BEZ’S BLOG #5 “Cells, Organs, Individuals, Populations”
Our bodies are just trillions of cells stuck together, and these cells are integrated into communities forming our organs. Your brain, heart, blood, kidneys, lungs, pancreas and skeleton are all specialized cellular systems. What do they need to be healthy? If a group of heart muscle cells are deprived of oxygen or glucose because of a clotted artery, they die and you have a heart attack. Similarly in the brain when you have a stroke. Besides the right quantities of oxygen and glucose, what a group of cells needs depends on the organ. How should we produce healthy organs?
For better health, we are told to eat right, exercise, don’t smoke, be easy on alcohol, see our doctor, use a condom, and so on. Unfortunately, none of those guidelines have meaning at the cellular level. You can’t tell a cell to exercise; that is not what they can choose to do. Blood cells move through your circulatory system because your heart pumps them. Bone cells are fixed in place. Similarly, you can’t tell your lung cells to not inhale cigarette smoke. That is the individual’s responsibility rather than the cell’s. The same goes for using a condom or eating right. If you keep yourself healthy following the individual precepts, you expect your organs, and their cellular components, to be healthy as well.
Medical care treats cells and organs, not the person. For example you may be advised to take aspirin (acetylsalicylic acid in Canada as Aspirin® is trade-marked by Bayer) to make platelet cells in your blood less sticky to lessen the risk of a heart attack. You may take Prozac® (fluoxetine) to treat the cells in your brain if you are depressed. Men can take Viagra® (sildenafil) to treat the smooth muscle cells in the corpora cavernosa of the penis to get a strong erection. If you have a heart attack with a clot in a coronary artery you will have a roto-rooter procedure to remove that clot and restore circulation in that artery feeding the heart muscle. If your kidneys aren’t functioning you can be placed on a renal dialysis machine to remove waste products in the blood. If you have an inflamed appendix you will likely have surgery to remove that part of your intestinal tract.
As an emergency doctor I would often see a homeless individual come in wheeling his shopping cart containing all his belongings saying he had been weak and dizzy for six months. Typically I had to see if there was a medical reason to admit him. Such investigations might cost a few thousand dollars. Often I would find no justifiable reason to admit him to the hospital. If the emergency staff were cooperative, and the studies had taken a long time, I might be able to get him a meal tray. But then I would have to street him, perhaps with a prescription for a drug to help with his dizziness that he would likely not be able to afford to fill. If we could treat the individual, rather than their cells and organs, then we would ensure he would have a safe place to live and meaningful work to do. Lacking these treatment options, however, by segregating medical care from human care, we are limited in our ability to treat individuals.
There are factors that produce health in populations beyond what individuals do. Elements affect populations that have no individual counterparts in the same way that individual health advice has no cellular equivalents? We need to discover/identify? those population level factors and get them operating. Then what individual humans do to advance their health doesn’t matter as much as we’re led to believe. This could explain why Japan is the country with the longest life expectancy despite its large proportion of male smokers. The population health approach utilizes such thinking—it finds out what produces health in a population and then implements those factors to make those within that population healthy. It is comparable to advising individuals to do what is best for their health. If individuals eat right, exercise, etc. their cells and organs become healthy as a byproduct of the entire body’s better health.
The British epidemiologist Geoffrey Rose, who we encountered in last month’s blog, distinguished between sick individuals and sick populations in a seminal 1985 paper. He looked not at why some individuals had hypertension or high blood pressure, but at why some populations had widespread hypertension and others did not. Some of the highest blood pressures among adults were found among African Americans in the United States, while some of the most consistently low blood pressures were found in Africans in Africa. What factors are producing such a distinct difference among populations seemingly so similar? Medical students are taught to consider why a particular patient has severe hypertension. The patient not taking their blood pressure medicine is a common reason, or they are obese, have kidney disease, or other risk factors. But doctors should broaden their gaze to consider why there is so much hypertension in the United States, or why we die so much younger than people in other societies. Unfortunately, we don’t ask these broader health questions because poor health has become normalized here.
Rose pointed out that prevention strategies in sick populations would be different than those for sick individuals. For individuals one needs a screening program to identify those at high risk, and then regimens to modify behaviours and otherwise treat their conditions. This expensive strategy leads to the astronomical costs of U.S. medical care. It is not effective given the poor health status we have compared to other nations. A prevention program aimed at the population might work to change societal norms. Let’s consider smoking as an example.
It is now illegal to smoke in restaurants, airplanes and most public places, and tobacco can no longer be advertised on TV, billboards or public transport. These bans led to plummeting smoking rates. One rarely smells cigarette smoke anymore—a stark contrast from the mid-twentieth century when children routinely grew up in clouds of cigarette smoke at home, and smokers routinely lit up in cars, restaurants, airplanes and elevators. To compensate for the lost sales, tobacco companies have increased internet advertising and point-of-sale marketing to specific groups defined by race, ethnicity and income, among others. The poor, trying to cope with high levels of stress associated with their poverty and low status, are now targeted online with discount coupons and free packs of major cigarette brands. In our pandemic era many smokers have increased their consumption (with big increases in electronic cigarettes which contain nicotine and other harmful chemicals). Fewer smokers sought help to quit smoking in 2020 and cigarette sales increased. Given the increased stress and isolation in our homes, with nicotine being among the most addictive chemicals, our cigarette consumption has not decreased in the pandemic.
The question these issues raise is if we did shift to a focus from the individual to the population, how would we go about treating the population? The answer is complex or simple depending on strategies. Since producing health is a political construct, we have to engage there.
Next month we begin by looking at conditions that have a socioeconomic gradient, namely those where the poorer do worse than the richer.