Antibiotic resistance and meat: why we should be careful in assigning blame

by C Tilli3 min read17th Jun 202014 comments


I have been planning on writing a post on antibiotic resistance as a cause area for some time, but during the recent EAGx Virtual I got a lot of questions specifically about meat production as a driver for antibiotic resistance and it seems like a more urgent topic to post about, so I will start out there and hopefully follow up with a more general post. This is my very first forum post so I would really appreciate feedback and comments!

The reason why I feel an urgency to write this post is because too simplified views about meat and antibiotic resistance could potentially lead to ineffective or even negative-impact advocacy and behaviour.

My main points in this post will be first to clarify the following:

· Common arguments, such as “more than half of the antibiotics today are used for meat production” are flawed in their logic

· The evidence base for agriculture as a driver is still relatively weak, and we should keep a nuanced view

And then to share my worries about the unintended consequences that misunderstandings could result in:

· People may think that ending meat production is “the solution”, which could make it harder to make progress on other ends

· Careless advocacy risks polarizing the issue in a way that could make collaboration and progress more difficult

To be clear, I do think that it would be a very good idea if we could eliminate the non-therapeutic use of antibiotics in agriculture, and I also think it would be very good to eliminate or drastically reduce meat production. I believe this post is especially important to read for people who share these views but do not have detailed knowledge of antibiotic resistance.

Part one: Things I’d like to clarify:

Common arguments are flawed in their logic

An often-used argument for why the meat industry is the most important thing to deal with in order to reduce antibiotic resistance is “More than half of the antibiotics today are used for meat production”. This is often followed by describing how these antibiotics are not even used to treat sick animals but to prevent them from getting sick despite horrible conditions or simply to fatten them up quicker for slaughter.

While this is indeed a big problem, the pure “amount” of antibiotics used is not a great indicator for how important this is as a driver. The amount here is measured in kilos, saying that more kilos of antibiotics is used in agriculture than for humans.

The main problem with this argument is that

More than half of the antibiotics are used for meat production

is often understood as

Meat production causes more than half of the problem of antibiotic resistance

While we lack detailed knowledge of what share of the problem of antibiotic resistance in infections on humans (see next section) is caused by agricultural use, I think we should be very careful with these kinds of potentially misleading indicators.

The evidence base for agriculture as a driver of antibiotic resistance is still relatively weak

To determine how much of the problem of antibiotic resistance (for humans) is caused by meat production, we have to look at the mechanisms by which resistance that develops as a result of use in agriculture transfer to infections on humans.

For detailed reading I would recommend this paper. There are basically three different mechanisms. The first one is that people might eat poorly prepared meat and get an infection like salmonella, which if it is resistant to antibiotics would be harder (or impossible) to treat. This infection would only affect the people eating contaminated meat, so even if it is bad, it’s not a significant driver of antibiotic resistance in infections on humans generally. The second mechanism is that resistant bacteria can jump the species barrier, so that a pathogen that previously spread only among cows, say, now spread among humans. There have been known cases of this happening, though it is difficult to study just how much it happens. The third mechanism is horizontal gene transfer, whereby resistant bacteria that has evolved in agriculture passes over some of its genetic material, including resistance genes, to bacteria that cause infections on humans. This last mechanism could potentially be the most important one, but we do not know how common such transfer is or what share of the resistance burden for humans it causes.

While it is remarkable that so much antibiotics are used in agriculture, and likely that this has a significant contribution to the incidence of resistant infections on humans, we should be aware that the evidence base is not solid and we should be very careful in claims about how much agriculture is to blame for antibiotic resistance in infections on humans.

Part two: Why this may have bad consequences:

People may think that ending meat production is “the solution”

One of the consequences that I worry about with this narrative is that people may be given the impression that ending use of antibiotics in agriculture, or ending meat production completely, is “the solution” to antibiotic resistance. It is unclear what fraction of antibiotic resistance would disappear if such measures were taken, but it would certainly not solve the problem.

There are many other very important drivers of antibiotic resistance that need to be addressed as well, and some of these directly relates to public awareness and behaviour – such as the understanding of that antibiotics should not be taken unnecessarily and that they should always be taken exactly as prescribed. Motivating the public to, for example, deal with minor infections without antibiotic treatment even in a case where the drug could have saved them a sick day or two will be a lot harder if they believe that most of the problem is anyway caused by agriculture and that their behaviour is insignificant in comparison.

Careless advocacy could lead to counterproductive branding

I also worry that advocacy that aggressively assigns the blame for antibiotic resistance on the meat industry, or that is clearly connected to for example animal rights advocacy, could also be counterproductive. I think there is a risk that this could polarize the broad issue of antibiotic resistance, giving it a political branding that makes it more difficult to collaborate and make progress.

At present, the cause of antibiotic resistance is politically quite neutral. If it were to have a similar development as the cause of climate change where it came to be seen as a mainly liberal or leftist issue, I think that could be a very negative thing.

To be clear, this does not in any way mean that I don’t think we need to deal with the use of antibiotics in agriculture. We definitely do. But we also need to know more before we can make strong statements about how it compares to the importance of eliminating misuse among humans, and we need to think carefully about how we frame the discussion so that we do not antagonize the industry we seek to reform.