Metaphor is an essential tool for exploring the unknown. After the triumphs of the scientific and industrial revolutions, the metaphor of the body as a machine illuminated the mystery of living organisms and made analyzable the mechanisms that enable life or explain disease. The isolated analysis of vital processes, as if they were circuits and parts of a device, has allowed us to understand how a hormone like insulin regulates blood sugar or why hypertension is so dangerous for the cardiovascular system, saving many lives along the way. And the ability to reduce the body to understandable elements has made possible discoveries that seemed impossible when the body was an enigmatic and unmanageable whole.
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However, it is not advisable to confuse metaphors with reality or become too attached to them, because just as they reveal, they can also conceal. Although we talk about bodies as computers that contain information and transcribe it to produce proteins and everything else, a cell is not composed of standardized and replaceable modules that execute a program sequentially. Thousands of processes happen simultaneously, with countless things that would be errors for a machine, but are normal in a living being, amalgamated over millions of years of evolution from imperfect organisms.
The presidents of Russia and China were carried away a year ago by the metaphor and discussed whether, thanks to transplants, like bringing a worn car part from Germany, they could live up to 150 years. It doesn’t work that way.
This way of understanding the body and existence has offered great successes in medicine, but it can also become a burden. Recently, an article published by the journal The Lancet showed part of the success and limitation of this way of seeing health that turns humans into machines and their vital problems into measurable parameters that can be managed with pills.
The work, led by researchers from Imperial College London (UK), reveals that since 1990, differences in blood pressure and cholesterol levels between those over 40 years old and people with a normal body mass index (BMI) have decreased or disappeared in several high-income countries.
In the industrial world of processed food, endocrine disruptors, and escalators, the prevalence of obesity has doubled in the last three decades, worsening cardiovascular health, particularly due to increased blood pressure and cholesterol. But although the machine civilization takes away, it also gives. Although the study is observational and cannot confirm that this is the cause, it attributes the improvement to the more frequent and intensive use of medications to reduce cholesterol, such as statins, and antihypertensive drugs. The result was even more striking among those over 60 in England and the United States, where people with obesity reached similar or even better levels than those who were thin.
The situation is different in those under 40 years old. In this group, differences in cardiovascular risk between people with obesity and normal weight barely decreased, coinciding with less use of preventive medication. Although treatments have reduced part of the cardiovascular risk associated with obesity, experts warn that it still has significant health consequences and requires continued attention.
The study did not attempt to verify whether these better results in tests correspond to a lower risk of heart attacks, strokes, or mortality or if it increases healthy life expectancy and raises a question about the limits of reducing health to measurable parameters: when we manage to normalize the numbers, are we making people healthy or just making their tests look like those of a healthy person? There are studies showing that lowering blood pressure is beneficial, even if the root of the problem is not addressed, but experts warn that these results should not convey the idea that obesity is now harmless.
In an article published alongside the study in The Lancet, Yuan Lu from Yale University warns that obesity is still related to diabetes, chronic kidney disease, fatty liver disease, cancer, sleep disorders, musculoskeletal conditions, and systemic inflammation, many of which are not reflected solely in blood pressure or non-HDL cholesterol levels (the bad cholesterol). “These findings should not be interpreted as evidence that obesity has become a harmless condition. Rather, they suggest that some of the cardiovascular consequences of obesity are increasingly being mitigated through medical treatment and management,” he concludes.
Andreea Ciudin, coordinator of the Comprehensive Obesity Treatment Unit at Vall d’Hebron University Hospital, recalls the results of a study they conducted at her hospital to understand the expectations of doctors and patients regarding the disease. “It was something we suspected, but we saw that our interests are not aligned. We are very focused on numbers and goals, on lowering blood pressure, glucose, cholesterol. And patients think more about what they can do, about being able to move or enjoy their family,” she explains.
“With diabetes, many years ago, we changed the goal from lowering glycated hemoglobin to giving the patient quality of life and avoiding diabetes complications; in obesity, we have to make that leap,” says Cristóbal Morales, endocrinologist at Vithas Hospital in Seville, who adds: “I would burn the weights from consultations, because the goal is not to lose weight but to gain health.” “With obesity, we must not confuse what is measurable with what is important and not lose sight of the patient’s interests, quality of life, and functionality,” Ciudin adds.
Another problem with setting goals based on measurements and drugs to fix test results is that this fragmentation ends with patients taking a lot of medication. “Maybe the nephrologist gives antihypertensives to reduce kidney risk and the cardiologist statins for cardiovascular risk. With that fragmented strategy, where no one sees the patient as a whole, there is a risk of giving unnecessary medications,” Ciudin continues.
Morales recalls that although there are markers like hypertension that are important to control, the root of obesity and associated metabolic problems is deep, and there is a risk of masking its origin with medications. “Before we only looked at kilos, but now I have a more global view looking at markers, body composition, inflammation…” he points out. “We have to go treat the roots of the problem, which are biological, environmental, and behavioral, and we must do it as soon as possible, from the womb, because in metabolic disease, as when we talk about stroke, time is gold,” he emphasizes. This requires, in addition to better drugs, political changes that facilitate good nutrition or adequate physical activity integrated into daily life.
Ciudin adds that care must also be taken when interpreting the separation between normality and pathology with a parameter like body mass index (BMI), which the authors of the The Lancet article use. “You can have a very high BMI without metabolic complications because your fat is basically subcutaneous and you have good muscle mass, and the opposite can happen because you have excess visceral fat,” she explains.
The aspiration of doctors now is to identify common pathways shared by different diseases, which often arise from complex interactions within biological systems and not just isolated molecular abnormalities. An example of the possibilities of this approach is GLP-1 agonists. Although they were designed to control glucose in diabetics, it turned out they participate in biological mechanisms that can manifest as obesity in some people, heart failure in others, or kidney disease in others. Understanding these common pathways would make less symptomatic treatments possible, not so focused on isolated molecular abnormalities and more effective.
Meanwhile, it would be advisable to look for new metaphors to reach the next level of understanding. British science communicator Philip Ball proposes abandoning the idea of the body as a computer and starting to think of cells as entities with intentions and interests, like humans who inhabit and sometimes lose sight of the meaning of their efforts to get good test results.
