Howard Friedman - The Longevity Project

If the “treatment” for this condition involves medication, then pharmaceutical companies chime in with strong support for a new standard. For example, it is very generally true that the higher your blood pressure, the greater your risk of heart disease and stroke. In response, the standards for normal blood pressure have been continuously lowered, with some medical boards now flatly proclaiming that normal blood pressure is “below 120/80.”

Physicians used to worry when a patient’s systolic blood pressure (the first number) was over 160; then the target was lowered to 150; and then for many years it was 140. Now some physicians will try adding medications to bring your blood pressure below 130 or even below 120. After all, anything higher can be called a disease, like “prehypertension.” There is no doubt that bringing down very high blood pressure has saved many lives—it is one of the triumphs of modern medicine. But can things go too far? Has an illness been invented?

Something odd is going on here, because applying such ideal standards to the whole population means that the overwhelming majority of people are “sick,” or at least abnormal, because they have a systolic blood pressure over 120. How can most people be abnormal? This can happen by setting a firm and arbitrary optimal standard for the population—probably a bad idea.

If you put very large numbers of people, including those who have only slightly elevated blood pressure, on various blood pressure–lowering medications for many years, a lot of them will encounter side effects. Some of these are known, but many are not. This problem gets worse because more people are on multiple medications than ever before, and the interactions or combinations of the drugs are even less well investigated or understood. Then there are the financial costs: the money being used for this medication is not being used for some other health purpose. To top it all off, it is usually the case that the added benefit of any intervention decreases as the condition becomes more mild. In other words, lowering someone’s blood pressure from 160/120 to 140/100 will have a much greater impact than lowering someone’s blood pressure from 130/90 to 110/70.

The same is true for physical activity and exercise. It is not yet well understood what an optimal level of physical activity should be for an average person. And it is certainly not known how to adjust such recommendations. Just as you can be too thin and your cholesterol can be too low, likewise you can exercise too much.

In fact, a tip-of-the-tail phenomenon is often ignored in medical discussions. Many studies of exercise, if you look closely, show that too much exercise can be unhealthy. Many of those exercisers at the highest part of the distribution of activity levels—those at the very tip—do not fare well. That is, physical activity definitely is associated with better health up until some point, at which many of the most active folks begin showing rising risk of injury, disease, and even premature mortality. All of which is to say that you can be perfectly healthy without being a marathon runner, and marathonlessness is not a disease.

Lest anyone accuse us authors of being lazy couch potatoes we should mention that we both enjoy outdoor activities. In fact one of us, Leslie, loves major physical challenges and ran the Marathon des Sables, something that is unusual for women to do. The Marathon des Sables is a six-day race (on foot) across the Moroccan desert, the hottest part of Africa. Runners have to carry their own food, bedding, and clothing the whole way, over 150 miles.

Nevertheless, the predictor of health should not be the end in itself. That is, while physical activity is associated with good health, forever increasing your physical activity to extremes will not necessarily produce better health.

Consider homocysteine, an amino acid in the blood that is a good predictor of risk of heart disease: a higher level indicates a higher risk. Folic acid and other B vitamins lower the level of homocysteine in the blood. So does taking vitamin pills with folic acid and other B vitamins dramatically reduce your risk for heart disease? The matter has been studied and, no, it probably does not help much, if at all. 49 49 For a study of the B vitamins, see C. M. Albert, N. R. Cook, J. M. Gaziano, E. Zaharris, J. MacFadyen, E. Danielson, J. E. Buring, and J. E. Manson, “Effect of Folic Acid and B Vitamins on Risk of Cardiovascular Events and Total Mortality among Women at High Risk for Cardiovascular Disease: A Randomized Trial,” Journal of the American Medical Association 299, no. 17 (2008): 2027-36.

Again and again, careful studies reveal that markers that seem associated with good health and long life are not the primary causes of good health and long life. Rather, the markers are simply that—markers or indicators. Leslie enjoys some extreme sports like running the Marathon des Sables, but for personal fulfillment as part of her active lifestyle, not as a desperate attempt to secure good health.

Some of Ancel Keys’s long-lasting influences involved the connections he made among cholesterol, activity, and clogged arteries. In addition to eating less saturated fat, millions of people hit the running tracks and trails every morning for better heart health. As we are seeing, this is healthier than sitting around, but probably not the optimal activity for everyone.

Millions of people take an aspirin tablet daily, in a related effort to prevent a heart attack, despite the many documented and serious side effects of aspirin treatment. For some people, especially those at high risk for coronary artery blockage and who are under close supervision by their doctors, the aspirin is probably very helpful. For many others, it is probably harmful.

The first important study showing the protective effect of aspirin on those at risk for heart attack (acute myocardial infarction) was done several decades ago. 50 50 This study of aspirin and heart attack is H. D. Lewis, J. W. Davis, D. G. Archibald, W. E. Steinke, T. C. Smitherman, J. E. Doherty, H. W. Schnaper, M. LeWinter, E. Linares, J. M. Pouget, S. C. Sabharwal, E. Chesler, and H. DeMots, “Protective Effects of Aspirin against Acute Myocardial Infarction and Death in Men with Unstable Angina: Results of a Veterans Administration Cooperative Study,” New England Journal of Medicine 309, no. 7 (1983): 396-403. The participants were 1,266 male veterans. These men were not your ordinary healthy guys. They suffered from unstable angina, chest pain due to circulation problems with the heart muscle. The men in this group who were given aspirin were less likely to have a heart attack, although many did anyway. Yet most readers of this study were willing to assume that aspirin might also be helpful to nonveterans, to women, to younger people, and even to those who were not suffering from unstable angina. After all, a human body is a human body.

Subsequent studies have confirmed aspirin’s value to some people but have also demonstrated its dangers. A physician who knows the at-risk patient should help make the decision in each case. Yet most have no trouble generalizing the treatment from the ill male veterans to people who are not ill male veterans. The same considerations should apply as we talk about the implications of the physical activity findings from the Terman participants. It is important to neither understate nor overstate the extent to which we can generalize findings. Just as recommendations about aspirin or about cholesterol levels have some generality but are best tailored to the individual, so, too, pathways to long life involving physical activity and associated personality and social relations are true in general, but best modified for the individual.