Edamame, soya milk, soya yoghurt, tempeh…the options to add soya in to our diets have become endless. Even if we are not consciously choosing to eat soya it has become a cheap “bulk out” invisible ingredient in many foods, from roast chicken to breakfast cereals. Often hailed as a superfood I decided to embrace the trend and enthusiastically poured soya milk on my muesli each morning for a week. About three days into that week I noticed I was spotting (as I am currently on the pill I should not expect any such spotting between my pill free weeks). As lovely as my GP is, and typical of GPs, she neglected to ask anything at all about my recent diet changes when we discussed the possible causes. Not convinced by any of my GPs explanations I racked my brain as to what could have triggered it. It was like a light bulb moment. I put my google doctor hat on and began researching soya’s link to spotting and was shocked at the clear link I found. My realisation that soya had caused the spotting was both an uplifting and a frustrating moment. I was uplifted to see such a direct effect between diet and symptoms, strengthening my firm belief that diet should be first point addressed with almost every health complaint, but it also highlighted our healthcare system’s poor understanding and neglect of diet when discussing symptoms. If medical students were taught anything substantial about food’s powerful influence on hormones then perhaps my GP might have questioned any recent diet changes.
So why did soya it lead to spotting…? Soya products contain large concentrations of phyto-oestrogens called isoflavones. These phyto-oestrogens powerfully mimic the hormone oestrogen in the body, either having a agonistic (stimulatory) or antagonistic (inhibitory) effect. Research has shown that two glasses of soya milk a day over the course of a month provides enough phyto-oestrogens to significantly alter the timing of a woman’s menstrual cycle. A Swiss report on the issue reported that 100mg of isoflavones taken by an adult women provides the oestrogenic equivalent of a contraceptive pill. This fact has led to the shocking estimation (based on an infant’s smaller body mass) that infants who are fed soya formula receive the oestrogenic equivalent of at least 5 contraceptive pills per day.
As well as unbalancing our oestrogen levels there is also concern that phyto-oestrogens might adversely impact our thyroid health, cognitive function, mineral absorption, contribute to some cancers and also lower sperm count and mobility. However, it is important to note that findings have been mixed and are often limited to animal studies only.
Although the research remains inconclusive it is clear that the potential adverse health effects should be more balanced against the health benefit claims so that us ladies can make a more informed decision before opting for that soya latte. So perhaps it is best to be a little more cautious with our soya intake until there is more information available, particularly if you suffer from any hormonal imbalances or are noticing any irregularities with your cycle. There are now so many brilliant dairy alternatives to try instead – I am a huge fan of almond milk and also the divine coyo coconut yoghurt (try it topped with nuts and blueberries and popped in the freezer for about half an hour before!)