24 February 2025

Have you heard of Ignaz Semmelweis? I had not (until a fellow member of the hiking club told me about him). He was a Hungarian physician and scientist of German descent who was an early pioneer of antiseptic procedures and described as the "saviour of mothers" (1818-1865), according to Wikipedia.

Semmelweis had noticed that they could reduce postpartum infections by getting obstetricians to wash hands. Revolutionary! Would you believe he was mocked by the medical community, who were offended that he would ask such a thing of them? Misunderstandings about his work led to him being bullied. He eventually suffered a nervous breakdown and was committed to an asylum, the guards beat him up, and he died of the resulting infection. Oh my!

This is certainly not how we treat people with new ideas today. Or is it? It's natural to be resistant to novel thoughts or the suggestion of change. If someone tells me “everything you thought you knew about [fill in the blank] is wrong", I'm highly skeptical. Especially if it's to do with nutrition. Nutrition is generally not a field of breakthroughs, but rather a slowly evolving science.

It sometimes seems like the advice for healthy eating changes weekly, but one factor with potential for the greatest impact on health hasn't changed in decades: ubiquitous inclusion of produce. It's not exciting, nor groundbreaking - it doesn't look like a silver bullet - and, of course, there's nuance - but a diet rich in whole fruits and vegetables protects against all of the major chronic diseases. (I can't wait to do a deep dive into the history of veggies in our Dietary Guidelines next week!)

There's another side to this, though. Our science is constantly evolving and the world is changing around us. Farming methods need to adapt to climate change. Nutrition science is now faced with the reality that over 50% of Americans' diets come from ultraprocessed food. We need to be open to new ideas…but with a level of discernment.

Ignaz Semmelweis never really got the credit he deserved. Long after his death, his findings finally gained acceptance, saving many lives. When I think about the principals of hygiene, though, I'm only familiar with Louis Pasteur, who confirmed Semmelweis' findings, and Joseph Lister, who demonstrated the efficacy of handwashing. Semmelweis, it seems, was not very good at communication.

Separating the Wheat from the Chaff

These days, with so many easy ways to disseminate information, it's important for consumers to have the skill to discern what is true (or - since good science acknowledges imperfection and evolution - what is most likely) and what is not. These are a few red flags - or perhaps I should say “yellow flags” - we may not want to immediately disregard the information presented, but to slow down and consider more thoughtfully:

1. Is it based on one study that contradicts decades of research? Don't assume it's wrong, but here's a situation where you'll want to look more deeply at the data and/or wait for other peer-reviewed studies to confirm their conclusions.
2. Does the person stating it have a financial interest in it being true? Are they selling pills or potions, or being sponsored by someone who has a vested interest in this inference?
3. Is the proponent of this idea an expert in their field? Most importantly, do they have the background to know what they don't know?
4. Does it sound too good to be true? Is it described as a “magic bullet” for health? Here, I want to interject with one exception: whole food, plant based diet is good for health, the planet and our palate!
5. Has the claim used absolute words like “always”, asserted that it works for everyone, and left no room for nuance? Nutrition is personal. Beyond basic allergies and genetic predispositions, there are real reasons why there is no one universal best diet for everyone.

Shameless plug for personal care from a Registered Dietitian Nutritionist: schedule a free 15 minute meeting with me or find another RD from the Academy of Nutrition & Dietetics .