Tag Archive for: cardiovascular disease

Stretch Your Body, Stretch Your Lifespan

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“Stretching reduces your risk of dying from all causes” was the message from Tuesday’s Memo. How does that work? Why would stretching decrease mortality? There are no definitive answers, but here are a few possibilities.

It may be that stretching strengthens the blood vessels as well as the connective tissue; that may decrease the potential for blockages or building up plaque in the arteries. Or it may be that the deep breathing that’s associated with most forms of stretching also contributes to the health of the heart and lungs.

One of the other benefits of stretching is a resultant increase in strength, which could help keep the muscles more pliable, and that’s important at any age. I’ve already mentioned that there may be an improvement in arterial function when undertaking stretching, but associated with stretching is a reduction in resting heart rate and an increase in vasodilation. Their possible net impact could lower blood pressure, which would reduce mortality.

I think that one of the most important benefits is going to be related to mobility and balance. We often only think of the flexibility of the muscles of our hips and our knees, but something as simple as raising your hands above your head can benefit stretching those lower joints as well. And all that contributes to your ability to move in space as you get older; maybe you move more if you stretch regularly. By regularly, that means five days a week, the criterion in one of the studies I mentioned.

Finding out the why stretching helps may take a while, but the fact is that there are benefits to what we would consider the easiest forms of exercise. As you move forward through this year, when you have a few minutes in every day, whether it’s waiting for the microwave to finish heating a cup of coffee, washing your hands after using the bathroom, or standing alone on an elevator, taking the time to do purposeful stretching may provide a benefit that you don’t envision. To take it one step further, put together a short routine of three to ten minutes that you do every day; if you have old injuries or joint issues, an appointment with a physical therapist can help you devise a routine you can do safely. And now that spring has sprung and you can get out of the house a little easier, try a class in yoga, tai chi, or qigong. Be sure to look for one that’s within your abilities; Paula and I tried a class a few years ago and were embarrassed that we couldn’t get up and down as easily as the 20-somethings.

The net effect should be that your muscles and your connective tissue will be more pliable. Who knows, you just may end up living a little while longer as well! Sounds like a good investment of time to me.

What are you prepared to do today?

        Dr. Chet

References:
1. Med Sci Sports Exerc. 2020 Dec;52(12):2554-2562

2. BMC Public Health. 2023; 23:1148.

Reducing Your Risk of Dying the Easy Way

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Quick! If I were to ask you which form of exercise would decrease your chance of dying, and especially your chance of dying from cardiovascular disease (CVD), what would your answer be? You’d probably pick some form of aerobic exercise such as running, elliptical training, walking, and cycling—any type of exercise that works the heart and the entire body to improve your cardiovascular fitness. That’s on the list for sure, but it’s not the form of exercise that seems to decrease your risk of dying the most. Data from two large observational studies show this form of exercise decreases your risk of dying the most: stretching.

Stretching? Stretching is that toe-touching and heel-to-butt type of stretching we were all taught in high school or some other fitness class. But that’s not all. What also counts as stretching would be activities such as yoga, tai chi, and qigong. They feature slow, elaborate movements that control the body in ways that result in stretching the muscles and other connective tissue. That all counts as stretching.

How much does it reduce mortality? In two large studies, 10% and 12% respectively over the course of several years, the highest reductions in both studies. You get more benefit if you combine it with other forms of exercise such as aerobic training and weight training. But stretching? How or why? I’ll cover that on Saturday.

The Insider Conference Call is tomorrow night at 9 p.m. Eastern Time. Get your questions answered about anything related to health including exercise if you become an Insider by 8 p.m. tomorrow.

What are you prepared to do today?

        Dr. Chet

References:
1. Med Sci Sports Exerc. 2020 Dec;52(12):2554-2562
2. BMC Public Health. 2023; 23:1148.

How Many Steps Do We Need?

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Last week, we talked about how to lower blood pressure using a form of weight training called isometrics. As I made clear, you won’t look like a body builder, but it can help your cardiovascular health. This week, we’ll look at two recent studies to clarify how much aerobic exercise we need to reduce the risk of all-cause and cardiovascular disease mortality.

The typical recommendation for aerobic exercise is 10,000 steps per day. That was based more on marketing than on science, but it has stood as the standard for years—until recently. Several studies have shown the actual amount may be between 4,000 and 7,000 steps per day.

In a recently published study, researchers included data from 17 studies and over 225,000 subjects. They tracked the subjects for just over seven years to find out all-cause mortality and cardiovascular disease mortality. One more thing: all the data were collected electronically as opposed to relying on some sort of mechanical device that underestimates or overestimates steps per day.

After using meta-analysis, the researchers used 3,900 steps per day as a baseline for the median risk of mortality. For every 500 additional steps per day, the mortality risk decreased 7% and for every thousand additional steps per day it decreased 15%. As the number of steps increased, the cardiovascular and all-cause mortality risk decreased until about 12,000 steps where it leveled off.

Going with our theme of doing just enough to reduce our mortality rate, it would seem that 4,000 steps per day, whether as part of your regular day or in addition to your everyday activity, gives a baseline of protection. But do you really have to invest that much time? We’ll check that out on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Eur J Prev Card (2023) 00, 1–11 https://doi.org/10.1093/eurjpc/zwad2292

Yes, Intensity Matters

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Can you get away with less time exercising and still protect your cardiovascular system? We know from Tuesday’s Memo that more time spent on physical activity will provide more protection. Can we save some time? Or perhaps better stated, can we do something in short bursts of time that can increase the moderate to intense exercise we get?

Before I answer that, remember that physical activity means everything you do that requires movement: walking to the kitchen, gardening, cooking, and the activity involved in your job. Exercise is also a part of your overall physical activity. In the study, all activity was registered by the accelerometer the subjects wore.

Intensity Matters to Reduce CVD Risk

With that in mind, the answer is yes: exercise intensity matters when it comes to protecting yourself from cardiovascular disease (CVD). I must admit that the charts and graphs published in the study were challenging to understand. They used a percentage of calories used per day as the way to measure outcomes. For the exercise intensity analysis, they considered the percentage of calories at moderate to high intensity. They found that as the percentage of activity at moderate to high intensity increased, the rate of CVD events decreased.

Here’s an example. Let’s take a 180-pound guy who uses a low amount of energy in physical activity such as five calories per kg body weight. The total calories he uses daily would be about 400 calories, including any exercise he did. But let’s say the percentage of moderate to severe intensity exercise rises from 10% of total exercise to 20% of that total. His risk of a CVD event would be reduced from 2% lower to 20% lower. He hasn’t invested any more time, yet he gets a jump in benefit just from increased intensity.

What Does That Mean for You?

Does this mean that everyone should be doing high-intensity interval training? Not in the classic sense; what’s high intensity for you may be impossible for your elderly neighbor and a breeze for your kid’s soccer coach. You don’t have to do special workouts such as high-intensity interval training where you’re going to bust a gut for 60 seconds and then take it easy for five minutes. That is intense, but it takes less time overall and you could do that if you want; there’s more info at drchet.com if you decide to try it.

In physical activity, everything counts from housework to walking the dog to breaking into a run to catch a bus. Those would show up as mild or moderate intensity, or high-intensity exercise for the running. It doesn’t mean that all the exercise you do has to be high intensity, but investing time in higher intensity exercise may provide you with additional benefits. Working a little harder is going to reduce your risk of cardiovascular disease and, while not assessed in this study, your risk of type 2 diabetes, hypertension, and cancer would be reduced as well.

Of course, the question is what’s high intensity for you. The chart above is geared toward weightlifting, but it will give you some ways to think about how hard you’re exercising, no matter what you’re doing. If you’re running for the bus, could you run one more block? If you’re cleaning house, do you have enough juice left to go for a bike ride?

The Bottom Line

You must be fit enough and ambulatory enough to actually do moderate to high-intensity exercise. But you know something? I know of one physical therapist who encourages patients to do jumping jacks while sitting in a wheelchair. Of course they can’t do the actual jumping part of it but for 60 seconds, their arms are going up and down, up and down, up and down at a very high rate, and maybe their legs are moving, too—and that’s high intensity for them. For others of you, it may be doing a two-minute walk up a very steep hill. The intensity of the exercise stresses the heart in ways that a nice easy walk does not. And for that, you get additional benefits, no matter where you’re starting.

So check with your doctor to find out your limitations as it relates to exercise intensity, and then get after it. Not to lose a whole bunch of weight, not to win the next 5K, not every day—but often enough to make your heart stronger and fitter.

What are you prepared to do today?

        Dr. Chet

P.S. Happy Canada Day to our neighbors to the north! We’re taking next week off to enjoy the July 4th holiday and hope you do as well (even if you’re not in the U.S.) We’ll be back with new Memos the week of the 10th. Meanwhile, it’s a great time to try increasing your exercise intensity.

Reference: Eur Heart J (2022) https://doi.org/10.1093/eurheartj/ehac613

How Hard Should You Exercise?

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Exercise is my most favorite thing to talk about—not surprising for an exercise physiologist. There’s no question that diet is important to our health, but if I had to focus on just one habit that people should adopt, it would definitely be exercise first before anything else. I believe we should all eat more vegetables and fruits, take supplements for gaps in our diet, and try to reach a normal body weight. But aside from quitting smoking, the most important thing you can do for your health is to be physically active.

Let’s look at the study. The subjects in the study were a subgroup of people from the United Kingdom Biobank study. The data were collected from 88,412 middle-aged adults, with 58% women, who were specifically chosen because they had not been diagnosed with cardiovascular disease before the study.

The researchers broke the data into three equal groups by activity level. The average age of the subjects in the study was 62, and the average BMI was 27. They tracked the subjects for 6.8 years, and in that amount of time there were 4,068 cardiovascular disease (CVD) events: ischemic heart disease (reduced blood flow to the heart) or cerebrovascular disease (reduced blood flow to the brain).

Their findings were interesting and confirmational. Using no or differing covariates in the statistical analysis, as the amount of physical activity increased, the incidence of CVD decreased. That would confirm what we would expect: regardless of intensity, the risk of CVD decreased and it continued to decrease for every level tested.

How does exercise intensity impact all this? We’ll take a look at intensity on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Eur Heart J (2022) https://doi.org/10.1093/eurheartj/ehac613

The Best Heart-Healthy Diet

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In assessing popular diets to find out which one follows the AHA heart-healthy dietary guidelines the best, the panel did a credible job. Instead of just using their expertise, which is substantial, they developed an objective way of assessing each popular diet. They did have one diet that received a point for each of the nine categories thus achieving 100%. That was the Dietary Approach to Stop Hypertension more commonly known as the DASH diet.

The researchers then assessed the dietary patterns and organized them into four tiers based on compliance with the AHA guidelines. I’ll break it down into the tiers for you.

Tier 1

This tier includes the DASH diet, the Mediterranean diet, the pescatarian or fish as protein, and the ovo-lacto vegetarian diets. The primary reason that the DASH diet ranked so high was its ability to get protein from every source: plant proteins such as nuts and legumes, fish and seafood, low-fat or fat-free dairy, and the ability to use lean cuts of all meats. The other diets in Tier 1 either did not recommend proteins from all sources or did not emphasize reducing the amount of salt intake, a key element of the DASH diet.

Tier 2

Tier 2 included the vegan diet and other low-fat diets. Their strength, of course, is the emphasis on vegetables and fruits as well as whole grains, but they all seek to use plant-based protein. Some of the low-fat diets can be quite extreme, such as the Esselstyn Program which restricts fat to less than 10% per day and restricts protein as well.

Tier 3

This included the very low fat diets as well as the low-carbohydrate diets. The reason these two are put together is the restriction on quality protein sources as well as whether people adhere to the diet at every meal.

Tier 4

The paleo diet and very low carbohydrate diets such as the ketogenic diet received the worst scores; that means they fall into the category of not being heart healthy at all.

Other Considerations

The panel also considered three primary issues. The first was how easy it would be to facilitate patients to adapt to the particular diet. To me, the strength of the DASH diet and to some degree the Mediterranean diet is the variety of proteins that can be used. When you get into the very low fat and the very low carbohydrate diet, the restrictions can become overwhelming for most people.

They also considered the challenges for the consumers. In my experience, there are always going to be questions about what could be included in any dietary approach, whether it’s the Mediterranean diet or the ketogenic diet. In order for people to adapt the diet, they need instruction and they need to be able to ask questions; those would be significant challenges when recommending the diets that restrict foods allowed, which could either be vegan, the very low fat, or the ketogenic diet.

The final consideration is the opportunities presented to provide patients with good information about the diet. The problem as I see it is that physicians, physician assistants, and nurse practitioners are not familiar enough with nutrition to be able to do that effectively in a medical practice, especially considering the time constraints for most healthcare practitioners. The obvious choice is to refer it to a dietetics department, but that type of consultation is not very often available in most medical practices and especially under most health insurance programs. I think the challenges are going to take years to overcome.

My Thoughts

I thought the researchers did a credible job in coming up with their recommendations. They analyzed popular diets objectively and assessed them based on the AHA Dietary Guidance.

What is lost is exactly how this is going to help people. Since 1974, more fruits and vegetables and a limit on fat intake were recommended as the foundation of every diet. No matter how many diets have come and gone, no matter how many are yet to be developed, we have not achieved the simplest and yet most obvious objectives. Food manufacturers certainly have had a role to play in this with low-fat and ultra-processed convenience food, but the choice is always with us.

There are three more things that I think must be considered. First would be the individual’s genetic tendencies. We simply don’t know enough about interaction between genes and nutrition and how that impacts input. Second, protein needs change over a lifetime. At some point, proteomics must be considered in dietary recommendations; it isn’t all about your heart.

Finally, they specifically did not consider the potential for weight loss or weight maintenance in every program. Regardless of diet, it was, it is, and it will always be about the calories. If someone can get to a normal body weight and maintain it, I think there might be room for just about any type of diet, providing it provides enough vegetables and fruits.

The Bottom Line

As the lead author suggested in an interview, there were four recommendations across all popular diets: eat whole foods, eat more non-starchy vegetables, eat less added sugar, and eat less refined grains. If we could start with that, I think our hearts would love us for it.

What are you prepared to do today?

        Dr. Chet

Reference: https://www.ahajournals.org/doi/10.1161/CIR.0000000000001146

How Popular Diets Impact Your Heart

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When the American Heart Association (AHA) speaks, news organizations tend to report what they say and people tend to listen. It’s doubly true when they rank all the popular diets according to how they relate to heart health. Because we seem to live in a society based on the “see food, eat food” diet, that can be meaningful. Here’s what a group of experts did to evaluate popular dietary approaches to diet and rank them according to AHA guidelines for a heart-healthy diet.

The AHA has ten dietary guidelines for eating a heart-healthy diet, such as “Eat plenty of vegetables and fruits” and “Choose healthy sources of proteins.” For the complete list, click on this link to the article; the scientific statement is open access on the AHA website.

Then the panel selected the most popular diets in the U.S. such as the Mediterranean diet, the DASH diet, several versions of a vegetarian diet, low-fat, paleo, and ketogenic diet. They gave each diet a full point for following each of the AHA guidelines or partial points depending how closely they followed the guidelines.

This was not an arbitrary assignment by a panel of experts; they used the best information available to determine the best heart-healthy diet. Who got the highest score? Mediterranean? Vegan? Ketogenic? I’ll let you know on Saturday along with my thoughts on the diets. One thing’s for certain: eat your fruits and vegetables. You may as well start with that right now.

What are you prepared to do today?

        Dr. Chet

How Coffee Relates to CVD

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Researchers in Germany used a unique approach in the Hamburg City Health Study: they selected the first 10,000 volunteers. Volunteers who didn’t drink coffee were eliminated from the study, so they ended up with 9,009 subjects.

The researchers collected dietary data along with a variety of other demographic and physiological variables, integrating lifestyle-related behavior, comorbidities, biomarkers, electrocardiographic and echocardiographic data, and finally major cardiovascular diseases (CVDs). They divided up the subjects by coffee intake: low = less than three cups a day, medium = three or four cups per day, and high = more than four cups of coffee per day.

Results

This epidemiological cross-sectional study resulted in the following:

  • High coffee consumption correlated with slightly higher LDL cholesterol
  • Moderate and high coffee consumption correlated with lower systolic blood pressure and lower diastolic blood pressure
  • Different levels of coffee intake didn’t impact heart rhythms or function
  • Most important, coffee intake did not impact the presence of CVD nor prior cardiac events such as heart attacks and heart failure

Were the results of coffee and LDL cholesterol concerning? No—the difference was just five mg/dl, well within measurement error.

Is Coffee Safe to Drink?

Coffee was always safe to drink; the question was how our bodies responded to consuming it. Neither of these studies was perfect, but they show that even high coffee consumers, including myself, may not be at any significant risk for promoting or advancing CVD or cardiovascular events.

I think for most people coffee and caffeine are closely linked. What most of us don’t realize is that coffee is a complex liquid consisting of more than 1,000 bioactive substances, including phytochemicals that have proven beneficial for many organ systems; it’s not only a nervous system stimulant because of the caffeine content.

The Bottom Line

When it comes to coffee, I think it’s person-specific. Taste aside, some people may process caffeine differently, which may impact how much coffee someone could enjoy. These studies add to a body of work which shows that coffee is safe for the heart and other organs; other benefits or issues require further study. For me, time for another mug of Sumatra Roast.

What are you prepared to do today?

        Dr. Chet

Reference: https://www.nature.com/articles/s41598-023-31857-5

Research Update: Coffee and Heart Rhythms

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In one of the first jobs I ever had, the foreman would pour a half-cup of coffee and fill it up with water; he’d had a heart attack and his doctor told him to limit his coffee intake. Fifty years ago, physicians recommended that people avoid coffee if they had high blood pressure or had a cardiac event such as a heart attack. The thought was to lower the stimulating effect of caffeine to keep heart rate and blood pressure lower. In the interim, some studies showed that coffee contributes to cardiovascular disease and more recently, that it may not. So if you love coffee the way I love coffee, you may be encouraged by a couple of recent studies.

The first study examined the effect of coffee on heart rhythms in 100 subjects with a mean age of 39 who served as their own controls. All subjects had a variety of blood tests as well as genetic tests to determine if they were fast or slow processors of caffeine. They also wore a new-age heart rhythm monitor for the 14 days of the study. I’ve worn that monitor, and it gives accurate EKGs to monitor heart rate and heart rhythm abnormalities such as premature atrial contractions and atrial fibrillation.

The subjects were notified the evening before whether they were going to be on a two-day coffee drinking cycle or two-day caffeine avoidance; the idea was to track immediate impacts. The good news: there were no differences in abnormal rhythms on coffee days versus non-caffeine days and no impact of caffeine processing. One interesting observation: on the days subjects drank coffee, they walked more steps. We’ll look at the impact of coffee on cardiovascular disease events on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: N Engl J Med 2023;388:1092-100.

Food or Supplements? Yes!

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The results of the polyphenol study examining the impact on cardiovascular (CVD) risk factors were mixed. Here’s what the researchers found:

  • Neither the polyphenol-rich foods (berries, spices, herbs, teas, nuts, seeds, etc.) nor extracts had a significant effect on LDL- or HDL-cholesterol, fasting blood glucose, IL-6, and C-reactive protein.
  • When looking at the studies using polyphenol-rich food, there was a significant decrease in systolic and diastolic BP.
  • The polyphenol extracts had a significant effect on total cholesterol and triglycerides and had a greater reduction of waist circumference.
  • However, when both whole-food polyphenols and polyphenol extracts were used together, there was a significant reduction in systolic BP, diastolic BP, endothelial function, triglycerides, and total cholesterol.

The Upside

Polyphenols in foods and supplements were effective in reducing risk factors for CVD, both independently and when combined. This wasn’t a seminal paper that changes approaches to nutrition forever, but there were benefits. I think that’s something that was needed. It supports what my approach has always been: eat as healthy a diet as you can, and fill in the nutritional gaps with supplements.

The Problems

There were several issues. The studies included in the meta-analysis had little cohesiveness as to subjects used, sources of the foods, or the type of supplements; some used capsules while others used juices or drinks.

The issue with foods, among many, is the digestion and absorption of the active polyphenols. There’s competition with other nutrients and then the issue of the microbiome—is it functioning properly in every subject?

The issue with supplements, besides the delivery system, is whether the dose is appropriate or therapeutic. Would the amount of quercetin found in apples be the correct dose, or would you need to eat 10 apples? Would it respond the same way in the body isolated from the other polyphenols, or would another factor come into play?

The Bottom Line

In spite of its flaws, I think this study was fantastic. It demonstrated that nutrients extracted from foods can be effective in reducing CVD risk. It demonstrated that foods alone aren’t the answer and neither are supplements; it’s their use in a complementary fashion where the benefits may be found. The researchers set the stage for putting more effort into nutrition research, because there’s so much we don’t know. Yet. Until then, your best bet to support your health is to eat your vegetables and fruit, add herbs and spices, munch on seeds and nuts—and then supplement your diet with quality supplements.

What are you prepared to do today?

        Dr. Chet

Reference: https://www.sciencedirect.com/science/article/pii/S2161831323000029