Several health functions of black beans: 1. Prevention of constipation: the crude fiber content in black beans is as high as 4%, much higher than that in soybeans. Crude fiber has a good laxative effect. Constipation is a common problem among middle-aged and elderly people. Modern people pay too much attention to delicacy in diet, so that the intake of crude fiber is too small, which increases the burden on the intestine, easily leads to constipation, and also leads to hemorrhoids and colorectal cancer. Eating black beans every day and increasing crude fiber can effectively prevent constipation. 2. High protein and low calorie: The protein content of black beans is as high as 36% to 40%, which is twice that of meat, three times that of eggs and 12 times that of milk. Black beans are rich in eighteen amino acids, especially eight essential amino acids, which are higher than the advanced protein standard stipulated by FDA. Black beans contain oil 19%, of which unsaturated fatty acids account for 80%, and the absorption rate is as high as 95%. In addition to meeting the body's demand for fat, they also have the function of lowering blood cholesterol. Cholesterol is the chief culprit of many senile diseases, while black beans contain no cholesterol, but only one phytosterol, which can inhibit the absorption of cholesterol by human body and reduce the cholesterol content in blood. For the elderly, it can soften blood vessels, moisten skin and delay aging, especially for senile diseases such as hypertension, heart disease, liver and arteriosclerosis. Third, enhance vitality and energy: according to the theory of traditional Chinese medicine, beans are the valley of kidney, black belongs to water, and water belongs to kidney, so black beans have many kidney functions. People's aging often appears from the function of the kidney. If you want to prolong life, resist aging and enhance vitality and energy, you should first pay attention to tonifying the kidney. In traditional Chinese medicine, black beans are used as medicine, while soybeans are not, which highlights the special disease-removing and health-care functions of black beans different from soybeans. Fourth, prevent brain aging: black beans contain about 2% egg yolk, which can strengthen the brain and improve intelligence and prevent the brain from being dull due to aging. Japanese scientists have found that there is another substance in black beans that can improve and strengthen the function of brain cells. Black beans are rich in trace elements. Every100g of black beans contains 370 mg of calcium, 577 mg of phosphorus and 0/2 mg of iron. Zinc, copper, magnesium, molybdenum, selenium, fluorine and other elements are not low. These elements can meet the needs of the brain and delay the aging of the brain. It can reduce blood viscosity and keep the body functional integrity. V. beauty beauty: Many important pharmacopoeias in ancient times recorded that black beans can beauty beauty, improve eyesight and blacken hair, making the skin white and tender; Su Dongpo, a writer in the Song Dynasty, once described the scenes of boys and girls eating black beans for beauty inside and outside the imperial palace in the capital of the Song Dynasty. Qibao Dumeidan, a famous beauty medicine in ancient times, mainly contains black beans. Why do black beans contribute to beauty? Because black beans are rich in vitamins, especially vitamin E and B vitamins, the content of vitamin E is five to seven times higher than that of meat, and vitamin E is the best substance found by human beings to keep young and healthy and prolong life.