The Hayflick limit is the number of times that a human body cell can divide successfully, and this number determines how long you might live. If you cannot replace your cells through cell division then you cease to exist.
The oldest documented person has lived over 120 years. The Guinness Book of Records verifies that Jeanne Calment, a French woman, lived 122 years. She died in 1997.
Interestingly, the maximum recorded life span for people has increased over the centuries, from 103 years in the 1700s, to 110 in the 1800s, 115 in 1990 and over 122 in 1997.
The reduction of infant mortality accounts for most of the increased longevity, but it has been noted that since the 1960s, mortality rates of people over the age of 80 have been decreasing steadily by about 1.5 percent per annum. This has been attributed mostly to public health efforts, rising standards of living, better education, healthier lifestyles and better nutrition.
Animal studies suggest that humans could extend their lifespan by caloric restriction and also ensuring adequate nutrition. Primate studies particularly suggest staying lean and choosing highly nutritious food promotes a longer healthier life. Other studies point to the measure of the volume of oxygen flow to the heart as being of prime importance. This measure is called the VO2 max, which normally decreases as one ages.
Scientists postulate that the maximum lifespan possible can be calculated by determining when a person’s VO2 max is likely to drop below the basal metabolic rate needed to sustain life. This number is 3 ml of oxygen per kg of body weight per minute. Athletic individuals, it is estimated, could live 100 to 125 years if they keep their activity up, so as to maintain a healthy oxygen flow to their heart.
Another exciting discovery in longevity studies is telomere support. Inside the nucleus of our cells, our genes are located on twisted, double-stranded molecules of DNA called chromosomes. At the endings of the chromosomes are bits of DNA called telomeres, which guard our genetic data, make it possible for our cells to divide and impact how fast we age at the cellular level. Telomeres have been likened to the plastic ends on shoelaces, because they prevent the chromosome ends from fraying during cell division. However, each time a cell divides, the telomere get shorter. When they get too short, the cell can no longer divide and it becomes inactive or dies. This process is associated with aging, cancer and death.
Telomeres can be protected by eating foods high in antioxidants, or by taking specially formulated telomere support nutritional products.
In summary, eating well, staying lean and exercising — especially cardiovascular exercise to keep your VO2 max optimal, and ensuring that your diet has an abundance of antioxidants either from food or from a reputable nutritional company — will help you age gracefully, and not show the signs of deterioration that we normally associate with the aging process.
• Jane Riley, M.S., B.A., C.P.T., Certified Nutritional Adviser, can be reached at firstname.lastname@example.org, 212-1451 or www.janerileyfitness.com.