Obesity Virus, Fat Chickens and Life's Mysteries
Obesity virus kills thousands … of chickens. And it also reveals how little we know about humans.
Viruses can make you fat — and your dirty-fingered friends can give these viruses to you.
That is the punch line — a known truth about the world. The set-up, though, is longer in the telling. It begins with a boy named Nikhil living in India.
When Nikhil Dhurandhar was young, his father directed a large obesity clinic in Bombay. Throughout his childhood, Nikhil saw thousands of his father's obese patients. They came in for some cure, whether salve or salvation. Instead, they received, again and again, the same advice: "Move more. Eat less."
It is what doctors around the world tell their patients. You might have heard the same advice. It echoes on TV, across magazines and everywhere else, bouncing throughout our society. Sometimes the advice works, but more often, it does not.
As he grew up, Nikhil came to feel a deep sympathy for the many patients who tried and failed to lose weight. He wanted to help, but he also wanted to do something more than offer advice. Despite huge sums of money spent on the diet industry each year in Bombay and nearly everywhere else, the best that doctors can do, short of pills and expensive surgeries, is to look their patients in the eyes and, in each of a hundred different languages, tell them what, in most cases, they already know.
Dhurandhar did what he could. He went to the U.S. for a master's degree in 1987 and then returned to Bombay to work as a clinician beside his father while simultaneously doing research for his doctorate. On the days he was in the clinic, he stood beside his father and said, "Move more. Eat less." He uttered those words so often that they became more like a prayer than advice. He imagined himself praying like this over his patients each day for the rest of his life. Then things changed.
In 1988, Dhurandhar was looking for insight and had grown curious about a family friend, Sharad M. Ajinkya. Ajinkya was a well-known and accomplished veterinary researcher. Dhurandhar began to read Ajinkya's work and noticed his papers on the virus SMAM-1, which had caused the deaths of thousands of chickens in India in the early 1980s.
One day, not much later, Dhurandhar and Ajinkya had a conversation that would change Dhurandhar's life. The topic of chicken viruses came up. Ajinkya mentioned that the chickens he had studied, the ones with the virus SMAM-1, were fat. They had big kidneys and fat around the abdomen. Ajinkya had noticed the chickens' fat, but he hadn't thought it unusual, not really, just one observation in a career of millions of noticed details.
As the two men talked, Dhurandhar grew excited. What started as dinner-party banter became something entirely different. "Stop right there. Did you say that the chickens had fat abdomens?" Dhurandhar asked.
"Yes, yes they did."
"Why is there fat in the abdomen?"
"Well, I'm not sure. I hadn't really thought about it."
"Is it possible that the virus made the chickens fat? That is, could the virus cause, in the chickens, obesity?"
Ajinkya's response was key to what would follow. Had he said "no," Dhurandhar might have continued along some other line of conversation — the monsoons or the rising price of gas.
Whole lives can turn sometimes on a single, well-placed word; so, too, the absence of one. Ajinkya didn't say no. He said, "I don't know." That, for Dhurandhar, was enough. Stokedby Ajinkya's observations and uncertainty, Dhurandhar's mind began to spin. He thought, or maybe he even said aloud: Is it possible that human obesity is caused by a virus?
With caution, the pair began to investigate.
Like two teenagers who have just found the entrance to a previously hidden cave, they pulled out their lights and began to look in. First, they would verify Ajinkya's observation experimentally. They located some healthy, germ-free chickens and gave them SMAM-1. Within six weeks, the infected chickens were 30 to 50 percent fatter than the uninfected individuals, even though they had eaten the same food. This was amazing! It could have been a fluke, though.
They hadn't tested many chickens, so they found a hundred more — one hundred Leghorn broilers — and did the test again. So much depended on those white chickens. The results came back: More fat chickens!
Not only were these chickens fat, they also had lower cholesterol and triglycerides than did the "healthy" chickens. Something strange — but to Dhurandhar's mind, wonderful — was going on.
Now came a point of reckoning for the two scientists. They were in too deep to turn back, but there were at least two paths. They could keep working on the chickens and figure out, in great detail, the biochemistry linking virus and fat, or they could go big and test their radical ideas on humans. If they wanted their findings to be believed, they probably needed to move slowly and cautiously. The most rational approach was to learn more about what was going on in the chickens and then come back to humans once they understood.
Yet, at that moment, prudence was the last thing on their minds. Dhurandhar had seen thousands of obese patients. If any single one of them could have been obese because of something as simple as a virus, he needed to know. He could not — would not — wait for details.
Temporarily, prudence won over. Dhurandhar was excited and ready to do more, but he was still not quite sure what it was that he and Ajinkya were seeing. He decided to try to figure out what else was known about diseases and fat. They had access to only a handful of scientific journals, so Dhurandhar did something both improbable and a little silly. In the days before the Internet or email, he wrote the U.S Library of Congress a letter that began, "Dear to whom it may concern …" asking that if anyone else had already published anything on fat and viruses, would the librarians please let them know what there was. It was a message in a bottle flung blindly at a faraway librarian.
Amazingly, someone wrote back. Some saintly human went and checked the shelves. He or she did better than that: They actually found the articles and sent them to Dhurandhar, breaking to him the news that there were older studies showing links between viruses and fat, albeit in mice. Dhurandhar was disappointed, in a way, to not have been the first, but he was also emboldened. His was not the only evidence. The more he thought about it, the more emboldened he became. He had the confirmation he had needed. It was time to go big. He and Ajinkya would test their theory on humans.
But how could they test their nascent theory on their fellow man?
"Come try a piece of my fat, infected chicken" just didn't seem appropriate or moral — or even legal. What they could do was to test humans for antibodies to SMAM-1 and see if the fattest individuals were also the most likely to have the virus.
Ajinkya and Dhurandhar tested 52 of Dhurandhar's patients. Ten of the patients had antibodies for SMAM-1. Lo and behold, those 10 were heavier than the other 42 patients and more of their body weight was made up of fat. Like the infected chickens, they also had lower cholesterol. Suddenly, Dhurandhar, thanks to his work with Ajinkya, had a grand, new, sweeping theory about fat in humans. What he had discovered, if he was right, was relevant to billions of men and women.
Nearly a fifth of people in developed countries are obese. Dhurandhar was convinced that obesity was a disease caused, at least sometimes, by a virus. He was beginning to think at least some obesity was contagious. Some days, he thought most obesity was contagious; other days, just some. Either way, if even a handful of cases had such an origin, such cases might be prevented with a vaccine. Perhaps he could someday tell some of his patients something more helpful than "Move more. Eat less."
In his excitement, Dhurandhar decided he needed to move to the United States. He needed to go somewhere his bold new research could get funded and where he could get better access to scientific publications. In addition, obesity is a bigger problem in the U.S. than perhaps anywhere else in the world, by some measures the biggest public health problemi. In his enthusiasm, he said goodbye to his father and the rest of his family and moved, with his wife and son, to America. He was prepared to do whatever it took, so he did what he had long told his patients to do — he moved more. If things got rough, he was prepared to eat less. He was traveling to a new life on hope and a theory. At least initially, this would turn out to be a mistake.
Up to that point, Dhurandhar had been lucky. In the U.S., he would try again. He visited scientists, made phone calls and wrote letters. His letters in particular seemed like a long, long shot — a Powerball ticket. He wrote to anyone doing work remotely related to his interests, to explain that he had a big new theory and that he was in need of a job. He mentioned that the theory included the idea that obesity was contagious. He also mentioned his as-yet-unpublished experiments on humans, which were, for all the recipients of his letters knew, entirely imaginary. He then waited. No one responded.
Dhurandhar's excitement about his idea was not shared. The scientists he hoped might enthusiastically hire him came to see him, he thought, as "that fat chicken guy," or even "that crazy fat chicken guy." And why wouldn't they? He was a young man with a wild idea and little to back it up. He had not yet done very much to make academics take notice.
He had published just a few scientific papers, one of them on the nutritional quality of dog food and another on fat chickens. On the basis of those papers and additional but unpublished research, he was proposing the radical idea that a virus, rather than just eating too much and exercising too little, was making people all over the world fat. Dhurandhar had only recently graduated from a doctoral program that was not well-known in the U.S. On top of that, there are thousands of doctoral students applying for jobs in any given year.
So when Dhurandhar came to the U.S., independent of whether or not his idea was good or not, radical or not, or passionate or not, he had just a slim chance of getting a job. It was likely that he would go unemployed and drift, along with his theory, into oblivion. That is what happened. By June of 1994, he decided to return with his family to Bombay. His dream had proven too improbable. He, and his wild idea, would head home.
Then an amazing thing happened: someone responded. One of his letters had landed on the desk of Richard Atkinson, an obesity specialist at the University of Wisconsin. Atkinson had himself thought about the idea that viruses might influence obesity. He offered Dhurandhar a job in his lab in Wisconsin working on chickens, viruses and fat.
From there, Dhurandhar tirelessly tested his chicken-fat theory again and again, now using the virus Ad-36 — which, unlike SMAM-1, is a human adenovirus and so, potentially, even more consequential — but this time in small steps. He would, he thought, make it to humans, but not all at once.
First he published a general paper on fatness in animals and the presence of viruses. Then he developed a new method to test for the effects of Ad-36. Then he showed that one chicken could catch fatness from another chicken because of the virus, and both would become fatter. Then, in 2002, he made a bigger jump: He showed that the virus, when given in the lab to rats or marmosets, made them fat, too. But even then, he didn't go back to humans — not yet.
Dhurandhar is now an associate professor at the Pennington Biomedical Research Center in Louisiana. He and his ideas have survived and now, finally, in the last few years, Dhurandhar has come back to working on humans. Dhurandhar and Atkinson recently checked over 500 lean and obese adults for Ad-36. Thirty percent of the obese patients showed evidence of the virus, but only 11 percent of the lean individuals did. His work on humans seems to show that when we are infected with this virus, it tells the body to make fat cells — cells that favor the viruses' own reproduction — though exactly how or why remains unclear.
In the end, there are two lessons from Dhurandhar's work, lessons bigger than the story of viruses and fat. The first lesson is that the wild workings of our bodies influence who we are. They influence our behavior, our weight, our metabolism and nearly everything else. We are what we eat, but we are also, it appears, what eats us.
The second lesson, though, is the broader one: that we are still so ignorant about our own bodies that a man at a dinner party in Bombay can have an insight during a conversation about chickens that fundamentally changes how we view who we are. We are so ignorant to the fact that the wildest ideas about what might be can sometimes really be.
We have gone to the moon, but nearer at hand, your life is a mystery, and so is mine and so are everyone else's — trillions and trillions of mysteries, some of them fat and some of them thin, and all of them grand.