A lot of people ask me if soy is safe to consume. Some are concerned about increasing their risk of cancer, while others are concerned about the ‘feminising’ effects.
Soy products are made from the soy bean – a type of legume similar to lentils, chickpeas and beans.
Soy products are are great source of protein - they contain all of the 9 essential amino acids, making them a complete plant protein. They also including omega 3 fats, fibre, iron and zinc.
A wide variety of soy products are available such as tofu, tempeh, miso, edamame beans, soy milk and yoghurt and soy based meat alternatives like sausages and burger patties. Some people also take soy in supplement form e.g. soy protein powder.
Soy contains phytoestrogens, such as isoflavone, which acts like estrogen. There has been concern around consuming large amounts of phytoestrogens and increased risk of hormone receptor-positive breast cancers. However there appears to be a link between a high soy consumption and reduced risk of breast cancer. Furthermore, the World Cancer Research Fund explains women diagnosed with breast cancer may have improved survival rates with soy consumption.
There is no need to be worried about the potential effects of soy having a ‘feminising’ effect on your body. The evidence shows no negative effects of soy on testosterone or on sperm as some people believe.
More research is needed in this space, but based on the current evidence we have, the recommendation is that moderate amounts of soy foods are safe for all genders and breast cancer survivors.