A Doctor's Honest Guide to The Grocery Store (What's Worth Worrying About)

You're trying to eat healthy, but how do you know the food you're buying is actually safe? By the end of this episode, you'll know what to look for at the grocery store, what's worth spending extra money on, which food safety concerns actually deserve your attention, and the simple changes that can reduce your exposure without making you afraid of everything you eat. All right. So why does buying healthy food feel so complicated? You walk into the grocery store trying to do the right thing. You pick up the salmon and wonder about the mercury. You reach for the strawberries. You think about the pesticides. You grab a bottle of water, remember something you read about. Microplastics, and then there's PFAS, heavy metals, food additives, plastic packaging, produce recalls, and suddenly buying healthy food doesn't feel so simple. And if you're paying attention to the headlines, you might start wondering, is any of our food actually safe? The answer is, well, more nuanced than a lot of what you see online because not every food safety risk is the same and not every scary headline deserves the same amount of your attention. There are the immediate risks we've worried about for decades, bacteria like Salmonella, E. coli, Listeria that can contaminate your food and make us sick. But there's another category that's getting a lot more attention, substances we may be exposed to in small amounts over and over again, things like pesticides, heavy metals, PFAS, microplastics, certain food additives, and chemicals that can migrate from packaging into our food. Now those are 2 very different conversations. And I think we've done a poor job helping people understand the difference because when everything's labeled toxic, you don't become a more informed consumer. You become an overwhelmed one. This episode was brought to you by Function. Get access to over 160 lab tests annually at functionhealth.com/mark. So today I want to make this practical. We're going to take a trip through the grocery store together. We'll start in the produce aisle and talk about pesticides and when buying organic is really worth the extra money. We'll head to the meat and seafood counter and talk about sourcing, contamination, and mercury. Then we're going to turn over some packaged foods and look at what's actually on the ingredient label. And then we'll talk about something most of us rarely think about, what our food touches before we eat it. Plastic containers, wrappers, cookware, other packaging. And finally, we'll bring everything home and look at some of the surprisingly simple mistakes we make in our own kitchens. And along the way, I'm going to help you separate the things that are genuinely worth paying attention to from the things you probably don't need to lose sleep over. Because the goal isn't to make you afraid of your food. It's to give you a simple framework for making better choices. What to prioritize, where you can reduce unnecessary exposures, and where the basics matter far more than the latest scary headline. Let's start where most of us begin every week, the produce aisle. Do you really need to buy organic? And how do you handle outbreaks like the ones we saw this summer? Because this summer gave us a pretty striking reminder that even foods we think of as some of the healthiest things that we can eat aren't immune to food safety issues. In July, the FDA and CDC began investigating a major outbreak of Cyclospora, which is a microscopic parasite that can cause a severe intestinal illness. The investigation ultimately pointed to iceberg lettuce sourced from Central Mexico. Now, the outbreak spread across 15 states with thousands of illnesses and hundreds of hospitalizations reported. And it wasn't necessarily the kind of contamination you could see. The lettuce didn't have to look spoiled. It didn't have to smell bad. Cyclospora is microscopic and it can contaminate food through water or fecal matter. And once contaminated, produce enters our increasingly complex food supply and it can end up on our plates hundreds or thousands of miles away. And so that's kind of understandably unsettling. So when stories like that appear in the news, I hear 2 very different questions from patients. The first is, how do I protect myself when there's an outbreak? And the second is, Would I be safer if I just bought everything organic? Well, those are actually 2 different questions. Let's start with the word organic and what it actually means. Organic doesn't mean a food is completely free of pesticides, and it doesn't mean that the food can never be contaminated with bacteria, parasites, or other pathogens. Organic farming standards govern how food is grown and produced, including which pesticides, which fertilizers, and other agricultural practices can be used. So when you're deciding whether to spend extra money on organic produce, I think it's helpful to ask, what risk am I actually trying to reduce? If you're trying to reduce your exposure to certain synthetic pesticides, choosing organic can be one tool. But if you're trying to protect yourself from a foodborne outbreak like cyclospora, simply choosing organic is not a guarantee. And that's an important distinction. So do you need to buy everything organic? For most people, the answer is no. And I really don't want concerns about pesticides to turn into another reason people avoid eating fruits and vegetables. If the choice is between eating conventionally grown broccoli or not eating broccoli at all, well, eat the broccoli. The bigger question is how to be strategic about where you spend spend your money. If you can afford to buy everything organic and that's important to you, great. But if you're working within a budget, and most people are, I'd prioritize. And one resource you can use is the Environmental Working Group's annual Dirty Dozen list, which highlights conventionally grown fruits and veggies and identifies those veggies that have higher levels of pesticide residues. I wouldn't use it as a reason to avoid these foods, but it can be a helpful starting point for deciding where you might prioritize buying organic. So think about which fruits and vegetables you eat most frequently. Think about foods you consume the skin in or the outer surface, and think about where switching to organic can meaningfully reduce your overall pesticide exposure. You don't need perfection. You try to reduce your total exposure over time. The next question is, should you wash your produce? Well, let's talk about something everyone can do regardless of whether you're buying organic or conventional. Wash your produce. Rinsing fruits and veggies under running water can help remove dirt and it can reduce some of the surface contamination, but washing isn't magic. It can't necessarily remove every pesticide residue, and it can't guarantee that contaminated produce is safe during an active outbreak. That's why when the FDA and CDC identifies and recalls a particular product, the answer isn't, I'll just wash it really well. The answer is, don't eat the recalled food, throw it away, or put it in the compost, or return it according to the recall instructions. That's exactly what happened with the iceberg lettuce implicated in this cyclospora outbreak this summer. So what should you actually use to wash your fruits and veggies? For everyday food safety, start with plain running water, then dry it with a clean towel or paper towel, which can further reduce bacteria on the surface. And here's something I don't recommend. Don't wash your produce with soap, dish detergent, or bleach. Produce is porous and those products aren't designed to be consumed. You also don't need an expensive commercial produce washer. What about vinegar and baking soda? Well, this is where we need to distinguish between germs and pesticide residues. If you're worried about pesticides, there is some research suggesting that soaking certain produce in a baking soda and water solution may remove more of some pesticide residues from the surface than just water alone. But it can't remove pesticides that have already penetrated into the food. And we don't have evidence that it works equally well for every fruit, vegetable, or pesticide. So I think of that as an optional extra step, not something everyone needs to do every time they eat an apple. For most people, the basics are simple. Running water, gentle friction, a clean produce brush when appropriate, dried afterwards. If there's an active recall, no amount of vinegar, baking soda, or washing makes recalled produce something I'd recommend eating. Washing can reduce the contamination, but it can't reliably eliminate pathogens, especially when contamination has gotten inside the produce. What about frozen produce? Well, here's another misconception. Frozen doesn't automatically mean sterile. In fact, this summer, the FDA also investigated an E. coli outbreak associated with recalled frozen organic blueberries. So frozen and organic don't mean a product is incapable of carrying a foodborne pathogen. That's another reason I want you to think less in terms of labels that make a food seem automatically, quote, safe, and more in terms of understanding the food system and responding appropriately when there's a specific problem. So how do you handle an outbreak? Well, let's make this really practical. You see a headline tomorrow, ooh, outbreak linked to produce. What should you actually do? Well, first, don't panic and don't stop eating every fruit or vegetable in your refrigerator. Find out exactly what's been implicated, what product, what brand, what lot, what date, which states, where was it sold? And then check the FDA and CDC, not just social media, to see whether the product you have is actually part of the recall. Now, if it is, Follow the recall instructions and don't assume washing or cooking will necessarily make it safe unless public health officials specifically say so. And if you've eaten a recalled food, pay attention to the symptoms. Officials will tell you what to watch for and also when to contact your healthcare provider if you're concerned, particularly if you're pregnant, older, immune compromised, or otherwise at greater risk of serious foodborne illness. Next stop in the grocery store is the meat and seafood counter. Now, this is another place where I think we've made healthy eating way more confusing than we need to. Grass-fed, grass-finished, pasture-raised, organic, wild-caught, farm-raised. I mean, there's a lot of words. We're surrounded by labels that seem to tell us one product is healthier or safer than another. But what do those labels actually mean? More importantly, does where your protein comes from really matter? Well, the short answer is yes. Maybe not always for the reason you think though. First, we need to make the same distinction we made in The produce aisle. Food safety and food quality aren't necessarily the same thing. When we're talking about raw meat or poultry, one of the most immediate concerns is contamination with pathogens that can cause foodborne illness. That's why the basics matter so much— keeping raw meat separate from other foods, storing it properly, washing your hands and surfaces after handling it, cooking it to a safe internal temperature. So what should you actually look for when buying meat? Now, that doesn't mean sourcing doesn't matter. It does. When I'm choosing meat, I'm thinking beyond the question of whether it will make me actually sick or acutely sick. How much of the thinking about the nutritional quality of the food. How was the animal raised? Was it fed good food or not? What was the environmental impact of how the animal was raised? And what about animal welfare? These are really important questions. And this is where all those labels on the package can get confusing. Grass-fed, grass-finished, organic, pasture-raised, no antibiotics. Sounds similar, but they're actually telling you different things. So let's break them down. Grass-fed generally refers to what the animal ate. For cattle, it means the animal received a forage-based diet rather than grain. But here's where it gets tricky. If you're specifically looking for an animal that was raised on grass for its entire life, look for 100% grass-fed or grass-fed and grass-finished, and ideally a credible third-party certification. Now, USDA Organic is a broader production standard. For meat to carry USDA Organic seal, The animals must be raised according to certified organic standards, including being fed certified organic feed, not being given antibiotics or added growth hormones, and having access to the outdoors. For ruminants like cattle, organic standards also include specific grazing requirements. Pasture-raised speaks more to how and where an animal lives, specifically access to pasture. But this is one where you want to look at a little deeper. The term doesn't necessarily tell you everything about how much time the animal actually spent outdoors, what it ate, or the quality of the pasture. A meaningful third-party certification can provide more context. Then you might see raised without antibiotics or similar language. Well, that refers specifically to antibiotic use during the animal's life. It's different from the FDA-required withdrawal periods designed to prevent unsafe antibiotic residues in meat sold for consumption. So when you're standing at the meat counter deciding whether it's worth paying a premium, don't just look for the label that sounds the healthiest. Ask yourself, what am I actually trying to prioritize? To dive deeper into what these labels mean for your health, check out my episode with Autumn Smith, the founder of Paleo Valley. Believe it or not, your brain is mostly fat and it's built from the food you eat. Think about that for a second. Every day your body is using nutrients to support your memory, your focus, your mood, your long-term brain health. The question is, are you getting enough of the right ones? Because when I look at lab data, I see the same nutrient gaps over and over again. Omega-3s, vitamin D, B vitamins, These nutrients play an important role in how your brain performs today and also how it ages over time. The challenge is that most people don't know where they stand, and that's why I always say test first and then build your plate. That's exactly why we built Function. Function gives you access to 160+ lab tests annually that measure signals in your blood, including nutrients, liver health, inflammation, and hormones. You can also complete your health baseline with an annual MRI that helps you see organs, tissues, and other changes. Check your health at functionhealth.com/Mark. And if you're one of the first 1,000 people this week, use the code MARK2026 for a $50 credit toward your $365 a year membership. Now let's talk about fish. The seafood counter introduces another question entirely because fish can be one of the most nutrient-dense foods to eat. It's a great source of protein and many types provide omega-3 fats along with nutrients like vitamin D, B12, iodine, selenium, iron, zinc, choline, But then people hear one word, mercury, and suddenly they wonder whether they should be eating fish at all. Now, I don't think that's the right takeaway. The better question is, how do we get the benefits of seafood while minimizing unnecessary exposure to mercury? And nearly all fish contains at least trace amounts of methylmercury, but they don't all contain the same amount. Mercury tends to accumulate as you move up the food chain. So generally the larger, longer-lived predatory fish that spend years eating Other fish can accumulate higher levels. And that's why your choice of fish kind of matters. The FDA and EPA put salmon, sardines, anchovies, shrimp, cod, trout, canned light tuna, among many others, in their best choices category on the lower mercury seafood, although I'd be suspicious about the tuna. At the other end are several fish with the highest mercury levels, including swordfish, shark, king mackerel, marlin, orange roughy, Gulf of Mexico tilefish, and bigeye tuna. Now, there's a really practical lesson here. Variety matters. Instead of eating the exact same fish, rotate your seafood choices. That's one of the simplest ways to get a wide range of nutrients while limiting your exposure to any one contaminant. Now, what about tuna? Tuna is a great example of why the details matter. People ask me all the time, is tuna healthy or unhealthy? But there isn't one answer because there isn't one kind of tuna. Canned light tuna is on the FDA's lower mercury Best Choices list. Albacore, white tuna, and yellowfin are in good choices category. Although again, you have to be careful and watch your mercury levels. Bigeye tuna is in the highest mercury category that the FDA recommends certain higher risk groups avoid. In fact, everyone should probably avoid it. If it's not good for pregnant women, why is it good for the rest of us? Basically, it's important. Same broad category of food, tuna, but very different mercury profiles depending on the kind, where it came from, how big the fish was, and so on. So rather than thinking tuna is bad, Learn which varieties you're actually eating and how frequently you're eating them and be careful. And then measure your mercury levels in your blood. You can use Function Health to do that. All right. Another thing we should think about is wild-caught versus farm-raised. Is farm-raised always bad? You know, we, this label creates a lot of confusion. Wild-caught, farm-raised. I hear people all the time say that wild fish is healthy and farm-raised is unhealthy. Not that simple. The nutritional profiles can differ depending on the species, depending on the feed, depending on the environment and the farming practices. There can also be environmental and sustainability considerations, but farmed doesn't automatically mean unsafe, just as wild doesn't automatically mean contaminant-free. In fact, farmed and wild-caught seafood sold in the United States are subject to the same FDA food standards. Ask a better question. What species is this? Where did it come from? How was it raised or caught? And how often am I eating it? Let's kind of get into it then. What do I buy? Here's a framework I use when standing at the meat and seafood counter. First, I think about quality and sourcing. When possible, I want to know where my food came from, how it was produced. Second, I don't confuse quality labels with food safety. No matter how well an animal was raised, I still have to handle and cook raw meat safely. Third, with seafood, I prioritize low mercury fish and seafood. I tend to choose nutrient-dense, lower mercury fish more often than large, heavily predatory fish like tuna or swordfish or shark. We're really not trying to create a perfect diet in a perfect food system. We're learning how to make better choices with the information we have. And now we're going to leave the perimeter of the grocery store and head into the center aisles, because that's where the questions change. Instead of asking where our food came from, we're going to start asking what's actually in it. Now we're heading into the center aisles, and this is where food safety gets a little more complicated because now we're not just asking, could this food be contaminated? We're asking what exactly is in this food and what happens when I eat those ingredients? Day after day, year after year. Walk through any grocery store and you're going to find thousands of packaged foods: cereal, crackers, granola bars, salad dressings, frozen meals, protein bars, plant-based milks, flavored yogurts. And here's a question I want you to think about: if an ingredient is allowed in our food, can we assume it's been proven safe? Well, the answer isn't quite as simple as you might think. You might have heard the term GRAS, which stands for Generally recognized as safe. It's part of the regulatory framework that the FDA uses for substances added to our food. But this system has been the subject of debate because under current rules, companies can determine that certain ingredients meet the GRAS standard without going through the same premarket approval process required for a new additive. This is really important. They can basically declare that ingredients are safe, even if they haven't been tested. Think about that. And I think this raises a really important larger question. How much evidence should we require before something becomes a regular part of the food supply? What matters is what is the substance? How much are you exposed to? How often are you exposed to it? And what is the evidence actually telling us? So processed food doesn't automatically mean bad, or often it does though. This is where we need to distinguish between processed food and ultra-processed food, or minimally processed food versus highly processed food. Almost everything we eat is processed in some way. Cooking is processing. Freezing is processing. Fermenting yogurts or sauerkraut is processing. Pressing olives to make olive oil is processing. Canned beans, frozen veggies, canned sardines— these are all processed foods. That doesn't make them unhealthy. The question is, how far has that food traveled from its original form? Take canned tomatoes. The ingredient list might say tomatoes, water, salt. You know exactly what you're eating. Now compare that with a product made from refined starches, isolated proteins, added sugars, industrial fats, colors, flavors, gums, emulsifiers, And preservatives. At some point, we're no longer simply preserving or preparing food. We're deconstructing ingredients and reassembling them into something designed to be incredibly convenient, shelf-stable, and often very hard to stop eating. It's designed to be addictive. That's what I want you thinking about when you hear the term ultra-processed food. Ultra-processed foods tend to contain a combination of refined carbohydrates, added sugars, fats, salts, additives, All designed to improve flavor, texture, appearance, shelf life, but not your health. And they're often engineered to be hyperpalatable. Think about how easy it is to eat an entire bag of chips compared with an entire bag of carrots. Not simply a failure of willpower. These foods have been designed to taste incredibly good and be incredibly easy to consume. And increasingly, research is linking diets high in ultra-processed foods with poor metabolic health and a whole range of chronic diseases. So when I talk about reducing ultra-processed foods, I'm not asking you to become afraid of everything that comes in a package. I'm asking you to make real food the foundation of your diet. Let's make this incredibly simple. You pick up a packaged food before you spend 5 minutes trying to decode the nutrition facts panel, turn it over and look at the ingredient list. I look for 3 things. Number one, what are the first few ingredients? The ingredients are listed by weight. So are the first ingredients recognizable whole foods, or am I seeing refined starches, flours, sugars, isolated ingredients? Question number 2, where's the sugar? And remember, sugar has a lot of names, 50 different names, cane sugar, corn syrup, dextrose, maltodextrin, rice syrup, fruit syrup concentrate, fruit juice concentrate. Don't just look for the word sugar. Look at the added sugars line on the nutrition fact labels too. Now, number 3, how much industrial formulation am I looking at? Are there a lot of flavors, colors, sweeteners, emulsifiers, gums, preservatives, When the entire product is built from refined ingredients plus additives designed to make it look, taste, and feel good, not so much something you should be eating. That's a sign I'm dealing with an ultra-processed product. I don't want you to stand in the grocery store terrified of every ingredient you can't pronounce. I want you asking a much simpler question. How close is this to real food? And there's one more part of the packaged food story we're really rarely thinking about. We've talked about what's inside the package, but what about the package itself? Can chemicals from plastics, wrappers, cans, and takeout containers actually make their way into our food? That's where we're headed next. The packaging. Think about your average day. You drink from a plastic bottle, you heat leftovers in a plastic container, you grab takeout, you open a can of beans, you cook a dinner in a nonstick pan. We spend so much time reading ingredient labels, but very little time thinking about the containers, the wrappers, and the cookware surrounding our food. And those materials matter. And they matter a lot. The FDA calls these materials food contact substances, everything from packaging and cookware, storage containers, coatings, and adhesives. Now, under certain conditions, components of these materials can migrate into food. But remember, our goal throughout this episode, reduce the exposures we can reasonably reduce without becoming afraid of our food. It's not about one exposure. It's about reducing the exposures that happen every day. And one of the simplest places to start is plastic. And here's one of my personal rules. Whenever possible, I don't heat food in plastic. In fact, I never eat food in plastic. Even if a container says it's, quote, microwave safe, I prefer transferring food to glass or ceramic first. Heat is one of the factors that can influence how food interacts with food contact materials. So what should you actually do? Here's where I keep it simple. For storing food, use glass whenever possible. For water, use glass or stainless steel. For reheating, use glass or ceramic instead of plastic. For cooking, stainless steel, cast iron, or quality ceramic are my go-to choices. But here's the bottom line. We're not trying to live in a bubble. You're going to encounter plastic. You're going to order takeout. You're going to buy packaged food. The goal is simply to reduce unnecessary repeated exposures when there is an easy alternative. So I'd avoid a blanket, your food packaging is poisoning you. And instead I'd ask, where can changing your food storage and packaging meaningfully reduce unnecessary exposures? All right. You get home. Is your kitchen creating more risk than the grocery store? We spent a lot of time talking about what's happening to our food before it reaches us, how it's grown, processed, packaged, transported. But here's the twist. Some of the easiest food safety risks to control are happening in our own kitchens. And the good news is you don't need fancy equipment or a total kitchen overhaul to reduce them. So let's do something a little bit different. I'm going to give you a quickfire round of some of the most common kitchen safety questions I hear. And what you actually need to know. Should you wash raw chicken? No. This is one of those habits that gets passed down through generations. Certainly my family did that. But washing raw chicken can actually spread bacteria. When water hits that chicken, tiny droplets can splash onto your sink, your counter, utensils, nearby food. Cooking, not rinsing, is what makes the chicken safe to eat. How long can leftovers stay in the fridge for? Well, for most cooked leftovers, think 3 or 4 days. If you know you won't eat something within that window, freeze it. And here's a tip, label your leftovers with the date, because if you're staring at a container thinking, was this from Tuesday or last Tuesday? That's probably not a game we're playing. Also, how quickly should I put cooked food in the fridge? Within 2 hours. And if food is sitting outside in temperatures above 90 degrees, think summer barbecue, that window drops to an hour. You don't need to wait until the food reaches room temperature before putting it in the refrigerator. Just make sure it gets cold. Can I just smell food to know if it's safe? No. The sniff test can tell you when something has obviously spoiled, but many of these pathogens that cause foodborne illnesses don't necessarily change the way food smells, tastes, or looks. So don't rely on your nose as a food safety test. When in doubt, look at how the food was stored and how long it's been there. All right, what's one of the biggest cross-contamination mistakes? Handling raw meat and then touching something you're about to eat. Imagine you're making chicken and a salad. You cut the raw chicken and then You use the same knife or cutting board for your tomatoes without properly washing them. The chicken's going to be cooked. The tomatoes aren't. That's how bacteria from one food can end up on another. Keep raw meat, poultry, seafood, and their juices away from foods you're going to eat without cooking. What's the safest way to defrost meat? Not on the kitchen counters. You have a few good options. Defrost it in the refrigerator or use cold water, changing the water regularly. Leaving frozen meat on the counter for hours can allow the outside to warm it The temperature range where bacteria can multiply while inside is still frozen. All right. So after everything we've covered today, here's what I want you to remember. Food safety isn't about eliminating every possible risk. It's about knowing which risks matter and knowing what you can actually do about them. Paying attention to recalls and outbreaks, wash and handle food properly, cook and store it safely. Be thoughtful about sourcing and packaging where you have a choice. And when it comes to contaminants like pesticides, mercury, or heavy metals, think about dose, frequency, and variety rather than You don't need to scrutinize every bite you eat. You need good information, a few smart habits, and the ability to separate a meaningful risk from scary headlines. Because ultimately, the goal isn't a perfectly safe food system. It's knowing how to navigate the one we have. If you loved that last video, you're gonna love the next one. Check it out here.