Soy, also known as soybeans, is a legume native to eastern Asia. It has an excellent nutritional profile that is vital for optimal health. The legume is a major source of protein, especially for those who follow a vegan or vegetarian food plan. Several products are made using soybeans, such as tofu, tempeh, soy flour, soy milk, and soy sauce. Here, we discuss the types, health benefits, and side effects of soy consumption.

Types
Based on their color, soybeans can be grouped into the following categories:

• Green soybeans
  Also called edamame, green soybeans are harvested prematurely when they are still green. They are large, have a sweet taste, and are available throughout the year.
• Yellow soybeans
  Yellow soybeans are typically used for making foods like tofu and miso. They are also ideal for making soy flour.
• Black soybeans
  Black soybeans are simmered or fermented and are an essential part of traditional Asian cuisines.
• Brown soybeans
  The matured soybeans are brown and have a short shelf life. They are available with and without the pod.

Benefits
Soybeans are a good source of plant-based protein. They contain all nine essential amino acids for growth, repair, and immunity-building. They are also rich in vitamins and minerals, including vitamins B1, B2, folate, copper, manganese, phosphorous, and thiamine. Every 100 grams of cooked soybeans contains approximately 172 calories, 6 grams of fiber, 8.4 grams of carbs, 18.2 grams of protein, and 9 grams of fat.

Due to its excellent nutritional profile, soy has various health benefits, some of which are discussed below:

• Improves heart health
  Soy foods can help lower bad cholesterol (known as LDL), improving blood flow to the heart and lowering the chances of heart disease. They contain compounds called phytosterols that work by inhibiting cholesterol absorption in the body, thereby reducing lipid levels.
• Supports bone health
  Soy may reduce osteoporosis risk in women after menopause. This disease affects bone density and increases the likelihood of fractures in older adults. The legume contains isoflavones, a plant-based compound that provides similar effects to the hormone estrogen.
• Helps prevent cancer
  The isoflavones in soy are also known to reduce the risk of certain cancers, such as prostate and breast cancer. The compound’s anti-inflammatory properties can also help prevent tumor growth.
• Manages blood sugar levels
  Soy has a low glycemic index; hence, it does not cause a sharp rise in blood sugar levels. The isoflavones reduce insulin resistance and can help manage diabetes.
• Essential for pregnancy
  Soy is also beneficial for pregnant women. These beans are a good source of folate and zinc, so they help prevent birth defects. Soy milk is also the best alternative for pregnant mothers who are lactose intolerant.
• Aids in digestion
  The fiber in soy helps stimulate the growth of healthy gut bacteria. It makes the digestive system run smoothly and regularizes bowel movements. Hence, people suffering from constipation can benefit from soy foods.
• Improves skin health
  Soy contains biologically active substances like tannins and isoflavonoids, which may help boost collagen production and improve skin elasticity. These components can also combat the effects of UV rays and reduce pigmentation.
• Improves mood and sleep
  People with sleeping disorders or depression may also benefit from soy foods. The estrogen in these beans can alleviate the symptoms of insomnia, restlessness, and depression. Their magnesium content can also help improve sleep quality.

Side effects
Soy is generally safe for most people; however, excess consumption can lead to certain side effects:

• Gastrointestinal issues
  Soy is high in fiber, which can lead to stomach distress if consumed in large amounts. It can cause gastrointestinal issues like bloating, nausea, and constipation.
• Mineral deficiency
  Soybeans have phytic acid that can prevent other minerals from being absorbed into the body, leading to a mineral deficiency. Consuming fermented soy is one way to reduce phytate content.
• Affects thyroid levels
  Soybeans can affect thyroid function if one’s iodine intake is inadequate. The legume contains goitrogenic compounds, which can harm the thyroid gland.
• Allergic reactions
  Soy foods may cause symptoms like itchiness, rashes, and breathing problems in people allergic to the food. The allergy is due to the immune system’s abnormal reaction to soy protein.
• Increases dementia risk
  Unfermented soy foods may affect brain function and increase the risk of dementia.
• Cancer risk
  Though soy may offer protection against certain cancers, it may also raise the risk of breast or endometrial cancer in some people due to its estrogenic effect.

Choosing the right soy products and eating in moderation is vital to avoid the above-mentioned adverse effects. Soybeans are sold in grocery stores in fresh, frozen, canned, and dried forms. It is best to choose whole soy foods like tofu, tempeh, soymilk, and soy bread, which offer a range of health benefits.