Longevity Studies Related to Lifestyle
In their classic study of nearly 7000 individuals living in Alameda County, California, they found that there were seven lifestyle factors that influenced how long people lived.These factors are listed in Figure 4: Belloc & Breslow's Seven Health Factors for Longevity.(4) The number of these habits that an individual followed made a tremendous impact on their longevity. After nine years, the number of healthful lifestyle practices a person followed was directly related to the likelihood of dying. The results are depicted in Figure 5: Relation of Longevity to Health Habits.(5) Notice that only about 5 percent of men and women who followed all seven health habits died in the nine year period, compared to 12.3 to 20 percent who followed three habits or less.
Another way of looking at the impact of lifestyle on longevity is by considering something referred to as “health age.” As an example, a 50-year-old who embraces enough healthful lifestyle factors may have the same health or physiologic age as the average 35-year-old person. We could say that this individual has a “health age” of 35. On the other hand, another 50-year-old who had no regard for a healthful lifestyle may have a much older health age, perhaps as high as 72. In other words, a person’s health age can be lower or higher than the actual chronological age, depending on the number of lifestyle factors adopted.
Health age tables have been created from the Alameda County statistics. They cover the chronological age range from 20 years to 70, and are based on the same seven health habits listed in Figure 4: Belloc & Breslow's Seven Health Factors for Longevity. One such table is depicted in Figure 6: Health Age Related to Lifestyle Habits.(6)
You can use this figure as a guide to get a feel for your own health age. For example, assume that you are an average 40-year-old Alameda county resident. If you are following only two of the seven Belloc and Breslow’s health habits, your health age is 40 plus 19.4, or about 59, indicating a dramatic shortening of your life expectancy. You would have the same life expectancy as the average individual 19 years older. If you continue the same lifestyle for 10 more years, when you are 50 your health age will be 50 plus 22, or 72. At age 40, you had a 19-year health handicap, but at age 50, the handicap will even be worse by 3 years. In 10 years you will age 13 years!
On the other hand, if you, at 40, are consistently following all seven of Belloc and Breslow’s health habits, your health age is only 27 (40 minus 12.9). Furthermore, at age 50 your health age will be only 35. In 10 years, you will only age 8 years! The concept of health age illustrates how much our lifestyle can either hasten or slow the aging process.
But What About Quality of Life at Old Age?
Some individuals believe that they are able to extend their lives, yet they fear the results of living longer. Tracy, a respiratory therapist, recently said to me, “I don’t want to live to be 70 years old. People that age seem to have so many problems. I think I want to die before I’m 70.”
I said in response, “Tracy, you may say that now, but wait until you’re 69. Then you will want to live until 70, and once you get to 70 you will likely want to live to 71, particularly if you have good health. I know many individuals in their 70’s and 80’s that are enjoying a good quality of life. The so-called ‘golden years’ are a reality for them.”
More recent research has further helped to answer Tracy’s concern. Although the original Alameda County reports focused primarily on the age at death, subsequent work has looked at quality of life issues. For example, the “Alameda seven” have emerged as powerful ways to prevent probably the most feared complication of aging: disability. A recent report demonstrated that those who followed the greatest number of these health habits experienced only half the risk of disability as those with the poorest habits. Those with an intermediate number of health habits also fared better than those who spurned most of Belloc and Breslow’s seven. They experienced only two thirds the risk of disability as the least health-conscious group.(7)
Note: all figures and footnote references (as denoted in parenthesis) are available in the text of Dr. Nedley's book Proof Positive.