[00:00:00] Shireen: In today's episode, we welcome Dr. Andrea Glenn. We'll discuss the cholesterol lowering portfolio diet, cardiovascular disease, and type 2 diabetes prevention, and the current state of our public health landscape. Stay tuned to learn more ways that you can use nutrition to lower your risk. Of certain chronic conditions.

[00:00:28] Dr. Andrea Glenn is a postdoctoral research fellow and registered dietician at the Department of Nutrition at the Harvard TH Chan School of Public Health. Her main research interest include dietary patterns and cardiometabolic disease risk. Welcome, Dr. Glenn.

[00:00:47] Dr. Andrea Glenn: Great. Thank you so much for having me today.

[00:00:50] Shireen: An absolute pleasure. So, Dr. Glenn, I would like to before we get a little bit more into the topic that we have set up for today, really want to understand what inspired you and what sort of led you to work this interest and focus on cardiometabolic diseases specifically.

[00:01:07] Dr. Andrea Glenn: What initially inspired my focus on cardiometabolic diseases was actually my experience training to become a registered dietitian.

[00:01:15] So I did that at Mount Sinai Hospital in Toronto. And during one of my placements at the Diabetes Education Centre, I really witnessed firsthand the important role of nutrition in managing diabetes. particularly in achieving optimal blood sugar control. And I really, really enjoyed this placement.

[00:01:33] And I also noticed significant confusion surrounding nutrition recommendations and research among patients and even among some healthcare professionals. So that actually really sparked my interest in digging deeper into the research side of nutrition to better understand how the evidence for clinical practice guidelines are developed for diabetes.

[00:01:51] So after my dietetic training, I worked as a research dietitian for several years. I was involved with several clinical trials on low glycemic index diets and its impact on patients with type 2 diabetes. And then through this experience, I really wanted to further develop my research skills and continue to advance knowledge in the field.

[00:02:10] So I ended up going back to school for a PhD under the mentorship of Dr. John Steven Piper at the University of Toronto. And during my doctoral studies, I focused on investigating the role of the portfolio diet in managing heart disease and type 2 diabetes. In several international protective cohort studies, and then today is a postdoctoral fellow.

[00:02:31] I'm continuing to explore the relationship between the portfolio diet as well as other dietary patterns and factors. on cardiometabolic disease prevention and I really hope that this research will be used to inform clinical practice guidelines for diabetes and heart disease.

[00:02:48] Shireen: I love that focus that you've taken.

[00:02:50] I do want to take a step back. So, you know, you mentioned a couple of times this cholesterol lowering potentiometer Forleo diet specifically for cardiovascular disease. Can you first tell our listeners a little bit more about what this diet entails and how does this differ from other well known popular common dietary recommendations?

[00:03:12] Dr. Andrea Glenn: Yeah, so of course, if you're not familiar with the diet, which I know not everybody is the first studies on the portfolio diet were actually published over 20 years ago and the idea of this dietary pattern came from Dr. David Jenkins and his team at the University of Toronto, and he was interested in dietary approaches to lower LDL cholesterol, so specifically LDL cholesterol, and at that time, there were several foods that had cholesterol lowering or coronary heart disease risk reduction health claims.

[00:03:41] So these foods include things like soy protein, viscous fiber sources, such as beta glucan from oats, barley, and psyllium, as well as pectin found in some fruits and vegetables, nuts, and foods fortified with plant sterols. So if you're at the grocery store, you may have seen these labels before, or maybe you'll notice them next time you go.

[00:04:02] You'll see foods like say things like may help lower cholesterol on like oats, for example, but David Jenkins was really interested in these foods because they only lowered LDL cholesterol of about 5 to 10%. So he was really interested if you combined all of these foods together in a dietary pattern, could you achieve large reductions?

[00:04:21] in LDL cholesterol because on their own, it was the lowering was a bit small. So this actually led to a series of six clinical trials to test the portfolio diet. And just to give some more background on exactly what the diet is it is a diet that includes less than 7 percent of energy from saturated fat.

[00:04:39] And then foods are added on top of that. It includes 50 grams per day of plant protein, mostly from soy, but that also includes beans, chickpeas, and lentils. It has 20 grams of viscous fiber sources. So like the oats, barley, and psyllium I just mentioned, but as well as eggplant, okra, citrus fruits, and berries.

[00:04:59] It has 45 grams of nuts and seeds, which can be any type. And then it has 2 grams of plant sterols. And in the trials, that was fortified margarine. Depending where you live, you might be able to find that in the supermarket. But for anyone not familiar with plant sterols, they are found naturally in cell walls of most plant foods, but in smaller amounts than 2 grams per day if you just eat them on your own.

[00:05:23] So to get enough plant sterols to really impact your LDL cholesterol levels, that's where the fortified foods come in. or supplements are needed. And then the last part of that diet is plant based MUFAs or monounsaturated fatty acids. So things like olive oil, canola oil, other oils or avocado, and that was provided in up to 45 grams per day.

[00:05:46] And when the studies were given, or the participants were given, the amount of food that I just mentioned, the portfolio diet lowered LDL cholesterol by 30 percent. So it's a lot larger than the foods on their own, and it's actually in line with some lipid lowering medications, which was pretty interesting to see.

[00:06:03] And then we also saw that the diet significantly lowered other blood lipids, so your non HDL cholesterol, your ApoB, triglycerides, as well as large reductions in the inflammatory marker C reactive protein. And a lot of this research was the basis for my PhD and postdoc work, so I led the examination.

[00:06:22] of longer term adherence to this diet and risk of developing heart disease and type 2 diabetes. And I found that the diet was also associated with a lower risk of these cardiometabolic diseases in several prospective cohort studies. And if we think about other dietary patterns that are frequently recommended.

[00:06:41] So people may be familiar with the Mediterranean diet or the DASH diet. I would say it is a bit more plant forward than these other dietary patterns and of course focuses more on specific foods that have been shown to lower cholesterol. Because that was the main idea behind the diet. So for example, the portfolio diet emphasizes plant protein more, particularly soy protein.

[00:07:04] It has the viscous fiber sources again, like psyllium, oats, and barley, and then the plant sterols which aren't really part of the other dietary patterns. But despite some of these differences, there's still a lot of overlap between them. So they all do recommend vegetables, fruits, whole grains, nuts and seeds and heart healthy oils like olive oil and canola oil.

[00:07:26] Shireen: And then the second part of like, how is this really different from what we're traditionally hearing in terms of the different types of diet?

[00:07:36] Dr. Andrea Glenn: I would say traditionally, I guess it would be more, you know, What we try to focus on is like a portfolio of foods, so you don't have to pick everything as part of the diet.

[00:07:45] So if you're really not into plant protein like soy, you can focus on the other parts of the diet like nuts and seeds or the viscous fiber sources. And I would say it does really focus on foods that are known to lower cholesterol. So I think that's good. That's probably the biggest differences between the other dietary patterns.

[00:08:04] Shireen: That's helpful. Now, with your focus on cardiovascular disease and type 2 diabetes, what are some of the most perhaps significant findings you've encountered regarding dietary patterns and then their effects on such conditions? And then also the second part of that is what kind of dietary practices would you recommend based on some of these findings?

[00:08:29] Dr. Andrea Glenn: Yeah, so in my research, I've encountered several significant and consistent findings regarding dietary patterns and their associations with cardiovascular disease and type 2 diabetes. So I think one notable finding is the, the linear relationship observed between these specific dietary patterns. So the portfolio diet, but I've also looked at the Mediterranean diet and the DASH diet and other dietary patterns.

[00:08:52] And we see that this is linear for heart disease and type 2 diabetes. So this means that as individuals incorporate more components of these healthy diets into their daily eating habits, we consistently observe greater reductions in disease risk. So it's really important to see and this also shows that The Linear Association also suggested that even modest additions of these foods to one diet can yield cardiometabolic benefits.

[00:09:16] So, I always think that's nice messaging where it means you don't have to do a complete overhaul of your dietary habits to see improvements. I think another area that's important is the similarity in risk reductions across these different healthy dietary patterns, which I find encouraging for healthcare professionals and dieticians.

[00:09:35] as it does allow for personalized recommendations tailored to individual preferences and lifestyle choices. So rather than prescribing, you know, one dietary pattern for everybody, we can really advocate a collaborative effort with our patients to identify and adopt the dietary pattern that's going to best align with them.

[00:09:55] And that's really important because we do know that, you know, the most important factor in someone's success is if they can stick to it long term. So based on that, my recommendations would be to emphasize flexibility and customization of these different dietary patterns. I encourage individuals to select the dietary pattern or even specific elements of these dietary patterns into their daily meals.

[00:10:19] That really resonates with their own lifestyle and preferences while still ensuring that you enjoy the food that you eat. So if we think of the portfolio diet this might mean replacing some meat in your diet with plant protein. like soy beans, chickpeas, or lentils each week, or maybe replacing some of their snacks with nuts if that's part of their diet.

[00:10:39] So just keeping it in line with what the patient wants and what really resonates with your own lifestyle.

[00:10:45] Shireen: And that's very interesting. I think when I, as I hear you speak about the diet, a lot of what also comes to mind is like plant based diet or vegetarian, like there's so many you know, there's almost, there's so many different versions of this, but where you're seeing this is very intentionally set out to be in such a way that even if you got to a a version of this diet doesn't have to be all or none is what I'm hearing you say here.

[00:11:08] Dr. Andrea Glenn: Yeah, absolutely. We see that in the trials as well and in my own cohort research. The more adherent you are, usually the better benefits you'll have for cholesterol lowering, but even if you're meeting the diet targets halfway or even 25%, you still see benefits, which I think is really great messaging if people may struggle with some of these foods, if they're not familiar with them particularly.

[00:11:35] Shireen: Now, one of the other things that you've also been working through is you've developed knowledge translation tools for patients with cardiometabolic diseases. First, can you help us understand what that is, why that matters? And then can you discuss the challenges involved in translating complex dietary and health data into more actionable, patient friendly information?

[00:11:59] Dr. Andrea Glenn: Yeah. So, I've had the privilege of helping. Develop several knowledge translation tools for patients with cardiometabolic disease. And I really love being involved with this as a way to communicate research findings to patients to hopefully be able to positively impact your health. And I'll just mention some of them because they are freely accessible online.

[00:12:17] So we have a low glycemic index food guide developed for Diabetes Canada and an infographic and health hap for the portfolio diet for the Canadian Cardiovascular Society. And I'd say one of the main challenges we face when developing these tools is the inherent complexity of nutrition science.

[00:12:35] So the evidence supporting nutrition recommendations is quite nuanced and it can really vary depending on the population you're studying. the foods you're studying, the study design et cetera. So we do need to balance the need to simplify this complexity for patients without misrepresenting the science.

[00:12:52] So that really requires careful consideration of the scientific evidence as well as effective communication strategies. So what we really think about is providing essential information to the patients. So you may have heard of things like need to know versus nice to know so that they're not overwhelmed by the tools and really just use them as a starting point to make dietary changes.

[00:13:14] And then once they use that and they're familiar with it, they can discuss any follow up questions or concerns with their dietitian or healthcare provider. And in terms of being actionable and more patient friendly, we tend to focus on promoting positive health behaviours such as like doing some food swaps maybe, or some additions to your diet, rather than relying on negative messages.

[00:13:38] So a good example of this approach is from the Portfolio Diet Infographic. So we focus on adding foods to your diet. to your diet. So positive message messaging, like trying some soy products, maybe some nuts or oats rather than focusing on foods you shouldn't eat. So in this case for LDL cholesterol, that would be foods higher in saturated fat.

[00:14:00] I'd say another significant challenge is the prevalence of misinformation and conflicting dietary advice in popular media and other online platforms. So patients are often exposed to these contradictory messages that can create confusion and skepticism around these recommendations. So of course we always have to make sure our tools are based on the best scientific evidence at hand without over promising their health effects as well.

[00:14:27] And along those lines, given that the science behind these recommendations can be quite nuanced, we also develop resources for healthcare professionals to support them when they use these patient facing tools. So that will help them better understand the science as well as help them answer any follow up questions from patients.

[00:14:46] And then I would say the most important aspect of tool development is user feedback and testing. So we always, you know, actively engage with the target audience of the education tools so we can gather insights and perspectives from them. And then we can refine those tools based on that feedback. And I think that's really important because as I said, researchers and healthcare professionals, we may really miss some important points that we think people will understand, but then the patients don't understand.

[00:15:14] And that's really just to help them effective or help us effectively support patients in making dietary changes.

[00:15:21] Shireen: That's incredibly helpful. You know if I am someone who's listening to this episode, can you help me understand? And also I'm someone who's trying to manage my health better, be it through heart disease, diabetes, whatever it may be, but as I'm sort of listening Listening to you speak.

[00:15:36] What are the what are the sort of tangible things? As we're talking about knowledge translation tools that I can expect or that I can have. Where do I go? How do I? How do I begin to sort of work in those in that direction by using these tools?

[00:15:52] Dr. Andrea Glenn: Yeah, so I think I'll use the portfolio diet one as an example.

[00:15:56] So we have like the five different pillars that I mentioned, the plant protein, the viscous fiber, the nuts and seeds, the plant sterols, and then the monounsaturated fatty acids. I think once you have these tools is really to think about your own diet and how those foods might fit into your diet. And generally, we don't want you to like overhaul your entire diet.

[00:16:17] We still want you to eat the foods you enjoy. So maybe there's some ways you could do some swaps in your diet or maybe some additions and really think about your own Cooking and your own preferences and how you're going to apply what's in that tool to your daily life. You also mentioned some tools for for physicians to use.

[00:16:37] Shireen: Tell us a little bit more about those tools and how does it help someone who is visiting their physician?

[00:16:43] Dr. Andrea Glenn: Yeah, so there, we generally call it like a backgrounder for healthcare professionals and it goes through a lot of the science behind The specific tool, so for example, the low glycemic index food guide, it has quite a few pages on the science behind it.

[00:16:57] It talks about some behavior change techniques as well, and it's really to support the clinician. Because clinicians are busy, and they don't always have time to dig through all of the, you know, resources out there. So we try and get the top points for them out there, so they can review it and feel more confident when they present that tool to their patient who may benefit from it.

[00:17:18] A low GI diet or the portfolio diet, for example,

[00:17:23] Shireen: you know, as, as we're coming toward the end of the episode, I'm going to try to squeeze a couple more questions in, but looking towards the future. What are some of the emerging trends or technologies in nutrition research that you find most exciting and How might they influence public health strategies related to diet and disease prevention in the next decade or so?

[00:17:47] Dr. Andrea Glenn: Yeah, it's a great question. And I think there are several emerging trends and technologies in nutrition research that will be particularly exciting that will really help us advance our understanding of diet disease relationships and hopefully transform some public health strategies in the future.

[00:18:03] So one area that I've personally been working on during my postdoctoral fellowship is incorporating metabolomics data into my research. And that's really to help better measure diet as well as understand the role of diet on cardiometabolic health. And I'm specifically using the portfolio diet in this case.

[00:18:20] And if you're not familiar metabolomics is the large large scale study of small molecules known as metabolites. They can be measured in different biofluids like blood and urine, for example. So I'm using blood in my case. And these small molecules and their interactions within your body are known as the metabolome.

[00:18:39] And they include things like lipids, carbohydrates, amino acids. phenolic compounds, among others. And it really is an active area of research in nutrition, and there's still a lot to learn. But it is promising in that these metabolites may be used as objective measures of diet. So they're going to help hopefully overcome some of the limitations of our current self report dietary assessment tools that are quite common in nutrition, and they can also help us better understand the underlying mechanisms between diet and disease.

[00:19:09] And there's also a possibility in the future that this data can be used for personalized nutrition approaches, which we're definitely not there yet, but this may certainly change in a decade's time. And from a public health standpoint, the incorporation of metabolomics into nutrition research may help identify subgroups.

[00:19:28] And then we can tailor those who will benefit the most from different dietary recommendations, and that will, you know, reduce the cost and side effects for those who may not respond as well to some of those recommendations. I think another exciting trend is the integration of digital health technologies and data analytics and nutrition research.

[00:19:49] So, mobile apps, smart devices artificial intelligence platforms. are increasingly used to track dietary intake and provide feedback in real time. So I do think this is an exciting area that will continue to develop and improve over the next decade. And then last, I think we can probably expect to see some greater integration of sustainability considerations into dietary recommendations.

[00:20:14] So we do see that around the world occurring, but not everywhere. So I think it'll be more on a global scale where we're considering. human and planetary health in our dietary recommendations. So lots, lots of sort of positive things for us to look forward to. At this point

[00:20:33] Shireen: Dr. Glenn, we are toward the end of the episode here.

[00:20:35] However, I would love for listeners to know how they can connect with you, learn more about your work.

[00:20:41] Dr. Andrea Glenn: Sure. Yeah. So I think the best way to connect with me is through Twitter or X. If you're on there my handle is at AndreaGlennRD and I do try to post a lot of my research on there. I am also on LinkedIn so listeners can also find me on there.

[00:20:57] But those are the only two social media platforms I use right now.

[00:21:02] Shireen: Lovely. And what we'll do is we'll link up everything in the show notes right below this episode. So wherever you're listening to us or watching us perhaps you'll on YouTube. You can just scroll below and you'll be directed to, to those.

[00:21:14] With that, Dr. Glenn, thank you so very much for your time to our listeners. Thank you for tuning into another, another episode of the Yumlish podcast. It is a time to answer the ask the listeners question, which for today we have our question, which is, What do you include in your diet to lower cholesterol?

[00:21:34] It's a very simple question. Again, what do you include in your diet to lower your cholesterol? And again, part of the answer was probably just answered in this podcast episode itself. So head over to our social media, you can find us there. at Yumlish on Instagram or on Facebook, find this podcast below to again, comment to say, what do you include in your diet to lower cholesterol?

[00:21:58] We'll continue the conversation there. Thank you so very much for listening to another episode and Dr. Glenn, thank you for your time again.

[00:22:05] Dr. Andrea Glenn: Thanks so much for having me.

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