News-Medical talks to Dr. Alice Lichtenstein about the American Heart Association’s latest guidelines for a heart-healthy diet, and how they can be applied across different lifestyles.
Please introduce yourself and tell us about your background in nutrition.
My name is Dr. Alice Lichtenstein. I am the Gershoff Professor of Nutrition Science and Policy at Tufts University. I am also the director of the Cardiovascular Nutrition Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts. My background is in nutritional biochemistry with a focus on cardiometabolic health.
What 10 key features have the American Heart Association (AHA) outlined for a heart-healthy eating pattern?
The 10 features of a heart-healthy diet are to, first, adjust energy intake and expenditure to achieve and maintain a healthy body weight. Second, to eat plenty of fruits and vegetables and to include a wide variety to ensure a good range of nutrient intakes. Another important feature is to choose foods made mostly with whole grains rather than refined grains. In terms of protein, we have some sub-features, and one is to choose mostly protein from plant sources, so that would be legumes and nuts.
Another is to ensure the regular intake of fish and seafood – it is best to do this two to three times a week. Also, to choose low and non-fat dairy products instead of full-fat dairy products, and, lastly, if one chooses to consume meat and poultry, to choose lean cuts and avoid processed meat.
The fifth feature is to use liquid vegetable oils. It is important not to consume a low-fat diet but to include healthy sources of fat, so that would be liquid plant oils rather than tropical oils and hydrogenated fat. The sixth feature is to choose minimally processed foods instead of ultra-processed foods.
The seventh feature is to minimize the intake of beverages and foods with added sugars, and that is going to vary among individuals, but people need to identify where their major sources are and then work towards cutting them down.
The eighth feature is to choose and prepare foods with little or no salt, and many times this has to do not so much with preparing foods but with choosing foods, because about 80 to 85% of the sodium, the salt, that we consume is coming from commercially prepared foods. We are fortunate now that we have the option to get a wide range of reduced-salt foods.
The ninth feature has to do with alcohol. If you do not drink alcohol, do not start. However, if you choose to drink alcohol, it is important to limit intake. To be clear, the Heart Association does not advocate starting alcohol intake to reduce cardiovascular risk, but if one is consuming it in moderation, it is fine to maintain.
Then the 10th feature is one that I think is particularly important, and that is to adhere to this guidance regardless of whether the food is prepared or consumed at home or away from home.
Over the past few decades, we have shifted where we get our food and where it is prepared, and this trend has been accelerated, in part, by the pandemic. When most of our food was prepared at home, guidance was focused on changes to be more consistent with heart-healthy dietary patterns.
Now, because a lot of the food we consume is prepared outside the home, and we need to shift guidance towards taking advantage of the food-based recommendations and available nutrient information to choose items most consistent with heart-healthy dietary patterns.
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How can the identified features be adapted for accommodating different tastes, cultural traditions, and how individuals consume meals?
Well, the way they can be adopted so that they fulfill preferences, cultural and ethnic traditions, and availability of food is to think more in terms of a dietary pattern. That means all the foods and drinks we consume.
Then it is a matter of thinking: for what is normally consumed, what do we have to shift to make that dietary pattern healthier? It does not necessarily mean giving up our favorite foods. It might mean decreasing frequency or perhaps portion size. For example, if we are used to consuming full-fat dairy products, perhaps this could be shifted to 2% dairy and then eventually 1% dairy and eventually fat-free. In terms of types of meat that we consume or animal products, we should again think a little bit more about frequency and portion size. Where might we be able to substitute with new sources of plant protein, things like beans and legumes, that we may not habitually be consuming? Where can we switch to leaner cuts?
In terms of whole grains, we are in a very good position because so many of the products made from grains that we normally consume are now available in whole grain options. So we should choose those, and it is important in that case to read the ingredient list because you cannot judge a whole-grain product by its color or its terminology.
Multigrain is frequently made mostly with a refined grain. Dark-colored bread does not always mean that it is made from whole grain. But if you just look at the ingredient list, at least 51% or that first ingredient should be whole grain.
As far as liquid vegetable oils go, the important thing is to use non-tropical plant oils like canola oil, soybean oil, and olive oil, and to avoid tropical oils such as palm oil, coconut oil, and palm kernel oil.
Again, it is better to focus on shifting a whole dietary pattern than on trying to redo your diet because you are more likely to stick with it. Usually, when we think about a diet, we think about a beginning and we think about an end, whereas what we are really talking about here is a whole dietary pattern that is maintained throughout the life cycle. That means retaining what you are used to and what you prefer but making it more heart-healthy.
The critical issue is sustainability. Small changes are more likely to be sustainable, and sometimes they can be done in stages. That way, you feel you can maintain it and you still actually enjoy your food. You do not feel deprived, yet you are working towards a heart-healthier diet. If you have children at home, you can be an excellent role model because what you have in the house and what you are eating is what children are going to pick up, and it is so much stronger to be a role model than to do as I say but not as I do.
What is in the house is what is going to be consumed. So if you want to follow and move more towards a heart-healthy dietary pattern and you want that for your children, then you have to think about when foods run out in the house, are you going to replace the white pasta with whole grain pasta? Are you going to avoid buying sugar-sweetened beverages? Are you going to have plenty of fruits and vegetables available, which could either be fresh, out on a table for snacking, or frozen, ready to mix in with stir-fries, soups, and stews?
What are the benefits of eating healthy for your heart throughout life, and what scientific evidence backs this up?
The scientific evidence that backs it up has a lot to do with LDL cholesterol levels, sometimes referred to as bad cholesterol. We have to keep in mind that it is difficult to actually measure the extent of cardiovascular disease in humans. Usually, we do not do that. Instead, we look for intermediate markers. The major one we look at is LDL cholesterol. The type of dietary pattern we are recommending with the 10 features is consistent with lower LDL cholesterol levels.
We have very strong data from lots of different sources that lower LDL cholesterol levels are associated with a lower risk of all-cause mortality and cardiovascular mortality. We also know that achieving and maintaining a healthy body weight reduces our risk of cardiovascular disease, and that is because we are less likely to develop hypertension and we are less likely to develop insulin insensitivity, which is associated with type two diabetes and increases one's risk of cardiovascular disease. In general, you tend to feel better.
I think the other important thing is that whilst we should make heart-healthy choices, we can still sometimes have something that is not completely consistent with our heart-healthy diet, as long as we do not have too much of it or have it too frequently. That is what I think helps sustain long-term dietary change.
Sometimes you do not have to think of it as a treat - it can be part of your dietary pattern. If somebody really enjoys cheese or they really enjoy chocolate, then it is just a matter of being careful how frequently they have it and how much they have it. The important thing is that we enjoy the whole pattern and that there is flexibility. That is one of the real advantages of these guidelines, that the focus is on the whole dietary pattern.
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What is a dietary pattern and why is it important to look at the total dietary pattern in individuals rather than individual food or nutrients?
The whole dietary pattern refers to all the foods and beverages that we consume. The reason that it is important is that what we have found in the past is that we may have gotten excited about an individual food or a nutrient that was going to solve all our problems. At one point, it was oat bran. Then it was coconut oil. Then it was vitamin E. Then it was vitamin D. But then, when randomized control trials were carried out, the effects were not what we had hoped for.
The strongest data actually comes from dietary patterns - considering everything together. It is not just that we are eating more fruits, vegetables, and whole grains, and less animal protein, but that this means we are eating less refined grains, fatty meat, and sugar. It is both what we are eating that is good for us and also what we are decreasing in our diet that is important.
Why is the routine assessment of patient dietary quality professionals important and how could this help prevent future disease?
I think it is important to have a routine assessment of dietary intake because there is a lot of information out there and we know that information from physicians is one of the most trusted sources.
If a physician administers a quick diet assessment and then, with the patient, identifies one or two things they can start working on and puts it in the medical record, it means that when a patient comes back, they can quickly bring up what they had discussed and find out whether the patient has made those changes or is shifting towards those changes. If not, they can explore why.
Just telling someone they should lose weight or improve their diet is not going to help. By having this routine assessment that is repeated at each visit, we will essentially provide positive reinforcement or a mechanism for overcoming any blocks to avoid frustration and patients just giving up.
Why is nutritional education so important?
Nutritional education is so important because there is so much legitimate nutrition information out there. We have labeling on packaged products. For almost any restaurant now, you can go on the web and get nutrient information. But unless we teach children, starting at a young age, how to use this information, it is not going to be all that available or useful to them.
People can also get taken in with what sounds almost better or easier, for example, "All I have to do is take this pill or this concentrated powdered form of vegetables." In terms of nutrition education, I think it should start early and be age-appropriate.
In the beginning, it is just about teaching children that apples come from a tree, sweet potatoes come from under the ground and milk comes from a cow, and then introducing them to different types of fruits and vegetables that they might not get exposed to at home or other forums.
Later on, we can do a lot with technology to teach basic cooking skills. Then, as they move into high school, they need to understand, for example, how many miles you have to run to burn off a candy bar. This can be done in math class or science class. They need to know the reasons why you need vitamins and minerals and then learn about metabolism and their co-factors for various metabolic processes.
In economics, they can learn about budgeting - when is it appropriate to buy a big size of something and when, even though it might be cheaper per ounce, is it not a good idea because it will go bad?
I think of it as hunting and gathering in the 21st century, as there are some really good choices in the supermarket and some less good choices. We cannot assume that all children have role models that are going to be able to provide that information.
After providing this information, we can hope that as they mature into independent adults some of the information will stick and they will remember how to use it. That is why I think early and consistent food nutrition education is very important.
What are processed foods and ultra-processed foods, and how can people avoid them?
Processed and ultra-processed foods have no hard and fast definition. In general, I suspect most people can figure it out. If it does not look like the original food, it is processed.
We have to remember that some processing is very good. Pasteurization is very important to keep milk from spoiling and to kill bad bugs. Heating is important. Freezing is important. Washing is important. However, certain processing where the food is manipulated is not so good. For example, processing from whole grain to refined grain removes the outer and inner parts - the germ and the bran. The germ and the bran have vitamins and fiber, which is very important.
A lot of processed food has sugar or salt added. An example of this could be something like peanut butter. You can buy natural peanut butter that is just 100% peanuts, or you can buy peanut butter that has added sugar, salt, and sometimes even fat.
It is not a hard and fast definition and I think a lot of people if they thought about it, would be able to figure it out, but most of the time we do not think about it.
We also do not have an exact definition for ultra-processed. People are using different definitions right now. In general, if it does not look like the original food, it is probably ultra-processed. How to avoid it? Essentially, go back to basic whole foods and then prepare them in a way that you enjoy them. Do not rely on somebody else to prepare them for you as they may be adding extra ingredients that are not necessary and they could be ones that you should be avoiding.
What does research show about replacing processed meat with other protein sources?
I am not aware of many studies that have done this. A recent relatively small-scale study found that when ultra-processed foods were replaced with whole foods, people tended to consume less. They lost some weight, and their biochemistry and blood measures were better. But that was a very controlled environment.
The other way we get scientific evidence is from what we know about diets that are high versus lower in salt or high versus lower in sugar. Diets that are frequently higher in fruits and vegetables and whole grains tend to be lower in ultra-processed foods. I cannot imagine taking a large group of people and, for a year, giving them a diet high in ultra-processed food versus food in its natural state. That would be tough and ethically problematic.
How does sustainability fit into the 2021 guidelines and why has this been included for the first time?
The reason sustainability has entered into the guidelines is that the last guidelines were published in 2006 and, although we were certainly aware of environmental issues, we did not really think about them that much.
Now, sustainability and carbon footprints are front and center stage. The reason for recommending that people shift to more plant-based protein sources initially came from them being higher in unsaturated fat and lower in saturated fat. However, it turns out that it reinforces what we want to do in terms of sustainability and our food supply.
Plant-based sources of protein have a lower carbon footprint than animal-based sources of protein. Furthermore, those that are less processed probably have a lower carbon footprint than those that are more processed because it takes energy to process food.
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What societal changes need to happen to bring about widespread heart-healthy eating?
Well, the societal changes that need to happen are that the default option needs to be the healthier option. For example, since 2000, Dietary Guidelines for Americans, the American Heart Association, have been recommending decreased refined grain and increased whole grain. Yet if you think about any restaurant, pre-pandemic, it is white bread, white pasta, white rice that is automatically served.
You can find alternatives, but you have to spend more time. Since most people eat what is put in front of them, if the default option was the whole grain products and you had to go out of your way to find the refined grains, then people would probably be eating more whole grains.
We have a very nice public health success story with trans fatty acids. One of the major sources was hydrogenated fat. After passing legislation such as including trans fat on the nutrient facts label, restricting the use of partially hydrogenated fat, and finally taking it off the Generally Recognized as Safe (GRAS) list, the default option is now the healthier option. Now there has been a dramatic decrease in trans fatty acid intake and people do not have to think about it or worry about it.
We have been advocating for a long time to decrease salt intake. Think about the little packets in your takeout or the packets of salt and salt shakers on the table at restaurants. Perhaps just having to ask for the salt shakers may encourage them not to use them.
There are so many little default options. The placement of food in a supermarket can also impact whether somebody reaches for the fruit, the high-quality frozen vegetables, and frozen fruits, or the less healthy options. It would be nice to see a concerted effort to make the default option the healthier option.
Furthermore, from a societal perspective, we need to bust some of the old myths about diet and food. One of the myths is that fresh fruits and vegetables are healthier than frozen fruits and vegetables. It turns out that this is not the case because the frozen fruits and vegetables tend to be processed at the point where they are harvested and ripe and then they are flash-frozen so that they keep their nutrient content.
Fresh fruits and vegetables can be very good, but they can lose nutrients as they sit in a shipping container and the supermarket. For certain uses, fresh is preferable. But for some uses, frozen may be preferable. Often, they are in big bags, already washed and cut up in the freezer, preventing waste and meaning people are more likely to use them.
I think another nutrition myth that we need to be concerned about is that farm-raised fish have fewer omega-3 fatty acids, the healthy fatty acids, than wild-caught fish. That is just not the case. The omega-3 fatty acid of farmed fish depends on what is being fed to them, and it is ensured that they are getting enough omega-3 fatty acids to make it equivalent.
There is some feeling that farm-raised fish are not as ecologically sustainable as wild-caught, but again, there have been a lot of changes and improvements made to fish farming.
What does the future look like for heart-healthy eating?
I think the future is always hard to predict. What we are hoping is that some of this advice will be taken up by individuals and some of this advice will be taken up by policymakers who can implement changes that make a default option the healthier option.
There is a lot of interest now in precision nutrition, and we may be able to give individualized dietary guidance to reduce cardiovascular risk. However, I think the important thing is people eat as households and they eat what is available, so whilst it could be a very valuable tool I do not think we should only look towards precision nutrition.
I also do not think we should just count on policymakers making sure that the default option is the healthier option. We cannot always assume that if we tell people to improve their dietary patterns it is going to happen automatically. We have to provide support.
For the future, if we are going to be successful, we have to attack the issue in a variety of different ways, and I think we have to be sensitive to what resonates with each person or each group of people. One of the things that we have to dispel is that a heart-healthy diet is going to lead to deprivation. That is just not the case.
Where can readers find more information?
About Dr. Alice Lichtenstein
Alice H. Lichtenstein, D.Sc., FAHA, the Stanley N. Gershoff professor of nutrition science and policy, and director and senior scientist at the Cardiovascular Nutrition Laboratory at Tufts University in Boston. Her research focuses on assessing the interplay between diet and cardiovascular disease risk factors. She has served on several American Heart Association scientific committees and served as the chair of the writing group for the Association’s 2021 dietary guidance scientific statement.
Lichtenstein's general research focus is on assessing the interplay between diet and heart disease risk factors, specifically addressing issues related to trans fatty acids, soy protein and isoflavones, sterol/stanol esters, novel vegetable oils differing in fatty acid profile and glycemic index, in postmenopausal females and older males. Selected issues are investigated in animal models and cell systems with the aim of determining the mechanisms by which dietary factors alter cardiovascular disease risk.
Additional work is focused on population basis studies to assess the relationship between cholesterol homeostasis biomarkers and nutrient biomarkers, and cardiovascular disease risk; and on the application of systematic review methods to the field of nutrition.