I was recently asked this question and thought it best to answer via a blog post.
Soya (or soy) is part of the legume family. The beans are used to made various products (i.e. milk, tofu, yoghurts etc) but can also be eaten cooked (e.g. edamame beans).
Soya became a popular vegetarian food mainly because it contains excellent levels of protein, is low in fat and high in important nutrients.
It originated in China, where it has been used for many many years. In Okinawa, Japan (thought to be one of the healthiest places on earth) they consume a diet high in soya.
So, is soya good or bad?
The biggest problem with the soya that we have access to us that a vast majority of it is genetically modified. It is also processed in a way that is far removed from the form the Chinese and Japanese eat.
Soya contains a high amount of isoflavones and phytoestrogens. This means it can mimic oestrogen in the body but in a much weaker form than natural oestrogen. There are very conflicting views about what this means. Some say you shouldn’t consume it because it is a hormone disruptor and can increase the risk of hormone related cancers. Others say that it can help to lower oestrogen and thus protect against major disease and help to balance hormones.
There are many studies that show soya to be beneficial.
However, the type you consume is extremely important.
The traditionally fermented forms of soya provide a great deal of excellent nutrients and health benefits. These include miso, soy sauce (the traditional type), tempeh and natto.
Non-fermented forms of soya include soya milk and tofu. If you buy the non-GM version, then these are fine to use.
Products such as soya yoghurts and soya desserts contain a lot of sugar and are not very healthy. Where soya is used as a meat substitute in products such as burgers or sausage these forms are not from a healthy source.
There are some exceptions:
- Soya is a known goitrogen, this means it can block the thyroid so don’t use it if you have an underactive thyroid.
- Soya is a large protein and can be hard for some to digest, especially those with cow’s milk protein allergy or intolerance.
- Always seek advice if you have a hormone related issue before consuming soya products.
In conclusion, I personally use soya products in moderation. These include tofu and soya sauce (the traditional one called tamari) in stir fries plus miso and tempeh. I also love the Edamame beans in Wagamama’s! I do not use soya milk or desserts.