There is nothing more fun than returning from a few days away from the garden and finding what has sprouted and ripened in my absence. This morning, after a weekend away camping, I discovered about 30 pounds of zucchini and a bumper crop of yellow string beans. I love planting beans and peas in my garden both for the delicious harvest and the nitrogen they give back to the soil. Let’s talk a bit about their specific health benefits as well:
Just about everyone has become familiar with the controversy surrounding soy and its effect on hormones. We know that soy contains a class of compounds called isoflavones, which have a phytoestrogenic effect on the body. Soy and soy products, particularly concentrated soy proteins (frequently found in bars, protein powders, and vegetarian “meat” products), are particularly high in these compounds, and can significantly impact the body’s hormone balance. Why is this important when we are talking about beans? While soy is particularly high in isoflavones, all members of the bean or pea family will contain some amount of these compounds.
So, what is a phytoestrogen? To understand this, we need to know a bit about estrogen. Estrogen is a hormone–a chemical produced by the body that stimulates a receptor on a cell and tells the cell what to do in a specific way. Estrogen is a growth stimulator, so it tells your body to change from a kid’s body into a grownup’s body. During the menstrual cycle, estrogen tells your uterus to grow the lining that will support a pregnancy. It also helps to maintain the strength and integrity of the bones. A phytoestrogen is a chemical that comes from outside the body that will stimulate an estrogen receptor. Phytoestrogens are generally not as strong as estrogen, so it stimulates that receptor weakly. So, for people who have very low estrogen levels a phytoestrogen will help the body feel like it has “more” estrogen, but for those with very high estrogen levels, a phytoestrogen may block those receptors and help the body feel like it has “less” estrogen. Because of this moderating quality of these compounds, it can be useful to help balance hormones for those who are both deficient in or have excess estrogen.
As with many botanical families, the legume family has these isoflavones in common throughout its members. This means that some amount of these compounds can be found in a wide variety of plants that belong to this family: licorice root, alfalfa, clover, lentils, dried beans, peas, and even those fresh green beans. It is important to keep in mind that isoflavones are only one class of chemical among many found in these foods. This phytoestrogenic effect will generally be gentle and will be accompanied by all the other benefits of legumes: fiber, minerals, protein, starches, and green energy in those beans that are eaten fresh.
Soy does tend to contain isoflavones in higher amounts than other members of the legume family, and they will be particularly concentrated in processed soy protein products and soy extracts. In this case, there will be a more specific medicinal effect because they are being used in a more drug-like manner. For people who are concerned about a history of estrogen-dependent cancers, this will be more relevant with soy protein products than with other legumes. Soy protein can also be inappropriate in large amounts for those who would normally have a very low amount of estrogen in their systems, such as young children and men.