Source: The Mercury, 11 November, 1997, p.26-27 Source: The Mercury, 11 November, 1997, p.26-27
WHAT can we do today to live longer? Some tips for sidestepping the land mines: * Stop smoking-quitting for five years adds two years to the average life expectancy. * Exercise-90 minutes a day for more than three years adds three years; 20 minutes a day for that long adds one year. * Reduce blood pressure- below 120/80 adds three years. * Cut fat-if less than 20% of total calories, adds two years. * Cut bad cholesterol - below 160 adds a year. * Boost good cholesterol- above 65 adds a year. * Prevent diabetes-adult onset diabetes cute a year. · Eat fruit and veggies - five servings a day adds one year. * Mate well - a happy marriage adds two years for a man, one for a woman. * Socialise-Seeing three social groups once a month adds two years. * Protect kids - Immunise, eliminate household hazards, teach swimming, avoid gangs. * Get tested-Between 40 and 65, begin routine teats for prostate, breast and colon cancer. * Drink in moderation. * Practise safe sex. * Use seat belts and child car seats.
GALAPAGOS tortoises can live to be 152 years old. Could we? The short answer is: no. The long answer is: A growing number of scientists doubt the longheld belief that humans have a genetically programmed "maximum age" of 120 to 125. They say there may be no limit to our lifespan. With healthier living and a few medical advances, we may be able to push the boundaries. At the least, living to 85 or 90 soon should become routine, and many more of us will reach the century mark, without years of debilitating illness. "A lot of people always said 'Who'd want to live to be 100?' Well, if you're healthy and active, you'd want to," said Ken Manton, a Duke University demographer. Manton said he tries to practise what he preaches, adhering to a better diet and exercising more. "I'm like everyone else," he said. "I want to live a long time." The single best way to live longer is to inherit good genes. Short of that, human ingenuity has helped. Americans' average age has climbed from 47 in 1900 to 76 today, thanks to healthier living, better medicine, and vaccines and sanitation that have wiped out killer infectious diseases. The ranks of the elderly are climbing rapidly. About 60,000 people topped the age of 100 last year. Four million beat 85, almost double that of 1980. By 2020, the US Census Bureau expects 214,000 centenarians and seven to eight million people over 85. One in nine Baby Boomers may live a century. At the end of World War II, only one in 500 made it. Picture your lifespan as a road riddled with potholes. Dodge one and your lifespan ticks up. As kids, the threats are infant diseases, accidents and parents who kill. Young adults succumb most to accidents and infectious disease (led by AIDS). Middle-agers must beat heart disease and cancer, twin killers that decimate those in their 60s and 70s. But make it to 75 and chances are good you will see 86. Reach 80, you'll live another eight years on average. Women typically live six years longer than men. Overall, however, some scientists believe none of us will ever approach the tortoises. They contend we can live only so long, that our cells are programmed to die after a given time. In this view, the average age tops out at about 85. The healthiest of us would hit a "brick wall" at about 120. Thing is, the wall keeps moving, according to researchers who doubt the theory. It was in 1800 that a person was first confirmed to be 100. (Tales of ancient Russians living to 120 have never been proved.) Proof of the first to reach 110 came in the 1930s, the first to reach 120, in 1986. This year, a French woman died at a confirmed age of 122. The increases in maximum age and average age have been accelerating. Studies predict a slow and steady increase in longevity, and by the 2065 expectations are the average age will be 86. Some scientists believe we can extend longevity to the mid-9Os simply by living right: no smoking, a low-fat diet, plenty of exercise. "It's not extreme behaviour that does it," Duke's Manton said. "It's not running a marathon. It's going out walking four or five times a week; it's eating a sensible diet with limited fat." Manton is not naive enough to think people will suddenly change their ways, given that. But he and others said generations reaching old age in the next few decades are better educated. They know more about healthy living, are more interested in it and are more wiring to try "There's tremendous capacity for advances even if there are no more medical breakthroughs," said demographer Sam Preston, of the University of Pennsylvania. "And you know there will be some of those." In the early 1900s, longevity jumped as antibiotics beat killers such as diphtheria. People lived long enough to die from heart attacks and cancer. Now we're making headway against the chronic diseases, sometimes with new uses for old remedies. Humble aspirin turns out to be a heart attack preventer. Ibuprofen may ease Alzheimer's disease. Most ulcers, we now know, are caused by a bacteria that is easily killed. Vitamin E boosts the immune system, combats free radicals and helps genes that fight cancer. New drugs can reduce the effects of a heart attack or a stroke in progress. People live longer with cancer. There's tremendous promise in the emerging field of genetics. Almost daily, researchers find another cause for disease and death within our 100,000 genes. Because genes are the inherited instructions for replacing cells, one mutation may have a big impact. In flies and worms, scientists have found that certain genes lengthen life, others shorten it. A mutation creates the opposite effect. One sequence of genes responds to adverse conditions by slowing the metabolism, which ultimately extends life. "The next big question for many gerontologists is whether there are counterparts in people," according to a 1996 report by the US federal National Institute on Ageing. In one recent breakthrough, researchers proved that mutations in a tumour-suppressor gene, p53, can lead to cancer. So called proliferative genes trigger fast reproduction, which unchecked can cause cancer. Meanwhile, other genes have been identified that combat overactive eels. Researchers believe dozens, if not hundreds of genes control longevity. Ultimately, they hope to learn to manipulate the process and lengthen life. "We're getting to a takeoff point where these technologies are going to start bearing fruit," Manton said. It was while tinkering with yeast last year that researchers challenged the notion of a "brick wall" maximum age. By tweaking a gene called LAG-1, they got the yeast cell to reproduce 28 times before halting. Normally, the maximum is 21. HUMAN cells have a similar cellular clock. No one knows exactly how the clock works. But the yeast experiment suggests it can be manipulated. Clues may come from genetic units called telomeres. These are chains of chemical codes on the ends of chromosomes. Each time the cell reproduces, the chain shrinks. Is a telomere merely an abacus counting down, or does it control cell division? Would lengthening them extend life? Scientists also are studying compounds that damage cells and shorten our lives. The leading culprit: free radicals. Every health- food store today pushes antioxidants to combat this evil horde. The normal act of burning food produces free radicals, which are oxygen molecules with an unmatched (free) electron. So desperately does the cell want a mate, it grabs an electron from another cell causing instability. Free radicals are linked to cancer, genetic damage, hard arteries and more. Pollution and smoking also spawn them. "Ageing is a biological disordering. As we get older, we go from an ordered state to a disordered state," said George Roth a physiologist at the National Institute on Ageing. Antioxidants such as vitamins E and A and beta carotene come to the rescue. They pair with the free radical, reducing damage. Doctors say, however, that taking supplements does not work as well as getting antioxidants through the diet. Hormone replacement therapy is easier and more beneficial. The decline in estrogen production after menopause can lead to osteoporosis, heart disease, Alzheimer's disease and cancer. Studies show hormone replacement can prevent them. But estrogen also can raise the risk of breast and ovarian tumours, so women with cancer in the family should think carefully before opting for. For now, the best advice from the experts is painfully familiar: Eat more fruits and vegetables, eat less fat and exercise. Exercise is emerging as an elixir in all of this. Even people over 90 benefit from simple walking or weigh/lifting. They have more muscle, strength and mobility. "Not only will you live longer, you'll be living with fewer health problems and infirmities," Manton said. Along the same line, a theory called caloric reduction says you live longer by eating noticeably less. It works in animals. Burning food wears down the body's machinery and creates free radicals and other byproducts. Less food, in this view, causes less harm. KRT
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