At 20, aging is something you'll think about later. Broken bones mend quickly, aches go away, and you haven't started making that small groaning noise when you step into a car. At 40, you start denial. You may begin to notice wrinkles that stay, an extra ten pounds that don't melt off with a little exercise, stiffness on Tuesday from a rigorous hike on Sunday, but you are too busy with work, family, vacations to think about aging. By 60, you may have had an operation or a major illness. Some of your friends or loved ones have died. You see a parent's aged face permanently etched on yours. You learn to accept the extra weight, stiff bones, general aches and pains, and even loss of mental agility as a "normal" part of getting older. You face the reality that you are on a downward slope leading to inevitable mental and physical disability and decline or, if you're "lucky," a quick death or final stay in a humane nursing home.

Research findings at the Harvard School of Public Health and around the world are revolutionizing this misleading concept of "normal" aging. "There are tremendous differences in how people age--from physical abilities to how energetic and engaged in life they are," says Ichiro Kawachi, associate professor of health and social behavior in the School's Department of Health and Social Behavior. "These variations at the end of life are the motivation for studying healthy aging." Scientists are finding that the physiologic changes often associated with aging in America--increases in blood sugar and insulin levels, weight gain, and higher blood pressure--should not be considered normal and therefore harmless. These conditions are precursors to chronic diseases that are often preventable. Innumerable studies are confirming that people at any age can make simple changes to promote a higher quality of life and delay physical and mental decline with exercise, diet, and social connections--and only about 30 percent of physical aging can be blamed on genetic heritage.

These insights into aging are critical because the world's populations are aging at unprecedented rates. Currently, there are about 600 million persons over 65 globally; by the year 2050, the number will grow to nearly two billion, with the aged outnumbering children for the first time in human history, according to United Nations estimates. In America at the turn of the century, about 6 percent of the population was over age 65. Today about 13 percent of the population is over 65, or about 34.1 million people, according to U.S. Census Bureau statistics. By 2030, about 69.4 million Americans or 20 percent are projected to be 65 plus. "We are in denial about the previously unimagined numbers of elderly Americans that we will soon have in society," says John W. Rowe, president and CEO at Mount Sinai NYU Health and former professor of medicine and founding director of the Division of Aging at Harvard Medical School. One of America's leading experts on aging, he co-authored Successful Aging (published in 1998), a summary of the 10-year MacArthur Foundation Study, which included dozens of the most extensive, comprehensive studies on aging ever undertaken in America. At Harvard's May Capital Campaign celebration symposia, Rowe, a featured speaker, told a packed audience that, in the short period from 1900 to 1990, life expectancy in America had risen from an average of 47 to an average of at least 76 years today. "This incredible increase in life span is even more impressive when we realize it took 4,500 years--from the Bronze Age to 1900--to bring the last life span increase of at least 27 years," he explains.

Historians attribute much of this increase to public health advances, including general access to clean water, fresh food, better pre- and post-natal care, immunizations, and improvements in sanitation. Early in this century, developed countries also made great strides in eradicating infectious diseases like smallpox, yellow fever, tuberculosis, and deadly pneumonia, which had traditionally ravaged America's cradles and schoolrooms. In 1900 only 19 percent of individuals who died were over age 65, while today 72 percent of all deaths occur in those over 65. However, more recent advances in technology, wider access to health care, and general prosperity have allowed even older Americans to live longer. As a result, those over age 75--or the "old-old"--now represent the fastest growing segment of our population.

Unlearning the Myths
These revolutionary trends in aging have triggered an equally unprecedented scrutiny of what it means to get old. "There is still incredible ageism in this country," says Rowe. "We have to unlearn the myths about aging." While popular culture--and even medical professionals--have typically presented the aging individual as physically feeble, mentally dim, and lost in memories of better days, research findings are smashing these stereotypes. Some basic facts from the MacArthur Foundation studies: only about 5 percent of all older people end up in nursing homes--and this rate is declining; and while chronic illnesses are still prevalent, research documents a dramatic reduction in the prevalence of the precursors to chronic disease: high blood pressure, high cholesterol levels, and smoking. This decline has resulted in amazing decreasing rates of disability. In one study, a full 89 percent of those aged 65 to 74 reported no disability whatsoever; of those between the ages of 75 and 84, 73 percent still reported no disability. In the short period between 1982 and 1994, the proportion of the population over age 65 that reported any disability fell from 24.9 percent to 21.3 percent--and the rate continues to decrease.

Barry R. Bloom, dean of the Harvard School of Public Health, points out that Òwith the wonderful advances in public health and clinical medicine, the challenge now is how to make sure those extra years of life are the most satisfying and productive--and to ensure that everyone has access to information on how to stay healthy in order to participate in rewarding activities and contribute to society until the end of life." Three major longitudinal studies conducted under the auspices of the School and the Channing Laboratory of Brigham and Women's Hospital have led to significant and widely publicized discoveries about lifestyle and diet choices and their impact on the diseases associated with aging. The first Nurses' Health Study (NHS1), begun in 1976, had 121,600 participants. The second Nurses' Health Study (NHS 2) enrolled an additional 116,100 nurses for a total of 237,700. These participants provided blood samples and plowed through hundreds of questions in rigorous alternate-year surveys that ask about all aspects of their daily lives, from fat consumption to contraceptive use and modes of exercise. To complement the all-female NHS, the Health Professionals Follow-Up Study (HPFS) began in 1986 and has enrolled 51,520 men in the health professions. Like the nurses, the male health professionals also provide blood samples and fill out detailed surveys every two years on health-related topics. The results from these studies are helping to transform how Americans eat and live.

The Impact of Food Choices on Disease
Walter C. Willett, Fredrick John Stare Professor of Epidemiology and Nutrition and chair of the School's Department of Nutrition, is a senior investigator on the NHS and HPFS studies. Based on findings from these studies and hundreds of others that examine the impact of food choices on disease, Willett summarizes, "We have found that both men and women who consume high levels of fruits and green, leafy vegetables, whole grains, and less meat and cheese have lower rates of heart disease, stroke, and cancer." Researchers found that breast cancer was actually 25 percent higher in women who ate few vegetables; prostate cancer was lower in men who ate more vegetables, especially tomato products that are rich in the carotenoid lycopene; and both men and women who ate more red meat developed colon cancers more frequently. Ongoing studies are investigating these relationships.

Another major finding arising from the nurses' and male health professional studies is that the type of fat--not the amount we consume--strongly influences risk for heart disease. Although Americans have reduced fat consumption from about 42 percent to 34 percent of total calories in the last 20 years, Willett points out that obesity is epidemic in America. Instead of eliminating fat from our diets, he recommends replacing saturated fat (found mainly in animal products, such as meat, butter, and whole milk) primarily with polyunsaturated and monounsaturated fats like olive, canola, safflower, sunflower, and soybean oils. The type of fat that should be totally eliminated from our diets, trans fat, unfortunately is widely consumed. To create a hard fat like margarine or vegetable shortening, food processors "hydrogenate" liquid vegetable oils, producing trans fats in the process. "If you look at grocery shelves, almost everything in a package contains partially hydrogenated vegetable fat--meaning trans fats," says Willett, "yet gram for gram they're even worse than saturated fat." Trans fats not only raise ldl levels, the "bad" cholesterol, but also have the unique distinction of reducing hdl, the "good" cholesterol, and increasing levels of triglycerides and lipoprotein(a), another undesirable blood fat. "That all adds up to a potent adverse effect on heart disease," Willett concludes.

If the trans fats in most commercial baked goods aren't enough to send you to the fruit bowl, consider that refined flour is stripped of 60 to 90 percent of critical vitamins and nutrients in the milling process, which removes the germ and bran from kernels of grain that are then smashed into fine powder. As a result, highly refined carbohydrates--like commercial cakes, breads, and cookies--must be fortified to partially replace some of the lost nutrients. Another major drawback in eating refined foods that lack whole grains (as well as foods with concentrated sugar like soda and fruit juice) is their high glycemic index--in other words, these foods are rapidly absorbed, causing sharp spikes in glucose and insulin levels. Not only does this quick rise and fall trigger overeating through a sense of hunger, eventually a diet based on refined carbohydrates leads to greater risk for obesity, diabetes, and heart disease. "Low-fat" products are often even more damaging, says Willett, because they usually include more sweetening--and more empty calories--to offset the loss of fat.

A Toast to Good Health
Other findings have shaken America's traditionally conservative attitude toward alcohol, which leans in theory--if not in practice--to zero consumption. "Moderate alcohol intake--about one to two drinks per day for a woman and two drinks per day for a man--can actually decrease cardiovascular disease--about 30 to 35 percent compared to those who don't drink at all," says Eric B. Rimm, associate professor in the Departments of Nutrition and Epidemiology and researcher with the health professionals' study since 1987. Moderate consumption of alcohol was also found to have a beneficial impact on reducing the risk of developing diabetes. "Alcohol blunts the pancreas's need to produce insulin," he explains. "We found much better insulin profiles in blood samples from people who drank moderately every day." Researchers have determined that the type of drink doesn't matter--red wine, gin and tonic, or beer--it's the ubiquitous ethanol alcohol that increases the good cholesterol and decreases the blood's propensity to clot. Rimm is quick to add that the positive effects of alcohol only occurred in those who consumed a drink or two daily--staying dry all week and bingeing on the weekend is not beneficial, nor is drinking more than a drink or two a day. Excessive drinking actually increases all the major health risks.

Complicating these results, however, was the vexing finding that a drink or two daily also increased the risk for breast cancer in the nurses and the risk for colon cancer in the male health professionals. With further analysis, Rimm and his colleagues found that moderate drinkers in the study who took daily supplements of about 400 to 800 micrograms of folic acid canceled out this elevated cancer risk. Which brings up another major controversy in America's quest to stay youthful: Can supplements help? "I take a multiple vitamin as do most of my colleagues," says Rimm. "While supplements can't replace a healthy diet, it is hard to get necessary amounts of some vitamins in natural form."Taking supplements of folic acid, a critical B vitamin, may be especially beneficial since it has not only been shown to lower cancer risk but is also associated with decreased risk for cardiovascular disease in both men and women; taking at least 100 ius of the antioxidant vitamin E also lowered risk for heart disease--up to 40 percent in both male and female participants.

Lifting away the years
No matter how well we eat--and drink--diet isn't enough to stay youthful and active into old age. Rimm adds his voice to the thousands of health practitioners and researchers who have admonished America's sedentary millions to exercise regularly and as frequently as possible. "And cut the hours in front of a TV," he adds. "In our studies, we found that the more TV you watch, the worse your biological profile becomes over the years." In the short term, Rimm describes a study in which cholesterol levels are measured after exercise and after hours of television watching. "Six hours of TV cancels out two hours of physical activity--even walking around the house or reading is better," he explains.

Fewer than 22 percent of adults have taken these findings to heart and exercise regularly, according to the Centers for Disease Control and Prevention; the majority of Americans are less active than ever, and over 55 percent of the total population is overweight (carrying about 20 to 40 extra pounds, depending on height and frame)--with onerous consequences. In the Nurses' Health Study, women who gained even 15 pounds in their middle years had significantly increased risk for chronic disease. Those who were obese had higher rates of heart disease, stroke, gallstones, and diabetes. Physically inactive men in the Health Professionals Follow-Up Study had increased risk for cardiovascular disease and colon cancer.

Those participants who did exercise had lower risk for most chronic diseases. In the MacArthur studies, researchers working with rats found that exercise increases chemicals that also encourage nerve growth in the brain; strenuous activity was one of the predictors of the maintenance of high cognitive function. Even loss of physical function is treatable and preventable through exercise. "Physical changes in aging are as much related to disuse as aging," says Miriam E. Nelson, associate professor of nutrition and director of the Center for Physical Fitness at the Tufts University School of Nutrition Science and Policy. "We've yet to see an age-related symptom that doesn't improve with exercise." Nelson is a zealous advocate for strength training--at any age--to prevent loss of bone and muscle mass and to maintain the strength necessary for productive daily life. "Swimming, walking, and bike riding are terrific exercises for the heart," she says, "but because they're low-impact and don't involve weight resistance, they do very little for your bones."

Nelson has written three fitness books and developed a Web site (www.strongwomen.com) on the impact of strength training and nutrition. In her most recent book, Strong Women, Strong Bones, she points out that by as young as 35, women begin to lose up to 1 percent of their bone mass each year; for more than 28 million Americans (including two million men), this loss of bone mass leads to osteoporosis and, in many cases, premature death. To prevent crippling disability and loss of productive daily life, Nelson lays out an easy-to-follow program of exercise and nutrition based on years of lab research. She has tailored these programs for nursing homes, community centers, and retirement communities to encourage even the most fragile seniors to start resistance training. The results have been astounding--from wheelchair-bound residents who can walk again to less disabled seniors who are once more able to golf, bike, water ski, or just bring in their own groceries. "Furthermore," Nelson adds, "the physical benefits are often accompanied by mental health gains, including increased self-esteem and self- confidence, decreased depression, and improved sleep."

People Who Need People
While appropriate exercise and nutrition are critical in maintaining health and function, researchers have found that social factors can play an equally significant role in how we age. Succinctly put, "Loneliness kills," says Ichiro Kawachi. In studies that examined the social interactions of 32,624 male health professionals, those who weren't married, had fewer than six friends or relatives, and did not participate in community networks were at increased risk for death from heart disease, stroke, and even accidents and suicide. Those who had cardiovascular dis ease lived longer if they had strong social networks. In a study headed by Lisa Berkman, chair of the School's Department of Health and Social Behavior and a member of the MacArthur Foundation Study research team, investigators followed 194 men and women older than 65 who were hospitalized for acute myocardial infarction; six months after the heart attack, 53 percent of those socially isolated and without emotional support died, compared with 23 percent of those with emotional support.

Participants in the second Nurses' Health Study who had strong relationships were also found to have less mental decline and lived more active, pain-free lives, without physical limitation. International studies support these findings. At the Stockholm Gerontology Research Center at Karolinska Institute in Sweden, scientists found that elderly people who live alone, have no friends, or have poor relationships with their children are 60 percent more likely to develop dementia than those with satisfying social contact. From these studies, Kawachi arrives at the startling conclusion that "social connectedness is among the most important predicators of health and independence as we age--almost as strong as not smoking or being overweight." Berkman speculates that social isolation may create a "chronically stressful condition to which the organism responds by aging faster." The authors of Successful Aging agree: "Human beings are not meant to live solitary lives.... Talking, touching, and relating to others is essential to our well-being," they write.

In other studies, Berkman and Kawachi have found that status in society also impacts how we age. "Socioeconomic position, level of education, and race are critical factors in surviving to old age without serious physical limitations or chronic conditions," says Berkman. In a MacArthur study of men and women between the ages of 70 and 79, low-functioning groups were almost three times as likely to have a lower income than high-functioning groups and were less likely to have completed high school. In summarizing race-related studies, Berkman notes, "Because blacks in the United States often experience the disadvantages of discrimination and some of lower socioeconomic status, they are typically at increased risk of acquiring most conditions and have a shorter life expectancy than whites." She concludes that low social position is linked to less access to health care, poorer nutrition, greater exposure to environmental toxins, and less control in one's personal life--and subsequently greater stress; all these factors are determinants of poor health in old age. Berkman emphasizes that much more research is necessary to determine which stress conditions--in which stage of life--may lead to disease and ultimately death. "What we do know is that growth and change is possible throughout life," she summarizes. As researchers like Berkman and Kawachi uncover why some individuals retain youthful vigor, productive daily life, and mental agility far into old age, many are convinced that with some positive shifts in behavior--from diet and exercise to social interactions--aging populations do not have to become a staggering burden for the ever-shrinking work force who must support them. "We're armed with enough data on how to maintain physical and cognitive function, reduce the risk for disease, and maintain productivity into old age," says Rowe, "but it's not enough to add years of life. To make longevity meaningful in our culture, we must learn to integrate the wisdom and contributions of older Americans. We must develop a society that provides individuals with opportunities of continuing engagement in life. That is the final step of longevity."

by Gabriele Amersbach photograph ©2000 Marnie Crawford Samuelson/Yankee Images