We all know what we eat is important to our health. But most of us think of our diet in terms of our physical health. But in fact, there’s growing science on the connection between what we eat and our mental health. Even more fascinating is the role played by our gut bacteria, and why the gut is being called the “second brain.” To find out more about “cognitive nutrition,” I recently sat down with Tess Bredesen for my WorkWell podcast. Tess is the Cognitive Nutrition Director at Thrive and an expert on the prevention of cognitive decline. She’s also the founder of Sia Health and works with clients around the world in one-on-one online consultations, developing and coaching.
Here are some highlights from our conversation. You can listen to the whole episode here.
Jen: So Tess, what is a cognitive nutritionist?
Tess: It basically means I’m using nutritional strategies to enhance cognition and prevent cognitive decline down the road. Cognitive health is essentially our ability to think clearly, learn, and remember things. So cognitive nutrition is using foods as a tool to enhance and protect those cognitive functions.
Jen: What do we get wrong in how we think about nutrition?
Tess: Often, when we think of nutrition, we’re siloed into this idea that it’s about our physical appearance or how it affects our weight or cholesterol levels. We rarely think about how it’s affecting things like our mood, productivity, focus, or our ability to prevent chronic disease down the line.
Jen: So what’s the connection between our diet and our mental health?
Tess: There’s been so much evidence in recent years linking nutrition with mental health that this new field of nutritional psychiatry has emerged. The science is robust and growing, but I think there’s a couple of themes at play here, including metabolic health, gut health, and inflammation.
Jen: Okay, so let’s dig into this — what does it mean to be metabolically healthy?
Tess: What it’s describing is how well, or how poorly we generate and process energy in the body. It’s about energy, how we make it, how we store it.
Jen: And does that determine our metabolism?
Tess: It helps to. We tend to think of metabolism as a static thing. We think, I have a fast metabolism, or I have a slow metabolism. But I like to think of it as metabolic fitness. In the same way you go to the gym to increase your physical fitness, you can do things to become more metabolically fit. It’s the foundation of whole health or true health.
Jen: And that also has to do with our cognitive health?
Tess: Yes, the flip side is that poor metabolic health is associated with worse brain functioning, lower energy levels, lower mood, and later on, higher risk for chronic disease.
Jen: How metabolically fit are most people?
Tess: It’s pretty surprising, but only about one in eight of us are metabolically healthy. But we can do things to help us promote healthy metabolism.
One thing we can do to help, is to consider what I like to call the “sugar rollercoaster ride”. So if we’re thinking of our day in terms of a sugar rollercoaster ride, we have toast and coffee in the morning, right? Maybe we spike and it goes a little bit high. Then we have a sugary snack in the afternoon that helps lift us up. But an hour or two after lunch we get the infamous 2:00 PM slump, where we find it hard to focus and be creative.
That’s the crash of the sugar rollercoaster. One of the best ways we can achieve metabolic health is by stabilizing that sugar rollercoaster with foods that act as sugar stabilizers. That’s foods that contain fiber or good fat, like nuts, non-starchy vegetables, spinach, broccoli, cauliflower, asparagus, avocados that contain both good fat and fiber. All of these are going to help to stabilize your ride.
Jen: So do you eat those at the same time as you eat the things that might spike your sugar?
Tess: That’s a great way of looking at it, because it doesn’t mean you can’t have these things that are increasing your blood sugar. It’s about using food pairings in a way that’s going smooth our ride. So if you’re looking at your plate, you think, okay, what’s my sugar rollercoaster ride going to look like if I just eat this bread or pasta, or dessert. So enjoy the cake, but if you some walnuts along with it, you’re going to help inhibit that sharp crash.
Jen: It seems like the glycemic index is a source of confusion for so many people. So what should we know about it?
Tess: The glycemic index is a measure of how quickly a food increases your blood sugar. Each food has a rating between 1 and 100. Table sugar has a glycemic index of 100. The higher glycemic index a food is the faster it’s going to put you on that sugar rollercoaster, and the lower it is, the more stable your ride will be. One caveat is that you can have a food that is low on the index and still not healthy, like fried pork. It doesn’t mean it’s a health food, but it’s not going to spike your blood sugar.
Compare that to the nutritional benefits of a sweet potato, which has a higher glycemic index. So I like to use it as a tool — using the glycemic index to balance out your plate and pair foods. If we add some olive oil to a roasted sweet potato, if we have a side of broccoli or something with good fat and fiber, the average index of our plate is lower.
Jen: Let’s talk about the connection between gut health and our brain, which is getting a lot of attention now.
Tess: We’re just scratching the surface of the role our gut health plays in our cognitive health. Your gut contains actually about 500 million neurons, second only to our brain. So it’s rightfully earned itself this nickname of our “second brain.” And about 90% of serotonin, the so-called “happy hormone,” is produced in our gut.
Our gut and our brain are communicating with each other much more closely than we realized. When we’re nervous and say we have butterflies in our stomach, that’s a two way street. When your gut is stressed, it’s sending signals back to your brain. And when your brain is stressed, it’s affecting your gut.
Jen: And gut health has to do with bacteria?
Tess: Yes, the gut contains both good and bad bacteria. The good bacteria help to produce neurotransmitters like serotonin and dopamine, which positively impact our mood. Then we have bad bacteria, which are going to thrive on all those foods that as a kid I loved and, truth be told, still love — those unhealthy sugars and processed food. We want to enhance the good and inhibit the growth of the bad.
Jen: And how do we do that?
Tess: In a few ways. So one of the things beyond nutrition to consider is stress. All it takes is about two hours of acute stress to completely change the ecosystem of gut bacteria, which can then negatively impact our mental health. So nutrition is not the only component, but it’s a major component of how we can help encourage the growth of good bacteria and relieve stress in the gut, and in turn in your brain.
Jen: What about probiotics?
Tess: Yes, that’s a trendy topic these days. They’re beneficial bacteria in our gut that help us digest foods and absorb nutrients. They also help make neurotransmitters, so they can improve cognitive function. Fermented foods like sauerkraut, yogurt, and kimchi are a source of probiotics.
Jen: And what about prebiotics?
Tess: They’re equally essential because they’re helping the good bacteria. Prebiotics are basically the food for the good gut bacteria and are found and in foods like beans, berries, oats, garlic, onions, and dandelion greens. Asparagus and jicama are also good sources.
Jen: That’s so helpful. And every time you mention one of these foods, I’m thinking, okay, I eat that, I don’t eat that.
Tess: Yes, it’s equally important to consider, okay, what do I like, and what do I not like? You don’t have to eat all of them, but can we get a few that you love in your meals a couple of times a week?
Jen: We hear a lot about inflammation and nutrition…
Tess: I’m happy there’s more interest in this, but we have to remember that not all inflammation is bad. If you think about acute inflammation, like, if you cut your finger and you notice some swelling — that’s just your immune system at work. It’s essential to our survival. But when we’re referring to chronic inflammation, that’s when your body is unable to eliminate the stimuli that it’s fighting, or when there’s repeated exposure to something that’s causing irritation. And there’s a link between chronic inflammation and mental health issues like anxiety, depression, and a number of age-related diseases, including Alzheimer’s.
Jen: And food plays a role in that?
Tess: A huge role, because you can eat foods that help lower inflammation. The common example is antioxidants – found in foods like produce that have beautiful colors, like berries or red cabbage. We can also help suppress inflammation by reducing foods that can increase inflammation, like those higher in omega six fatty acids like cheese, red meat, corn oil, and palm oil.
Inflammation is also influenced by the pairings of foods. For example, saturated fat eaten with simple carbohydrates in the absence of fiber leads to hyper inflammation — like a cheeseburger and a soda. Except if you make a small change — like, can we get a side salad on our plate? Can we get some nuts or roasted broccoli?
Jen: So you write that it’s not just about what we eat, but how we eat. So how should we be eating, and then talk about the role that technology plays in that.
Tess: This is a major point. It goes back to this idea that food is so much more than just food — food is also language. So what is this food telling us about what we need? But it’s very hard to listen to this language of food these days with so much background noise. Because most of us are not really in tune with the food we’re eating. I’m absolutely guilty of this as well. 88% of us are what’s referred to as “zombie eaters” — eating while looking at a screen.
Jen: That me this morning over breakfast!
Tess: We’re all guilty of it. It’s just part of our modern society. We tell ourselves that taking time to simply sit down and eat is time taken away from a more productive task. There’s no judgment — we’ve all built meals around multitasking. It doesn’t have to be every single meal, but can we do one screen-free meal a day to start? If that’s hard, let’s try one per week. Think about it as an investment in your mental health and your future cognitive function. One of the best ways we can prevent burnout is by simply allowing this time, even 15 minutes, to just be about the meal and the senses.
Jen: I love that. What are some of your other favorite Microsteps for better cognitive nutrition?
Tess: One is putting meal times on your calendar. It’s a way to hold yourself accountable, but also to send a signal to co-workers. This is especially important for leaders and managers to set this good example, particularly when we’re working from home. It takes time to prepare even a simple meal, and then it takes some time to eat that meal. So if you can put a block, even 20 or 30 minutes on your daily calendar, that’s time for you and an investment in yourself.
Or try putting your phone away during meals. One of my favorite ways is with a phone stacking game. When you’re out to eat, all your friends stack their phones in the middle of the table. The first person to reach for their phone has to pay for dinner.
Probably my favorite Microstep is using gratitude at the beginning of a meal. Everyone can do this. Even if you don’t have time to eat away from your desk, Just think about one or two things you’re grateful for that day. It can just be, I’m really grateful for this delicious meal I’m about to eat. Tapping into gratitude is powerful and can shift our mindset to being more mindful as we eat.
Jen: I’m a huge fan of gratitude, and can’t think of a better way to end this than saying thank you, Tess, for all of the wisdom you’ve shared with us today.
Tess: Thank you so much for having me. We all have room for improvement, myself included. We’re all on a journey, and it’s always better to do it together.
This article originally appeared on Thrive Global, September 28, 2022.