The Medical Advantages and Dangers of Edamame Consumption

Superfood Research Paper: Edamame

Edamame is a traditional Japanese food that is grown and eaten in many Asian countries such as China, Japan, and Korea. An important legume in Asia, edamame demand has been increasing in the United States with the popularity of Asian cuisine. This nutritional superfood is a part of the legumes family and can be purchased at a local grocery store or be domestically grown. Though grown mostly in Asia, the soybean is not just being imported as it is also grown in the United States. Particularly in the south, states such as Kentucky and Arkansas have become the perfect fit for growing edamame as they have both the ideal climate and soil (Kaiser). Since soybeans are a warm-season crop, they are best grown when the soil is at least 60 degrees. The plant is usually harvested by hand to avoid damaging the crops stems and leaves. The green soybean pods are picked before they are fully ripened, and therefore taste sweeter in this stage as they contain more sucrose than soybeans picked later in the growing season. Once the pods are picked, they can be sold at local supermarkets and are usually bought frozen. Preparation for the edamame bean is simple. The pods can be boiled in water, steamed, or microwaved. When boiled in water, the edamame can be cooked for about 3 to 5 minutes or until bright green. The beans are then drained and typically sprinkled with salt for taste. The beans can also be used as an ingredient in many recipes, such as edamame hummus, edamame-avocado dip, and edamame-cilantro pesto.

Edamame is a nutrient-packed legume and therefore has countless health benefits, such as being a high-quality source of protein and fiber, having high levels of vitamin K and folate, and containing low levels of saturated fat. Unlike most plant proteins, edamame provides all the essential amino acids the body needs, and is therefore an excellent source of protein for vegan diets. The high source of protein may also help reduce insulin resistance, kidney damage, and fatty liver with people with diabetes (Arnarson). Edamame is rich in vitamins and minerals such as iron, copper, riboflavin, and especially in vitamin K and folate. One cup of these soybeans will contain about 52% of the RDI for vitamin K, which aids in building strong bones and preventing heart disease. A cup of edamame also provides more than 100% of the RDI for folate, which aids in DNA synthesis and repair (Magee). Moreover, edamame contains isoflavones, which are naturally occurring estrogenic compounds found in soy. A Chinese University of Hong Kong study showed that the isoflavones in the soybean significantly reduced overall cholesterol and LDL cholesterol, while raising HDL cholesterol. In fact, the meta-analysis concluded that consumption of soy protein rather than animal protein drastically decreased concentrations of total cholesterol, LDL cholesterol, and triglycerides without significantly affecting HDL cholesterol levels. Since high levels of cholesterol are linked to an increased risk of cardiovascular problems, the reduction of LDL and increase in HDL from the isoflavones assists in the reduced risk of heart disease (Chan). Not only do the isoflavones help in reducing heart disease, but they also provide an anti-inflammatory effect, which is important in the prevention of osteoporosis, or bone loss (Arnarson). A study done on postmenopausal women indicated that the isoflavone phytoestrogen genistein found in soybeans reduced participants’ bone less and increased their bone mineral density (Marini).

Though possible risks in consuming soy foods such as edamame have been heavily debated, many recent studies indicate that the phytoestrogens found in soy may lead to adverse effects in females, specifically in ovarian function (Magee). Ovarian function in women is controlled by the primary hormone estrogen which circulates the body. Estrogen is mostly produced in the ovary and enters the circulation where it then signals the brain for a response. Since the female reproductive system is dependent on hormones, other estrogenic substances such as phytoestrogens found in soybeans can potentially interfere with these hormonal signals if levels of activity are high enough to cause a response. In extreme cases, studies even showed that women who consumed over 60 grams of soy a day for a month had temporarily shut down their menstrual cycles because the phytoestrogens overrode the hormonal circulation of the reproductive system (Jefferson). In addition to the phytoestrogen isoflavones that act as endocrine disruptors, soybeans may also interefere with the function of the thyroid. The isoflavones in soy function as goitrogens, which may inhibit the action of the enzyme thyroid peroxidase, the essential enzyme for the production of thyroid hormones. One study in 37 Japanese participants revealed that 30 grams of soybeans a day for three months raised levels of the thyroid stimulating hormone, an indicator of impaired thyroid function. As a result subjects experienced hypothyroidism such as constipation, sleepiness, and thyroid enlargement. Only after the participants stopped consuming the soybeans did the symptons went away (Magee).

Despite the possible health concerns of a too high consumption of soybeans, the edamame legume is a nutrient-dense food and is the perfect snack for an excellent source of protein, fiber, vitamins, and many other powerful benefits when eaten in moderation.