increased during the fermentation process. Therefore, even fermented soy products should be avoided if you are trying to get pregnant.
When sperm encounter genistein, the sperm peak prematurely, robbing them of the necessary vitality they typically have to complete the long journey toward your waiting egg. So, avoiding soy, particularly during ovulation, will likely increase your chances of getting pregnant.
Commonly found items that contain soy include:
- Soy milk, yogurt and ice cream
- Soy mayonnaise and soy-based dressings
- Soy hot dogs, soy burgers and other soy-based “meatless” products
- Soy nuts and snacks, including some protein (energy) bars
- Soy breads, cookies and other baked goods with soy flour
- Many prepared vegetarian-style foods
- Some frozen pizzas
- Foods with texturized vegetable protein (TVP) listed among the ingredients
Researchers have also identified genistein in vegetables such as beans and peas, although it has not yet been determined if the amounts found in these foods present the same level of fertility risk as they do in soy.
Diet and nutrition are an important part of a good pre-conception program. The healthier and stronger your body is, the better chance you have of becoming pregnant and bringing a strong, healthy baby to full term. It also improves the quality of your baby’s organs and tissues as it develops, both inside you and out.
It’s important to make the healthiest choices you can and not just once you’re pregnant. Good health is an intrinsic part of becoming pregnant and so smart choices should be made well in advance of even trying to become pregnant.
If you are convinced that soy is a good choice for you in general and you wish to continue including it in your diet, it’s recommended to avoid it completely the week before and during your most fertile period each month while you are still trying to become pregnant.
If you are still having difficulty getting pregnant, try cutting it out of your diet altogether until you do become pregnant. Once you have conceived, you can reintroduce soy to your diet.