What to know about Glycine max (soybean) before using it medicinally

Glycine max, commonly known as soybean, is a herbaceous legume that has been used for centuries to improve heart health, reduce inflammation, and support bone health due to its rich content of isoflavones and protein.

Cultivated worldwide, it is a hardy crop that grows up to 3 meters in height, requiring a warm and humid climate to thrive. The botanical properties of Glycine max reveal that it belongs to the Fabaceae family and is a member of the genus Glycine, characterized by its compound leaves and white or purple flowers.

Ancient Chinese and Japanese civilizations have valued Glycine max for its medicinal properties, with records of its use dating back to the 17th century as a treatment for various ailments, including fever and indigestion.

This article explains the medicinal, horticultural, botanical, and historical aspects of Glycine max.

What are the medicinal properties of Glycine max?

Glycine max helps with cardiovascular health by reducing triglycerides, lowering LDL cholesterol, and improving HDL cholesterol levels. It also has antioxidant and anti-inflammatory properties, which may help protect against cancer and neurodegenerative diseases. Additionally, it has been shown to improve symptoms of menopause and osteoporosis.

The active constituents of Glycine max include isoflavones (genistein and daidzein), saponins (glycosides), and polyunsaturated fatty acids, which are responsible for its medicinal properties. These compounds have been shown to have estrogenic, anti-inflammatory, and antioxidant effects. They also have a potential role in reducing the risk of certain cancers and cardiovascular diseases.

The most commonly used parts of the plant for medicinal purposes are the seeds, leaves, and root. The seeds contain the highest concentration of isoflavones and saponins, which are believed to have the most medicinal benefits. The leaves and root are also rich in antioxidants and have anti-inflammatory properties.

Improper use of Glycine max may lead to side effects such as estrogen dominance, allergic reactions, and interference with blood clotting. Excessive intake of isoflavones may also cause gastrointestinal symptoms and interact with certain medications. Pregnant and breastfeeding women should use it with caution.

When using Glycine max medicinally, precautions should be taken to minimize potential side effects. These include starting with low doses, monitoring for signs of estrogen dominance, and avoiding use in individuals with thyroid disorders or bleeding disorders. Additionally, pregnant and breastfeeding women should consult a healthcare professional before using it.

What are the horticulural aspects of Glycine max?

Glycine max grow well in full sun to partial shade, requiring a temperature range of 65-95°F (18-35°C). Soybeans are sensitive to extreme temperatures, drought, and flooding, and require well-drained soil with a pH between 6.0 and 7.0.

For optimal growth, plant soybeans in rows 20-30 inches apart, with seeds 1-2 inches deep and 6-8 inches apart. Soil should be tilled to a depth of 8-10 inches to loosen and aerate the soil. Soybeans require 60-90 days of warm weather to mature, and are typically planted in late spring or early summer.

Soybeans are ready to harvest when the pods are dry and the leaves are yellowing. Cut the plant at the base, leaving 2-3 inches of stem attached. Dry the soybeans further by tying the plants in bundles or by spreading them on a dry surface. Harvest within a few days to prevent spoilage.

Soybeans are susceptible to several pests and diseases, including aphids, whiteflies, spider mites, powdery mildew, and root rot. Aphids and whiteflies can be controlled with insecticidal soap or neem oil, while powdery mildew can be treated with fungicides. Regular watering and crop rotation can help prevent root rot.

What are the botanical aspects of Glycine max?

Glycine max is an annual legume with a slender stem, 0.5-1.5 m tall, and pinnate leaves with 3-5 leaflets, 3-10 cm long, with 2-4 pairs of leaflet pairs.

Glycine max belongs to the Fabaceae family, genus Glycine, and species max, native to East Asia. Its taxonomic classification is: Kingdom: Plantae, Clade: Angiosperms, Clade: Eudicots, Clade: Rosids, Order: Fabales, Family: Fabaceae, Genus: Glycine, Species: G. max.

The plant has several variants, including: 'CNS', 'Kumiai', 'Dongfang', 'Braga', and 'Mukuna', among others, differing in seed type, color, and yield. Variants can be grouped into: determinate, indeterminate, and semi-determinate growth types.

Glycine max is widely cultivated in tropical and temperate regions, particularly in: China, the United States, Brazil, Argentina, and India, with smaller areas in Europe, Africa, and Oceania. It thrives in well-drained, fertile soils with adequate moisture.

The life cycle of Glycine max is as follows: seed germination (1-10 days), seedling establishment (1-2 weeks), vegetative growth (1-4 weeks), reproductive growth (1-4 weeks), flowering (1-4 weeks), pod formation and seed maturation (2-4 weeks), and harvest (3-5 months).

What are the historical aspects of Glycine max?

Glycine max is one of the oldest cultivated legumes, with a history dating back to around 11000 BCE in East Asia. It was primarily used as a food source, particularly in China, where it was considered a staple crop.

In ancient Chinese mythology, the soybean was associated with the goddess of fertility, Shennong, who was said to have domesticated the plant. In Japanese mythology, the soybean was connected to the sun goddess, Amaterasu. These mythological references reflect the significance of the soybean in ancient cultures.

The soybean has been imbued with symbolic meanings across cultures. In Confucianism, the soybean represents abundance and fertility. In Japanese culture, it symbolizes good luck and prosperity. In Hinduism, the soybean is associated with the goddess of the harvest, Lakshmi.

Historical texts, such as the Shu Jing, a Chinese classic, and the Kojiki, a Japanese mythology, document the soybean's cultivation and significance in ancient times. The texts describe the soybean's uses, from food to medicine, and its importance in cultural and spiritual practices.

Archaeological findings have revealed the soybean's historical importance in ancient cultures. Excavations in China's Yangtze River valley have uncovered soybean remains dating back to around 8000 BCE. In Japan, soybean artifacts, including pottery and tools, have been discovered in the Jomon period (14,000-300 BCE).