How much can human life span be extended?

Abstract

The question about extending human lifespan put forward by the famous journal Science is reviewed in this paper. In the present, average life expectancy of the residents in most developed countries is over 80 years old. It reaches 82 in Shanghai and Beijing cities of China, consistent with that in the developed countries. According to accumulating documents, maximum individual lifespan of human being is about 120 years old, suggesting that average life expectancy can be obviously improved in the future. In addition, the lifespan-affected factors, such as longevity genes, epigenetic factors, technology of biomedicine, life style, personality traits and environmental factors are discussed. So far, several longevity genes, such as FOXO3a (Forkhead box O 3a), CETP (cholesteryl ester transfer protein) and Sirtuins, have been identified. SIRT1, one member of Sirtuins has a lot of physiological functions, such as antitumor, regulation of glucose metabolism, anti-inflammation and neuron function. It can be activated by resevratol, a main compound in red wine. Suppressions of insulin/insulin-like growth factor-1 signaling pathway and mammalian TOR (target of rapamycin) signaling pathway have been greatly extended lifespan from single cell organism yeast to mammalian animal mice. Human lifespan has also been affected by epigenetic factors, which play a role for trans-generations. In a word, it is suggested that if you want to be a centenarian, you should have best genetic background of longevity. The trend of modern medicine is precisely taking drugs, minimally invasive surgery, diagnosis and treatment based on big data and intelligence nursing. It will reduce the mortality and extend human lifespan, especially for elderly. Life style is also an important factor for human lifespan. Over-weight and obesity become popular in the globe due to sufficient food supply. Healthy eating and taking regular exercise are best ways to keep healthy state. Calorie restriction, a way of food supply with lower calorie and rich trace elements and protein, greatly extended lifespan in various kinds of model organisms. It shows beneficial to human health. Psychological factors play a very important role in health. According to the data from Baltimore Longitudinal Study of Aging (BLSA) for five decades, personality traits for longevity are activity, emotional stability and conscientiousness. Several longevity areas, such as Sardinia in Italy, Jeju in South Korea, Okinawa in Japan, are well-known. In China, these distribute along with river and are keeping in good ecological condition. Trace element selenium is rich in the soils. It shows a lot of functions, such as antioxidant, antivirus and antitumor actions. In conclusion, the tread of extending human lifespan will be kept in the near future. Novel type of research and effective health education are valuable for improving public health.