Broad Street, Soho.
In this small suburb of London, more than 500 people succumbed to a devastating cholera outbreak in the span of merely 10 days. The brightest minds in medicine were uniformly convinced that miasma — “toxic air” — was the cause not only of these cholera outbreaks but other notorious epidemics of the time, including chlamydia and the bubonic plague. One physician, Dr. John Snow, was highly skeptical of this prevailing theory. From his expertise of interviewing and treating patients who contracted cholera during prior epidemics, he observed that the onset of this disease was very sudden, whereas the exposure to miasma was chronic. He considered that, perhaps, it was something they ingested. However, to the woe of public health, his arguments were largely ignored or even publicly ridiculed. In an attempt to seek proof for his theory, Snow mapped out the locations and source of the outbreaks and connecting exposures to later outcomes — applied techniques that would later form the pillars of modern epidemiology. He noted that the density of cholera cases increased dramatically in the vicinity of a single water pump. Despite equivalent exposure to miasma, individuals in these adjacent neighborhoods had drastically different fates. Snow, unlike his colleagues, began to suspect that contaminated water piped out of the Broad Street pump was the real culprit. After a series of appeals to the local Board of Guardians, the pump handle was ordered to be temporarily removed. While the delinquent Vibrio cholera would manage to escape justice for another three decades, Snow’s conviction to call for the removal of the handle on the Broad Street pump, spared countless men, women, and children from this horrendous disease and death.
The epidemics of diabetes, cardiovascular disease, cancer and dementia roll through the United States and across much of the world, eerily reminiscent of the sweeping cholera outbreaks of Snow’s era. Even in the majority of low- and middle-income countries, these chronic illnesses have already displaced infectious diseases to become the leading causes of death and disability. Yet, the majority of these are potentially preventable.
As medical students, we are taught in excruciating detail the complex pathophysiology of these chronic diseases and their corresponding therapeutics, often invoking elaborate pharmaceuticals or surgical techniques. Rarely, however, are we instructed in the true causes of these diseases: the everyday exposures we encounter through our lifestyle — diet, physical activity, smoking, alcohol, sleep hygiene and stress management (or lack thereof). Our medical education solely emphasizes the downstream effects we see in the clinics and on the wards, rather than the upstream “contaminants.” Medical education, instead of touting the care, maintenance and attempted restoration of health, becomes solely focused on disease management delay of death after illness has already taken hold. In turn, unlike John Snow, we become physicians who avidly prescribe the best drugs in an effort to treat the epidemics that have unfurled in our community rather than preventing their existence in the first place. We forget to focus on the water pump.
The infographic When and Why People Die in the United States, 1990-2013 further confirms that the priorities in medical education may not fully align with our population needs. While it is true that cardiovascular disease, diabetes and cancer are still the top reasons for death, the associated risk factors demonstrate the true causes. Dietary risk is the number one risk factor for death in both men and women, exceeding even tobacco smoking and low physical activity. Working down the list: blood pressure, body mass index, fasting plasma glucose and total cholesterol are all strongly influenced by our lifestyle. Overall, many bodies of evidence have demonstrated that the contribution from our genetics to our overall health and risk of disease is modest at best. And yet, the overwhelming impacts of these modifiable risk factors as well as approaches to counsel patients on how to achieve a favorable profile receive little mention in our medical school curriculum or the broader United States Medical Licensing Examinations (USMLE).
Perhaps it doesn’t work as well as a pill.
Historically, most lifestyle factors such as diet, physical activity, sleep and stress have been investigated through observational studies, typically considered a weaker form of evidence than the gold standard: randomized double-blind placebo-controlled trials often required for pharmaceuticals. However, even for avid believers in evidence-based medicine, it is worth noting that there still has not been a single trial in which healthy individuals have been randomized to tobacco smoking, just like there has not been a trial to determine whether parachutes truly work. In recent years, large landmark clinical trials including the Diabetes Prevention Program and the Prevención con Dieta Mediterránea (PREDIMED) dietary intervention have shown that lifestyle changes in diet and physical activity produce comparable or even greater reductions in the risk of several major chronic diseases compared to the prescription drugs doctors so often reach for. Heart disease was shown to be potentially reversible with the appropriate lifestyle interventions. Even cognitive decline, a disease process thought to an inevitable part of ageing, can be ameliorated through dietary interventions. These disease reductions were achieved at a fraction of the cost of pharmaceuticals. Besides reduced financial burden on our healthcare system, lifestyle changes produce minimal and often even good side effects, allowing an individual to perhaps reduce medication use and improving their overall quality of life. Instead of worrying about the serious adverse effects of such drugs, physicians could instead celebrate the positive effects that come with prescribing lifestyle changes. For example, an individual who can make dietary changes to bring his or her blood pressure under control may be able to cut back on hypertensive medications, which often have unpleasant and even potentially life-threatening side effects.
Perhaps people won’t adhere to these changes.
As medical professionals, we are forever chasing the elusive goal of patient adherence. For both lifestyle and medication use, numerous reasons can diminish a patient’s compliance. While adherence to a healthy lifestyle is often more difficult than popping a pill, the cumulative benefits across the lifespan is much larger than can be derived from drugs or surgeries. Optimistically, it is important to emphasize that even seemingly minimal adherence to healthful lifestyle patterns can improve clinical outcomes. Furthermore, it is important to recognize the importance of physicians in providing patients with not only reliable knowledge but also actionable approaches. In our medical training, we learn how environmental and social determinants dictate decisions past individual decision making and personal responsibility. Personal responsibility of course plays an important part in living a healthy lifestyle, but physicians must similarly take up the sacred role of providing the proper wherewithal to patients. Making these prevention and treatment options available is the crucial step in empowering patients to take control of their own health. In turn, lifestyle training in medical school can be an inception into how to enact effective and personalized recommendations for healthy behavioral changes within each patient’s context.
It is clear that lifestyle has complementary strengths to the prevention and management of many chronic diseases. What isn’t clear, is why it does not receive a comparable level of attention in our medical training. Individual medical schools ought to offer structured longitudinal, multi-component program to educate physicians who are competent in lifestyle knowledge and counseling to serve the growing needs of our community. Rather than having isolated topics on nutrition interspersed throughout a biochemistry or physiology course, stand-alone lectures or seminars on nutrition should be offered longitudinally throughout all four years of medical school. In schools which offer population health classes, lifestyle modifications — and not only smoking cessation — should be emphasized alongside the presentation of the associated landmark studies. Clinical skills course and objective structured clinical examination (OSCE) encounters could consider the inclusion of special sessions devoted to developing and rigorously practicing the skills effect behavioral modifications, based on current evidence-based models. The benefits are twofold: many of the skills practiced in behavioral modification — setting shared goals, scheduling follow-up visits, gathering regular feedback and motivational interviewing — also improve patient adherence to other treatment modalities.
Currently, while the USMLE Step 1 and Step 2 exams contain questions about nutrient supplementation, weight management and smoking cessation, important topics such as specific dietary patterns, sleep and stress management for the maintenance of health and reduction in chronic diseases are rarely addressed. On the national level, changing the USMLE to incorporate lifestyle knowledge and counseling questions could be an effective way of ensuring a certain degree of mastery of lifestyle concepts and pressure medical schools to teach more of these topics by institutionalizing them as a required training. Moreover, knowledge of approaches to effect sustainable behavioral changes could also be included in the USMLE. They can be examined in the context of clinical encounters during Step 2 Clinical Skills (CS), which would allow for the assessment of these skills that cannot be adequately evaluated on multiple choice exams.
Lastly, leading by example is important. We need to abandon the “do as I say, not as I do” mentality, which is clearly not offering useful and actionable advice to our patients. Several studies have shown that physicians and medical students who practice healthy lifestyles themselves are more likely to recommend such practices to their patients. At the same time, patients who perceive healthful behaviors among their physicians are more motivated to adopt these practices. In turn, lifestyle education includes equipping medical students with specific competencies including: healthy diets and convenient ways of preparing healthy meals, exercise routines and approaches to manage stress while on busy schedules. This approach will be much more efficacious than teaching and testing medical students on how to repeatedly say: “You need to eat better and watch less television.” It is important to recognize that the education of medical students on lifestyle topics could be the beginning of a cultural shift in medicine to prevention and cultivating well-being. Medicine in the United States often employs the strategy of identifying individuals at high-risk for or with prevalent disease and then providing the corresponding treatments. On the other hand, as Sir Geoffrey Rose stated in his seminal 1985 paper, physicians who focus on “sick individuals” often miss a large swathe of people who are at medium- to low-risk but nevertheless contribute more to the overall disease burden. This idea of treating “sick populations” which is in many ways akin to health maintenance is often missing from the training and practice of medicine in the United States. Optimistically, one can surmise that the integration of lifestyle counseling into medical training will one day become the mainstream behaviors for the majority of individuals in the United States and around the world.
We face a much greater challenge today in medicine than John Snow did in his time. Complex chronic diseases such as cardiovascular disease, cancer and dementia do not have a simple exposure like cholera, which could be resolved by removing a single pump handle. Just as John Snow did not know what Vibrio cholera was, we similarly lack the final answers on how to protect everyone from these chronic diseases. Nevertheless, we have an overwhelming amount of evidence that the important lifestyle choices we make contribute substantially to our long-term health and avoidance of diseases. We have already mapped out the true causes. While we need not de-emphasize the utilization of life-saving medications and surgical procedures granted by modern medicine, we cannot rely on these tools to “treat” ourselves out of the chronic disease epidemic. At the end of day, however, to save the largest number of lives possible, we need to follow in Dr. Snow’s footsteps: to be pro-active — to take the handle off the toxic water pump and offer our patients a drink from the spring of health and vitality.