#615: Why Processing Doesn't Determine the Healthfulness of Plant-Based Diets – Alysha Thompson, PhD

**Danny Lennon** (0:00)
Hello, and welcome to Sigma Nutrition Radio. This is episode 615 of the podcast. My name is Danny Lennon, and you are very welcome to the show.
Today, we're gonna be discussing a set of really interesting and often debated topics within nutrition science at the moment, through the lens of a recent paper that was published that sheds light on some of these questions. And I think, as we'll see, there are many interesting questions embedded within the original research question. And so we're gonna be taking a look specifically at a prospective cohort study that was titled Plant-Based Diets, Ultra Processed Foods, and Risk of Mortality and Major Chronic Diseases. And so to walk through not only the paper, which is really interesting in and of itself, but some of the larger implications and some of the bigger research questions that it relates to, I'm gonna be talking with the lead author on that paper, Dr. Alysha Thompson. Dr. Thompson is a research fellow at the Co-Center for Sustainable Food Systems and Institute for Global Food Health at Queen's University, Belfast. She has a PhD in nutritional epidemiology and most of her work relates to working with large perspective data sets. For example, today we'll be looking at her work that used the UK Biobank, and she's involved in a range of work that relates to plant-based diets, flavonoids, and how some of these things connect to chronic disease risk, like type 2 diabetes, cardiovascular disease, cancer, and kidney-related outcomes. For those of you who are premium subscribers of the podcast, you will be able to get a set of detailed study notes that breaks down the paper, go through everything that we mentioned in today's episode as well, in addition to useful graphs, explanations of certain key terms, definitions, and so on. So that will be available linked in the description box where you're currently listening. And after this episode, you will hear a key ideas roundup. For those of you listening on the public feed of the podcast, if you're interested in getting more out of your podcast listening, and be able to get access to our detailed study notes for each of these episodes, as well as a premium exclusive episode each month, then take a look at Sigma Nutrition Premium. It's our membership that not only supports the podcast directly and allows us to keep doing this, but gives you these extra educational resources that will not only supplement your learning, but hopefully allows you to recap over that much easier, to revise this content much more effectively, and to be able to retain more of what you actually listen to. So that will be linked up in the description box where you're listening right now, or just check out sigmanutrition.com and we'll have some details there. And for anyone that considers becoming a member, thank you and hopefully you enjoy the content. So with that out of the way, let's jump into this conversation between myself and Dr. Alysha Thompson.
A very big welcome to the podcast to Dr. Alysha Thompson. Thank you so much for taking time to come and talk to me.

**Alysha Thompson** (3:07)
Thank you. Thank you for having me. It's great.

**Danny Lennon** (3:09)
I think as I mentioned to you, as I'm sure we'll get to a bit later on, after reading one of your publications, I thought it was an excellent paper that we'll talk about, but it also raises some really important points that are big topics in nutrition science at the moment. And so it's a good gateway into those types of conversations. But before we get to any of my questions, can you let people know a bit about your work, your research interests, anything else you think might be relevant to them?

**Alysha Thompson** (3:35)
Thank you for having me here, Danny. My name is Alysha Thompson, and I'm a research fellow at the Co-Centre for Sustainable Food Systems at Queen's University Belfast. And broadly, my work is within nutritional epidemiology.
So I'm interested in how habitual dietary patterns relate to long-term health outcomes, particularly chronic diseases like Type 2 diabetes, cardiovascular disease, cancer, and also mortality. So a lot of my work thus far has been on plant-based diets, but really trying to move beyond the simple question of whether someone eats a plant-based diet or not. I'm interested in the quality within the plant-based dietary pattern, because two people can have very different plant-based diets. They eat quite different foods nutritionally within that as well. Alongside that, I've also worked on flavonoids, flavonoid rich foods, which fit quite naturally into this area. So foods like tea, berries, citrus fruits, and other plant foods that contribute to a range of bioactive compounds. And we're interested in how these patterns are also associated with better long-term health. And then more recently, this paper on plant-based diets and ultra-processed foods has come about. And again, we're just again delving into the area of plant-based diet quality and what contributes to this. So yeah, that's the sort of quick overview of my work so far.