Soybeans are one of the world's most important crops. Soy, like wheat and corn, plays a substantial role in feeding large numbers of people throughout the world.
Soybeans have been part of the Chinese diet for at least 5,000 years. Indeed, many Asian countries have been consuming a wide range of soy products for centuries, and it is often to the soy-rich diets of these cultures that scientists now attribute their populations' heart health and longevity. Because many soy products originated in Asia, they have Asian names
America has grown soybeans for only a fraction of the time that they have been cultivated in Asia. Soybeans were introduced in the U.S. in the mid-1700's, but their acceptance as a food crop was slow: Soybeans were valued almost exclusively as animal feed.
That opinion started to change in the early 1900's when people like Henry Ford began to explore soy's role as a source of human nutrition. As the 1900's progressed, soy slowly began to enter the American diet. Americans were hesitant to accept soy primarily because many of the soy products back then were designed for the largely unfamiliar Asian palate or were poorly made.
Within the last 30 years, this has all changed. The quality of soy products has increased dramatically. Increasing numbers of soy products are being developed and produced specifically for American palates and lifestyles.
There is also a growing body of credible scientific research supporting the beneficial health effects of soy:
- According to The Food & Drug Administration's 1999 unqualified health claim, eating 25 grams of soy protein per day as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease.
- Soy shows great promise in reducing the risk of certain cancers including breast and prostate cancer.
- Evidence suggests that isoflavones in soybeans may reduce bone loss in post-menopausal women, and relieve menopausal symptoms.
- Soy is also perfect for lactose- or gluten-free diets since soy contains neither or them.
- Ongoing research indicates that soyfoods may help diabetics control their blood sugar and lower their risk of complications of the disease, like kidney disorders.
These two developments—the improved quality of soyfoods and the increasing evidence of significant health benefits—are responsible for increasing soyfoods' appeal to American consumers and consequently their accelerated entry into the mainstream American diet.
Getting to Know the Soybean
Soybeans thrive in the hot, wet climate of the Midwest, which is why most (two-thirds, in fact) of the American soybean crop is grown in the heartland states of Iowa, Illinois, Indiana, Minnesota and Nebraska. Twenty-six more states make up the remaining one-third of all soybean-growing states, which include Tennessee, Kentucky, the Dakotas and Kansas.
Soybean plants take 70 to 80 days to grow from seed to harvest. The mature plant is about 18 inches tall and bears slightly fuzzy, three- to four-inch pods, each encasing two to five soybeans. The look a little like sweet-pea pods, only longer, plumper, and more rugged in texture.
The soybean plants are harvested mechanically with a combine, and, depending on their variety, the harvested beans can range in color from light to dark shades of yellow, black and green. These beans are the only part of the plant that humans eat.
Soybeans are legumes like peas, beans, lentils and garbanzo beans. Unlike other legumes (or any kind of vegetable), soybeans "fix" their own nitrogen which allows them to produce all of the nine amino acids essential to human life. Soybeans also contain the two essential fatty acids.
These two qualities—the amount and quality of protein ("complete" protein) and fat.—are what make them one of nature's most beneficial and unique crops, and truly unique in the plant kingdom:
Soybeans contain about 38% protein, which is a high percentage for plants. (By comparison, wheat is no more than 15% protein.) Additionally, all that protein is complete protein, meaning that it contains all the amino acids in the correct proportions necessary to sustain human life, as described above. Complete proteins are most commonly found in meat sources, which also contain cholesterol. For this reason, and because soybeans are a cholesterol-free protein, soy makes a nutritionally sound alternative to meat in most American diets, and an ideal protein source for vegetarians.
The Fat, the Fiber & the Carbs
In addition to the quantity and quality of its protein, soybeans are also an excellent source of fat. Soybeans contain about 18% oil and it’s the kind of oil that has a positive effect on health and well-being.
Soy oil is cholesterol free, very low in saturated fat and high in mono- and polyunsaturated fats. In addition, soy oil contains important amounts of both essential fatty acids: linoleic acid and linolenic acid. An essential fatty acid is essential to support human life but cannot be produced by the human body—we can only get it from the food we eat. Sufficient intake of these essential fatty acids is crucial for optimal health. Soybean oil also contains lecithin, an emulsifier used extensively in food manufacturing.
The balance of soybeans is moisture (14%) and carbohydrate (30%). Soybeans are considered an excellent source of dietary fiber because half of their total carbohydrate (15% of total soybean composition) is dietary fiber. The rest is soluble carbohydrate.