Who’s not confused about soy? Is it good for you or does it cause cancer? When has any food had such extremes in its reputation? Well, when it comes to fertility there are some take home rules about soy products, but let’s have a look at where some of these soy rumours have stemmed from.
Firstly, soy can be found in almost 50% of foods, which makes it hard to avoid. It’s in everything from protein bars, powders, sauces, cereals and even fast food. Soy in its processed form is a cheap filler and has a neutral taste so it doesn’t upset the flavours of its carrier (eg. a Big Mac). You can find it listed on labels as ‘soy protein’, ‘hydrolyzed veg protein’ and ‘textured veg protein’! Keep an eye out because in this form soy can cause an array of problems.
Over 3,000 research studies have been devoted to this topic, hence all the hype. If you are trying to become pregnant then it’s important to understand the difference between ‘processed soy’ and ‘natural soy’ products. Over the past 20yrs we have consumed a lot more soy, mostly in its processed form. What we do know is that soy is a phytoestrogen which can mimic the body’s natural estrogen and disrupt the normal production of hormones. Aspects of these phytoestrogens can cause stress on sperm, leading to DNA damage and increased risk of miscarriage. Recent studies report that the link between higher consumption of phytoestrogens foods over the last 20yrs and a decrease in sperm quality and pregnancy rates is of a major concern. Genistein, which is a phytoestrogen, can also sabotage sperm on its journey to the egg. This then leaves the egg unfertilized once again. Not only is it an issue for couples trying to conceive but also for health in general. Over consumption in its processed form has been linked to many cancers.
So, why would anyone in their right mind eat it? Well, to be fair, most of the major studies were conducted with ‘processed soy’ which is quite different to the effects of ‘natural soy’. When it’s processed the nutrients are stripped away, sugars and fats are added and its isoflavones (or phytoestrogens) are modified. In its ‘natural form’ those isoflavones help regulate cell growth which can actually protect us from some cancers. Also, in this form soy can help regulate cholesterol levels and reduce pressure against vessel walls of the arteries. It is a much better form of protein for our heart health than animal derived protein and can even reduce the risk of a heart attack, along with Type 2 diabetes and osteoporosis.
Studies also show that ‘good soy’ in moderation can improve sperm quality because the phytoestrogens can act as antioxidants and repair DNA damage. So, what is meant by ‘moderation’? The most recent reports are that 1-2 servings of soy are recommended daily. One serving would be equivalent to 1/2 cup of tofu or a cup of soy milk. The best forms to eat are organic tofu, edamame (soy beans), and fermented soy such as miso and tempeh. These fermented forms are full of probiotics which are great for our gut health and high in B12 which is needed to metabolize fats and carbs.
By keeping your intake of soy within the recommended serving size and of the appropriate quality, you can feel comfortable that you’re doing good for your health. Don’t consume too much and avoid ‘processed soy’ as much as possible. When you do become pregnant, don’t fall into the trap of feeding your baby a formula containing processed soy as studies have shown that babies who were fed this type of formula had 6-11 times higher levels of phytoestrogens than adults on a high-phytoestrogen diet. This can have consequences later in life when these babies are all grown up and trying to start their own families.
So in most cases it’s pretty easy to follow the soy rules if you buy organic and stay away from products that have expiration dates too far down the track which generally means they have more additives. Also, if you’re on thyroid medications then please leave a few hours in between taking meds and eating soy as it can affect how the body absorbs the medication within the GI tract.
Moderation and quality…the best rule!