Do you want to know if you can live a long life?
Do you want to live a long life? If the answer is yes, then congratulations, as someone living in the 21st century, you will almost certainly outlive your grandparents.
With the improvement of medical level and quality of life, the average life expectancy of human beings is increasing year by year, which is an indisputable fact. The question is, will this upward momentum slow or even stop? Many people intuitively think that the upward trend must be slowing down year by year, but the research results are contrary to intuition. Dr. Jim Orpen of the University of Cambridge in the United Kingdom and Dr. James Vaupel of the Max Planck Institute in Germany studied the increase in average human life expectancy from 1840 to 2002. The two used the year as the X-axis, with the longest life in that year The average life expectancy of the country is used as the Y axis, and a chart is made, and it is found that these data points are almost connected in a straight line, and the rate of increase has always remained at the level of an increase of three months per year. In other words, human life expectancy is still on a straight-line rise, showing no signs of slowing down.
The paper was published in the May 2002 issue of Science. The two authors also further studied the reasons for the increase in life expectancy, and found that the increase before 1960 benefited from the decline in the death rate of young and middle-aged people, that is, the increase in the level of basic medical care, while the increase after 1960 was mostly due to the death of the elderly The rate of decline, which is what most readers care about “longevity”. This result shows that the average life expectancy of the elderly still has a lot of room for improvement, and it is far from reaching the limit at present.
The next question is: Do you want to know how long you can live? There used to be a very popular online game. Players input basic information such as their gender, age, family situation, eating habits, living habits, income, and family life expectancy into the computer, and the computer would calculate how long they could live. This game has some scientific basis, because many studies have proved that a person’s living habits and genetic type can have an impact on his lifespan. However, living habits and dietary conditions are acquired factors, which basically depend on a person’s willpower. This is not the case with genes, which are unchangeable factors and are more suitable for “fortune-telling”.
So, is there such a thing as a “longevity gene”? Before answering this question, let’s discuss the “death gene”. Many people believe that there must be such a gene in the biological world, which will automatically attack and kill the owner after a certain period of time. This statement does not conform to the theory of evolution, because most organisms in nature are eaten by natural enemies before the arrival of old age. The so-called “old death” rarely occurs, so there is no need to specially evolve a “death gene”.
From this perspective, the evolutionary power of “longevity genes” is not great, because most organisms lose their reproductive ability in their later years, and “longevity” is of little value for species reproduction. However, this does not prevent organisms from evolving some genes that can reduce the incidence of disease, thereby indirectly increasing lifespan. In fact, scientists have been trying to find these “longevity genes”. Unfortunately, in the era when genome sequencing was still very expensive, people could only speculate on the impact of genes on lifespan by studying twins. This kind of research has been done many times, and the conclusion is about 25%, that is, the contribution of genes to longevity is only about 1/4, and the other 3/4 comes from the influence of acquired environment.
After the widespread availability of genome sequencing technology, the scope of such research has rapidly expanded to include ordinary people. Dr. Paula Sebastiani, a professor of biostatistics at the Boston University School of Public Health, and a research team led by her studied the genes of 1,055 American Swiss (centenarians) and compared them with 1,267 ordinary people. , and it was found that 150 genetic loci (SNPs) differed between the two groups. The researchers used a special statistical method to study the results and found that these 150 gene loci can be used to calculate whether a person can live longer, and the accuracy is as high as 77%!
This article was published in the July 2010 issue of “Science”. The magazine obviously thought it was a big news, and announced the news on the Internet a week in advance. It soon attracted doubts from many scientists, and the doubts mainly focused on the gene chips used by researchers. For reasons unknown, the researchers used different types of microarrays, a practice thought to be likely to introduce errors in the genetic analysis. Dr. Carly Stufferson of a gene sequencing company in Iceland even named the chip in question——Illumina610. He concluded through calculations that as long as 10% of the subjects used this chip, it would be enough. leading to deviations in forecast results. And 108 out of 1055 people used this chip, exactly 10%.
But one by-product of this research deserves our attention. Dr. Sebastiani found that the number of disease-causing genes in these people is no less than that of ordinary people. The reason why they live longer is that the “longevity genes” they carry can offset or inhibit the disease-causing genes. hazards. This finding, if proven correct, could explain why geneticists have had such a hard time figuring out how diseases are inherited. In other words, many disease-causing genes are covered by other “disease-resistant genes”, so they cannot be detected.
To put it bluntly, people all die of illness, and the root cause of longevity is not to get sick. Therefore, instead of studying how to predict longevity, it is better to study how to cure diseases.
