00 the average life span was 47years now 1990 itincreased to 75 years. This advancement is mainly because of medicalimprovements and sanitation improvements.On the other hand maximum human life span seem to be a problem. There is no evidence that this has changed for thousands of years despitethe fabled fountains of youth and biblical tales of people living to be 500years. Life expectancy has moved from legend to laboratory. Gerontologist explore the genes , cells, and organs envolving aging. theyare tring to uncover more secrets of longevity.What Determines Longevity?There are certain factors that determine how long we can live. Sometimes these factors can have a fairly large impact on us.The first is genectics. We cannot change the genectic hand we aredealtin life. Some of us are inherently predisposed to various degenerativediseases and cancers. Others are given a very long life span, if they dontmess it up. Those with a bad genectic background can change theiroutcome through appropriate vigilance and behaviors. Collated Damge should be avoided. Meaning if you have lung cancer, refrain fromsmoking.The second would have to do with oxidation damage. The chemicalprocess of oxidation is involved in many of the changes of aging, includingheart disease, the promotions of many cancers, and Alzhimers disease. Oxidation is increased with exposure to the sun, radiation (includingx-rays, ultra violent light, and cosmic radiation) and various chemicals. The process is slowed down by the bodys anti-oxidant system whichrelies on a number of different vitamins, minerals, and other compoundsfound in foods.The third is Trama. Physical and chemical damage can shorten ourlife span, by a little bit at a time or in whole chunks. Physical trama includes sun damage and that caused by improper exercise or beingoverweight. Chemical trama can be from pollution with tobacco or excessalcohol, many physical and chemical tramas are those we put ...
