Adenovirus Penton Base

25 Years of Research on Viruses Causing Obesity

In 1982, Michael Lyons published the first finding that a virus could cause obesity. More than a quarter century later, quite a pile of evidence has accumulated. And yet, the notion of viruses causing obesity seems far from the mainstream. Why is this so?

The Long Road for a Counter-Intuitive Finding

It’s been more than a century since Peyton Rous first observed that a virus could cause cancer. The scientific world largely rejected his finding. The response was so hostile that he abandoned cancer research for 20 years. Then in 1933, Richard Shope discovered that a papilloma virus could cause cancer in rabbits. Fifty five years passed and Rous received a Nobel Prize. But it took another 40 years before a papilloma virus vaccine received approval (in 2006) to prevent cervical cancer.

Even today, ignorance gets in the way of preventing cervical cancer with this highly effective vaccine.

Obesity Is Not What It Seems

Much more so than cancer, everything about obesity is counter-intuitive. Politicians think that hectoring people with obesity will bring it under control. The presumption is that obesity is a simple matter of bad habits. Eating too much and moving too little.

Bias is so pervasive that many people living with obesity, after years of unsuccessfully fighting their own physiology, come to believe that they are somehow bad people. That’s called internalized stigma, and it leads to much worse health outcomes.

Obesity is not what it seems. And that illusion gets in the way of progress.

Knowledge Prevails Over Ignorance – Eventually

In Obesity Reviews, we now have an excellent compilation of a quarter century’s evidence on viruses causing obesity. Nikhil Dhurandhar, senior author on that paper, tells us:

We have quite a lot going for us in the pursuit of viruses causing obesity. AD36 is the most studied adipogenic virus. We can isolate the virus from infected animals, give it to other animals, and they become fat. We’ve explained the underlying mechanism. We’ve demonstrated a clear association in humans in several different ways.

The weight of the evidence will eventually lead to acceptance. Just like smoking and lung cancer, there is no study showing a causal relationship. But the evidence is so compelling, we accept causal relationship based on observational data.

AD36 is not the only explanation for obesity. But the science is compelling and it tells us that it’s part of the picture. Building upon this science has potential to bring us better solutions.

Click here for the review by Akheruzzaman, Hegde, and Dhurandhar of this fascinating science.

Adenovirus Penton Base, photograph © Cryo Mariena / flickr

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January 8, 2019

4 Responses to “25 Years of Research on Viruses Causing Obesity”

  1. January 08, 2019 at 9:16 am, Al Lewis said:

    It also took years before someone (who won a Nobel Prize) was able to convince people that ulcers were also caused by a pathogen (a bacterium, not a virus). So there is precedent.

    The bad news is that this particular insight didn’t really change many treatment plans, because the bacterium in question proved hard to eliminate from one’s stomach. The same might be true for a virus causing or contributing to obesity: it might be provable but doing something about it would be difficult.

    • January 08, 2019 at 9:52 am, Ted said:

      True enough. Back in 1911, who knew that cervical cancer would be preventable? But you never know where the facts will take you. Maybe that’s why people are more comfortable with their presumptions. And heretics like Galileo are unpopular.

      However, I will note that better understanding the pathology of peptic ulcer diseases seems to be helping. Hospitalizations are down ( and so is the global prevalence (

  2. January 09, 2019 at 5:26 am, Margaret Beck said:

    You are so right in all you say. You care so deeply for your patients you are indeed a saint to those who don’t know where to turn or to whom to go to. Patients need a kind and practical guidance because they do not get the right attitude from medical staff or from other people.