Low Risk, High Risk: Taking Control of Your Health

How would you answer the following questions?

1. You are about to plan a 1,000 mile journey, and you aren't pressed for time. Rank the following means of transportation from the safest (#1) to the riskiest (#4):
   ___ bus
   ___ train
   ___ plane
   ___ passenger car
2. What would you say kills more Americans annually?
   1. heart disease
   2. cancer
   3. automobile accidents
3. You're a healthy 45-year-old man, slightly overweight. Your father and his brother both dies in their fifties of heart disease. Your mother, now 65, has had Type II diabetes for several years. Are you likely to get one of these ailments?
   1. yes
   2. no
4. Winston Churchill, not to mention your Aunt Harriet, drank brandy, smoked habitually, and was overweight. Both lived into their eighties and died peacefully in their sleep. Does that prove there's something health experts don't know?
   1. yes
   2. no
5. You're 50, female, and a smoker. Your last checkup showed that both your blood pressure and blood cholesterol level were somewhat higher than they should be. You know this means that you risk a heart attack or stroke, but you read an article that said that even 50-year-old male smokers with high blood pressure and elevated cholesterol have only a 13 percent chance of getting sick within six years. So you're looking on the bight side: you've got an 87% chance of staying healthy for the next six years. Is this a constructive attitude?
   1. yes
   2. no

Answers

Of these questions, only the first two have fairly straight-forward answers. You're safest in a bus, and in greatest danger in an automobile. (More than 10 people die per billion automobile and taxi miles; but it takes more than 2 billion but miles to produce a fatality. Trains and planes are 10 times safer than cars, but only about half as safe as buses.) But whether they travel or stay at home, more people in the U.S. die from heart disease each year than from anything else. The purpose of the questions above however- all of which will be discussed in the course of this article- is not so much to produce correct answers as to invite you to figure your odds.

Efforts to identify health risks- and reduce them, if possible- are as old as medicine itself. Hippocrates advised his fellow physicians to "consider the seasons of the year and what effects each of them produces" and to take note of what people drank and ate and how they lived. Scientists today are still looking for the determinants of health, albeit with a little more sophistication and scientific knowledge. Epidemiology (literally, the study of epidemics) is the attempt to identify the factors that cause diseases and injuries to determine what the probabilities are that they will cause them, and to determine how to decrease of eliminate the identified risk. This is often referred to as risk hazard appraisal, which is of growing importance in medical science, especially in the effort to prevent disease and promote health. Once the risk factors are known, the next job is to make changes in the environment (for example, to persuade manufacturers to install seat belts of a certain design) and to persuade people to change their behavior (for example, convince them to faster the belt).

When we speak of risk, like a horse-player at the race track, we're simply quoting odds. No one can honestly assure you that doing one thing will kill you, while refraining from doing it will keep you safe. For example, on the average, 1 out of 10 smokers gets lung cancer, but only a rare nonsmoker gets it. If you are an average smoker, you chances of getting lung cancer at any time of life are 24 times higher than those for nonsmokers, and the risk increases as the amount of smoking increases.

Thus you're asked to draw your own conclusions. In the science of risk assessment, there's no such thing as absolute safety, but you can choose to widen or narrow your safety margins. And though scientists may assess the risks, how you manage your life is up to you. It's often hard to evaluate what the experts say, and the press seldom makes your task simpler. The headline "Alcohol shown to cause breast cancer" will attract more readers than "Study suggests alcohol intake slightly increases breast cancer risk for some women." It is always easier to oversimplify than to tell people how complicated things really are.

If your father died young of a heart attack, you have a good chance of following in his footsteps. Knowing your inherited liabilities, though, gives you an excellent opportunity to alter them. The genetic odds may be lowered significantly if you are not overweight, keep your blood pressure under control, and maintain a low blood cholesterol level. If your mother has diabetes, that's an indication that weight control and exercise are crucially important for you.

For many of us, familial tendencies constitute an emotional trap. People whose parents or grandparents died at comparatively young ages of heart disease or cancer, or some other disease with a genetic component, usually realize that this heritage works against them and may falsely conclude that taking care of their own health is irrelevant. On the other hand, if all of your relatives were as indestructible as Winston Churchill or the hypothetical Aunt Harriet, you may have an equally false sense of invulnerability.

Researchers may one day unravel the genetic code and come closer to accurately predicting your chances of getting a disorder such as heart disease or hypertension. But today only a few diseases are known to have purely genetic causes, for example, hemophilia, in which a bloodclotting factor is absent; sicklecell anemia, a blood disorder that occurs most commonly among people of African descent; cystic fibrosis; and certain forms of kidney disease.

In many ailments that show signs of running in families, such as cancer, heart disease, or diabetes, heredity is only one factor in the mix. Your biological and cultural heritage and your environment interact, and it's the interaction that counts. Your diet or exercise habits or your environment may foster, or foil, the tendencies you were born with.

A 50-year-old smoker, male or female, with elevated blood cholesterol and blood pressure is seriously courting cardiovascular disease. You may have only a 13 percent chance of developing it, since neither you nor your doctor has any way of predicting whether you'll fall into the lucky 87 percent who do not develop heart disease or the unlucky 13 percent who do. If these sound like favorable odds, you may decide not to make any changes in your habits. However, a more realistic way to consider the odds is as follows. If your risk factors were low (that is, you didn't smoke and your blood pressure and blood cholesterol levels were low), your chances of having a heart attack between age 40 and 64 would be only 6 percent. However, if you continue to smoke and do nothing about your other risk factors, your chance of having a heart attack during these years is 40 percent. This is a very big difference. Giving up cigarettes, controlling your blood pressure, and lowering your blood cholesterol level would significantly widen your safety margin. Obviously, that's the constructure action to take.

Another example of this kind of reasoning can be seen in the relationship between oral contraceptives and heart attacks. High-dose oral contracaptives increase the risk of heart attack by a factor of 4.7. This sounds like a very large increase. However, if you're a 20- to 24-year-old woman, your heart attack risk is less than 5 in 500,000 (or 1 in 100,000). This means that if all 8.5 million women in the U.S. in this age group were to take oral contraceptives, 80 of them (instead of the expected 17) would have heart attacks. This would produe many fewer deaths than might result from unwanted pregnancies in the same age group. And even this small risk has been markedly reduced but the new low-dose estrogen contraceptives.

So be cautious in interpreting articles that talk about doubling or tripling your risk of getting a specific disease. To make sense of a twofold or three-fold increase in risk, first you have to know how likely you are to get the disease anyway. For example, if your chances of developing a certain illness are 1 in 100,000, a doubled risk brings you up to 2 in 100,000 (or 1 in 50,000). Those are still pretty low odds. However, if 1 out of 10 people develops this illness and you do something that doubles your risk, your chances are now 1 in 5. That's a very significant increase.

Reprinted by permission from the University of California at Berkeley Wellness Letter, © Health Letter Associates, 1988.