Are phytoestrogens good or bad? Now more than ever we are seeing the science and nutrition community back flipping on their advice on what to eat and what not to eat. A prime example is a link between saturated fat, cholesterol and heart disease. Scientists have now acknowledged that they were wrong and that fat is not the evil nutrient that we were lead to believe that it was. Just like we thought that replacing cow’s milk with soy milk would rid us of breast cancer, we now realise that it is a lot more complicated than that.
It seems like for every study that comes out declaring a nutrition fact, there is another one that contradicts it. As a nutritionist it can be overwhelming, so how on earth does everyone else sort through the nutrition fact from fiction?
So let’s look at the myths around phytoestrogens. Phytoestrogens are plant based oestrogens that when eaten behave in the body somewhat like our natural oestrogen does. They have the ability to both mimic oestrogen and bind to oestrogen receptors on our cells, and they can act as an oestrogen antagonist (opposite action to oestrogen).
Sources of phytoestrogens include flaxseed, soy, oats, barley, lentils, sesame seeds, yams, apples, carrots, pomegranates, wheat germ and red clover.
There is another class of oestrogens that we are exposed to that is not made in the body. These are the xenoestrogens that we are exposed to from certain plastics and pesticides. Whilst I won’t go into detail about these oestrogens here, it is important to be aware of these and to avoid them as much as possible.
The first thing we need to acknowledge here is that a hormone that is not made by our own body, whether it is plant based or synthetic, will never behave the same way as our own naturally produced hormones. Even if the chemical structure appears to be the same. Our bodies are smarter than that and it knows what is real and what is not.
This is not to say that we can’t benefit from plant based hormones. What is important to realise is that possibly only some people will benefit, whilst for others, it may be detrimental to their health.
Our bodies produce a few different forms of oestrogen, some stronger than others. It is well accepted that excess amounts of certain oestrogens can increase the risk of infertility, polycystic ovarian syndrome, endometriosis and certain types of cancer in young women.
When oestrogen is the driver of these conditions it makes sense that we would want to avoid excess oestrogen at all costs.
However, phytoestrogens are much weaker than our own oestrogens so it is thought that if these weaker oestrogens attach to our oestrogen receptors, then there is less room for our own natural stronger and more aggressive oestrogen to get into the cells. It is this exact theory that there is so many conflicting reports about. At this stage, there is still no clear answer on these theories, so this is where you need to speak with your naturopath to determine what is best for your individual situation. A naturopath is able to take into account your full health profile and family history to see what would most benefit you.
Most of the studies around phytoestrogens are about its link with breast cancer. There are countless studies out there showing that the daily intake of phytoestrogens can prevent breast, ovarian and prostate cancer, reduce tumour size and enhance the effectiveness of breast cancer medications (1,2,3). This all sounds amazing until we hear studies that certain phytoestrogens can promote breast cancer and inhibit certain drugs that treat the disease. Exhausting huh!
One thing we do know is that peri-menopausal women who have naturally declining oestrogen levels experience a reduction in menopausal symptoms when they supplement their diet with phytoestrogens. These plant based oestrogens help to boost declining levels and thus reduce symptoms of menopause.
Also, menopausal and postmenopausal women experience a reduction in bone breaks and an increase in bone density when they supplement with phytoestrogens and vitamin D (4).
Other positive studies have also shown that phytoestrogens can reduce your risk of heart disease as they can reduce the build-up of plaque in the arteries (5,6).
It is clear that menopausal women benefit from a regular intake of phytoestrogens. For these women, I would recommend freshly ground flaxseeds as the best source. You need to be wary of soy as so much of it is from genetically modified sources. Adding a couple of teaspoons of freshly ground flax seeds to your morning breakfast, smoothie or over a salad is a great option.
For everyone else, I still encourage the inclusion of phytoestrogens in the diet, but just watch your intake. Adding a few teaspoons of freshly ground flax seeds to your meals several times a week can provide you with some great nutrients and essential fatty acids. Keep in mind, that if you notice an increase in PMS symptoms or breast tenderness, then this may be an indication that phytoestrogens are not right for you.
As a general rule, I would not advise pregnant women and children to consume excess phytoestrogens. The reason for this is that there is just not enough long-term information out there to tell us what effects phytoestrogens have on unborn babies and growing children.
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