Your Diet Key To Lowering Blood Pressure

Justin Charles, MD

I’m great, thanks for having me.

Laurie Marbas, MD, MBA

I’m excited to share your recent research and get into what the science says about how we should approach hypertension. Maybe we can get started with the basics of your most recent research article and speak to what the evidence says about diet, for example, and hypertension.

Justin Charles, MD

Sure. We were asked to write a review article recently for a Current Cardiology Report in the hypertension section, reviewing the evidence for plant-based diets and hypertension. One of our coauthors, Dr. Shivam Joshi, had written an excellent article just a year or two ago in the American Journal of Lifestyle Medicine, and I said, “There’s no way I can write a better article than the one by an established lifestyle medicine nephrologist.” We, along with several other coauthors, decided to summarize a high level of what the current evidence says and then translate that into how a busy clinician can help patients adopt a plant-based diet for the prevention, treatment, and reversal of hypertension. A lot of the cutting-edge research is reformulating what we’ve known for decades, if not longer, about how to treat hypertension. That’s using a minimally processed plant-based diet. We wanted to show some of the more well-known evidence-based diets and how, if you distill them down to their key elements, they work best as a minimally processed, plant-based diet or a Whole Foods plant-based diet, as we say in the article. 

The DASH diet is probably one of the more well-known dietary approaches to stopping hypertension, and that works quite well, if not better than some of the leading hypertension medications with optimal adherence. When you look at that diet, a lot of people say, Well, it’s because it’s a low-sodium diet. But it originated to try to get all the benefits of vegetarian diets while making them more palatable for the average consumer. When you look across sub-analyses of diets like the DASH diet and the Mediterranean diet that we know so well and have a great deal of evidence for, we find that the more healthful plant-based foods they contain, the better people generally do. The cutting edge is summarizing a lot of the more recent research, a lot of the more recent randomized controlled trials, and high-level data to distill down into what we know about eating real food—not too much, mostly class. Our job was easy. We were standing on the shoulders of the great people who came before us, and we were just highlighting that. What are the mechanisms of a plant-based diet? The exciting thing that we added was: What are the main principles of a healthy plant-based diet for hypertension? What does that look like, and how do you translate it into having a patient in front of you in 7 minutes? 

Laurie Marbas, MD, MBA

That’s fantastic. Can you speak to the specific mechanisms of a whole plant-based diet? Like, what are these foods in particular that we should focus on? If any, is it just the general symphony of all these amazing nutrients that are occurring? Or maybe you can just highlight some of those foods that may come up in the research.

Justin Charles, MD

We focused more on the overall dietary pattern than on any one superfood. Certain drinks and foods, like beetroot juice, have been studied for hypertension, as have hibiscus tea and other forms of hibiscus. However, we focused on the overall healthy dietary pattern of a healthy plant-based diet. getting your vegetables, fruits, whole grains, ideally intact whole grains, legumes, nuts, seeds, and avocados, and avoiding highly processed foods, animal products, meat, dairy, eggs, etc. We did focus on the mechanistic evidence for why a plant-based diet works in terms of having more of certain healthful components and fewer of certain unhealthful components. For example, whole-food plant-based diets are lower in sodium and higher in potassium. They have adequate amounts of magnesium and calcium. Fiber, which is only found in plant foods, is high in plant-based diets. That can affect the gut microbiome, which is an area of emergent research and shows beneficial profiles of patients who have more plant-based diets on their gut microbiome and the bacteria that make up our digestive system. They’re also high in natural nitrates rather than synthetic nitrates, which lead to colon cancer and other metabolic diseases, and then have numerous amounts of phytonutrients that show benefits across a spectrum. Or we eat that rainbow of fruits and vegetables. It was less of the eat this one food and more make sure you balanced plant-based diet that you’re not adding processed plant-based foods that are super high in sodium or saturated fat. You’re eating across the rainbow. You’re making sure that you have plenty of potassium, magnesium, and calcium, which most people associate with dairy but can be found especially in low-oxalate greens and other excellent plant-based choices. So how we can optimize this whole food plant-based diet for hypertension, it’s already quite good by itself.

Laurie Marbas, MD, MBA

I like the word optimize. It’s like people say, Well, you need this way to boost your immune system to help optimize. It’s the same idea, and I like to stay away from the ideas of superfoods, but there are certain components of the plant-based diet that we need to maybe highlight. Speaking of which, there’s the positive benefit of a wholesome plant-based diet. Can we speak a little bit more about the sodium content of these ultra-processed vegan foods? Or maybe also speak to the animal products about what they’re doing to cause hypertension or make them less beneficial when they’re still included in the diet.

Justin Charles, MD

We had to backtrack a little bit. The way we got into writing this article was that I wrote an editorial along with Dr. Sarah Hall, a cardiologist at Yale. I did my last residency. Dr. Arthur Caplan, an ethicist at NYU, on the moral imperative for plant-based nutrition. We wrote that: What are the harms of animal products beyond just the benefits of plant-based foods? That’s how we got invited to do this review article in the first place. animal products: one, the animal protein itself; the make-up of animal proteins tends to be harder on the kidneys. It tends to promote more inflammation and oxidative stress. So even just the animal protein outside of some of the other components I’ll talk about tends to promote hypertension, metabolic disease, and overall poor cardiovascular health. In addition, we know saturated fat is not good for the arteries, despite attempts at new looks at old data to try to prove otherwise. Then we have some new players on the block like TMAO, which, when we consume choline in our diet, which is often found in foods like eggs, our gut microbiome translates that into this TMAO, which tends to be again inflammatory and pro-pathogenic, causing plaques in the arteries, but interestingly, in vegans or people who follow a long-term plant-based diet, our gut microbiome is fortunately not as good at converting the choline into TMAO. If you have a vegan steak, which I wouldn’t recommend you do, they wouldn’t make as high levels of TMAO. There’s also synthetic nitrate. 

Before that, I mentioned things found in deli meats, cured meats, and other processed foods that tend to again promote hypertension, cardiovascular disease, certain types of cancer, and then advanced glycation end products, which, when different parts of the body become caramelized and the vessels become caramelized, like happens in type 2 diabetes from high blood sugar when we consume them obviously from outside and animal products that can also again promote this cauldron of cardiometabolic disease. It’s not just enough to have more plant foods, though that’s certainly beneficial, minimizing the animal products and also minimizing the processed plant-based foods. There’s been some great literature recently looking at plant-based diets as they become more popular and more processed. Looking at not just a plant-based diet, but a healthful, minimally processed food versus an unhealthful food with a lot of processed fake meats, etc., they find consistently that healthy plant-based diets promote health, reduce your risk of diabetes, and reduce your risk of cardiovascular disease like hypertension, whereas unhealthful plant-based diets increase your risk. It’s not just enough to eat plant-based foods with some animal foods. If we want to optimize, we want to have healthy plant-based foods and minimize animal-based foods.

Laurie Marbas, MD, MBA

You mentioned in your summary of your report that you have developed a ten-point dietary recommendation for patients with hypertension. Can you just highlight what those are? Maybe help people understand? For example, when you say ensure sufficient consumption of dietary fiber, like how much dietary fiber, what are the best foods, or things like that.

Justin Charles, MD

I will be completely honest and say that this was done by Brenda Davis, who’s an excellent registered dietitian and a fantastic person. I highly recommend looking at her work and her books. She’s an inspiration to us all. She developed this ten-point dietary recommendation for how to optimize a whole-food plant-based diet. The first is the foundation of the diet: whole-plant foods. Make sure that you’re including five or more servings of vegetables, four or more servings of fruit, three or more servings of whole grains, three or more servings of plant-based proteins like beans, peas, and peanut butter, and one or more servings of nuts and seeds. There are plenty of calcium-rich choices, like nondairy yogurts and low-oxalate greens. Think of your broccoli, bok choy, and kale soybeans, as well as having generous amounts of herbs and spices on the table. In the article, there are examples of serving digestible sizes, a pun intended for the people reading the article to understand what to do. 

As far as the second point, there is sufficient consumption of dietary fiber. The general recommendation is about 14 grams per 1000 calories. 25 grams for women, and 38 grams for men, depending on your calorie goals. Fiber is only found in plant foods. It’s only found themselves with cell walls. Plant cells have cell walls. Animal cells don’t. About 95% of people are deficient in fiber. It’s important to consume high-fiber foods. If you’re consuming a variety of healthy plant-based foods, you will likely get enough fiber, unless you’re not eating enough. The next point is limiting sodium to less than 1500 milligrams a day. This is in line with recommendations from the American Heart Association; the most common source of sodium in the diet is from processed foods and restaurant foods. Not the salt shaker, not salt added with cooking. If we can get rid of processed foods, especially ultra-processed foods like deli meats, potato chips, your pretzels, etc., we can help people minimize their sodium intake, and they’ll get enough from what’s naturally occurring in the fruits, vegetables, and whole grains. Look at the nuts. Cooking at home is important. 

One point is minimizing the intake of added sugars, so no more than 5% of your calories are added sugar, or six teaspoons of sugar in a 2000-calorie diet. because we’re not having foods with added sugar, so that’s not a banana, which is naturally sugary. This is adding teaspoons of table sugar, high-fructose corn syrup, and other processed sugars. It’s still okay to eat fruit and naturally sweet foods, but avoid those processed sugary drinks, sugary cereals, etc. Point five is minimizing added fats, and this is not to say that fat is bad. Fat is one of the three key macronutrients we need, but we want to have helpful components of fat and healthy amounts of fat. The worst offenders are the solid fats, or trans fats, which are fortunately mostly out of the food supply but are solid, tend to be higher in saturated fats like butter, margarine, and shortening, and tropical oils like coconut oil, palm oil, and palm kernel oil. We are trying to minimize the use of oil, which is a processed food, and use the least processed forms of oil that we can. also avoid cooking oils with omega-3-rich oils, not because they’re bad but because they oxidize and become unhealthy when we cook them at higher temperatures. When we’re drizzling oil, which we should do sparingly, those omega-3 oils are helpful, but we should make sure we’re using oils that don’t oxidize at too low a temperature. Otherwise, that creates reactive oxygen species, and that’s not good for our bodies. Speaking of fats, we also want to have plenty of omega-3 fatty acids. While those are found in fish, they are also found in flaxseeds, chia seeds, hemp seeds, and walnuts. Some people choose to supplement with direct sources from microalgae, which is where the fish get it from. If people are going to consume fish, which we don’t recommend, at least avoid mercury-containing fish because the last thing we want is excess mercury and pollutants in our bodies. 

Point seven is to make plants your primary protein source. We tried to write this article for all readers and didn’t want it to be too black and white. at least promoting, minimizing the intake, if not eliminating, which would be ideal, and especially avoiding branded processed meats, whole eggs, or egg yolks. Point eight is having rich sources of antioxidant and anti-inflammatory foods at each meal. The deeper the naturally occurring color of something, the better the antioxidant content. Think of blueberries. They’re such a rich blue, they’re almost purple. A great source of antioxidants. Our leafy greens are fruits, especially berries, and legumes, whole grains, especially colorful ones, nuts, seeds, and sprouts, fermented foods, herbs, spices, green and herbal teas, and a ton of phytonutrients, antioxidants, and anti-inflammatory compounds, which tend to just generally promote good health, including for your arteries. Point nine, which you’ve already mentioned, is the way highly processed foods are processed. that includes ultra-processed snack foods and also refined starches like white flour, white rice, and white pasta, instead of choosing the more whole-grain, minimally processed option.

Then we talked in point ten about nutritional adequacy, especially some of those key nutrients. I mentioned before for hypertension. for potassium, having about 3400 milligrams for men and 2600 milligrams for women; for magnesium, 420 to 430 milligrams for men; 310 to 320 milligrams for women; and calcium, a thousand milligrams unless you’re a woman over 50 or a man over 70, when you should have 1200 milligrams; and recommending that vitamin B12, which is not naturally present in most plant-based foods other than nutritional yeast and fortified foods; vitamin D and iodine are often not reliably included in plant-based diets either. Make sure you get that in supplements, food that’s fortified, or special foods that are naturally occurring with those substances. Those are our ten points. There’s more detail than I shared, and it’s written in a way, again, for the reader to be able to understand and apply it. Then we created a menu based on those ten points. by us, broader. You can see some of the options for how a day in your life can be eaten in line with this form of diet.

Laurie Marbas, MD, MBA

That’s perfect. A good place to break here for the moment. But thank you so much for joining us today, and I hope you found our conversation insightful and engaging. If you’re a summer purchaser, stay here because we’re about to dive deeper into this discussion and speak to the implementation of everything that was just recommended. But if you’re clicking on the bottom button below or to the side, you’ll get access to the rest of the conversation. 

Now, if you’re watching this, thank you for being a visible member of our community. Let’s continue the conversation with Dr. Charles. Can you speak a little bit about the implementation of testing what you’ve mentioned as a sample diet? How do you recommend a physician and see patients? How do they embrace these types of things?

Justin Charles, MD

One of the most common pitfalls is assuming that people don’t want to or won’t change and not bringing it up, which is a matter of informed consent. If someone has breast cancer and we say they don’t look like a surgery person, even though that’s first-line therapy, I’ll just offer them chemo. You would lose your license and be on the front cover of the New York Times. But with lifestyle behaviors and especially nutrition, we will often say, I don’t think that patient will change their diet, and we won’t talk to them. Step number one is to just bring up the fact that nutrition is important, even if you don’t know the first thing about it or the recommendations. Patients will review recommendations for their clinicians with high regard. Just at least attempt to talk about it. Just like with anything, we can’t change what we can’t measure. 

Finding ways to assess diet with patients, we outlined a few in the article. I tend to use a 24-hour dietary recall where you get everything that someone eats or drinks in a day, whatever you use. When you ask people generally about their diet, they will misreport, often unintentionally, what they would like to eat rather than what they do eat. Some excellent evidence-based screenings can be done in as little as 5 minutes, and then getting into the basics of how you set goals and talk to patients in a way where you’re more of a coach than an expert is important because patients are the ones who are experts in their lives. We have expertise in a lot of different things, but we don’t go home with the patient; we wake up with them and live with them every day. Helping them find their motivation rather than being patient and figuring out where they want to change, what goals they want to set, and how they can troubleshoot within their lives. Things like brief action planning, which can be done as a quick goal setting and takes five minutes or less, where you help someone identify a goal, assess their confidence, do some brief troubleshooting, and get them to restate their goal and commit to it. 

That can be helpful, as can the principles of motivational interviewing, and we went to a great article written by a few colleagues of mine that looked more into brief action planning and motivational interviewing, and then some more basics of goal setting with the SMART goal that is specific, measurable, achievable, relevant, and time-sensitive, rather than general goals like I want to eat healthily. What does that even mean? Setting nutrition prescriptions, just like we will prescribe medication. But if we prescribe the wrong dose or frequency, it doesn’t work as intended. Knowing how to set positive prescriptions, add three servings of broccoli four times a week for the next two weeks, and negative prescriptions, cut back on one soda a day, four or five days a week, for the next month. We can give people specific advice after we’ve gained their initial understanding, motivation, and goal-setting.

Laurie Marbas, MD, MBA

I like the idea of goal-setting. Can you speak a little bit because most of our audience will be on the receiving end of this? Maybe go see a sample of what it means to have a SMART goal. Like what? What does that acronym look like in a real-life setting?

Justin Charles, MD

We do have a sample patient-physician script that you can read through in the article once it’s published. a SMART goal Again, be specific, measurable, achievable, relevant, and time-bound. Using the example I gave before, a lot of times people will say, first, I want to lose 10 pounds, and we try to direct people toward more process behavioral goals rather than outcome goals, which can be very multifactorial, and say I want to lose 10 pounds in my back pocket. But what are you going to change to get there? Food. I want to eat healthy. That’s a very general goal. It’s very vague. What does healthy even mean? There’s no way we can measure it. I have no idea if you can do it because of something about it. 

Let’s make it more specific. Are there any foods you want to eat more or less of? I don’t eat vegetables. Are there more vegetables you like? I like broccoli. How much more broccoli do you want to eat? When do you want to eat it? What are all the details? How do we turn this idea into something that can become an action plan? To fast forward to the end, the final goal could be that I want to include broccoli in the soup I make every week, which I eat four times a day. I’m going to do that once a week until I get to meet with you again. Now we’ve turned. I want to eat healthy as a very clear, measurable goal that’s relevant to what a patient wants to do. We have a clear plan in place and a follow-up plan, so we can check in with them.

Laurie Marbas, MD, MBA

I like to see it. It’s almost like you’re taking the theory and the thought and translating it to the physical and the reality of what needs to happen. It comes down to the saying that if you fail to plan, you plan to fail.

Justin Charles, MD

I like that.

Laurie Marbas, MD, MBA

Because it’s very important. Then, to your other point, what’s not measured is not managed. It’s very clear. There was a study I don’t recall; it’s been a while since I read it, where they looked at registered dietitians doing a recall and they were off calories. It was a calorie recount, and dieticians know how many calories are included in all 5,000 calories a day.

Justin Charles, MD

Wow.

Laurie Marbas, MD, MBA

So if you have someone who’s educated and this is what they do for a living and they’re off by a thousand, imagine the layperson who is less informed about the caloric advantage. what we’re trying to recall, so I love leaving those documents while they’re doing it.

Justin Charles, MD

Not to mention, a lot of times people will just go into counseling before understanding anything about what a patient’s doing; they might already be doing a lot of healthy things. So you’re going to be giving them unhelpful recommendations and then invalidating their experience and all of their positive ones. One thing I will say with this is that we don’t want to overinflate and tell people they’re doing good things when they’re not, but trying to identify and bring up explicitly what people’s strengths are is a good way to motivate them, to improve self-efficacy, improve their confidence, and say, since we last spoke, I know you’re not eating as healthy as you want, but you gave up soda, and that’s not easy. Good job. If you can do that, I have no doubt you’ll be able to achieve your next goals. Just see the look on people’s faces. When you tell them they did a good job with something, it’s great, and it can change the dynamic.

Laurie Marbas, MD, MBA

We’re our worst critics. All of us have that voice inside our heads telling us that what we’re doing is failing all expectations when in reality we’re doing a phenomenal job and people don’t understand it. But I like the idea, too, that, as physicians, we need to help the patient. But we’re the guide, not the hero. We’re not the heroes in this story. We’re just here to help someone along their journey. When they trip and fall, we’re here to help get them back on their feet and get them out running again. But yes, there are so many points here. But what I love about it is that you’re a young, informed physician, creating opportunities and checklists for action items for physicians. 

That’s the one thing that I found over time with some medicines, we need these on a checklist of simple actual items for doctors to have these conversations with physicians like our patients. How do we prescribe medications? That’s another big area that I feel is large. How I approach it is, honestly, trial and error. In my experience, this is nice. I love checklists, and my patients love checklists because it’s like you’re like, okay, these things I need to do every day, Then they wrap their heads around how they can do it. It’s almost like you need a diagnosis before you can even implement a plan of treatment. I need to know now so I can create the plan. This is the most helpful thing to do.

Justin Charles, MD

Give a scaffold instead of just going that way and making a left, and to everybody else.

Laurie Marbas, MD, MBA

There are so many ways to approach this, but this is a valid and strong way to do it. It’s very doable, usable, and simple to implement in practice. then patients can embrace it, do what they feel based on their values, and make the decisions that they want to make. That’s the other piece. As physicians, accepting that people will always do what we’re encouraging them to do is like leading a horse, whereby you can’t force them to drink. That’s okay, too. But you’ve done your due diligence, and you’re not being medically negligent, like you mentioned earlier. You’re not going to withhold options of treatment when you’ve taken your perspective, you’ve already decided for the patient. You’re taking away their self-efficacy and their ability to make those decisions for themselves. That’s the model that you mentioned, and that’s an important point.

Justin Charles, MD

We don’t want to take away our autonomy. Dr. Beth Motley, who is a mentor of mine, would say to teach 100% and then meet someone where they’re at. We’re giving people if you want optimal. Here’s what I would recommend: generally based on the evidence. But not everyone wants to choose that I will work with you no matter what you decide to do. What are your thoughts? What are you willing to do? If we miss either one of those components, then we’re either essentially withholding valuable information or we’re making people think there’s an all-or-nothing decision they might have wanted to go 50, 60, 70, or 90% of the way, and then we’re being too black and white and not helping people along that beautiful, colorful spectrum in between.

Laurie Marbas, MD, MBA

Absolutely. We try to operate in absolutes because it’s comforting to think, we’ve done the absolute thing and told them we have to be okay with uncertainty and understand that people aren’t going to always want to do everything we’re recommending. Sometimes that recommendation will change over time as evidence advances with research. We have to be okay with that too. It’s a great way to approach medicine, so thank you.

Justin Charles, MD

This is great.

Laurie Marbas, MD, MBA

I’m sure everyone here who’s listening will find this super helpful, and it will be in. What’s the Journal again?

Justin Charles, MD

It will be a Current Cardiology Report in the Hypertension Section, and we’re working on having it open access so more people will be able to read it, but that’s still TBD. We’ll find out in the coming weeks.

Laurie Marbas, MD, MBA

Perfect. We’ll thank you again for doing that work. I know it’s not a fun thing to go looking and reading, writing the reports, and all that. It can be quite a stressful event trying to get something published.

Justin Charles, MD

I had fun, though. It was a good team, and it was an interesting project. The best way to learn is through teaching. I gained a lot from it.

Laurie Marbas, MD, MBA

Watch one, do one, teach one. That’s how you do it.

Justin Charles, MD

Absolutely.

Laurie Marbas, MD, MBA

That is what I get in medical school. Thank you all again, everyone, for listening. We hope you find this insightful, and we’ll see you in the next conversation.

Justin Charles, MD

Take care.