Various emotions are related to the state of brain function and the concentration of certain substances in the brain, such as happiness, tranquility, peace, comfort and other pleasant emotions, and the brain 5-hydroxytryptamine content is adequate; anxiety, irritation, sadness, frustration, fear and other bad emotions, and the increase of norepinephrine in the brain. German nutritional psychologist Professor Pader pointed out that bananas can help the human brain to produce 5-hydroxytryptamine substances, prompting a person’s mood to become tranquil, happy, and even reduce pain. Manic depression patients, the brain will not have enough 5-hydroxytryptamine. From the diet to regulate, should try to choose containing vitamin A (such as milk and dairy products, carrots, beets, celery, kale, peppers, onions, bananas, cantaloupe, etc.), vitamin C (such as tomatoes, bitter melon, asparagus, lemons, grapes, hawthorn, oranges, kiwi, etc.) and vitamin E (such as whole wheat, oats, soy, nuts, whole grains, peanuts, almonds, walnuts, sesame, corn flour, vegetable oil etc.) type of food. These vitamins activate superoxide dismutase and slow down the progress of oxidation in the brain. Regular consumption of fish can also improve brain function. Professor Maykel Cullowfield of the Institute of Brain and Nutritional Sciences in the UK found that the higher IQ of Japanese people in general is related to eating more fish in general. In addition, by increasing the level of glucose in the blood, the level of fibroblast growth factor in the brain will rise, thus activating the brain, and memory will be consolidated and enhanced. Most of the glucose in the body is stored in the liver and kidneys, where it remains for about 8 hours. After dinner, after a night of sleep, the next morning when you wake up, the level of glucose in the blood is at its lowest level and brain function is at its worst. Therefore, getting into the habit of eating breakfast on time and in quantity to replenish the level of glucose in the blood in time is also an effective way to improve brain function. Recently, the Japanese Dental Association recommended that people eat by chewing fully, chewing each bite at least 30 times before swallowing. This not only helps digestion, but also excites the masticatory muscles, the taste nerve of the tongue and the olfactory nerve, which greatly stimulates the brain cells, thus speeding up the blood circulation in the brain, activating the secretion of brain hormones, promoting brain metabolism, and further stimulating the hypothalamus and hippocampus tissue, which can enhance memory and improve brain function. At present, some foods can have a negative impact on brain memory, such as potato chips, hamburgers, instant noodles and other fast food. These foods tend to produce lipid peroxide and free radicals in the body, which promote the decline of brain function. Lipid peroxide and free radicals are the basic substances that accelerate the aging of the human body, which accelerates the aging of brain function and atherosclerosis. Medical research proves that atherosclerosis begins after a person enters the age of 30, only at the beginning, the symptoms are not yet obvious. Once cerebral atherosclerosis occurs, blood circulation to the brain will be impaired, manifested as forgetfulness or dementia . Eating high-fat, low-carbohydrate foods regularly can cause damage to brain function and make memory decay. This is because high-fat foods can affect brain function by promoting resistance to insulin, a hormone that controls blood sugar. Insulin resistance is when the body loses sensitivity to insulin, which can lead to obesity and diabetes, and can also cause brain function and memory to decline. Foods lacking in carbohydrates also cut off the brain’s supply of energy glucose, making the brain’s neurological signaling blocked and eventually leading to a decline in brain function.