Monday, March 22, 2010

Aging and Mortality: Risk Factors

Ah yes, in our youth-obsessed culture, the advancing specter of growing old becomes something to be tirelessly avoided. Perhaps because we're that much closer to the final passage, the fear and denial of death causes us to try to maintain the facade of youth in the face of the inevitable and gradual diminishment of our capacities. What's usually overlooked is the tremendous storehouse of knowledge and wisdom that we've accumulated, the gifts we can give to subsequent generations.

Our society's beliefs about growing old don't honor the eldership status of our seniors. These beliefs become part of a person's indoctrination, so they may slip into a sense of powerlessness and resignation. Challenging these beliefs by remaining active and curious about the world, making learning and education a top priority, and staying involved in family and community can help someone approach this transition and era with greater enthusiasm and acceptance.

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History of the world is replete with tales of individuals trying to stave off aging and death. King David wooed young virgins in search of youthfulness. Wealthy people go to private European medical centers for lamb cell injections. Many individuals take mega doses of vitamin E, drink Kombucha tea, use coenzyme Q10 etc., all in the hope of finding the "fountain of youth". The difficulty is to separate fact from myth.

Researchers know unequivocally that there is no elixir of youth, but are finding out that some of the biological hallmarks of age can be postponed. This can result in increased vitality in later years.

First, we will present a few facts. It would appear that the body reaches peak efficiency at the age 30 and then declines in many ways. Using age 30 as reflective of 100% performance, we see the following: (a) pumping efficiency of the heart is reduced about 20% when a person reaches 55, (b) kidney function is reduced about 25% at 55 years of age, (c) maximum breathing capacity declines about 40% by 55 and 60% by 75 years, (d) basal metabolism rate goes down about 10%.

The average life span has been significantly expanded so that theoretically it is conceivable that a person could live to 140 years, if we are able to deal with the chronic ailments associated with aging i. e. heart disease, cancer, Alzheimer's Disease, stroke etc. By eliminating these chronic ailments, lives will be healthy and productive and will only end because of unstoppable biological declines.

Pathologists report that at least thirty percent of people older than 85 years have minor traumas that their bodies would withstand at earlier ages, but now cause death. As mentioned in the above article on respiratory diseases, the immune system loses its ability to effectively deal with new minor infections resulting in death among the elderly, but not among young people. The more youthful your immune system, the more likely you are to become a centenarian, as seen in a study done at the University of Kentucky on individuals between 100 and 103 years of age.

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Interestingly, cancer accounts for 30 % of the deaths among people 65 to 69, but only 12% of those over 80. Cancers seem to grow slower, the older one becomes. Amount of the heart disease related deaths have declined among the 40 to 60-year-old group, but is increasing among the older group. This would appear to be a function of the efforts by the government to get individuals to reduce their risk of heart disease with low-fat diets, stopping smoking, watching their weight and monitoring blood pressure levels. It seemed a cost -effective method in dealing with the medical costs that were burdening our society.

Today, 80% of coronary deaths are in the over-65 group. This group will soon include a large population of our "baby-boomers" which suggests the need for greater effort to find effective ways to handle coronary attacks in the elderly. Our population now has a life expectancy at birth of 76 years. In 1900 it was 47 years. According to an article in the Wall Street Journal (Feb. 27, 1997), "If mortality rate had remained at 1900 levels throughout the 20th century, the U.S. population would be 139 million in 2000, rather than the expected 276 million…The population would have grown just 72% over the 100 years, rather than the actual 240% it will have grown."

Exercise, while not prolonging life, can retard some of the functional declines that accompany aging, such as the loss of muscle mass, capacity for physical effort, flexibility, endurance, bone strength and efficiency of the heart and lungs. It can also help normalize blood pressure, blood sugar and blood cholesterol levels, as well as ward off depression. Exercise does not improve pulmonary function, but increases the amount of oxygen consumption resulting in the reduction of the workload on the heart.

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Yet indications are that adolescents are smoking more, are heavier and are exercising less than their parents. It is estimated that obesity affects more than one-third of the United States population, with prevalence exceeding 40% in blacks and Hispanics. At the same time, 50% of patients are moderately malnourished on admission to a hospital.

It is fairly common to speculate as to what triggered a heart attack in the elderly. Was it any of the known risk factors (heredity, old age, high blood pressure, inactivity etc.)? Or are there other factors…

One such factor is homocysteine, an amino acid, which appears to be implicated in heart disease. Studies, which compared individuals who had heart attacks or strokes with healthy cohort group, found that high homocysteine levels distinguished the two groups. Two longitudinal studies ( a study which follows people who are healthy over a long period of time to determine what happens to them), one in Boston and the other in Norway found that men who were highest in homocysteine levels faced a threefold greater risk of having a heart attack and young women have a higher risk of stroke.

While genetics may be important, diet also plays an robust role, both as cause and a treatment. We get homocysteine from dried beans and peas, enriched whole-grain cereals, nuts, dark green, leafy vegetables and orange juice. You can also supplement your diet with the consumption of folate or folic acid. Jane E. Brody, in her "Personal Health" column ((Feb. 26,1997) states: "Dr. Robert Russell of Tufts estimated that raising folic acid intake to 400 micrograms a day could prevent at least 13,500 deaths from heart attacks each year. Currently, only about 40% of Americans consume that much."

Another fairly common disorder seen in the elderly is stroke. Yet, 28% of patients with stroke are under 65 years of age, and women account for 40% of the new cases. Blacks in the United States have a rate of mortality due to stroke roughly twice that of whites. The United States has one of the lowest mortality rates due to stroke and the rate continues to decline, most probably due to changes in life style.

According to a review article in The New England Journal of Medicine (Nov. 23, 1995) "Hypertension is currently the most consistently powerful predictor of stroke; it is a factor in nearly 70% of strokes. Hypertension promotes stroke by aggravating atherosclerosis in the aortic arch and cervicocerebral arteries; causing arteriosclerosis and lipohylaninosis in the small-diameter, penetrating end arteries of the cerebrum; and contributing to heart disease, of which stroke is a complication." The authors go on further to report that "In elderly patients (more than 60 years of age), antihypertensive therapy has decreased the risk of stroke by a range of 25% to 47%." Again, we point out that physical activity (i.e., exercise) reduces the risk factors for cardiovascular disease. We would suggest that everyone needs to increase their levels of physical activity. Surveys indicated that among people 18 to 74 years of age, only 24% reported moderate physical activity and only 14% reported vigorous activity.

Other interesting research going on in the field of Geriatrics, is the role of caloric intake and aging. The results of animal testing indicates that eating fewer calories in a well balanced, nutrient dense diet does wonders for the health and longevity of rodents. (See: Scientific American, January 1996, "Caloric Restriction and Aging" by Richard Weindruch, 46-52.) Weindruch concludes his article with "It may take another 10 or 20 years before scientists have a firm idea of whether caloric restriction can be as beneficial for humans as it clearly is for rats, mice and a variety of other creatures." There are many caveats in his article including lack of knowledge of the effect of low calorie intake on an individual’s ability to withstand stress and its effect on fertility in females.


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