What is the limit of human life? Scientists have been looking for answers. Recently, the British "Independent" wrote that there is still room for improvement in human life expectancy. Researchers at Harvard Medical School have found a "longevity gene" in mice. By replicating this gene in mice, they have extended the life span of mice by half. Scientists believe that it is not a dream for people to live to 150. How long can we live? What affects our life span? The reporter interviewed Professor Jiang, an expert in gerontology at the Institute of Population Studies, School of Social Population, Renmin University of China, and a famous professor of traditional Chinese medicine in Shandong Province. According to the calculation method of cell division, human life span is the product of cell division times and division cycle. The number of cell divisions in chickens is 25 times, the average cycle is 1 year and two months, and the life span is 30 years. Hayflick of the United States made an experiment in 196 1, and found that when the fetal cells divided into 50 generations, all the cells aged and died. Human cells divide from the embryonic stage, and the interval of every/kloc-0 division is 2.4 years, so people's life span should be around 1 20 years old. According to the calculation method of sexual maturity, the life span of mammals is generally 8 ~ 10 times that of sexual maturity. The age of sexual maturity is 14 ~ 15 years old, so it is estimated that the life span of people should be around 1 10 ~ 150 years old. According to the calculation method of growth period, the life span of mammals is equivalent to 5 ~ 7 times of its growth period. If the growth period of a dog is 2 years, its life span is 10 ~ 15 years; The growth period of cattle is 4 years and the life span is 20 ~ 30 years. The growth period of horses is 5 years, and the life span is 30 ~ 40 years. From this, it is estimated that the growth period of people is 20 ~ 25 years, so the life span of people should be around 100 ~ 150 years old. Elmont, a famous biologist in the former Soviet Union, thinks that there is a coefficient of variation in human development and life span, which is 15. 15. A person's gestation period is 266 days. Multiplying it by15 is 1 1 year, and multiplying it by15 is 167 years, which is the highest life expectancy of human beings. ★ Ethnic and racial factors ★ The life span of people in different countries is closely related to many factors such as their economic level, cultural quality, customs and habits, medical and health conditions, geographical environment, climate and so on. In a sense, the average life span of human beings is an important symbol of modern civilization. In the bronze age with low productivity, the average life expectancy of people was only 18 years old, while in ancient Rome it was 23-25 years old. In the future, with the development of production and the progress of science and technology, the average life expectancy will be higher and higher. Before liberation, the average life expectancy of our population was only 35 years old. After liberation, with the improvement of people's material living standards and medical and health conditions, the average life expectancy of the population has increased by nearly 1 times, from 1.985 years to 68.92 years, and is now close to 70 years old. If the national population over 60 is calculated, 10. 1% at the end of 1999,1%in 2000 and 20% in 2025, it is expected to reach the peak of growth in 2050, and the total number will exceed 400 million. ★ Environmental factors★ A beautiful natural environment is not only beneficial to health, but also beautifies people's lives and hearts. It provides a comfortable, quiet and beautiful living environment for families and individuals, and is the cradle of health, happiness and longevity. For example, the world-famous five longevity areas-Caucasus in the former Soviet Union, Hanseatic in Pakistan, Cali in Ecuador, Nanjiang in Xinjiang, China, and Bama in Guangxi. It is an area with beautiful environment, suitable temperature, green mountains and green waters, fresh air and clean water sources. People's life span is not only related to the external environment, but also closely related to the internal environment. The internal environment affects life span through injury, load and disease. For example, intracellular oxygen load has a direct impact on cell aging. Oxygen free radicals can cause DNA damage, which is an important factor affecting the aging process. ★ Genetic factors ★ The influence of heredity on longevity is more prominent in people who live longer. Generally speaking, parents live longer and their children live longer. German scientists investigated 576 centenarians in 15 years, and found that the average age of their parents' death was 9 ~ 10 years older than that of the general population. According to the survey of centenarians in Guangdong Province, 84.6% of them live a long life in their families. Statistics show that the older the population, the higher the family longevity rate. For example, among the elderly aged 80-84, the longevity rate of their families is 52%. In the population aged 105, the family longevity rate is 7 1%. ★ Dietary nutrition factors★ Dietary nutrition is closely related to longevity. The diet structure of centenarians in Changshou area of Chinese mainland is mainly low in calories, fat, animal protein and vegetables. Although milk, dairy products, sheep and beef protein are the main dietary sources of the elderly in Xinjiang, they often eat coarse grains and have no other bad hobbies. There are 1000 centenarians in Sichuan, most of whom are vegetarians and often eat vegetables and bean products. In recent years, with the development of economy, great changes have taken place in the diet structure of China residents. Compared with the 1980s, meat consumption increased by more than 80% in the early 1990s. In areas with high consumption of meat, eggs and fat, the mortality of cancer, cardiovascular and cerebrovascular diseases and diabetes is obviously higher, which shows the influence of changes in diet structure on life expectancy. ★ Psychological factors★ People's psychology and emotions are closely related to health and longevity. People who are often in a state of psychological tension are often prone to illness. On the contrary, optimism and perseverance can enhance the body's disease resistance. Because excessive tension will make the heart beat faster, blood pressure rise, shortness of breath, insufficient blood supply to gastrointestinal organs and so on. Over time, it is easy to cause cerebral vascular rupture or fatal myocardial infarction, and some will also have gastrointestinal spasm and pain. If you are too sad, you will also get sick, leading to short life. ★ Lifestyle factors ★ Diseases caused by unhealthy lifestyles are the biggest cause of death for human beings in the world. In developed countries, 70% ~ 80% people die of heart disease, stroke, hypertension and tumor. So far, these so-called "lifestyle diseases" account for more than 50% of their deaths. The unhealthy lifestyle is mainly eating too much oil, too salty and too sweet, drinking hard liquor, smoking a lot, coveting enjoyment, staying overnight for a long time and exercising less. ★ Disease factors★ Disease is the most important factor affecting life expectancy. The ranking of diseases as the cause of death is constantly changing with the progress of the times and the development of science and technology. For example, at the beginning of the 20th century, the main life-threatening diseases were infectious diseases, pneumonia and tuberculosis. At present, the biggest threats to human life are cardiovascular and cerebrovascular diseases, tumors and accidental injuries. Moreover, some diseases, such as immunodeficiency, Alzheimer's disease, AIDS and so on. It does pose a great threat to human health and life. ★ Family factors ★ A person spends most of his life at home. The quality of family environment, especially the relationship between husband and wife, is directly related to the psychological and physical health of human body, and then affects life expectancy. Medically speaking, quarreling and sulking between husband and wife will lead to an increase in hormones in the body, which will lead to diseases. Moreover, nervous family members and bad mental state can easily lead to many physical and mental diseases and damage life expectancy. Therefore, it is very important for people's physical and mental health and family happiness to maintain harmonious, friendly and pleasant family relations and treat everything with optimism, cheerfulness, always smiling and generosity. ★ Gender factors★ Life expectancy is obviously related to gender. It is universally acknowledged that women live longer than men. This is mainly determined by the biological characteristics of different sexes, and may also be related to the lower metabolic rate of women than men and the endocrine differences between men and women. ★ Occupational factors, etc ★ Life span is also related to occupation. People engaged in dangerous occupations have high mortality and short life expectancy, such as high mortality of aircraft pilots; Workers engaged in radiation research have a short life span. Among the many factors that affect life span, which are the main ones? According to 1992 published by the World Health Organization, everyone's health and longevity depend on themselves, 15% depends on genetic factors, 10% depends on social factors, 8% depends on medical conditions, and 7% depends on the occurrence of climate (such as hot summer or cold). Therefore, health and longevity mainly depend on ourselves, and life is in our own hands. Want to know how long you can live? American scientist Pearl summed up the formula for calculating the approximate life span by studying all kinds of behaviors that are beneficial to the human body and those that are unfavorable to the human body, and according to the clinical experience in medicine. If you are a male, please take 86 years old as the base, answer the following questions in turn and calculate; If you are a woman, please base yourself on 89 years old. 1. Marriage: Married life will extend the life expectancy of men by three years, but it has no effect on women; 2. Excessive pressure: excessive pressure will shorten the service life by 3 years; 3. Long-term separation from relatives: life expectancy is reduced by 0.5 years. 4, sleep less than 6 hours a day: poor rest reduces life expectancy 1 year; 5. Overworked work: overworked, life expectancy is reduced by one year; 6. Think that you may be sick, or feel old: life expectancy is reduced by one year; 7. Smoking 10 cigarettes a day: life expectancy is reduced by 5 years; Smoking 40 cigarettes a day shortens life 15 years! 8. Drink a cup of tea every day: life expectancy is extended by 0.5 years; Drinking caffeinated drinks every day: life expectancy is reduced by 0.5 years; 9. Drinking more than 3 cups of beer/3 cups of alcoholic beverages/4 cups of white wine every day: life expectancy is reduced by 7 years; 10. Don't brush your teeth: bad hygiene habits will reduce your life span by one year; 1 1. No sun protection measures/frequent sunbathing: life expectancy is reduced by one year; 12. Obesity: life expectancy is reduced by 5 years; 13. Eating undercooked meat every day: life expectancy is reduced by 3 years; 14. Regular consumption of junk food: life expectancy is reduced by 2 years; 15. like unhealthy and nutritious fast food: life expectancy is reduced by one year; 16. Eat sweets once a day: life expectancy is reduced by one year; 17. physical exercise: long-term inactivity will reduce life expectancy by one year; Exercise for at least 30 minutes every day: life expectancy will increase by 5 years; 18. There is no guarantee to defecate at least once every two days: life expectancy is reduced by 0.5 years; 19. Regular physical examination to avoid cancer: life expectancy increased by one year; 20. Blood pressure is a bit high: life expectancy is reduced by one year; Hypertension: life expectancy is reduced by 5 years; High blood pressure: life expectancy decreased 15 years; High cholesterol in the body: life expectancy is reduced by 2 years.