A Virus that Causes Food Addiction?!

New Data Published Yesterday in Nature Metabolism suggests a Virus May Contribute to Food Addiction. This is not a joke...

There is now a video covering these data. Prefer to watch? Click below. Prefer to read? Carry on. And make sure to see the end of this letter for news about an exciting initiative!

This letter is going to speak about new data, published just yesterday in the journal Nature Metabolism, that suggests a virus can contribute to food addiction.

We’re going to break down what the data say, what they don’t, and why this might actually be a hopeful finding!

Food Addiction is Real

First, let me clarify that Food Addiction is real and can be defined using criteria for a substance use disorder from the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), including:

1. Taking a substance in larger amounts than was intended

2. Inability to control its use

3. Taking a substance for a longer period of time than was intended

4. Continued use despite adverse consequences.

Specifically, Yale Food Addiction Scale (YFAS) and YFAS 2.0 (published in 2016) have gained widespread acceptance as a clinical tool for assessing this condition.

Gut-Brain Axis

Now, here’s another fact: the brain talks to the gut and the gut to the brain.

More to the point, the microbiome – the community of bacteria and other microorganisms living in our intestines – can influence our brains and minds. That’s not controversial; it’s biological fact.

Now, here’s a question: What shapes the microbiome?

There are many things, but one fact that has gone understudied is viruses.

Specifically, bacteriophages, viruses that attack bacteria, have the capacity to shape the microbiome and, by extension shape human metabolism and even the human brain.

Microviridae viruses associates with Food Addiction Scores

So, running with this logic, the researchers behind this study first looked to see if there was an association between any viruses and higher Yale Food Addiction Scale scores.

Indeed, one family of viruses stood out: Microviridae.

The presence of Microviridae viruses was positively associated with food addiction scores in not just one population but also in a validation population. In other words, to confirm the finding, the researchers checked multiple independent population and found the same association:

The presence of Microviridae viruses, in humans, was associated with worse Food Addiction.

And to add the story, they also went beyond BMI and looked at waist circumference – a better measure of abdominal fat – and found an even stronger association.

Specific Microviridae associates with brain changes on functional MRI

Then, to dig a little deeper, the looked at what specific species of Microviridae virus was most abundant and found it was a virus called Gokushovirus WZ-2015a.

Then, if that weren’t enough, they did fMRI scans of the brains in another cohort to look at how Gokushovirus WZ-2015a associated with changes in brain activity, and found that higher levels of Gokushovirus WZ-2015a associated with changes in dopamine networks in the brain. In fact, they found changes that align with research on the brain dopamine effects of drugs like morphine and cocaine.

So, now we have a specific species of virus (Microviridae Gokushovirus WZ-2015a) associating with higher clinical Food Addiction scores and brain activity states on fMRI.

The virus is transmissible and may “cause” Food Addiction

Then, to demonstrate a causal relationship, the researchers transplanted human samples with and without Gokushovirus WZ-2015a to mice and found that the human to mouse Gokushovirus WZ-2015a transplant did, indeed, cause Food Addiction like behavior (including motivation and persistence in obtaining food) in the mice.

So, now we have a specific species of virus – that can be transmitted between organisms and, in so doing, transmit the features of Food Addiction.

But, again, we can ask, ‘How?’

Virus messes with dopamine and serotonin pathways

Well, to spare you a lot of technical details and a science jargon tsunami, they found that Gokushovirus messes the with metabolism of the precursors to dopamine and serotonin, which the amino acids tyrosine and tryptophan, respectively.

But more to the point, an intermediate of tryptophan metabolism, named anthranilic acid that is lower in humans with more Gokushovirus actually showed a protective effect against food addiction when supplemented to Food Addicted mice.

Exactly how it does so is not yet clear, nor whether this relatively simple molecule could protect human patients against this ‘Food Addiction Virus.”

But given what we now know about higher Microviridae Gokushovirus levels in humans associating with more food addiction and obesity and dopamine brain changes… well, the spotlight of metabolic knowledge is shining bright on this hot topic, and the black box of mental health is looking quite a bit more illuminated.

Isn’t this exciting! Let me know your thoughts. Please share this Newsletter if you found it informative. And, as always, StayCurious!

CME-Credits!

I’m proud to be collaborating with Metabolic Health Initiative—the ACCME-accredited medical education organization behind The Metabolic Health Summit and The Metabolic Link podcast. Together, we are working to get some of my content CME-accredited, including this video!

This creates an incentive for doctors to learn about metabolic health, as part of our broader efforts to Make Metabolic Health Mainstream! If you’re a healthcare practitioner, CLICK HERE.

And if if you want to put the Metabolism is Medicine, watch the video and share this post!