Friends are the "right-hand man" to promote health. Fu Chunsheng, a member of the Mental Health Counseling Center of the Institute of Psychology, Chinese Academy of Sciences, said that making friends has at least five advantages.

1. Not easy to get sick. Brent said that people who lack friends or have long-term bad interpersonal relationships tend to have higher levels of stress hormone cortisol, and this long-term tension will damage their health. This also explains why lonely people have a higher risk of cardiovascular disease and are more susceptible to infection. But if you have friends, the cortisol in your body is reduced, and people are relatively less likely to get sick.

2. Sleep better. A study by the University of Chicago found that the more lonely people are, the more insomnia they have. A Swedish study also shows that people who lack friends often suppress and hide their feelings, which makes them more prone to insomnia and may induce depression.

3. Better memory. Dr Lisa berkman, from the Department of Human Development and Health, School of Public Health, Harvard University, USA, found that the memory of elderly people who have less social interaction declines twice as fast as those who have more social interaction. He said that socializing can improve age-related memory decline and fully develop the potential of the brain.

4. smarter. Oscar Barra, a professor at Michigan State University, found that making friends can make people smarter, because making friends requires dealing with strangers, which is equivalent to exercising cognitive ability. For example, if we want to extract sports, entertainment, life, fashion and other topics of interest to different people from the brain "database", the cerebral cortex will always get excited.

5. Long life. Lynn Iles of Flinders University in Australia found that the death rate of the elderly who kept in touch with more than five close friends dropped by 22%, with an average life expectancy of seven years. Fu Chunsheng said that sharing hardships can halve sadness, and sharing happiness can double happiness. This may be because friends can help people relieve stress, solve difficulties, get support and maintain healthy living habits together.