October was Breast Cancer Awareness Month.
Call me late to the party, but as I considered all the people I’ve personally known to have struggled with cancer (breast or otherwise), it got me thinking about diet and cancer risk.
I remember in my very first nutrition class (before nutrition was my major) hearing about how certain plant foods contained phytoestrogens. These are estrogen-like compounds from plants, such as soy or flaxseed meal. The thought of increasing estrogen with plant foods unnerved me.
Ever since then, I have limited and avoided most overt soy products (tofu, soy milk, etc). Embarrassingly enough, it wasn’t until more recently that I took the time to research more thoroughly just what exactly the link between phytoestrogens and hormone-related cancers (like breast and prostate) might be.
Should people (specifically women) with cancer or a family history of it avoid soy or other phytoestrogen-rich foods? Let’s take a quick look at how estrogen is produced in the body and how these unique plant compounds influence its effect on the body and our overall health.
Several factors influence the level of estrogens in the body and how they are used.
The two main factors include: 1,) the actual production of estrogens (we call this endogenous estrogen metabolism or production), and 2.) the activation of specific estrogen receptors responsible for the activity and function of estrogen in the body.
Let’s begin with estrogen production.
Depending on a woman’s age, there are different types of estrogens produced and circulating in her body. When estrogen is made, it can go down two main pathways. One is called the 16-hydroxy estrone pathway, and the other the 2-hydroxy estrone pathway.
Stick with me here.
The 16-hydroxy pathway is a negative pathway, as it increases cell proliferation (production). It is associated with cancer risk.
The 2-hydroxy pathway, on the other hand, has the opposite effect: It decreases cell proliferation. It is not associated with cancer. Remarkably, lifestyle and diet significantly enhance or diminish these pathways.
Conditions like inflammation, obesity, insulin resistance, hypothyroidism and pesticide toxicity increase the specific enzymes that move estrogen down the negative 16-hydroxy pathway. Insulin resistance actually increases the enzyme responsible for the initiation of estrogen production in the first place, which increases total circulating estrogens in the body.
This means that insulin resistance both makes more estrogen total and pushes it down the less preferred pathway. The result? You get more of a bad thing.
Gut dysbiosis (an overgrowth of bad bacteria or a lack of beneficial bacteria) can also affect estrogen levels by increasing yet another enzyme – this time in the gut – that breaks apart the body’s discarded estrogen from its special chauffeur bile.
One of bile’s jobs is to escort the unwanted estrogen out of the body and into the stool. However, with the increase of this enzyme, estrogen cannot bind to bile and thus recirculates. This drives the total body levels upward.
It is good to remember that estrogen is not an enemy. However, it is easy for it to get out of hand in the body, and (as we shall see a little later) depending on what receptor estrogen attaches to, it can have vastly different effects in the body (good and bad).
The good news is that lifestyle and dietary factors can likewise have a positive effect on suppressing the negative pathway and stimulating the beneficial one. In addition to managing blood sugars, losing weight if needed, reducing pesticide exposure, managing thyroid conditions and promoting a healthy gut there are specific things you can eat that positively affect estrogen levels.
Eating plant foods rich in phytoestrogens (like non-GMO soy and flaxseed meal) actually decreases the production of cancer-associated estrogens.
You read that right: Phytoestrogen (estrogen-like compounds from plants) do NOT promote hormone-associated cancers. They actually have a protective effect!
Other foods have this effect as well: green tea, Omega-3s, cruciferous veggies (broccoli, kale, cabbage and Brussels sprouts, etc.) and polyphenolic compounds in plants (like olive oil).
The way it works is that phytoestrogens preferentially direct estrogen metabolism down the 2-hydroxy (good) pathway and shifts it away from the 16-hydroxy pathway. Incredible, isn’t it? But wait, there is more!
I mentioned there were two factors that influence estrogen in the body. One was its original production (which we just discussed), and the second affects the activity and function of estrogen in the body.
The activity and function of estrogen have much to do with the type of estrogen receptors in different tissues in your body. The alpha receptor is in organs like your liver and uterus, the beta receptor is in the bones. The significance of these two receptors is that their different actions have very different effects in the body. The alpha receptor is not good. The beta is best. They actually have opposite effects on tissues.
For example, hormone replacement therapy drugs (and birth control pill) attach to the alpha receptors. These stimulate the liver to push out more blood clotting factors than it otherwise would, increasing a woman’s risk of blood clots and stroke.
In contrast, phytoestrogens from foods like soy and flaxseed meal do not do this because they preferentially bind to the beta receptors. In fact, this is why these foods are associated with health benefits like alleviating menopausal symptoms or increasing bone density! Studies have shown that one cup of soy milk a day can increase bone mineral density and decrease the rate of fractures over time.
It is important to realize that soy’s beneficial effects were seen with whole foods (not supplements or isolates from soy protein powder) using a very realistic amount that a person could consume in a day (such as one cup of soy milk). Whole forms include edamame pods (often in the frozen section of the store) or fermented forms like tempeh and miso. Organic, non-GMO soy milk can work as well (it’s best to buy it unsweetened, if possible.)
So, will phytoestrogen rich foods cause cancer? It would appear that the opposite is true. In fact, several studies have demonstrated that the administration of whole soy foods during and after cancer diagnosis reduced mortality rates (meaning people lived longer) and improved recurrence rates!
The assistance of the amazing phytoestrogen compounds help in regulating healthy levels of the best forms of estrogen make them a desirable option for regular consumption. Pass the soybeans, please!
Oh, and if you are worried about soy allergy, rest assured that it’s one the last ones on the list of the “big 8” food allergens (at least 10 times less frequent than a milk allergy). Soy allergies also do not typically present the same ways as more serious peanut allergies (such as a life-threatening anaphylactic response).
Healthy tips
If your interest is piqued, I would recommend watching a series of videos from Nutritionfact.com.
Use the search word “soy” and you will find numerous videos.
For now, here are some practical takeaways for foods to focus on that help your metabolize and process healthy levels of estrogen:
♦ Include phytoestrogen-rich foods to your diet. Daily if possible.
♦ Soy (choose whole foods like edamame (one-half cup) miso, tempeh, natto, or organic tofu (3 oz. is a serving size). Soy milk works too (1 cup is a serving size). Just opt for low sugar and non-GMO).
♦ Flaxseed meal (add to smoothies, muffins, cereals, casseroles or as an egg replacer in baking, 1 Tbsp. flaxseed meal to 3 Tbsp.water)
♦ Cruciferous veggies (roasted is my favorite way in winter!)
♦ Green tea
♦ More plant foods in general in your diet decrease circulating estrogens
♦ Maintain health gut microbiome (mostly influenced by eating lots of plants in your diet and NOT just taking a probiotic !)
♦ Manage your blood sugars. You don’t have to be a full-blown diabetic to cause damage to your body (as we have seen!). Eating regular meals and snacks consisting of whole foods that include fiber, protein and fats will help with this.
– Cathryn Arndt is a Registered Dietitian Nutritionist. She lives in Lebanon, Oregon, with her husband and daughters. Visit her Facebook page or YouTube channel by searching under “Dietitian Cathryn.” Find her blog at thepantrylab.com.