Throughout history dry beans have been used as a staple of the diet, and their benefits have been well recognized. Documentation of their use goes back far into the past, long before biblical times. Evidence of dry bean use in Southeast Asia, the Middle East, Africa, the Americas, India and China is available from archaeological evidence.
Most Americans are not eating enough beans, although people in the southern and western regions of the United States consume more than those in the Midwest and Northeast, even though half of the beans grown in the country are from North Dakota and Michigan. Americans consume about 6.5 pounds of dry beans yearly which is equal to a little more than 1/4 of the 2005 Dietary Guidelines for Americans’ recommendation of 3 cups of beans per week (dry weight ~200 g).
Dry beans provided abundant nutrients per calorie. Increased intake will provide nutritional benefits to the diet, and may help to reduce disease risk and enhance longevity. In a recent multicultural study, the consumption of beans was shown to be the only dietary component related to longevity. In a study called the “Food Habits in Later Life Study,” investigators found that for every 20g intake of legumes (including dry beans), the risk ratio of death was reduced by 6% in the older people (aged 70 and older) studied.
Dry Beans are Nutritionally Rich
Although dry beans vary considerably in flavor, size, color, and shape, their composition is remarkably similar. They are packed with protein, carbohydrates, vitamins and minerals, and are low in fat. One half cup of cooked dry beans contains approximately 115 calories and provides 8 grams of protein. Dry beans contain several types of phytochemicals such as Lignans, flavonoids, and phytosterols. There compounds may play a role in preventing osteoporosis, heart disease, and certain cancers.
Dry Beans Provide Complex Carbohydrate sand Fiber
Sixty to 65% of the calories in dry beans are from carbohydrates, predominantly in the form of starch. Dry beans are rich in both soluble and insoluble fibers, so they provide the nutritional benefits of both fiber classes. Beans contain some complex sugars of the raffinose family. These are the sugars that cause digestive issues with bean consumption because the required enzymes not available in the human and microbial action in the colon results in gas production. These sugars can be removed from the beans by soaking and then cooking them, discarding the soaking and cooking liquids.
Dry Beans are a Major Source of Dietary Protein
Dry beans are very good source of low fat protein. In many parts of the world, they provide a substantial proportion of the total protein intake for the population. The intake of dried beans as a protein source is extremely important worldwide as they provide a good source of protein at minimal cost relative to the production of animal protein sources.
Dry Beans are Low in Fat
The fat content of dry beans is very low (less than 2% of total content), and they contain predominately unsaturated fatty acids. There is some variation based on variety and growth conditions, but most beans contain about 85% of their fat as unsaturated fatty acids. Because dry beans are plant foods, they are cholesterol-free.
Dry Beans are Plentiful in Vitamins and Minerals
As for vitamins and minerals, beans are an excellent source of copper, phosphorus, manganese and magnesium—nutrients that many Americans don't get enough of. Most dry beans are a rich source of iron, which makes them ideal for vegans who do not get an animal source of iron. The nutritional content of most dry beans is very similar, with the exception of iron content. White beans have almost twice the iron of black beans, while kidney beans are somewhere in between.
Dry beans are an excellent source of the water-soluble vitamins thiamin and folic acid and a good source of riboflavin and vitamin B6.
Nutrient dense dry beans are low in fat, high in fiber and packed with protein. Dry beans provide a rich source of vitamins and minerals as well as plant phytochemicals. Including 3 cups of cooked dry beans in the diet on a weekly basis will meet the U.S. Dietary Guidelines for Americans. In addition, they will enhance health-promoting aspects of the diet and be important in reducing risk for chronic diseases such as obesity, cancer, diabetes and heart disease.