Alvin L. Wing

Physical Activity, All-Cause Mortality, and Longevity of College Alumni

We examined the physical activity and other life-style characteristics of 16,936 Harvard alumni, aged 35 to 74, for relations to rates of mortality from all causes and for influences on length of life. A total of 1413 alumni died during 12 to 16 years of follow-up (1962 to 1978). Exercise reported as walking, stair climbing, and sports play related inversely to total mortality, primarily to death due to cardiovascular or respiratory causes. Death rates declined steadily as energy expended on such activity increased from less than 500 to 3500 kcal per week, beyond which rates increased slightly. Rates were one quarter to one third lower among alumni expending 2000 or more kcal during exercise per week than among less active men. With or without consideration of hypertension, cigarette smoking, extremes or gains in body weight, or early parental death, alumni mortality rates were significantly lower among the physically active. Relative risks of death for individuals were highest among cigarette smokers and men with hypertension, and attributable risks in the community were highest among smokers and sedentary men. By the age of 80, the amount of additional life attributable to adequate exercise, as compared with sedentariness, was one to more than two years.

The Association of Changes in Physical-Activity Level and Other Lifestyle Characteristics with Mortality among Men

BACKGROUND Recent trends toward increasing physical exercise, stopping cigarette smoking, and avoiding obesity may increase longevity. We analyzed changes in the lifestyles of Harvard College alumni and the associations of these changes with mortality. METHODS Men who were 45 to 84 years of age in 1977 and who had reported no life-threatening disease on questionnaires completed in 1962 or 1966 and again in 1977 were classified according to changes in lifestyle characteristics between the first and second questionnaires. We analyzed changes in their level of physical activity, cigarette smoking, blood pressure, and body weight, and the relation of these factors to mortality between 1977 and 1985. RESULTS Of the 10,269 men, 476 died during this period (which totaled 90,650 man-years of observation). Beginning moderately vigorous sports activity (at an intensity of 4.5 or more metabolic equivalents) was associated with a 23 percent lower risk of death (95 percent confidence interval, 4 to 42 percent; P = 0.015) than not taking up moderately vigorous sports. Quitting cigarette smoking was associated with a 41 percent lower risk (95 percent confidence interval, 20 to 57 percent; P = 0.001) than continuing smoking, but with a 23 percent higher risk than constant nonsmoking. Men with recently diagnosed hypertension had a lower risk of death than those with long-term hypertension (relative risk, 0.75; 95 percent confidence interval, 0.55 to 1.02; P = 0.057), as did men with consistently normal blood pressure (relative risk, 0.52; 95 percent confidence interval, 0.40 to 0.68; P < 0.001). Maintenance of lean body mass was associated with a lower mortality rate than long-term, recent, or previous obesity. The associations between changes in lifestyle and mortality were independent and were largely undiminished by age. Our findings on death from coronary heart disease mirrored those on death from all causes. CONCLUSIONS Beginning moderately vigorous sports activity, quitting cigarette smoking, maintaining normal blood pressure, and avoiding obesity were separately associated with lower rates of death from all causes and from coronary heart disease among middle-aged and older men.

Dietary Fiber, Glycemic Load, and Risk of NIDDM in Men

OBJECTIVE Intake of carbohydrates that provide a large glycemic response has been hypothesized to increase the risk of NIDDM, whereas dietary fiber is suspected to reduce incidence. These hypotheses have not been evaluated prospectively. RESEARCH DESIGN AND METHODS We examined the relationship between diet and risk of NIDDM in a cohort of 42,759 men without NIDDM or cardiovascular disease, who were 40–75 years of age in 1986. Diet was assessed at baseline by a validated semiquantitative food frequency questionnaire. During 6-years of follow-up, 523 incident cases of NIDDM were documented. RESULTS The dietary glycemic index (an indicator of carbohydrates ability to raise blood glucose levels) was positively associated with risk of NIDDM after adjustment for age, BMI, smoking, physical activity, family history of diabetes, alcohol consumption, cereal fiber, and total energy intake. Comparing the highest and lowest quintiles, the relative risk (RR) of NIDDM was 1.37 (95% CI, 1.02–1.83, P trend = 0.03). Cereal fiber was inversely associated with risk of NIDDM (RR = 0.70; 95% CI, 0.51–0.96, P trend = 0.007; for > 8.1 g/day vs. < 3.2 g/day). The combination of a high glycemic load and a low cereal fiber intake further increased the risk of NIDDM (RR = 2.17, 95% CI, 1.04–4.54) when compared with a low glycemic load and high cereal fiber intake. CONCLUSIONS These findings support the hypothesis that diets with a high glycemic load and a low cereal fiber content increase risk of NIDDM in men. Further, they suggest that grains should be consumed in a minimally refined form to reduce the incidence of NIDDM.

Physical activity and incidence of cancer in diverse populations: a preliminary report.

Physical activity relates inversely to mcidence ofcoronary heart disease and delays allcause mortality, but its influences on cancer are less clear, perhaps because cancer is a matrix of diseases differing in etiology, site, timing, symptoms, and course. Data on four populations studied primarily for hypertensiveatherosclerotic disease have been reviewed further for incidence of cancer in relation to levels of physical activity on the job and in leisure time. The present report compares and contrasts these four studies with a view to assessing significant variations in their findings on exercise and cancer.

Changes in physical activity and other lifeway patterns influencing longevity.

We studied the adoption or maintenance of physical activity and other optional lifeway patterns for their influence on mortality rates of Harvard College alumni. Men aged 45-84 in 1977, surveyed by questionnaire in 1962 or 1966 and again in 1977, were followed from 1977 through 1988 or to age 90. Of 14,786 alumni, 2,343 died in 165,402 man-years of follow-up. Relative risks of death, standardized for potential confounding influences, for men who between questionnaires increased their physical activity through walking, stair climbing, and sports or recreational activities to 1,500 kcal or more per wk were 0.72 (95% confidence interval 0.64-0.82), compared with 1.00 for men who remained less active. Corresponding relative risks for men who adopted moderately vigorous sports play (> or = 4.5 METs) were 0.73 (0.65-0.81) vs 1.00 for men not adopting such sports; and for cigarette smokers who quit, 0.74 (0.65-0.84) vs 1.00 for persistent smokers. Men with recently diagnosed hypertension had a lower death risk than long-term hypertensives (0.80; 0.70-0.92), as did men with consistent normotension (0.52; 0.47-0.58). Changes in body-mass index had little influence on mortality during follow-up. These findings fit the hypothesis that adopting a physically active lifeway, quitting cigarette smoking, and remaining normotensive independently delay all-cause mortality and extend longevity.

Prospective study of physical activity and the risk of symptomatic diverticular disease in men.

The relationship between physical activity and risk of symptomatic diverticular disease has not been investigated directly. This association was examined in a prospective cohort of 47,678 American men, 40 to 75 years of age, and free of diagnosed diverticular disease, colon or rectal polyp, ulcerative colitis, and cancer before 1988. During four years of follow up, 382 newly diagnosed cases of symptomatic diverticular disease were documented. After adjustment for age, energy adjusted dietary fibre, and energy adjusted total fat, overall physical activity was inversely associated with the risk of symptomatic diverticular disease (for highest versus lowest extremes, relative risk (RR) = 0.63 (95% confidence interval (CI) 0.45, 0.88). Most of the inverse association was attributable to vigorous activity, for extreme categories RR = 0.60 (95% CI 0.41, 0.87). For activity that was not vigorous the RR was 0.93 (95% CI 0.67, 1.69). Several specific activities were inversely associated with the risk of diverticular disease, but jogging and running combined was the only individual activity that was statistically significant (p for trend = 0.03). For men in the lowest quintile for dietary fibre intake and total physical activity (compared with those in the opposite extreme), the RR was 2.56 (95% CI 1.36, 4.82). Physical activity, along with a high fibre diet, may be an important factor in the prevention of symptomatic diverticular disease.

A prospective study of alcohol, smoking, caffeine, and the risk of symptomatic diverticular disease in men

The relationship between smoking, caffeine, and alcohol intake and the risk of symptomatic diverticular disease has not been investigated directly. We examined these associations in a prospective cohort of 47,678 US men, 40 to 75 years old. During 4 years of follow-up (1988 to 1992), we documented 382 newly diagnosed cases of symptomatic diverticular disease. After adjustments for age, physical activity, and energy-adjusted intake of dietary fiber and total fat, alcohol intake (comparing those who drink > 30 g of alcohol/d to nondrinkers) was only weakly and nonsignificantly associated with risk of symptomatic diverticular disease (relative risk (RR) = 1.36; 95 percent confidence interval (CI), 0.94 to 1.97; P for trend = 0.37). We observed no association between caffeine, specific caffeinated beverages, and decaffeinated coffee and the risk of symptomatic diverticular disease. Current smoking was not appreciably associated with risk of symptomatic diverticular disease compared to nonsmokers (RR = 1.25; 95 percent CI, 0.75 to 2.09) after adjustment for age, physical activity, and energy-adjusted intake of dietary fiber and total fat. In a subset analysis restricted to men who had undergone sigmoidoscopy or colonoscopy, a modest positive association was seen between smoking and risk of symptomatic diverticular disease. These results suggest that smoking, caffeine, and alcohol intake are not associated with any substantially increased risk of symptomatic diverticular disease.

The Influence of Physical Activity on the Incidence of Site-Specific Cancers in College Alumni

The past dozen years have seen wide acceptance of epidemiologic evidence that adequate physical activity promotes physical fitness and counters tendencies toward development of coronary heart disease, a chief cause of early debilitation and premature death. But the evidence that physical activity influences cancer incidence is less clear, perhaps because cancer is a variety of diseases differing in underlying cause, age of onset, organ of involvement, induction period, and clinical course. Since exercise is a natural function of the body, its health benefits are thought to be achieved through its effects on all body systems, and accordingly it deserves serious study in relation to any effect it may have on prevention or delay in cancer occurrence.

A prospective study of alcohol, smoking, caffeine, and the risk of duodenal ulcer in men.

The associations between smoking, caffeine, and alcohol intake and the risk of duodenal ulcer have rarely been investigated prospectively. We examined these associations in a prospective cohort of 47,806 men, 40–75 years of age, using a mailed baseline questionnaire in 1986, with follow‐up every 2 years through 1992. During 6 years of follow‐up, we documented 138 newly diagnosed cases of duodenal ulcer. After adjustment for age, energy‐adjusted dietary fiber, body mass index, and use of aspirin or other nonsteroidal antiinflammatory drugs, current smoking was not associated with a substantial risk of duodenal ulcer [relative risk (RR) = 1.07; 95% confidence interval (CI) = 0.61–1.89]. Overall, past smokers were not at increased risk compared with never‐smokers (RR = 0.99; 95% CI = 0.69–1.42). Adjusting for other risk factors, alcohol intake (comparing those who drink >30 gm of alcohol per day to nondrinkers) was not associated with higher risk of duodenal ulcer (RR = 0.74; 95% CI = 0.42–1.29). We observed little association between caffeine, caffeine‐containing beverages, and decaffeinated coffee and the risk of duodenal ulcer. These results indicate that smoking is not associated with a substantial increase in risk of duodenal ulcer, nor is high intake of alcohol and caffeine.

Physical Activity, Other Personal Behaviors, Cardiovascular Disease, and Longevity

Epidemiologic methods are a major way of evaluating the roles of physical activity and other personal behaviors in influencing cause or prevention of chronic disease, and their relationships to longevity per se. The literature contains a miscellany of epidemiologic studies exploring personal athleticism and less energetic physical activities as defense against coronary heart disease (CHD) and other chronic diseases (Leon 1984; Morris et al 1980; Morris et al 1953; Morris and Smith 1984; Powell 1985; Paffenbarger and Hale 1975; Paffenbarger et al 1984). The parallels of exercise and one’s state of health have long been debated, including their possible effects on longevity. While increasingly certain that sedentariness shortens life expectancy, many paradoxical arguments have failed to conclude that adequate exercise extends survival. Nevertheless, there is a growing belief that if adequate exercise is essential to the maintenance of good health, it is also a key to longevity.