The elderly should avoid overcooking vegetables.

　　Statistics show that in developed countries, communities elderly The prevalence of vitamin B12 deficiency is 12%; the prevalence among hospitalized elderly is as high as 30%-40%. In order to avoid this situation, Shan Shouqing, a popular science writer from the Chinese Medicinal Diet Research Association, reminds the elderly to avoid overcooking when eating vegetables.
　　
　　Shan Shouqing pointed out that although the human body needs only 2-5 micrograms of vitamin B12 every day, as long as the daily diet is balanced, vitamin B12 will be decomposed after heating to 100 degrees Celsius for 30 minutes or 120 degrees Celsius for 15 minutes.
　　
　　The elderly have a weak constitution. If they always eat overcooked vegetables, they may easily develop malignant diseases due to lack of vitamin B12. anemia or multiple nerve and psychotic symptoms. Shan Shouqing suggested that the elderly can control the cooking time and heat. Different foods take different cooking times. Leafy foods take less time, while roots and meat foods take more time. In terms of heat, stir-frying is generally done over high heat, while cooking is done slowly over medium to low heat.
　　
　　The elderly also need to learn to distinguish the cookedness of food from the shape, color, feel and taste of the dishes. Generally speaking, dishes that are medium-cooked and cooked look relatively complete in shape and retain their original color. After being picked up with chopsticks, they feel a little hard and can be picked up with a pinch. They need to be chewed before swallowing. In this way, nutrients, especially vitamin B12, can be preserved as much as possible. In addition, if the elderly eat food with appropriate hardness, they can still exercise Chewing ability helps the intestines and stomach better absorb nutrients from food.