S1: Welcome in San Diego. It's Jade Hindman on today's show. What U.S. food safety right now reveals about our systems and values , then the impact of a vegan diet on epigenetic patterns in aging and inflammation. This is KPBS Midday Edition. Connecting our communities through conversation. Concerns over food safety are growing this summer. After a series of scares , you've likely heard of the massive Cyclospora outbreak that came from contaminated iceberg lettuce. There have also been reports of salmonella found in eggs and jalapenos , E coli in frozen blueberries , and much more. While foodborne illnesses generally go up in the summer , some experts say it's a window into a broken food system. I'm here with Aaron Gross. He's the director of the center for Food Systems Transformation at the University of San Diego. Professor gross joins me now. And welcome back to the show , to you.
S2: Good to be here again.
S1: Glad to have you. So the parasite Cyclospora has been making headlines all this summer. While infections seem to be going down nationally , many people are really just reevaluating where they get their produce and how they prepare it. What's the rippling effect that you've seen so far from this outbreak?
S2: Well , it's in some ways really good to see this much attention on our food system. Obviously , this is a , you know , really unfortunate and dramatic case of foodborne illness. Cyclospora is , you know , something that can leave you sick for weeks. This is not your typical kind of 24 hour flu. And , you know , the CDC's description is explosive diarrhea. This is pretty bad. So I'm , you know , unfortunate circumstances raising really significant awareness. So definitely people are asking what they can do , but what most folks are going to find out is that this is a social problem. There are very minimal things you can do in your own kitchen , and you're probably already doing them. So one of the things I'm really delighted to be seeing is people are , you know , wondering , are all these cuts in the government have an effect? What sort of responsibility infrastructure do we have? And those questions could lead to us all being safer.
S1: I want to dig in more to those questions , but I also have to talk about the current outbreaks here. Salmonella in jalapenos being one of them. You found there's actually a San Diego connection right there.
S2: Yeah , it's quite interesting. So we have a kind of storied San Diego company , uh , Coast Citrus , which is the distributor. And so these these jalapenos ran through them. And what's a particularly interesting detail here is this is a company we can really , you know , be proud of being in San Diego for 75 years. They had no foodborne illness a kind of public problems. So if there were issues , we we never heard about them. And they were sold just a year ago , and now they are at the center of this national operation. Sold from being a family owned business. The Alvarez family , which built it up from scratch over 75 years to being owned by , I believe , it's Grub Market , which is a San Francisco based kind of technology driven company entering this space. And what we can say is there. They're probably not responsible for the outbreak occurring. That is that would be a strange thing to attribute it to the leadership change. But the way this was handled , they have not provided the kind of information that would have really helped the regulators identify this quickly. The original recall they did was too small and they had to follow it up with a larger one. But that was after the government had intervened and asked them to do that. So we certainly see some signs that the new ownership may not be the good actor , that it was under previous ownership.
S1: So from where you sit , are tech companies or , you know , the industrialization of of food production. Is that a problem here?
S2: It seems like it is. What we have going on is consolidation. And this is happening over a long period of time so we can witness it having happened right here in San Diego just in the last year. But this is a broader a broader phenomena. So the iceberg lettuce , you know , is produced by this absolutely massive , uh , company , Taylor Farms , which is , you know , many billions of dollars , just absolutely huge. And that's a stories of of decades of consolidation. Now , this doesn't have to be a bad story , but it's combined with a kind of dropping of regulations , and especially since the current administration has been kind of an elimination of basic traceability. So we've got these corporations which aren't going to have the same motivations to address things like food safety that , say , a family owned business which knows people in the town has. So we've handed it over to these more anonymous entities as we've eliminated the infrastructure that could regulate them. And that seems to be clearly a problem. So I don't want to say getting big is the problem , but the way we've handled it is , is creating more danger.
S1: So we've eliminated the infrastructure to handle these things and spot them. What tools do we have right now to identify outbreaks and other issues with food safety , like if something needs to be recalled? Yeah.
S2: Yeah. So the word was eliminating. We certainly still have an infrastructure in place. But just to give a sense of how rapidly is disappearing. So if we're talking about the Food and Drug Administration or the USDA , which in different ways are responsible for checking for food safety tracing , back when we have outbreaks like we have holding people accountable , they've lost something like 20% of their workforce. And when we start to drill down and look at the parts of their workforce that they have lost. This is where to me , it gets really alarming. We see that it's the most experienced personnel are being eliminated. People with 15 to 20 years experience. We saw , especially at the USDA , that the cuts were concentrated specifically among the people doing investigative work. One of the kind of regulations put on hold by the administration was a traceability rule that would have basically required producers like , you know , like Coco Citrus here in San Diego to provide a lot more information when a recall occurs. As it turned out , in the case of some of these recalls recently , we've had literally volunteer retirees compiling the list of retailers because they couldn't get it from the companies. So we've got a kind of diminution of the staff , particularly the investigative staff. The postponing of a traceability rule which the government developed and we could talk about. Other rules that have been suspended. And when you look at the picture and you look at who's lobbying for these various suspensions , it seems pretty clear we're talking about making it harder to identify who is responsible when these things occur. And that means they go on longer. There's less incentive for the companies to improve. You know , with salmonella , we've had initiatives to address it for decades. And the the actual number of people getting sick is getting worse. And there's reasons it's a policy failure. It's not an accident.
S1: When did these policy changes start? The.
S2: The. Well , the ones I'm referring to are with the Trump administration. But I would not want to say that we have a situation where agriculture was wonderfully regulated , and then the current administration came in and changed it. This is , from my perspective , a bipartisan problem where the food industry simply has disproportionate power. I don't see any industry getting away with the kind of things that the food industry gets away with , and 90% of the time , what I mean by that is really the meat , poultry and egg industry. The salmonella recall we're dealing with is a great illustration. It's only something that is potentially illegal and problematic because it's on jalapenos. If that same salmonella was on your chicken , there would be nothing the government could do about it. It would just be your responsibility to deal with that toxin in your chicken.
S1: Cook it at what degree? Right. That's that's exactly that's the solution. Yeah. Yeah.
S2: Yeah. And you should definitely do that. That's a sure thing to do. But you know , should you really have to have a biohazard if you , you know , have that chicken on your cutting board and don't properly sanitize it. And then you do some salad on that cutting board or that knife , that's where we get the contamination. So I presume people are cooking their chicken. In that sense , it's understandable.
S1: People don't know whether to wash their chicken or just cook it at this point. Right. Because , oh , we would we wouldn't want to spread salmonella is what I'm hearing. Yep.
S2: Yep. That's the it's it's a challenge. There's you know I'll leave it to the , you know , expert rules on the best way to clean your your chicken. Um , but I would say we could have a system that doesn't have the most virulent strains of salmonella on the chicken , because part of the story here , it's not salmonella , is a wide range of virulence. And the kind of salmonella we are now having most of the time is stuff that makes us really sick , stuff that is multi-drug resistant. We have data that this has been increasing over a decade , which is why we can't blame anyone. Administration. I do think we have a kind of situation of an industry that doesn't want to be regulated , not enough public awareness , and they are taking advantage of all sorts of minutia in the rules. And what we're seeing right now is kind of a heyday of them getting all sorts of wish list of things they've wanted for a while. That traceability rule I mentioned was in the works for a long time , and these are very wonky technical things that are worked out with industry , so they have lots of input in the process and then to be implemented January and delayed 30 months. You know who gets a 30 month extension on finishing their job? You know , it's a it's a gift to the industry. It's literally traceability we're talking about here that they're resisting.
S1: When we're talking about policies that could be put in place to prevent this. Is there a gap here between , uh , what lawmakers should know about food safety and what's safe for people to be eating and consuming , and how to produce that and the laws that are passed? Or is there just , you know , what's what? Where does this lack of political will to do better come from?
S2: I mean , what we could do right now is simply implement some of the regulations that have been in the works for years. The traceability rule is one of them. There's another that would classify salmonella as an adult trend for poultry in the same way or in a similar way. If we get into the details , it's not exactly the same way. But as I mentioned before , the government will do something to protect us from salmonella in jalapenos , but not in our chickens. And that just doesn't make any sense in a very if it sounds like it doesn't make sense , you don't need a PhD to figure out why. And it's industry lobbying that created that gap. So just going in and getting those things that were set to go in place in the last two years and getting them in place would be , you know , a place to exert political will. So there was a coalition , a group I'm on the board of Farm Forward was one of many non-profits that supported it that was to rescind that postponement of the traceability rule. Same thing with that regulations around salmonella. Those things are politically tractable right now. And in the long term , I think we need people in office who are not doing everything they can to make cuts for industry that put the public in danger , which is what we seem to have. Mhm.
S1: Mhm. I mean , there seems to be this big gap between public values and how our food system is currently structured. Talk more about that.
S2: Yeah , this is a case where it's not a matter of the nation is divided on what's right. This is basic honesty. This is basic safety. This is fair wages. And we just historically don't have the kind of attention on agriculture. I mean , part of what I see is , you know , there's this strong sense that farmers should be , you know , left to their own devices , trusted. And there's really good reason , we think that if you go back 150 years in America , if you look at most of our founding , certainly the first century , that meant trusting the majority of people. Basically , that meant trusting the democratic process. Now , it's not that farmers have become untrustworthy , that actual human being farmers have no power in this situation. What we're talking about is it really being massive corporations that have extremely narrow profit interests that are often functioning globally , and we're giving them the same kind of blank check to self-regulate. And this persistent problem with food illness is one of the results of that. We can name a lot of others antibiotic resistance. You know that multidrug resistance is another one where we can pretty see it as a direct kind of conflict between the public interest. In other words , I'm going to assume that being pro antibiotics , working as a bipartisan issue. And yet we've got industry doing things which we know our year on year , reducing the effectiveness of our antibiotics. And this is real simple policy kind of changes that could be implemented. So there is a genuine gap , as you said , between what our our values are , the things we actually agree upon as a nation and what is happening.
S1: What other vulnerabilities do these outbreaks reveal about our food system?
S2: Centralization , you know , with the the the Cyclospora outbreak. The scale of it reveals one of the dangers in a system that's this big. You have such centralization that , you know , the the jalapeno , for example , you know , it moves through one company. But we're dealing with 30 states. So when we hand things over to these corporations and these more bureaucratic structures , we get certain efficiencies. But if we don't build a regulatory apparatus , what we get is really big problems , because when they break , it is not just a local farm , it's this massive system. So I think there has to be a kind of recognition if we want to make these trade offs moving from , you know , aggregate , you know , continue with the trade off we've largely made , which is to eliminate smaller producers in favor of large producers that themselves have to aggregate. So we just have massive companies. We really need to be as a public attentive to how we're regulating them , because if we're not , these are the sort of results we get. Drugs not working. Outbreaks that are bigger and badder and secondary harms the quality of our water , the quality of our air , our risk of having another pandemic. These are really fundamental issues that I don't think there should be disagreement about , and we don't really have it. What we have is a lack of attention and a powerful , active big ag lobby. Mhm.
S1: Mhm. So you point to a few solutions there and what you're saying some systemic solutions. What do you do individually. Like what are you doing right now. Are you eating salads. Are you washing your chicken in this. What are you doing. Yeah.
S2: Yeah. So in terms of in terms of food safety , my , you know , behavior has not changed. When things are not cooked , you want to be a little more careful about them if you're bringing certain items and careful.
S1: What does that mean you pay an extra fare or what do you mean? Careful?
S2: No , I. The great , great question. So the rules about , you know , washing your hands , washing your cutting boards , having separate sponges for different things. Those are the ones I would follow. I would also say it's , you know , your risk depends on what you're bringing into your house. I , you know , I'm , I myself am a vegan , so I don't have to worry about chicken , which is the , you know , the thing that you can count on having salmonella. And as of the last couple of years , you can count on it having a virulent form of salmonella. So there's a little bit of extra work you're going to have to go through there. You're going to have to basically treat that like a biohazard because it's not uh , maybe it's almost certainly it has salmonella on it. Your jalapenos should have been clean , you know , so I , you know , and and , you know , 99% of the time they will be , you know , so I wouldn't stop eating raw jalapenos except if I saw them implicated in an actual recall , which is , you know , very hard to do. This is what I mean by fundamentally , we are trusting the system. I'm trusting the system. And you know what you choose to eat. You know , I mentioned I'm a you know , I'm a vegan. The animal products have a set of issues associated with them which plant based products don't. So that is a personal decision one can make for a lot of different reasons. You know , with this food safety issue , I wouldn't say necessarily eliminate your risk because it can come from those blueberries or jalapenos or anything. It does make it easier though , because , yeah , because you don't have to worry. You're not bringing in something which you know , has salmonella. You just have to worry about the exceptional circumstance when something that was supposed to be clean , that the law says is supposed to be clean like jalapenos had it.
S1: That's so interesting to hear you say that it becoming vegan does make it a little easier. Yeah. At this time. Yeah. Um , especially given our next guest who. Yeah.
S2: Yeah. Know. Quite interesting that. Some.
S1: Some.
S2: New research.
S1: Regarding that , that diet. So. Well , I sure appreciate all of your insight on this. And of course you were. You're someone will be continuously reaching out to as these issues persist. I've been speaking with Aaron Gross. He's the director of the center for Food Systems Transformation at the University of San Diego. Professor , thank you so much for joining us.
S2: Thank you. It's been great being here.
S1: Up next , the impact of a Vegan Diet on Epigenetic Patterns in aging and inflammation. KPBS Midday Edition is back after the break. Welcome back to KPBS midday edition. I'm Jade Hindman. You heard it from our last guest , Professor Aaron Gross. It's possible a vegan diet could simplify things in the midst of food safety issues. But did you also know new research shows that just one month on a vegan diet may lead to meaningful changes in your epigenetics? The study comes out of UC San Diego and the University of Freiburg in Germany. The findings reveal bigger questions about what else might influence our epigenome. Joining me to talk about it is Jerome Mertens. He's co-author of the study and associate professor of neurosciences at UC San Diego. Professor , welcome.
S3: Thank you for having me.
S1: So glad to have you here. First , help us understand the basics. When we say epigenome and epigenetics , what are we referring to?
S3: So basically , the epigenome is a layer of chemical modifications that sits on top of our DNA. And part of its role is to control which genes are actually used , which ones are turned on and which ones are turned off. And another type is somewhere in the dark genome , where it seems to be recording a lot of the things that we actually experience in life. And one important type of this epigenetic control is actually DNA methylation , which is what we studied in this in this project.
S1: And what exactly is DNA methylation.
S3: So DNA methylation , you can understand it kind of as a chemical tag that sits on our DNA sequence without changing it. So epigenetic control does not change the sequence of our DNA , but it kind of marks genes for actually being used or not used. Interesting.
S1: Interesting. So what kind of things sort of leave an imprint on our epigenetics?
S3: So our data actually fits kind of in a in a larger pool of emerging evidence that lifestyle changes such as sleep , stress , age actually all get recorded in our DNA. The basic understanding of of how epigenetic control works actually comes from developmental biology , where a certain stem cell divides into different types of cells , and then the epigenetic profile dictates if one cell becomes a brain cell and the other cell , for example , a liver cell , because they obviously have different jobs and need to use different genes. Okay.
S1: Okay. So with that , let's talk more about your data with this study. What were you trying to find or prove and what did the experiment include? Yeah.
S3: Yeah. So basically we wanted to understand whether a controlled short term , one month change in diet can actually leave a mark on our genes on on the epigenome at all. And for this , we worked with the clinical research group back in Germany and analyzed the DNA methylation data set from one of their clinical studies where they have assigned randomly assigned a group of healthy adults into either following a strictly plant based vegan diet or to follow a very strong , meat rich diet. And for one month. And what we asked basically first is , does this at all show up in our epigenetic profiles? Is there something measurable and perhaps even meaningful happening?
S1: Okay , so tell me a bit more about what the participants were eating , what was different and what was equal.
S3: Yeah , this is this is really an important question because of course , the two groups ate very differently for one month. One strictly vegan. The other lots of meats. But before that also they ate basically the same mixed diet for a week , bringing them all to a baseline. And what was also really important about this particular study is that this was an ISO caloric setup. So typically vegan diets are associated with less calories. It's less calorie dense food. So vegan diets already come usually hand in hand with. Calorie restriction and weight loss. And in order to be able to isolate the effects of the nutrients that we eat from weight loss. This was designed that the vegans had to catch up , for example , with nuts and also sugar was allowed with a meat rich diet to bring them to the same daily calories. So we could compare the two profiles more , more neatly.
S1: Yeah , well , I want to break down the findings because this is where it gets really interesting. What stood out to you?
S3: So first of all , we found that just after this one month , and this was somewhat surprising , that the two groups showed quite distinct and measurable changes just between the groups. So many of these regulatory marks we saw in genes regulating metabolic pathways , for example , insulin. But then in the vegan group , we also saw that genes that are involved in cell growth or that might be related to cancer. Were less shut down. They were a little bit more active while less active. Sorry. They were shut down and less active. And while genes that were tied to cellular and molecular repair and even longevity seemed to be activated a little more , and even on the level of biological aging clocks , we saw signs of a slowed down aging rate in the vegan diet , which was not using oil clocks , but some of the more lifestyle predicting clocks showed this trend , which was actually quite interesting. But globally , what surprised us the most that just one month of diet change actually left some some measurable marks here. Wow.
S1: Wow. How likely is it that , you know , changes in epigenetics actually affect health outcomes? What are some examples?
S3: So first of all , these are not directly tied. So these are predictions based on on genes and profiles. Right? And it's not a prediction for one individual. One thing that the study included is that we also use the DNA methylation data to predict blood cell counts. And what we found here is that the DNA methylation signatures told us that there were actually changes in the inflammatory profile towards less inflammatory profiles in the vegan group , which was predicted by less fewer counts of neutrophils , which are cells that that operate , um , acute inflammation , where there was a certain type of regulatory T cell to be increased in the vegan group , just based on the DNA methylation data , that usually helps to keep the immune system in check or balanced. And this was very important. And this is not so new because this matched really closely to earlier data from that same clinical group that actually took the blood , put it under a microscope and counted the blood cells and found basically the exact same thing. So this , of course , gave us a lot of confidence that there are measurable and meaningful biological realities that can be predicted from from DNA methylation data. Wow.
S1: Wow. So help us put these findings into context. What is so significant about dietary changes affecting the epigenome in this way?
S3: So the data fits with data that stress , sleep exercise for example , can change how our genes are used. And diet is just really one of those. But I think it's a really important one because we can learn about it and we can we can actively and consciously change our diet to maybe have a meaningful effect on our on our epigenome.
S1: Our epigenetics passed down.
S3: Some of it are , but classically they are viewed to be not passed on , but they stay in your body. Okay.
S1: Okay. So so maybe perhaps adjusting your diet in this way will help you specifically. Exactly.
S3: Exactly. And I think this is really what sparked so much interest in this because of course. I mean , it's science. So we ask one question , we get one answer , and then we have three more questions that we think are really important. And one of the new questions that really came up from this is that we observed that not all participants moved in the same direction consistently , which is not just true for our study , but it's often observed in human studies that we are actually quite different to each other. And these epigenetic profiles might actually be able to help us find so-called biomarkers or indicators of what actually works for us. So , for example , you go ahead and try a vegan diet or a meat rich diet and not just see how you feel after one month , but actually get epigenetic data back that points you in the right direction. And I think this is really important that we think of personalized ways and data based evidence to maybe optimize our diet and lifestyles.
S1: How might someone get epigenetic data back?
S3: So there are the first companies already forming around these epigenetic clocks , which may or may not yet have a meaningful life biology attached to them. But people are very eager about learning about their epigenetic ages and epigenetic clocks. And I think using these with caution and paying attention to data , I think is a really interesting developing field that can eventually like be like used basically at home and you get data back , kind of like genetic ancestry tools that have been around for quite some years. Interesting.
S1: Interesting. And epigenetic data is different than what you would typically get in your lab work from your primary care provider. Exactly.
S3: Exactly. So you would not get that in your primary work. You would have to go to a private company or what to ask. But I think what's more important is that we design the research and we can actually fill this with meaningful data. And I think that this is important , that just within one month you can make a change. What this change really means in terms of biology , in terms of health. We only partially know. So we've seen this , for example for the blood cell counts. But one really important thing to do next is to tie also the other signatures where we see changes in biological aging rates , where we see changes related to insulin production , where we see changes related to cell growth and cancer related genes , to actually find a real biological correlate , to see if the patterns we see are actually meaningful. Interesting.
S1: Interesting. And as you mentioned , there were some limitations with this particular study. What what else are you hoping to find out?
S3: One major limitation is for sure the small sample size. So these are only 50 participants that we looked at. And with seeing some of them moving in other directions. Of course , we need more participants. And the other questions that that's really still out there is if these changes are actually persistent , you would imagine with how the epigenome works , it's usually quite slow and sluggish and stable , which so surprised us that after one month we saw those changes. Um , also , you would think that these changes would deepen , but there's no guarantee that this is true. Maybe this is a is an immediate response effect. And after one month or two years or many years of vegan or meat rich diet , these would again level out and not really have an effect. And we don't really know that yet. And more studies , longer studies with more participants are needed to really close those gaps.
S1: What fascinates you most about epigenetic research?
S3: Epigenetics are really quite fascinating , and initially they have been recognized as a way to regulate genes. And what I today find so fascinating is that a lot of these epigenetic changes are happening somewhere in the dark matter of our genome , where there's not a gene to control , but there the epigenome seems to act. Kind of like a like a flight recorder that is quietly recording a lot of the decisions and things we are experiencing. May it be exercise , diet , progressive aging from which none of us can escape , and that this is a flight recorder that is more or less untapped , that we're just learning to , to , to to get the information out of it and to interpret it in an interesting and and useful way. And I think that's what fascinates me most these days. Yeah.
S1: In the last few seconds , all of this , you've done this research. Have you considered ditching meat , going vegan? Are you vegan?
S3: Before the study , I was a flexible vegetarian , eating mostly plants but not leaving cheese completely off my plate. But working on this study has also given me some consciousness to , like , center even more around plant based meats and a plant based foods and leave the meats a bit to the side , a little bit more even. But I'm not very strict , to be honest. Okay.
S1: Okay. All right. You do what feels good for you. Exactly. The lesson to take away for sure. All right. I've been speaking with Jerome Mertens. He's an associate professor of neurosciences at UC San Diego and co-author of the study. We've been talking about. You can read more about it on our website , KPBS. Professor Mertens , thank you so much.
S3: Thank you very much for having me.
S1: That's our show for today. I'm your host , Jade Hindman. Thanks for tuning in to Midday Edition. Be sure to have a great day on purpose , everyone.
