Growing older isn`t what it used to be. Today`s 40-year-old looks, acts and feels like yesterday`s 30-year-old, says trend-spotter Faith Popcorn, and 50 now is like 40 was a generation ago. Popcorn calls it ”down-aging,” a culture-wide revision of life`s timetable.
Has an obsession with youth turned into a national inability to act our age? Not quite.
Science is in fact validating our new youthful lifestyle and outlook. As Americans live longer-about 30 million are older than 65, compared with 17 million 25 years ago-research on aging has boomed.
For example, the Baltimore Longitudinal Study of Aging, conducted by the National Institute on Aging, has tracked more than 2,000 people through their 90s, with thorough physiological and psychological tests every two years. One major finding: Much of the slowing and breakdown that a decade ago was considered the inevitable result of time is actually caused by disease, lifestyle and environmental wear and tear. Most symptoms of age can be postponed, and in some cases prevented.
”To an extent, you can take control of your own aging,” says James Fozard, who directs the Baltimore study. If you eat right, stay active and avoid health-sapping habits, you`re likely to be younger-physically, mentally and in spirit-than your 40-, 50- or 60-year-old counterpart was a generation ago.
Here is what you can do to head off the effects of time.
Vision generally remains unchanged through the 30s, but as the lens of the eye loses flexibility, it becomes harder for it to bend to bring close objects into focus. Farsightedness almost certainly will force you to hold the newspaper at arm`s length sometime in your 40s and to keep you trading up to ever-stronger glasses.
But a far more grave threat to vision may be slowly progressing, beginning in your teens. Cataracts, the clouding of the lens that often dims vision in the 60s, are the result of lifelong oxidation damage, a byproduct of normal body chemistry, says Paul Jacques, research associate at the United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University. Jacques` study found that people without cataracts had higher levels of antioxidant nutrients-vitamins E and C and beta-carotene-in their blood and got them more from natural sources (fruits and vegetables)
than from supplements. Studies done at Johns Hopkins University have linked cataracts to smoking and sun exposure, both avoidable.
By your 20s, you also begin to lose your ability to hear high tones, says James Jerger, a professor of audiology at Baylor College of Medicine in Houston. Most people don`t notice the slow, progressive muffling until their 60s, when they start to find speech hard to follow, although women are less likely to go deaf than men. Jerger says, though, that some people still have perfectly good hearing into their 90s.
Maybe it`s not just luck. A high-fat diet can clog the blood vessels that nourish the delicate hearing organs, and years of rock concerts can cause cumulative trauma.
A gradual decline in organ efficiency occurs throughout adulthood. The kidneys filter waste a little more slowly each decade. By your 40s, kidney stones will appear if you`re predisposed to them. Women who have had children may find by their 40s that they leak a few drops of urine when they cough or sneeze, but simple exercises are very effective in strengthening stretched pelvic muscles.
It won`t be until your 60s that your liver will metabolize toxins more slowly, but barring heavy drinking and chronic hepatitis, it will function perfectly well for a lifetime. Between your early 20s and age 80, it`s natural to lose 40 percent of your pulmonary function. Yet nature gave us lung power to spare: If you`re healthy, you won`t notice the difference.
Blood pressure goes up every decade after 40 among Americans; overall, fewer women than men suffer from hypertension, but it still strikes 32 percent of women between 25 and 74. Coronary heart disease is uncommon in premenopausal women; estrogen seems to work as a kind of protector, possibly by affecting the level of HDLs, the ”good” cholesterol that keeps the
”bad” cholesterol in check. The benefits of estrogen seem to last 20 years after menopause, but by 65 women`s death rate from heart disease is almost as high as men`s. According to statistics from the institute on aging, one of four women more than 65 suffers some form of cardiovascular disease.
Yet despite these statistics, abundant research shows that a lifelong low-fat diet and an ongoing exercise program can help protect against heart disease, even during the most vulnerable later years.
As for the more visible shape we`re in, the decades do leave their mark. At 20, the average woman`s body is 26.5 percent fat; by her 40s, it`s 33 percent; and by her 50s, 42 percent. By 70, she`ll have lost 30 percent of the muscle she had at 20. Flabbiness in the thighs, abdomen and upper arms can show up as early as the 30s.
But changes in muscle tone and body composition-the ratio of fat to muscle-can be minimal until nearly 50 for women who keep up a good fitness program, says Everett Smith, director of the biogerontology laboratory at the University of Wisconsin.
”I have a lot of staffers in their mid-30s who have better muscle tone now than in their 20s.”
Your functional capacity-the ability to generate energy for work and play-will drop 7.5 percent a decade, after a peak in the early 30s. At 40, many women find that stairs seem steeper and that they run out of steam earlier in the day. Much of this fatigue may be accounted for by the fact that most women in their 40s are under more pressure than they were at 20, and they devote less time to exercise, Smith says. Those who exercise regularly cope better with business and family stresses, and exercise can slow dramatically or even reverse the energy drop.
In one study, sedentary women from 35 to 65 were enrolled in a program of aerobic exercise.
”After 10 years their functional capacity was 6 percent higher than when they started,” Smith says.
Training can build muscle at any age. In one program, a group of men and women with an average age of 90 worked with weights, increasing muscle size by 10 percent and nearly tripling their strength. Because lean tissue burns more calories than fat, muscle maintenance also makes it easier to stay slim.
Creaky knees and stiff shoulders may creep into your life between 35 and 50. The health of your joints depends on the strength of the muscles supporting them, so again, regular exercise, especially weight lifting, running or walking, is important. Stress and physical change make lower-back pain more common in the 30s, 40s and 50s (the discs that cushion the vertebrae in the spine gradually degenerate), but pain often can be prevented by strengthening lower body and abdominal muscles.
Healthy bones are crucial for heading off osteoporosis, one of the major health problems of older women. This disease, which causes bones to become thin and porous enough to fracture easily, accelerates at menopause and strikes one of four white women past age 65 (black women tend to have denser bones and so are less susceptible). The stronger your bones are before menopause, the less affected you`ll be, so it`s important to ”bank bone”
when you`re young, says Sheryl Sherman, project director for osteoporosis at the aging institute. Adequate calcium in your diet, about 1,000 milligrams a day (8 ounces of skim milk has 302 milligrams), and regular weight-bearing exercise (walking or running) will help build strong bones while you`re young, then slow the drain as you age.
Brain tissue begins to deteriorate in your 20s, but it will take 50 years or more before there`s a noticeable change in your mental functions. Although some people believe they`ve already lost some of their edge by their 30s-they forget names and don`t concentrate as well-there`s no evidence at all to tie this to aging, says Dr. Gene Cohen, acting director of the aging institute.
From the 30s onward there is a slight mental slowdown, such as in reaction time, which determines how quickly you step on the brake and how fast you come up with the answers in ”Jeopardy.” But other functions, such as vocabulary, get better through your 50s and 60s.
Biologically, the brain continues to develop throughout your adult life. Although some brain cells die each year, the connecting branches between them- pathways for the nerve impulses that create thought, feeling and memory-keep on sprouting and spreading, compensating for the loss of cells, Cohen says. Studies show that intellectual challenge can enhance this growth. Mice that were put in a complex maze (the rodent equivalent of an adult-education course) sprouted extra intercell bridges.
Physical exercise can help brain functions too. Robert Dustman, chief of the neuropsychology laboratory at the Salt Lake CityVeterans Administration Hospital, found that aerobically fit individuals in their 50s, as well as those in their 20s, had more mental flexibility, adjusting more quickly to changing tasks, than same-age couch potatoes.
”Fitness seems to slow mental decline, perhaps by bringing more oxygen to the brain,” Dustman says.
Says Fozard, of the Baltimore study, ”A physically fit 60-year-old may have the same reaction time as a sedentary 20-year-old.”
The bottom line is that the passing years should leave mental powers pretty much unscathed.
”In healthy people,” Cohen says, ”intellectual performance remains robust throughout life.”
When the Social Security Administration surveyed centenarians some years ago, it found no lack of creativity and intellectual activity; one still wrote a daily newspaper column.
If you already are enjoying a satisfying sex life in your 30s and 40s, you have even more to look forward to.
”Women tend to report that sex is better as they get older-much better,” says Patricia Schreiner-Engel, director of psychological service at the obstetrics and gynecology department at Mt. Sinai Medical Center in New York. ”They become more sexually responsive and comfortable with sex.” The longer a woman has been orgasmic, the more easily she will achieve orgasm.
Although it`s true that the drying and thinning of vaginal tissues at menopause can make intercourse painful, a topical estrogen cream usually can help. Regular sex is the best treatment for the problem.
There`s no age limit on the joy of sex. Schreiner-Engel describes a conference in which a group of doctors, all women, were discussing this issue. ”At what point does sexual desire really start to go down?” they asked one doctor, who was 75. ”I`ll let you know,” she said.
At any age, a drop in desire or sexual interest may be caused by depression, physical illness or relationship difficulties. All are treatable. Life expectancy has risen dramatically, from 47 at the turn of the century to nearly 80 today. But optimum life span is still about 116 years, says Huber Warner, deputy associate director of the biology of aging program at the NIA. Some scientists believe that sooner or later we must run into a brick-wall genetic program for death.
The future may revise this too. Studies of animals have shown that drastically limiting food intake can vastly extend the maximum life span. Rats given a very low-calorie diet live to 50 months, compared with their normal 32. Whether the same thing can be done with humans, creating a race of 170-year-old Methuselahs, is far from certain.
”It`s not a goal of modern research,” Warner says. ”Extending the healthy life span is.”
