Unless you’re talking about fine wine, some cheeses and assorted other foodstuffs, aging has a slightly negative connotation. Getting older we can stand, but aging has the uncomfortable subtext as being never-ending, a slow deterioration leading to inevitable decrepitude and (whisper) death. Frankly, it’s something we’d rather not do.
We are all familiar with the outward signs of aging, but what is it that actually sets the process in motion? Why do some people seem almost "ageless" while others seem to "get old before their time?"
What is aging?
Biologists call it senescence and it is defined as "the combination of processes that contributes to the gradual deterioration of an organism." There we go again, "gradual deterioration.." More unpleasant words! There are many theories as to why things age. Ancient philosophers believed that each living being possessed a finite amount of life-
giving substance, or a pre-determined number of breaths and that we declined and eventually died as our supply of substance or our number of breaths were used up.
The relatively recent science of Gerontology, or the study of aging, aims to find the answer not a single theory, but looks to understand how some of the main theories popular today may explain the process of aging.
Is it all in the programming?
Programming theories of aging rely on the fact that every species of animal, and for that matter, plants, seem to have a natural lifespan. While individuals within a species may live longer than others, all eventually succumb to disease and death. Proponents of the programming theories argue that aging is a necessary part of the evolutionary process—if we didn’t need feel the biological imperative to replicate ourselves, we probably wouldn’t. We would choose to live forever, and therefore stop evolution in its tracks. Our cells are programmed to die because in a perverse way, our lives depend on it.
Telomeres, a copying glitch?
If you’ve watched Dr. Mehmet Oz on the Oprah show, you’ve probably heard of telomeres. Telomeres are sequences at the end of our chromosomes that in the past were considered "junk DNA", bits of proteins that, because they were not true genetic material, were thought not have a particular purpose. Or none that science could determine at the time.
Today, however, telomeres have emerged as one of the leading contenders in the modern theories of aging.
The theory is this: telomeres, though not genetic material themselves sit at the ends of the chromosomes, and their function seems to be that of protecting the chromosomes from damage. When cells reproduce, the tips of the chromosomes do not reproduce exactly, making the chromosome shorter and shorter with each duplication. Think of photocopying the photocopy of a printed page, and each time, not placing the paper on the copier exactly. Eventually the first line of the page will be cut off, and with each copy, more and more of the first line gets cut off, and becomes, after many reproductions, becomes unreadable. Much the same thing happens with telomeres. Shorter telomeres leaves the cell unprotected and vulnerable to damage.
Free radicals, the rogues of the aging process
It may sound like a throwback to the hippie culture of the sixties, but the free radical theory of aging is one of the most widely accepted by mainstream medicine, and may be the reason many of us swallow “antioxidants” like Vitamins C and E daily. First conceived by Dr. Denham Harmon in 1954, the free radical theory suggests that as our cells go about their normal metabolic functions, they produce highly unstable, oxygen byproducts that Dr. Denham labeled “free radicals”. Without getting too complex, unlike other molecules that come in pairs, free radicals are unpaired, and seek to pair up with other molecules in a sort of degenerative mating dance. Once they attach themselves to other molecules, they cause damage by chemically altering them, often permanently. Free radicals damage collagen, elastin, and even our DNA, which scientists say, explains among other things, the sagging skin and the degenerative diseases that come with increasing age.
Wear and tear—it happens to bodies too
Way back in 1882, Dr. August Weismann, a German biologist credited with being one of the founders of the science of genetics, posited that the body’s cells became damaged over time through sheer use and abuse. Toxins, both in the body and in the environment, and excessive consumption of fat, sugar, caffeine, and nicotine, he believed, wore down
the body’s tissues and contributed to the body’s decline.
The endocrine theory—our hormones are to blame
First proposed by Drs. Vladimir Dilman and Ward Dean in the 1960s, this theory points to the fact that the endocrine system, the complex of glands that secretes hormones throughout the body, changes as we age: the thymus gland, for example, often referred to as the “youth gland’, shrinks from an average 250 grams in infancy to a mere 3 grams in late adulthood. The reduction in size seems to correlate with suppression of the immune system which itself, it is theorized, leads to our vulnerability to age-related conditions.
Our genes, ourselves?
Other theories focus on our genetics. In the genetic theory of aging, it is assumed that the body, much like an automobile, has a sort of built-in obsolescence. The outer limit of the human lifespan we now know is about 120 years. This is potentially possible for all of us, but our individual genetics dictate our personal lifespan and aging schedule. We all know people who, without plastic surgery, look "young for their age", while others seem to be on an accelerated pace to old age.
All of these and the other hundreds of theories seem to have some basis in fact. But whatever the theory, the result remains the same—gradual decline. But is aging an inevitable fact of life? As we discover more about human genetics, might our theories of aging change along with life expectancy?
Changing the aging landscape
Despite the news headlines about obesity, diabetes, high blood pressure and all the other diseases that are shortening the American lifespan, we are living longer. The US Census Bureau, in June 2008, estimated that there are about 95,000 Americans over the age of 100. This number is expected to more than quadruple to an estimated 1.1 million by 2050. If we take heed and take better care of ourselves, might we continue to push the limit of the human lifespan?
The Methuselah Foundation, named for the Biblical oldster who in the book of Genesis is said to have lived an impressive 969 years, thinks so. The Foundation’s stated goal is the "defeat of age-related diseases and the indefinite extension of the healthy human lifespan." To achieve this goal, the Foundation funds two projects the MPrize, a research prize for the successful extension of the life-span of the laboratory mouse, and the SENS (Strategies Engineered Negligible Senescence) Project. This dual-pronged research, they hope, will give us humans the tools to repair "all known forms of aging-elated damage to the body."
Defeat of age-related diseases? Is this even possible? We’re not there yet, but we are getting closer. We’ve been told that healthy diet, exercise, and stress reduction contribute to healthy aging, and there are communities of people worldwide who seem to have done a remarkable job of remaining healthy and vibrant well into their advanced years.
Back in the late 70s, yogurt manufacturer, Dannon, launched television ads featuring men and women in then Soviet Georgia who, fueled by bacteria-filled yogurt lived to energetic old age free from the diseases of their American counterparts. The Hunzakut who live in the lush Hunza valley in
North Pakistan, the area said to be the inspiration for the fabled Shangri-La, are also touted to live long, disease-free lives. Okinawa island in Japan, boasts the largest concentration of centenarians in the world. There are also significant numbers of centenarians in regions as wide-ranging as the Nicoyan Peninsula in Costa Rica and the island of Sardinia in the Mediterranean where Western diseases like heart attacks stroke, cancer, dementia, and obesity are rare.
Why do these populations do much better at aging than we do? Well diet for one. People living in these regions eat a variety of locally grown mostly unprocessed foods, and consume roughly 1,900 calories per day compared to the 3,300 fat-and sugar-laden calories for the average American. They also live relatively stress-free lives, have a strong sense of
community, and live in extended families.
Insights from the very old
The oldest woman on record, Jeanne Louise Calment who at her death in France at age 122, was relatively healthy and lucid to the very end, probably ate the typical Mediterranean diet and had the glass of resveratrol-filled red wine that doctors recommend today, but she also smoked until she was 117, giving it up briefly for a year when advised against
it, before resuming the habit at 118. Madame Calment attributed her longevity to her genes—her father lived to 97, but her two children predeceased her, dying in their thirties.
Dutchwoman Henrikje van Andel-Schipper, was also a bafflement to modern science. After her death at 115, an autopsy of her brain showed none of the degeneration that would be expected in a woman of her age. Not only that, but van Andel-Schipper was extensively studied for her cognitive functioning at age 112-113, and was found to perform at the
level of the average 60-75 year old. Weighing a frail 3.5 pounds at birth, she jokingly attributed her durability to the picked herrings she had enjoyed all her life.
Maria Esther de Capovilla of Ecuador, 116 at the time of her death in August 2006, had never smoked, was deeply religious and ate small, regular meals. She surmised that the donkey milk she had drunk since childhood contributed to her long and healthy life. Four months later, Elizabeth, “Lizzie” Jones Bolden, the daughter of freed slaves, also died at
age 116 in Memphis Tennessee. Ms. Bolden revealed no great secrets to her longevity. In failing health in her later years, she nonetheless lived long enough to see her 40 grandchildren, 75 great-grandchildren, 150 great-great-grandchildren, 220 great-great-great grandchildren and 75 great-great-great-great-grandchildren.
So how do we live to a "ripe old age?" After all the theories and explanations, it seems clear that aging is an intricate mix of genetics, chemistry, or individual physiology, and behavior that we are still trying to sort out. We can attempt to achieve healthy old age by following the recommendations of doctors and using common sense about diet, stress, and exercise, but in the end, Jeanne Calment’s advice might be the simplest, and the most telling: "Keep breathing."