Evidence-based medicine may interfere with an understanding of nutrition

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Even a basic understanding of current nutrition science and human health allows a physician to use food as medicine and to counsel patients to avoid unhealthy foods.

I am a big supporter of Evidence Based Medicine (EBM). Through randomized controlled trials (RCTs) clinical truths are often revealed and untruths are rejected.One of my most memorable experiences in medical school was meeting David Sackett as a visiting professor. Dr. Sackett of McMaster University in Canada is widely regarded as the founder of EBM and his definition of EBM as “the conscientious, explicit and judicious of the current best evidence in making decisions about the care of the individual patient” (BMJ 1996) is still in use today.

Dr. Sackett made an impression on me as a physician scholar who was flexible in choosing the best available evidence.He embraced the role that scientific discovery plays in medical evidence.EBM today is so focused on randomized controlled trials that scientific discovery is not recognized by most practicing physicians.

Nutrition is a vital area of medicine that does lend itself well to the single variable RCTs.Getting accurate population data on people’s nutrition is fraught with uncertainty since self-reported information is often inaccurate. A nihilistic cynicism often results. A better understanding of the role of nutrients comes from the study of human biology. For example the role of the carbohydrate insulin axis in causing fat storage is now clear. Excess carbohydrates make people overweight and obese much more than eating fats. (See Mark Hyman, MD, Eat Fat Get Thin, 2016).


Every physician studied human biology in the first two years of medical school.I found The Pathophysiology of Disease my favorite course since it gave me a deep understanding of human health and the biology of diseases. The lifelong learning of a physician should include the evolving knowledge and understanding of medical science, not just what the latest clinical trials conclude. Nutrition science has come up with paradigm shifting discoveries over the last 20 years that elude most practicing physicians.

For example, every person has a carbohydrate threshold and when that is exceeded, insulin resistance and fat storage occurs. Informed patients will ask me, “What do you think my carbohydrate threshold is?” For men it is usually around 50 grams but for women it can be as low as 25-30 grams. Most primary care physicians do not know this and it is not routinely taught in residency training.

Another important area of new knowledge is the central role of the microbiome in human health. Hippocrates understood that “all diseases start in the gut” and current science understands that this is “leaky gut” from dysbiosis, an unhealthy microbiome from overly processed foods. Leaky gut or small intestinal bacterial overgrowth (SIBO) may be the root cause of most autoimmune diseases.

Even a basic understanding of current nutrition science and human health allows a physician to use food as medicine and to counsel patients to avoid unhealthy foods. The RCTs of EBM in nutrition are usually helpful and my cloud the understanding that comes from learning the biology.

All physicians should be scientists who are able to apply the latest understanding of human biology to help patients. As I strive to do that, practicing medicine is very rewarding and cynicism is avoided.

Joseph E. Scherger, MD, MPH, is a family physician at Eisenhower Health in La Quinta, California, and is a member of the Medical Economics® editorial advisory board. He is also a core faculty member with the Eisenhower Health Family Medicine Residency Program. Dr. Scherger is clinical professor of family medicine at the Keck School of Medicine at the University of Southern California (USC), and is a leader in transforming office practice.