Getting What We Deserve: Health and Medical Care in America

3. GENES: Sometimes “Destiny,” Sometimes Not

26 6 6 6 3 Genes Sometimes “Destiny,”Sometimes Not So much has been written about the future benefits of the “genetic revolution” that it is left to me to play the Grinch. A little balance and reality testing are in order. Genes are important, but not nearly as important as the media and NIH funding priorities would have us believe. They may be “destiny,” but for the most part genes do not determine our state of health. If they did, how could life expectancy have doubled over the past century? We did not alter our genome dramatically during that short period of time. The biggest thing we’ve learned from decoding the genome is that biological processes are infinitely more complicated than had been thought. Humans have far fewer genes than had been imagined ; these somehow make more proteins and pieces of proteins than initially seemed possible. These proteins, genes, bits of genes, and even dark stretches once thought to be “genetic junk” signal one another in impossibly complex ways that modulate and regu- Genes 27 late cellular functioning.Thus far,I am describing the complexity of a single cell, not a complex organism as intricate as humans. As LudwigWittgenstein once said aboutvision,“We find certain things about seeing puzzling because we do not find the whole business of seeing puzzling enough.”1 If seeing is a complicated function, imagine the complexity of the systems responsible for all of human functioning, health, and life! Future research will reveal a great deal more about how cells and genes work,which is a good thing.Those doing that research are on an exciting ride. For the rest of us, the important point about genes for the moment is that most major diseases are influenced by the complex interactions between many genes (and other molecular and cellular elements) and our“environment.”Many of the diseases in which genes probably play a role can be prevented now, without our knowing anything more about how genes function or awaiting the development of tools and techniques needed to change someone ’s genetic makeup. Genes operate within the context we provide. If a Japanese man immigrates to the United States, his risk of stomach cancer plummets while his risk of heart disease skyrockets. He did not change his genes while flying across the Pacific. What he changed was the environment in which his genes now operate—principally, his diet. The high risk of stomach cancer in Japan is thought to be related to a diet rich in cured foods. The high risk of cardiovascular disease in the United States is related, at least in part, to a diet rich in salt and fats. We stimulate our epidemiology students each year with this provocative thought: “In a country where everyone smokes, lung cancer would be considered a genetic disease.” Most people my age know someone who smoked two packs of cigarettes a day and never developed lung cancer. We also know people who smoked “only” half a pack a day and got cancer. This suggests genetic vari- 28 Getting WhatWe Deserve ability in the risk of developing lung cancer from smoking. A “genetic ” orientation to prevention would emphasize the need to find lung cancer–causing genes and innovative ways to block their effects. As best we know, this will take years of additional research. Alternatively, people could simply stop smoking! I was dramatically reminded of these two different approaches to prevention while serving on a panel looking into “The Future of Medicine and Public Health.”We had presented our thoughts at an evening session of the annual meeting of the American Public Health Association. People nodded politely and then left for dinner. A few months later, we repeated the exercise at the annual meeting of the American Medical Association. Just a few days earlier, the media had widely reported the discovery of a molecule in tobacco smoke that hooked up to the P53 gene, which might explain how smoking causes lung cancer. This report initially dominated the evening’s discussion. While I found the report intellectually stimulating , I didn’t believe it represented a major public health breakthrough . A member of the audience thought differently:“Now that we know what the receptor site looks like, the pharmaceutical industry can design a drug to block the offending molecule.” “Let me see if I understand what you are suggesting: we tell everyone to take a red pill...