high blood pressure

600th Issue Celebration

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Nutrition Advances Over The Last Two Years

Author: Dr. Stephen Chaney 

celebrationIn the nearly twelve years that I have been publishing “Health Tips From The Professor”, I have tried to go behind the headlines to provide you with accurate, unbiased health information that you can trust and apply to your everyday life.

The 600th issue of any publication is a major cause for celebration and reflection – and “Health Tips From The Professor” is no different.

I am dedicating this issue to reviewing some of the major stories I have covered in the past 100 issues. There are lots of topics I could have covered, but I have chosen to focus on three types of articles:

  • Articles that have debunked long-standing myths about nutrition and health.
  • Articles that have corrected some of the misinformation that seems to show up on the internet on an almost daily basis.
  • Articles about the issues that most directly affect your health.

Here are my picks from the last two years:

Weight Loss Diets

weight lossSince it is almost January, let’s start with a couple of articles about diet and weight loss (or weight gain). I have covered the effectiveness of the Paleo, Keto, Mediterranean, DASH, vegetarian, and Vegan diets for both short and long-term weight loss in my book “Slaying The Food Myths”, so I won’t repeat that information here. Instead, I will share a few updates from the past 100 issues.

Is Time-Restricted Eating Better Than Other Diets? Time-restricted eating is one of the latest fads. But is it really better than other diets for weight loss and improved health? In this article I reviewed two studies that compare time-restricted eating with diets that do not restrict time of eating but cut calories to the same extent. You may be surprised at the results.

Can You Lose Weight Without Dieting? In this article I share 8 tips for losing weight without going on a diet. The article is based on research by Dr. Brian Wansink, a behavioral psychologist who specializes in studying how external clues influence our eating patterns. As you might suspect his 8 tips for losing weight have nothing to do with counting calories or going on restrictive diets.

Healthy Diets

dairy foodsIs Whole Fat Dairy Healthy? For years dietary guidelines have been telling us to select low fat dairy foods. But some health gurus are telling you that isn’t true. They claim whole fat dairy is healthy. So, you are probably wondering, “What is the scoop (as in ice cream) on whole fat dairy?” In this article I look at the study behind the headlines and answer that question. But the answer is not a simple “Yes” or “No”. The answer is more nuanced. It turns out that whole fat dairy is healthier in some diets than in others. 

Are Low Carb Diets Healthy? Are low carb diets good for you or bad for you? It depends on which study you quote. Two major studies in recent years have come to opposite conclusions. In this article I help you sort through the conflicting studies and rephrase the question. Instead of, “Are low carb diets healthy”, the question should be, “Which low carb diets are healthy?”

Are All Plant-Based Diets Healthy? Plant-based diets have acquired a “health halo” in recent years. Your mama told you to eat your fruits and vegetables. And many health gurus have been telling you not to neglect your grains, legumes, nuts, and seeds as well. But some of these foods require a lot of food preparation.

Never fear! The food industry has come to your rescue with a wide variety of processed plant-based foods. No need for food prep. But are they as good for you as the unprocessed plant foods they replace? In this article I review a study that answers that question.

You probably know what that answer is, but the article is worth a read anyway. That is because the study also asks whether vegan and vegetarian diets are healthier than other primarily plant-based diets. And you may not know the answer to that question.

Diet And Heart Disease

egg confusionAre Eggs Bad For You? For years we were told that eggs are bad for us because they contain cholesterol. Then we were told that eggs in moderation may not increase our risk of heart disease. And recently studies have appeared claiming eggs may be good for our hearts. What is the truth about eggs and heart disease? In this article I review a recent study claiming eggs are bad for our heart and put that study into the context of other recent studies to clear up the “eggfusion”.

Which Diets Are Heart Healthy? Every popular diet claims to help you lose weight, reduce your risk of diabetes, and reduce your risk of heart disease. All these claims can’t be true. Which diets deliver on their promises, and which are just pretenders? In this article I review a recent study that answered that question for heart disease.

This study was a very large metanalysis of over 40 studies with 35,548 participants that looked at the effect of different diets on heart disease outcomes. The study identified two diets that significantly reduced the risk of heart disease. There are other diets that might reduce the risk of heart disease, but their benefits have not been proven by high quality clinical studies. They are merely pretenders.

The Dangers Of Processed Foods 

In previous issues of “Health Tips From the Professor” I have shared articles showing that diets high in processed foods are associated with an increased risk of obesity, diabetes, and heart disease. But the story keeps getting worse. Here are two articles on recent studies about processed foods that appeared in “Health Tips From The Professor” in the last two years.

Why Does Processed Food Make You Fat? We already know that eating a lot of highly processed food is likely to make us fat. But what is it about processed food that makes us fat? In this article I review a recent study that answers that question.

This study is interesting for two reasons.

  • It identifies the characteristics of processed foods that make us want to eat more.
  • It identifies some minimally processed foods that have the same characteristics and suggests we should choose minimally processed foods wisely. Simply put, knowledge is power. We may want to avoid minimally processed foods that have the same obesity-inducing characteristics as processed foods.

Do Processed Foods Cause Cancer? Previous studies have shown that processed food consumption is associated with a higher risk of obesity, diabetes, and heart disease. Can it get any worse? In this article I review a recent study that shows processed food consumption is associated with an increased risk of several kinds of cancer.

Maintaining Muscle Mass As We Age

As we age, we begin to lose muscle mass, a process called sarcopenia. Unless we actively resist loss of muscle mass it will eventually impact our quality of life and our health.

We can prevent this loss of muscle mass with resistance exercise, adequate protein intake, and adequate intake of the amino acid leucine. Previous studies have shown people over 50 need more of each of these to maintain muscle mass, but the amount they need has been uncertain until now. Three recent studies have given seniors better guidelines for maintaining muscle mass.

Can You Build Muscle In Your 80s? In this article I review a recent study that enrolled a group of octogenarians in a high-intensity exercise program to see if they could gain muscle mass. They were able to increase their muscle mass, but the intensity of the exercise required may surprise you.

Optimizing Protein Intake For Seniors. In this article I review two recent studies that looked at the amount, timing, and kind of protein needed for seniors in their 60s and 70s to maximize gain in muscle mass.

How Much Leucine Do Seniors Need? In this article I review a recent study that determined the amount of leucine seniors in their 70s need to optimize gains in muscle mass and strength.

The Benefits And Risks Of Supplementation

Omega-3s And Heart DiseaseIf you listen to Big Pharma or the medical profession, you hear a lot about the “risks” of supplementation and very little about the benefits. In “Health Tips From the Professor” I try to present a more balanced view of supplementation by sharing high-quality studies showing benefit from supplementation and studies that put the supposed risks into perspective.

The Good News About Omega-3s and Stroke. Multiple studies have shown that omega-3 supplementation reduces the risk of ischemic strokes (strokes caused by a blood clot). But it has been widely assumed they might increase the risk of hemorrhagic strokes (strokes caused by bleeding). In this article I review a meta-analysis of 29 clinical studies with 183,000 participants that tested that assumption.

How Much Omega-3s Are Best For Blood Pressure? Multiple studies have shown that omega-3 supplementation can reduce high blood pressure. But the doses used vary widely from one study to the next. In this article I review a meta-analysis of 71 double-blind, placebo-controlled clinical studies that determined the optimal dose of omega-3s for controlling blood pressure.

Omega-3 Supplements Are Safe. As I said above, it has been widely assumed that omega-3 supplementation increases the risk of bleeding and hemorrhagic stroke. In this article I review the definitive study on this topic. More importantly, it reveals which omega-3 supplements might increase bleeding risk and which do not.

Are Calcium Supplements Safe? Big Pharma and the medical profession have been warning us that calcium supplements may increase heart disease risk. In this article I review the definitive study on this topic.

Prenatal Supplements

prenatal dha supplementIf you are pregnant or thinking of becoming pregnant, your health professional has likely recommended a prenatal supplement. You probably assume that prenatal supplements provide everything you need for a healthy pregnancy. Unfortunately, recent research has shown that assumption is not correct.

Is Your Prenatal Supplement Adequate? In this article I review a study that should serve as a wakeup call for every expectant mother. It showed that most prenatal supplements were woefully inadequate for a healthy pregnancy.

What Nutrients Are Missing In Prenatal Supplements? In this article I review a study that identified additional nutrients that are missing in most prenatal supplements.

Prenatal Supplements Strike Out Again. In this article I review a study that looked at the diet of pregnant women to determine their needs and compared that to the nutrients found in prenatal supplements. Once again, most prenatal supplements were woefully inadequate. Is it, “Three strikes and you are out”?

Exercise

Walking FastWalking Your Way To Health. We have been told that walking is good for our health. But how many steps should you take, how fast should you walk, and does it matter whether these steps are part of your daily routine or on long hikes? In this article I review a study that answers all these questions.

Which Exercise Is Best For Reducing Blood Pressure? If you have high blood pressure, you have probably been told to exercise more. But which exercise is best? In this article I review a study that answers that question. And the answer may surprise you.

Did You Know? 

Question MarkIf you have been reading “Health Tips From the Professor” for a while, you probably know that I enjoy poking holes in popular myths. Here are two new ones I deflated in past two years.

Is Low Alcohol Consumption Healthy? You have probably heard that low alcohol intake (that proverbial glass of red wine) is good for you. But is that true? In this article I review a recent study that shows that myth was based on faulty interpretation of the data and provides a more nuanced interpretation of the data.

Is HDL Good For Your Heart? You have been told that increasing your HDL levels reduces your risk of heart disease so many times it must be true. But is it? In this article I review HDL metabolism and a recent study to provide a more nuanced interpretation of the relationship between HDL and heart disease risk.

How To Talk With Your Doctor About Cancer 

Because of my years in cancer research, I am often asked whether someone should follow their oncologist’s advice and go on a recommended chemotherapy or radiation regimen. Of course, it would be unethical for me to provide that kind of advice.

In this article I tell you the questions to ask your oncologist about the prescribed treatment regimen, so you can make an informed decision. However, I also recommend you only ask these questions if you can handle the answers.

The Bottom Line

I have just touched on a few of my most popular articles above. You may want to scroll through these articles to find ones of interest to you that you might have missed over the last two years. If you don’t see topics that you are looking for, just go to https://chaneyhealth.com/healthtips/ and type the appropriate term in the search box.

In the coming years, you can look for more articles debunking myths, exposing lies and providing balance to the debate about the health topics that affect you directly. As always, I pledge to provide you with scientifically accurate, balanced information that you can trust. I will continue to do my best to present this information in a clear and concise manner so that you can understand it and apply it to your life.

Final Comment: You may wish to share the valuable resources in this article with others. If you do, then copy the link at the top and bottom of this page into your email. If you just forward this email and the recipient unsubscribes, it will unsubscribe you as well.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 _______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com/lifestylechange/.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Which Exercise Is Best For Reducing Blood Pressure?

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How Can You Keep Your Blood Pressure Under Control? 

Author: Dr. Stephen Chaney 

high blood pressureHypertension (high blood pressure) is called a silent killer. That’s because you often don’t notice any symptoms until you die from a stroke or heart attack.

Nearly half of all American adults (120 million or 48%) have high blood pressure. Of Americans with high blood pressure:

  • About half (46%) of them don’t know it.

And of those who know they have high blood pressure:

  • Only half of them have it under control.
    • In case you weren’t doing the math, that means that only 1 in 4 Americans with high blood pressure has it under control.

That is scary because every 20 mm Hg increase in systolic blood pressure:

  • Doubles your risk of death from a stroke or heart attack.

And if the personal costs of high blood pressure were not enough, the cost of high blood pressure to our health care system is enormous.

  • The CDC estimates that the cost of high blood pressure in the United States is around $131 to $198 billion per year. And this may be an underestimate because it does not include productivity losses from non-fatal illnesses caused by high blood pressure.

Medications are effective at reducing blood pressure, but they have significant side effects. And those side effects have two unintended consequences.

  • Around half of patients stop taking their blood pressure medication within the first year because of side effects or cost.
  • For patients who continue taking blood pressure medication, they are usually prescribed other medications to reduce the side effects from their blood pressure medication.

This is often the start of a downward spiral in which they need more medications to reduce the side effects of the medicines they were just prescribed. And they end up on multiple medications, and a poor quality of life because of it.

Because of this, many patients and health care practitioners are looking for natural ways to keep blood pressure under control. One of the most recommended approaches is to increase exercise, and the type of exercise most frequently recommended is aerobic exercise.

But is that the best advice? That advice is based on clinical studies performed 20 to 30 years ago. And those studies were an excellent example of “the tail wagging the dog”.

Let me explain. In the early days most experts believed that aerobic exercise would be the most effective exercise for reducing blood pressure. So, most of the original studies on the effect of exercise at reducing blood pressure were done using aerobic exercise.

From those studies we knew that aerobic exercise was effective at reducing blood pressure, but we didn’t really know whether it was the most effective exercise for reducing blood pressure. And more recent studies have suggested a more nuanced view of exercise and blood pressure control.

For that reason, the authors of the current article (JJ Edwards et al, British Journal of Sports Medicine, 57: 1317-1326, 2023) decided to conduct a comprehensive review of all randomized controlled studies between 1990 and February 2023 on the effect of exercise on reducing blood pressure.

How Was The Study Done? 

clinical studyThe investigators performed a comprehensive, systematic review of all randomized controlled studies (meaning patients were randomly assigned to an exercise or non-exercise group) looking at reductions in blood pressure following an exercise intervention of ≥ 2 weeks.

They excluded studies that:

  • Included dietary counseling or exercise recommendations in the control group.
  • Included dietary counseling, supplementation, or medication in the exercise group.

However, there were no exclusions based on the health or disease state in the patient population.

Their analysis included 270 randomized controlled trials with a total of 15,827 participants. All the studies reported systolic and/or diastolic blood pressure before and after the exercise intervention.

Exercise interventions were divided into five classifications:

  • Aerobic exercises.
  • Resistance exercises.
  • Combined exercises (a combination of aerobic and resistance exercises).
  • High-intensity interval exercises (high-intensity, short-duration exercises).
  • Isometric exercises.

Several of these exercise classifications were further subdivided into individual exercises (see below)

Which Exercise Is Best For Reducing Blood Pressure? 

When the reduction in systolic blood pressure was considered, the rank order of exercise effectiveness was:

  • High-intensity interval exercise (4.08 mm Hg reduction).
  • Aerobic exercise (4.48 mm Hg reduction).
  • Resistance exercise (4.53 mm Hg reduction).
  • Combined aerobic and resistance exercise (6.04 mm Hg reduction).
  • Isometric exercise (8.24 mm Hg reduction).

When the reduction in diastolic blood pressure was considered, the amount of reduction was less but the rank order of exercise effectiveness was the same:

  • High-intensity interval exercise (2.50 mm Hg reduction).
  • Aerobic exercise (2.53 mm Hg reduction).
  • Resistance exercise (3.04 mm Hg reduction).
  • Combined aerobic and resistance exercise (3.54 mm Hg reduction).
  • Isometric exercise (4.00 mm Hg reduction).

When the exercise classifications were subdivided into individual exercises.

  • Running and cycling were significantly more effective than walking for aerobic exercise, with running being the most effective form of aerobic exercise.
  • Cycling was the most effective form of high-intensity interval exercise.
  • No effect of exercise type was seen for the effectiveness of resistance training.
  • Isometric wall squats and leg extensions were much more effective than isometric handgrip exercises.

There was not enough data from diastolic blood pressure studies to subdivide into individual exercises.

There were two other results of interest.

  • Aerobic exercise interventions were slightly more effective with lower exercise frequency, suggesting that 3 times a week may be more effective than 5 or more times a week.
  • All exercise interventions were much more effective for people with significantly elevated blood pressure than for people with slightly elevated blood pressure or normal blood pressure.

Of course, the important question for people with normal blood pressure is the effectiveness of exercise in preventing future increases in blood pressure, and this study is not designed to answer that question.

The authors concluded, “Various exercise training modes improve resting blood pressure, particularly isometric exercise. The results of this analysis should inform future exercise guideline recommendations for the prevention and treatment of arterial hypertension.”

What Does This Study Mean For You? 

Question MarkThe takeaways from this study are clear.

If you wish to reduce your blood pressure:

  • Any kind of exercise is helpful, but current recommendations that prioritize aerobic exercise may be misleading.
  • If you want to get the most “bang for your buck”:
    • Isometric exercise is the most effective and high intensity interval exercise is the least effective.
    • Aerobic and resistance exercise are equally effective.
    • A combination of aerobic and resistance exercise is more effective than either alone.
  • And if you want to know the most effective individual exercises:
    • Wall squats and leg extensions are the most effective isometric exercises.
    • Running and cycling are the most effective aerobic exercises.
    • Any kind of resistance exercise is equally effective.

Here are my thoughts about this study:

  • If you haven’t been keeping up with clinical studies on exercise and blood pressure (like me), the conclusions of this comprehensive review are probably a surprise. I would not have expected isometric exercises to be more effective than aerobic exercises for lowering blood pressure.
  • The authors of this review postulated that isometric exercise decreases blood flow to the muscles involved. When those muscles relax, blood flow increases which sends metabolic signals that cause blood vessels to relax.
  • This study is good news for people with health conditions that limit their ability to do aerobic exercises or traditional resistance exercises.
  • We also need to remember that lowering blood pressure is not the only value of exercise.
    • Aerobic exercise improves cardiovascular function.
    • Resistance exercise increases muscle mass, which is particularly important for seniors who are trying to maintain muscle mass and function. Regular resistance exercise also helps minimize bone loss as we age.

Isometric exercise can be considered a form of resistance exercise, but it may need to be supplemented with resistance exercises that target other muscle groups.

  • As I said above, this study shows that all forms of exercise reduce blood pressure. The most effective exercise for you is the one you enjoy and will do on a regular basis.
  • Finally, while this study looked at the effectiveness of different exercises at reducing high blood pressure, these findings are probably also applicable to the types of exercise that can reduce risk of developing high blood pressure as we age.

How Can You Keep Your Blood Pressure Under Control?

dash dietExercise alone is not a “magic bullet” for controlling blood pressure. And therein lies a story.

One reason so many people choose medications to control their blood pressure is that there is no “magic bullet” natural approach for controlling blood pressure. Exercise is just one part of a holistic approach for controlling blood pressure that also includes:

  • The DASH (Dietary Approaches To Stop Hypertension) was designed to prevent high blood pressure. I refer to it as an Americanized version of the Mediterranean diet.

Both diets are rich in fruits, vegetables, and whole grains and limit high fat meats and dairy products. And both diets have been shown to reduce the risk of high blood pressure.

  • Weight control. Overweight and obesity are both associated with increased risk of high blood pressure. One estimate is that every two pounds of weight gain increases blood pressure by 1 mm Hg.
  • Supplementation. The most effective supplements appear to be:
    • Omega-3 fatty acids.
    • Supplements containing grape seed extract and/or nitrates from beetroots and leafy greens.
    • Calcium and magnesium if dietary intakes are not optimal.

Diet, weight control, supplementation, and exercise are the top 4 lifestyle factors for keeping blood pressure under control, but a comprehensive holistic approach to controlling blood pressure includes:

  • Low sodium/potassium ratio. I mention it here for completeness, but it is an integral part of the DASH diet.
  • Stress management. Chronic stress can increase blood pressure.
  • Adequate sleep.

We may be outliers, but my wife and I have followed this approach for years and in our 80s have the blood pressure of teenagers.

The Bottom Line 

Most experts recommend aerobic exercise for reducing blood pressure, but these recommendations are based on outdated studies. A recent study examined the effectiveness of various exercises at reducing blood pressure based on all randomized controlled clinical trials between 1990 and 2023.

This study shows:

If you wish to reduce your blood pressure:

  • Any kind of exercise is helpful, but current recommendations that prioritize aerobic exercise may be misleading.
  • If you want to get the most “bang for your buck”:
    • Isometric exercise is the most effective and high intensity interval exercise is the least effective.
    • Aerobic and resistance exercise are equally effective.
    • A combination of aerobic and resistance exercise is more effective than either alone.

For more information on this study, what it means for you, and recommendations for a holistic approach for controlling blood pressure naturally, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_____________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

How Much Omega-3s Are Best For Blood Pressure?

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What Does This Study Mean For You?

Author: Dr. Stephen Chaney

high blood pressureI am continuing my series on recent omega-3 breakthroughs. Today I am going to cover a recent systematic review and meta-analysis (X Zhang et al, Journal of the American Heart Association, 11: e025071, 2022) that analyzed 71 double blind, placebo-controlled clinical studies with 4,973 subjects to determine the optimal dose of omega-3s needed to lower blood pressure.

But first, I will cover why this study is so important.

High blood pressure is called a “silent killer”. For most of us our blood pressure creeps up year after year, decade after decade. Factors like inactivity, obesity, smoking, poor diet, and excess alcohol consumption speed the increase.

Unfortunately, the symptoms of high blood pressure – things like headaches, anxiety, fatigue, and blurred vision – are easy to ignore or confuse with other health problems. And if these symptoms are ignored long enough, the result can be sudden death due to a stroke or heart attack.

Alternately, the consequence could be things like congestive heart failure, kidney failure, vision loss, and memory loss that change your quality of life forever. And once the genie is out of the bottle, it can never be put back again. The damage is permanent.

Omega-3s are often recommended for keeping blood pressure in the normal range. In fact, in 2019 the FDA approved a qualified health claim stating, “Consuming eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 fatty acids in food or dietary supplements may reduce the risk of hypertension (high blood pressure) and coronary heart disease.”

But the amount of omega-3s needed to reduce the risk of high blood pressure is uncertain. Previous studies have come up with conflicting results. That is the question the study I will discuss today was designed to answer.

How Was This Study Done?

Clinical StudyThe investigators included 71 studies published between 1987 and 2020 with a total of 4,793 subjects ranging in age from 22 to 86 years in their systematic review and meta-analysis. The studies were all randomized, placebo-controlled trials looking at the effectiveness of omega-3 intake (primarily in the form of food or supplements containing both EPA and DHA) at lowering blood pressure. The placebo used in these studies was olive oil or other vegetable oils.

The studies included in this meta-analysis:

  • Included omega-3 intake from both diet (mackerel, salmon, trout, or tuna) and supplements (fish oil, algal oil, or purified omega-3 ethyl esters).
  • Were conducted in populations from Europe, North America, Australia and other Pacific islands, and Asia.
  • Included subjects with normal blood pressure as well as those with high blood pressure.
  • Ranged in length from 5 to 52 weeks (the average was 10 weeks).
  • Included approximately equal numbers of men and women.

The meta-analysis excluded studies that:

  • Lacked a placebo.
  • Lasted less than 4 weeks.
  • Included blood pressure medications.
  • Included individuals with preexisting cardiovascular events.

The data from these trials was analyzed by a statistical method called a 1-stage cubic spline regression model. This is a recently developed statistical method which the investigators stated was superior to the statistical methods used in previous studies because it reduces the likelihood the results are influenced by investigator bias.

How Much Omega-3s Are Best For Blood Pressure?

Fish Oil and Blood PressureWhen the investigators combined the data from all 71 studies:

  • The maximum reduction in both systolic and diastolic blood pressure was observed between 2g/d and 3 g/d.
  • The dose response was non-linear. Doses above 3 g/d offered no additional benefit.

When the investigators looked at subgroups within the studies:

  • Reduction in blood pressure was seen in both subjects with normal blood pressure and those with high blood pressure.
    • However, reduction in blood pressure and the dose response were different in the two groups.
      • In subjects with normal blood pressure the dose response was non-linear with the optimum reduction between 2 and 3 g/d.
      • In subjects with high blood pressure the reduction in blood pressure was greater and the dose response was linear. The authors recommended a dose ≤ 3 g/d EPA + DHA for people with high blood pressure.
  • Subjects with hyperlipidemia had a greater reduction in blood pressure than subjects with normal lipid levels, and the dose-response was linear.
  • Subjects over the age of 45 had a greater reduction in blood pressure than subjects under the age of 45, and the dose response was linear.
  • There were no significant differences between:
    • Diet versus supplementation.
    • Type of omega-3 supplement (natural fish oil versus purified ethyl ester).
    • Sex.

The authors concluded, “This dose-response meta-analysis demonstrates that the optimal combined intake of omega-3 fatty acids for blood pressure lowering is likely between 2 g/d and 3 g/d. Doses of omega-3 fatty acid intake above the recommended 3 g/d may be associated with additional benefits in lowering blood pressure among groups at high risk of cardiovascular disease.”

I should probably explain the reasoning behind this conclusion.

  • 79% of the studies included in this meta-analysis were performed with subjects who had normal blood pressure. This group had a non-linear reduction in blood pressure with an optimal reduction between 2 and 3 g/d EPA + DHA.
    • Because of its size this group exerted a major influence on the results, which explains why the average results for the entire group showed a non-linear reduction in blood pressure with an optimal reduction between 2 and 3 g/d EPA + DHA.
    • Subjects with normal blood pressure and normal lipid levels are at low risk of cardiovascular disease. The high-risk groups (high blood pressure, high cholesterol and/or triglyceride levels, and over 45) all had a linear dose response suggesting that doses above 3 g/d EPA + DHA may be optimal.

The authors also said, “We found associations [between omega-3 intake and blood pressure] among both hypertensive (high blood pressure) and nonhypertensive (normal blood pressure) groups, suggesting that omega-3 fatty acids could be beneficial for controlling blood pressure even before the onset of hypertension.

This means that the intake of omega3 fatty acids could have implications on a person’s future risk of stroke, ischemic heart disease, and all-cause mortality.”

In other words, they are saying their data suggests that EPA + DHA intakes in the 2-3 g/d range may prevent high blood pressure and the effects it can have on our health.

What Does This Study Mean For You?

Question MarkThe authors of this study claim their data support a dose of 2-3 mg/d of EPA + DHA to prevent a future increase in blood pressure and all its associated health consequences. They also say that an EPA+ DHA dose ≥ 3g/d may be optimal for people who already have high blood pressure and/or other risk factors for heart disease.

I am not an expert on statistics, so I cannot evaluate the author’s claim that their statistical method was superior to the methods used in earlier studies that gave conflicting results.

However, their results are consistent with recommendations of several major health and government agencies.

  • For example, the European Food Safety Authority has said, “An intake of EPA and DHA of ~3 g/d is required to bring out the claimed hypotensive (blood pressure lowering) effect”.
  • The FDA has approved qualified health claims stating that consuming EPA and DHA in foods or dietary supplements may reduce the risk of hypertension (high blood pressure) and coronary heart disease but did not recommend a dose to achieve these results.
  • The American Heart Association has recommended ~ 1 g/d of EPA + DHA for patients with documented coronary heart disease and 2–4 g/day of EPA + DHA to lower triglycerides.
  • And the American Heart Association features this article on their website with the headline, “Consuming about 3 grams of omega-3 fatty acids a day may lower blood pressure.”

When we contrast that with the fact that the average American gets less than 100 mg/d of EPA + DHA from their diet it is obvious that many Americans would likely benefit from increasing the amount of EPA and DHA in their diet.

The Rest Of The Story

ProfessorThere are four additional points I would like to make:

  • In trying to explain the differences between dose response in high and low risk subjects, the authors said, “There could be mechanistic differences in bioavailability and efficacy of omega-3 fatty acid intake in these populations.”

In last week’s “Health Tips From the Professor” article I reviewed a study that measured individual differences in the utilization of EPA and DHA and concluded that a blood measurement called Omega-3 Index was a more reliable indicator of health outcomes than the dose of omega-3s consumed.

For that reason, I recommend personalizing your dose of EPA + DHA to reach an Omega-3 Index of 8%, which appears to be optimal for heart health and provides significant blood pressure reduction. This is an iterative process which will require frequent measurement of your omega-3 index and adjustment of EPA + DHA dose until you find the level of EPA + DHA supplementation you need to achieve an Omega-3 Index of 8%.

  • This study and similar studies measure the health benefits of the long chain omega-3 fatty acids EPA and DHA. Short chain omega-3s from nuts, seeds, and plant oils are healthy, but their conversion to EPA and DHA is very inefficient.
  • Both the FDA and American Heart Association recommend that doses of EPA + DHA above 3 g/d should be taken under a physician’s supervision because high doses can cause bleeding problems.

This is another reason for basing your intake of EPA + DHA on Omega-3 Index rather than on the dose recommended by a clinical study. Based on dozens of clinical studies, an Omega-3 Index of 8% appears to be safe unless you have a bleeding disorder or are on a blood-thinning medication (see below).

  • If you are on a medication to thin your blood, you should consult with your physician before increasing or decreasing your omega-3 intake because changes in dietary omega-3s can affect the optimal dose of medication they prescribe.

The Bottom Line 

A recent study looked at the dose of EPA + DHA needed to lower blood pressure.

  • The study concluded that a dose of 2-3 mg/d of EPA + DHA was optimal for preventing a future increase in blood pressure and all its associated health consequences.
  • It also concluded that an EPA+ DHA dose ≥ 3g/d was optimal for lowering blood pressure in people who already have high blood pressure and/or other risk factors for heart disease.
  • Based on previous studies, I recommend optimizing your omega-3 index rather than relying on a dose of EPA + DHA that may not be right for you.

For more details about this study and what it means to you read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 ______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance 

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Eating Of The Green

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Why Is Eating Green Good For Your Heart? 

Author: Dr. Stephen Chaney

You may be one of the millions of Americans who celebrated St. Patrick’s Day a couple of weeks ago. If so, you may have sung the famous Irish folk song “The Wearing of the Green”. If you are Irish, that song has special meaning for you. However, when I hear that song, I think of “Eating of the Green.”

And when I think of eating green, I don’t mean that everything we eat should be green. I am thinking of whole fruits and vegetables in a variety of colors. We have known for years that fruits and vegetables are good for our health. Consumption of fruits and vegetables is associated a lower risk of high blood pressure, heart disease, cancer, inflammatory diseases, and much more.

For today’s health tip, I am going to focus on heart health and an unexpected explanation for how fruits and vegetables reduce our risk of heart disease.

Why Is Eating Green Good For Your Heart?

health benefits of beetroot juiceWe have assumed that whole fruits and vegetables lower our risk of heart disease because they are low in saturated fats and provide heart-healthy nutrients, phytonutrients, and fiber. All of that is true. But could there be more?

Recent research has suggested that the nitrates found naturally in fruits and vegetables may also play a role in protecting our hearts. Here is what recent research shows:

  • The nitrates from fruits and vegetables are converted to nitrite by bacteria in our mouth and intestines.
    • Fruits and vegetables account for 80% of the nitrate in our diet. The rest comes from a variety of sources including the nitrate added as a preservative to processed meats.
    • Although all fruits and vegetables contain nitrates, the best sources are green leafy vegetables and beetroot. [Beet greens are delicious and also a good source of nitrate, but beetroot is the part of the beet we usually consume.]
  • Nitrite is absorbed from our intestine and converted to nitric oxide by a variety of enzymes in our tissues.
  • Both reactions require antioxidants like vitamin C, which are also found in fruits and vegetables.

Nitric oxide has several heart healthy benefits. For example:

  • It helps reduce inflammation in the lining of blood vessels. Inflammation stimulates atherosclerosis, blood clot formation, and is associated with an increased risk of heart disease.
  • It relaxes the smooth muscle cells that surround our blood vessels. This makes the blood vessels more flexible and helps reduce blood pressure.
  • It prevents smooth muscle cells from proliferating, which prevents them from invading and constricting our arteries. This, in turn, has the potential to reduce the risk of atherosclerosis.
  • It prevents platelet aggregation. This, in turn, has the potential to reduce the risk of heart attack and stroke due to blood clots that block the flow of blood to our heart or brain.

It is well established that nitrates from fruits and vegetables reduce blood pressure. More importantly, they can help slow the gradual increase in blood pressure as we age.

However, few studies have asked whether this reduction in blood pressure translates into improved cardiovascular outcomes. This study (CP Bondonno et al, European Journal of Epidemiology, 36: 813-825, 2021) was designed to answer that question.

How Was This Study Done?

Clinical StudyThis study made use of data from the Danish Diet, Cancer, and Health Program. That program enrolled 53,150 participants from Copenhagen and Aarhus between 1993 and 1997 and followed them for an average of 21 years. None of the participants had a diagnosis of cancer or heart disease at the beginning of the study.

Other characteristics of the participants at the time they were enrolled in the study were:

  • 46% male
  • Average age = 56
  • BMI = 26 (>20% overweight)
  • Average systolic blood pressure = 140 mg Hg
  • Average diastolic blood pressure = 84 mg Hg

At the beginning of the study, participants filled out a 192-item food frequency questionnaire that assessed their average intake of various food and beverage items over the previous 12 months. The vegetable nitrate content of their diets was analyzed using a comprehensive database of the nitrate content of 178 vegetables. For those vegetables not consumed raw, the nitrate content was reduced by 50% to account for the nitrate loss during cooking.

Blood pressure was measured at the beginning of the study. Data on the incidence (first diagnosis) of heart disease during the study was obtained from the Danish National Patient Registry. Data were collected on diagnosis of the following heart health parameters:

  • Cardiovascular disease (all diseases of the circulatory system).
  • Ischemic heart disease (lack of sufficient blood flow to the heart). The symptoms of ischemic heart disease range from angina to myocardial infarction (heart attack).
  • Ischemic stroke (lack of sufficient blood flow to the brain).
  • Hemorrhagic stroke (bleeding in brain).
  • Heart failure.
  • Peripheral artery disease (lack of sufficient blood flow to the extremities).

Is Nitrate From Vegetables Good For Your Heart?

strong heartIntake of nitrate from vegetables ranged from 18 mg/day (<1/3 serving of nitrate-rich vegetables per day) to 168 mg (almost 3 servings of nitrate-rich vegetables per day). The participants were grouped into quintiles based on their vegetable nitrate intake. When the group with the highest vegetable nitrate intake was compared to the group with the lowest vegetable nitrate intake:

  • Systolic blood pressure was reduced by 2.58 mg Hg.
  • Diastolic blood pressure was reduced by 1.38 mg Hg.
  • Risk of cardiovascular disease was reduced by 14%.
  • Risk of ischemic heart disease (angina and heart attack) was reduced by 13%.
  • Risk of ischemic stroke (stroke caused by lack of blood flow to the brain) was reduced by 14%.
  • Risk of heart failure was reduced by 17%.
  • Risk of peripheral artery disease was reduced by 31%.
  • Risk of hemorrhagic stroke (bleeding in the brain) was not significantly reduced.

Two other observations were of interest:

  • Blood pressure and risk of peripheral artery disease decreased with increasing vegetable nitrate intake in a relatively linear fashion. However, the other parameters of heart disease plateaued at a modest intake of vegetable nitrate intake (around one cup of nitrate-rich vegetables per day). This suggests that as little as one serving of nitrate-rich vegetables a day is enough to provide some heart health benefits.
  • Only about 21.9% of the improvement in heart health could be explained by the decrease in blood pressure. This is not surprising when you consider the other beneficial effects of nitric oxide described above.

The authors concluded, “Consumption of at least ~60 mg/day of vegetable nitrate (~ one serving of green leafy vegetables or beets) may mitigate risk of cardiovascular disease.”

Are Nitrates Good For You Or Bad For You?

questionsYou are probably thinking, “Wait a minute. I thought nitrates and nitrites were supposed to be bad for me. Which is it? Are nitrates good for me or bad for me?”

It turns out that nitrates and nitrites are kind of like Dr. Jekyll and Mr. Hyde. They can be either good or bad. It depends on the food they are in and your overall diet.

Remember the beginning of this article when I said that the conversion of nitrates to nitric oxide depended on the presence of antioxidants? Vegetables are great sources of antioxidants. So, when we get our nitrate from vegetables, most of it is converted to nitric oxide. And, as I discussed above, nitric oxide is good for us.

However, when nitrates and nitrites are added to processed meats as a preservative, the story is much different. Processed meats have zero antioxidants. And the protein in the meats is broken down to amino acids in our intestine. The amino acids combine with nitrate to form nitrosamines, which are cancer-causing chemicals. Nitrosamines are bad for us.

Of course, we don’t eat individual foods by themselves. We eat them in the context of a meal. If you eat small amounts of nitrate-preserved processed meats in the context of a meal with antioxidant-rich fruits and vegetables, some of the nitrate will be converted to nitric oxide rather than nitrosamines. The processed meat won’t be as bad for you.

Eating Of The Green

spinachYour mother was right. You should eat your fruits and vegetables!

  • The USDA recommends at least 3 servings of vegetables and 2 servings of fruit a day.
  • Based on this study, at least one of those servings should be nitrate-rich vegetables like green leafy vegetables and beets.
  • If you don’t like any of those, radishes, turnips, watercress, Bok choy, Chinese cabbage, kohlrabi, chicory leaf, onion, and fresh garlic are also excellent sources of nitrate.
  • The good news is that you may not need to eat green leafy vegetables and beets with every meal. If this study is correct, one serving per day may have heart health benefits. That means you can enjoy a wide variety of fresh fruits and vegetables as you try to meet the USDA recommendations.

Finally, if you don’t like any of those foods, you may be asking, “Can’t I just take a nitrate supplement?”

  • For blood pressure, there are dozens of clinical trials, and the answer seems to be yes – especially when the nitrate comes from vegetable sources and the supplement also contains an antioxidant like vitamin C.
  • For heart health benefits, the answer is likely to be yes, but clinical trials to confirm that would take decades. Double blind, placebo-controlled trials of that duration are not feasible, so we will never know for sure.
  • Moreover, you would not be getting all the other health benefits of a diet full of fresh fruits and vegetables. Supplementation has its benefits, but it is not meant to replace a healthy diet.

The Bottom Line

We have known for years that fruits and vegetables are good for our hearts. We have assumed that was because whole fruits and vegetables are low in saturated fats and provide heart-healthy nutrients, phytonutrients, and fiber. But could there be more?

It is well established that nitrates from fruits and vegetables reduce blood pressure. More importantly, they can help slow the gradual increase in blood pressure as we age.

However, few studies have asked whether this reduction in blood pressure translates into improved cardiovascular outcomes. A recent study was designed to answer that question.

When the study compared people with the highest vegetable nitrate intake to people with the lowest vegetable nitrate intake:

  • Blood pressure was significantly reduced.
  • The risk of cardiovascular disease was reduced by 14%.
  • Risk of ischemic heart disease (angina and heart attack) was reduced by 13%.
  • Risk of ischemic stroke (stroke caused by lack of blood flow to the brain) was reduced by 14%.
  • Risk of heart failure was reduced by 17%.
  • Risk of peripheral artery disease was reduced by 31%.
  • Blood pressure and risk of peripheral artery disease decreased with increasing vegetable nitrate intake in a relatively linear fashion.
  • However, the other parameters of heart disease plateaued at a modest intake of vegetable nitrate intake (around one cup of nitrate-rich vegetables per day). This suggests that as little as one serving of nitrate-rich vegetables a day is enough to provide some heart health benefits.

The authors concluded, “Consumption of at least ~60 mg/day of vegetable nitrate (~ one serving of green leafy vegetables or beets) may mitigate risk of cardiovascular disease.”

Of course, you may have heard that nitrates and nitrites are bad for you. I discuss that in the article above.

For more details about this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Which Foods Affect Stroke Risk?

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Why Is Diet And Stroke Risk So Confusing?

strokeOne day we are told vegetarian diets reduce our stroke risk. The next day we are told they increase stroke risk. It’s the same with red meat, dairy, and eggs. We keep getting mixed messages. It’s enough to make your head spin. Why is diet and stroke risk so confusing?

Part of the problem is that there are two distinct types of stroke. The technical names for them are ischemic stroke and hemorrhagic stroke.

An ischemic stroke occurs when an artery in the brain becomes blocked, shutting off blood flow and damaging part of the brain. This is usually caused by the gradual buildup of fatty deposits and cholesterol plaques in the arteries. When a blood clot forms and lodges in one of the narrowed arteries leading to the brain, an ischemic stroke occurs.

  • Ischemic strokes account for 87% of all strokes.
  • Ischemic strokes are associated with obesity, elevated cholesterol, diabetes, high blood pressure, and smoking.

A hemorrhagic stroke occurs when a weakened blood vessel bursts and bleeds into the surrounding region of the brain. Because our brains are surrounded by a protective skull, that blood has nowhere to go. Pressure from the buildup of blood damages brain cells in the vicinity of the bleed.

  • Hemorrhagic strokes account for only for only 15% of strokes but are responsible for 40% of stroke deaths.
  • The most common cause of a hemorrhagic stroke is the localized enlargement of a blood vessel due to chronic high blood pressure. This weakens the wall of the blood vessel, making it prone to rupturing.

Part of the confusion about diet and stroke risk is because many earlier studies did not distinguish between the two types of stroke.

  • If the studies just measured the incidence of stroke, the data were dominated by ischemic strokes (87% of strokes are ischemic).
  • However, if the studies focused on stroke deaths, hemorrhagic stroke made a larger contribution to the data set (40% of stroke deaths are hemorrhagic).

Fortunately, recent studies have started to focus on the effect of diet on ischemic and hemorrhagic strokes separately. However, many of those studies have been too small to accurately assess the effects of diet on hemorrhagic stroke.

The latest study (TYN Tong et al, European Heart Journal, ehaa007, published February 24, 2020) is one of the largest studies to look at the effect of diet on both kinds of stroke. It has enough patients in the hemorrhagic group to get an accurate estimate of the effect of diet on hemorrhagic stroke.

How Was The Study Done?

Clinical StudyThis study analyzed data on diet and stroke from 418,329 participants in the EPIC (European Prospective Investigation into Cancer and Nutrition). Although the study has cancer in the title, it actually investigated the effect of nutrition on multiple diseases (Presumably, the study title was chosen because EPIC is a more appealing acronym than EPID (European Prospective Investigation into Diseases and Nutrition)).

The participants were recruited from 9 European countries (Denmark, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the UK). The average age of participants was 50, and they were followed for an average of 12.7 years.

At the beginning of the study participants completed country-specific dietary and lifestyle questionnaires.

The dietary assessment was a food frequency questionnaire that asked participants about their dietary intake for the year prior to enrollment in the study. The food frequency data were used to estimate daily intake of red meat, processed meat, poultry, fish, dairy products, eggs, grains, fruits, vegetables, legumes, nuts, seeds, and dietary fiber (It measured total fiber and fiber from grains, fruits and vegetables individually).

The outcome measured was the incidence of ischemic and hemorrhagic strokes during the 12.7-year follow-up.

Which Foods Affect Stroke Risk?

Heart Healthy DietFor ischemic stroke:

  • Each 200 gram/day increase in consumption of fruits and vegetables decreased ischemic stroke risk by 13% (200 grams roughly corresponds to one large apple or one large orange without the skin).
  • Each 10 gram/day increase in consumption of fiber decreased ischemic stroke risk by 23%. Most of this decreased stroke risk was due to fiber from whole grains, fruits, and vegetables.
    • Each 4 gram/day increase in fiber from whole grains decreased ischemic stroke risk by 10%.
    • Each 4 gram/day increase in fiber from fruits and vegetables decreased ischemic stroke risk by 12%.
  • Dairy foods decreased ischemic stroke risk with the following breakdown:
    • Each cup of milk decreased ischemic stroke risk by 5%.
    • Each half cup of yogurt decreased ischemic stroke risk by 9%.
    • Each ounce of cheese decreased ischemic stroke risk by 12%.
  • Each 50 grams/day (2 ounces) of red meat increased ischemic stroke risk by 14%.
    • However, red meat was only half as likely to increase risk of ischemic stroke when the diet was also rich in fruits, vegetables, whole grains, and legumes.

For hemorrhagic stroke:

  • Each 20 gram/day increase in consumption of eggs increased hemorrhagic stroke risk by 25% (20 grams roughly corresponds to about 1/2 of a small egg or 1/3 of a jumbo egg).
  • This study did not measure the effect of salt intake on hemorrhagic stroke risk.

No other foods measured in this study had a significant effect on hemorrhagic stroke risk.

high blood pressureHowever, hemorrhagic stroke is highly associated with high blood pressure. When we look at the influence of foods on high blood pressure, here are the Harvard School of Medicine recommendations for keeping blood pressure low:

  • Eat more fish, nuts and beans in place of high-fat meats.
  • Choose fruits and vegetables instead of sugary, salty snacks and desserts.
  • Select whole grains rather than refined grains.Eat fruit instead of drinking fruit juice.
  • Use unsaturated fats like olive, canola, soybean, peanut, corn or safflower oils instead of butter, coconut oil, or palm-kernel oil.
  • Use herbs, spices, vinegar, and other low-sodium flavorings instead of salt; Choose low-sodium foods whenever possible.

Why Is Diet And Stroke Risk So Confusing?

egg confusionAs I mentioned at the start of this article, part of the reason that the headlines about diet and stroke risk are so confusing is:

  • Many studies did not distinguish between the two types of stroke.
  • Other studies were too small to reliably estimate the effect of food on hemorrhagic stroke risk.

However, there are still some unexplained inconsistencies among recently published studies. It is these inconsistencies I would like to address. For example:

1) In a recent issue of Health Tips From the Professor I reported on a major study (500,000 people followed for 8.9 years) in China. That study came to the opposite conclusion about eggs and risk of hemorrhagic than the EPIC study I discussed above. It found:

  • People consuming one egg per day had a 26% decrease in hemorrhagic stroke risk and a 28% decrease in hemorrhagic stroke deaths compared to people who never or rarely consumed eggs.

In other words, the two studies came to opposite conclusions. In the China study eggs decreased risk of hemorrhagic stroke. In the European study (EPIC) eggs increased risk of hemorrhagic stroke. The reason for this discrepancy is not clear, but one can speculate it might be explained by differences in the underlying diets of the two countries:

  • In China the diet is primarily plant-based. The addition of an egg/day may provide needed protein, fat, and cholesterol (Some cholesterol is essential. We just overdo it in this country).
  • In Europe the diet is already high in protein, saturated fat, and cholesterol. Getting more of them from eggs may not be such a good thing.

In short, if your diet is primarily plant-based, the addition of an egg/day may be a good thing. However, if your diet is already high in meat, saturated fat, and cholesterol, the addition of an egg/day may not be a good thing.

Vegan Foods2) In another recent issue of Health Tips From the Professor I reported on the EPIC-Oxford study that claimed vegetarians had 20% increased risk of hemorrhagic stroke compared to meat eaters.

Interestingly, the EPIC-Oxford study represented a very small portion (~10%) of the overall EPIC study and differed from the rest of the EPIC study in two important ways.

  • It looked at the effect of diets rather than foods on stroke risk.
  • Oxford was the only one of the 22 research centers involved in the EPIC study to invite people following a vegetarian diet to enroll in the study, so it had a much higher proportion of vegetarians than other centers that participated in the study.

The current study did not find any evidence that fruits, vegetables, nuts, seeds, beans, or whole grains influenced the risk of hemorrhagic stroke. In other words, in this much larger data set there was no evidence that the foods associated with a vegetarian diet increased hemorrhagic stroke risk.

However, most of the participants in larger EPIC study were also eating meats. They were not following a pure vegetarian diet.

As I said previously, “If the data on hemorrhagic stroke risk in the EPIC-Oxford study are true, it suggests it may not be a good idea to completely eliminate meat from our diet. However, you don’t need to add much meat to a vegetarian diet. The fish eaters in this study were consuming 1.4 ounces of fish per day. That was enough to eliminate the increased risk of hemorrhagic stroke.”

What Does This Mean For You?

Questioning WomanFor ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

  • Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)
  • Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.
  • These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

  • If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.
  • If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.
  • A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.
  • The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

In terms of an overall take-home lesson on diet and stroke risk, my advice is: “A primarily plant-based diet is a good idea, but you don’t need to become a vegan purist. Nor do you want to follow fad diets that eliminate whole food groups. We have 5 food groups for a reason. Eliminating any of them may not be a good idea.”

The Bottom Line

A recent study examined the effect of various foods on the risk of the two major forms of stroke.

For ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

  • Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)
  • Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.
  • These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

  • If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.
  • If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.
  • A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.
  • The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

In terms of an overall take-home lesson on diet and stroke risk, my advice is: “A primarily plant-based diet is a good idea, but you don’t need to become a vegan purist. Nor do you want to follow fad diets that eliminate whole food groups. We have 5 food groups for a reason. Eliminating any of them may not be a good idea.”

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

Do Omega-3s Lower Blood Pressure?

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The Good News About Fish Oil

Author: Dr. Stephen Chaney

High Blood PressureHigh blood pressure or hypertension is a major problem in this country. Over 60% of Americans have high blood pressure. Only 47% of those with hypertension are adequately controlled. 20% of them don’t even know that they have high blood pressure.

In this case, ignorance is definitely not bliss. That’s because high blood pressure significantly increases the risk of stroke, heart attacks and congestive heart failure.

The causes of high blood pressure are many. Genetics, obesity, lack of exercise, sodium, alcohol, saturated fats and too few fresh fruits and vegetables all play a role. Age also plays a role. As we age, our blood vessels become less flexible and our blood pressure rises by about 0.6 mm Hg per year.

Medications can help, but many of them have significant side effects and often aren’t fully effective in controlling blood pressure. That’s why natural approaches are so important.

Because there are so many causes of hypertension, natural approaches for lowering your blood pressure are not simple. Natural approaches start with weight loss, restricting sodium intake, increasing physical activity, moderating alcohol intake and something called the DASH diet. In short, there is not just one simple change that you can make that will totally eliminate hypertension. It requires a complete lifestyle change.

That’s why the latest study on the effect of omega-3s on blood pressure is so exciting. If the headlines are true, adding omega-3s to your diet may be one of the most effective things you can do to lower your blood pressure naturally. So let’s examine the study to see if the headlines are accurate.

How Was The Study Designed?

This study (Miller et al, American Journal of Hypertension, doi:10.1093/ajh/hpu024) was a very large, well designed study. It is a meta-analysis of 70 randomized, placebo controlled clinical studies. Key characteristics of these studies were:

  • The mean study duration was 69 days. That means these beneficial effects occur relatively quickly.
  • The mean EPA + DHA dose was 3.8 g/day (range = 0.2 – 15 g/day). A wide range of doses was included.
  • The EPA & DHA came from all sources (seafood, EPA+DHA fortified foods, fish oil, algal oil, and purified ethyl esters. The source did not affect the outcome.
  • Olive oil was the most commonly used placebo, with omega-6 vegetable oils being used as placebos in a few studies. The choice of placebo did not affect the outcome.
  • None of the people in these studies were taking blood pressure lowering medications. That means these studies were specifically designed to see whether omega-3s lowered blood pressure, not whether they had any additional benefit for people already taking medications. This is important because if you only focus on groups who are already taking multiple medications, you tend to obscure the beneficial effects of omega-3s (see my recent Health Tip “Is Fish Oil Really Snake Oil?”)

Do Omega-3s lower Blood Pressure?

Fish OilThe authors of the study reported that:

  • Compared to placebo, EPA+DHA reduced systolic blood pressure (that’s the upper reading) by 1.52 mm Hg and diastolic blood pressure (that’s the lower reading) by 0.99 mm Hg.
  • When they looked at those participants who already had high blood pressure, the numbers were even more impressive – a 4.51 mm Hg decrease in systolic blood pressure and a 3.05 mm Hg decrease in diastolic blood pressure. That’s important because for each 2 mm Hg reduction in blood pressure there is a 6% decrease in stroke mortality, a 4% decrease in heart disease mortality, and a 3% decrease in total mortality.

More to the point, the authors of the study concluded that “A decrease of 4.51 mm Hg in systolic blood pressure among those with high blood pressure could help an individual avoid having to take medication to control blood pressure levels”.

  • When they looked at the study participants who had normal blood pressure the numbers were still significant – a 1.25 mm Hg decrease in systolic blood pressure and a 0.62 decrease in diastolic blood pressure. The authors pointed out that this could prevent, or at least delay, the age-related progression towards hypertension.
  • The effect of omega-3s on systolic blood pressure (4.51 mm Hg decrease) was comparable to the most successful lifestyle interventions – 3-10 mm Hg decrease for 10 pound weight loss, 4-9 mm Hg decrease for increased physical activity, 2-8 mm Hg decrease for sodium restriction, and 2-4 mm Hg for decreased alcohol consumption.
  • A dose of at least 1 gm/day of EPA+DHA was required for a significant decrease in systolic blood pressure, and a dose of over 2 gm/day was required for a significant decrease in both systolic and diastolic blood pressure

While this is a single study, it is consistent with a number of previous studies in this area. Based on the existing body of literature I would recommend omega-3s as part of a holistic approach for keeping your blood pressure under control.

The Bottom Line:

1)     A recent meta-analysis of 70 published clinical studies (AJH, doi: 10.1093/ajh/hpu024) has shown fairly convincingly that omega-3 fatty acids are effective at lowering blood pressure. Moreover, this study is consistent with a number of previous studies. The evidence appears to be strong enough for omega-3s to be considered as part of a holistic approach to keeping your blood pressure under control.

2)     If you already have high blood pressure, you should know that omega-3s caused blood pressure to decrease by 4.51 mm Hg in people like you. The authors of the study concluded that this decrease in blood pressure is large enough that some people may be able to avoid blood pressure medicines entirely. For others addition of omega-3s to their diet will likely allow their physicians to reduce the dose of medications required to keep their blood pressure under control – thus minimizing the side effects of the medications.

3)     If you already have slightly elevated blood pressure that has not yet progressed to clinical hypertension, you should know that omega-3s also give a modest decrease in blood pressure in people like you. The authors of the study concluded that this decrease was enough to prevent or delay the age-related onset of hypertension.

4)     The effect of omega-3s on reducing blood pressure is equivalent to the most successful lifestyle changes (weight loss, increased physical activity, sodium restriction and alcohol moderation). That doesn’t mean that you should pop fish oil pills and forget the other lifestyle changes. The idea is to combine as many of those lifestyle changes as possible so that you may never have to worry about high blood pressure again.

5)     You need at least 1 gm/day of EPA+DHA to reduce systolic blood pressure and more than 2 gm/day to reduce both systolic and diastolic blood pressure.

6)     Contrary to the hype you may have been reading elsewhere, the source of EPA+DHA didn’t matter. The only caveat is that many people really struggle with trying to get 1-2 gm/day of EPA+DHA from fish. It’s a bit too much of a good thing.

7)     Don’t think of hypertension as a “Do it yourself” project. Hypertension is a silent killer. It’s one of those diseases where the first symptom is often sudden death – or, even worse, a life that is no longer worth living. Work with your physician. Let them help you find the right balance between lifestyle changes (including omega-3s) and medications to keep your blood pressure under control.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Is There Really Such A Thing A Positive Stress?

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Stress Can Be Your Friend

Author: Dr. Pierre DuBois

Motorbike racing on the track.Do you consider yourself an optimist or a pessimist? When the going gets tough, the optimists among you can take heart—new research that has found that viewing stress positively can be of benefit to both the mind and body.

When the brain perceives stress (either physical or psychological), it reacts by releasing cortisol, adrenaline and norepinephrine to prepare the body for a “fight or flight” response. Fortunately for us, this response is not triggered in most people today as frequently as it once was or for the same kinds of reasons.

After all, relatively few of us are in life-threatening situations on a regular basis. Today’s “modern” stresses are more likely to be caused by wrestling with the IRS, trying to escape a traffic jam or competing with a coworker for a promotion.

It is interesting to note that stress, in itself, is not necessarily a negative thing. It is how we perceive it that makes it either good or bad for us. This is a hopeful discovery, as most people have only limited control over how much stress they experience. The everyday stresses of modern life are difficult to escape. But if we can train our minds to view them as a challenge rather than a threat, it could actually help to bring about better health.

Scientists from a handful of universities, including Yale University and Columbia University, examined the effects of stress on 300 investment bankers who had just emerged from a round of layoffs (I know it’s difficult to feel bad for the stress of investment bankers, but stay with me here). In the study, published in the Journal of Personality and Social Psychology, scientists divided the participants into two groups, and tried to alter the perception of half of them to view stress as debilitating and the other half to view it as an enhancement.

The first half of the participants were shown videos of people succumbing to stress. The other half were shown videos of people meeting challenges, such as sports figures accomplishing a difficult goal. The results showed that those who had a more optimistic view of stress had fewer health problems, including headaches and muscle pain, and performed better at work than the pessimistic group. In addition, levels of cortisol (the stress hormone) were lower in those who viewed stress as potentially enhancing.

There is actually a term for positive stress, called eustress, which was coined by endocrinologist Hans Selye in the 1970s. It has been proven that stress in moderation improves cognitive performance and improves memory.

Good stress involves the kind of challenges where we feel that we are in control and are accomplishing something. It boosts the immune system and can improve heart function. So eliminating all stress from our lives is probably not a good idea.

The stress to watch out for is the chronic, long-term emotional stress, which causes stress hormones to remain at persistently high levels, leading to many chronic ailments such as heart disease, high blood pressure and depression.

However, viewing certain stressors as challenges rather than threats can be a positive thing and can help ensure that you have a healthy, satisfying and exciting life.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Does Skipping Breakfast Increase Heart Disease Risk?

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Should You Eat Breakfast Every Day?

Author: Dr. Stephen Chaney

Mature Man - Heart AttackDoes skipping breakfast actually increase your risk of heart attacks? You’ve probably heard the saying “Eat breakfast like a king, lunch like a prince, and dinner like a pauper”.

You’ve probably also heard that skipping breakfast is associated with increased risk of things like:

 

  • obesity
  • high blood pressure
  • and diabetes

If you believe those associations are true, the latest study showing an association between skipping breakfast and heart disease risk just makes sense. After all, obesity, high blood pressure and diabetes all increase the risk of heart disease.

But, how good is the evidence skipping breakfast actually increases the risk of any of those things?

The evidence for the link between skipping breakfast and heart disease risk:

Let’s start with the current study linking breakfast skipping with heart disease (Cahill et al, Circulation, 128: 337-343, 2013) because its study design is similar to the studies linking breakfast skipping to obesity, high blood pressure and diabetes. This study surveyed the eating habits of 27,000 men (45+ years old) enrolled in the Health Professionals Follow-Up Study in 1992 and followed those men for 16 years.

The results were pretty dramatic. After correcting for other factors that might influence heart disease risk, the men who skipped breakfast were 27% more likely to develop heart disease over the next 16 years than the men who ate breakfast on a daily basis.

As impressive as the association between breakfast and heart disease was, there was an even more impressive association that never made it into the headlines.

There was no association between skipping breakfast and eating late in the evening. However, those men who ate late in the evening were 53% more like to develop heart disease than men who did not.

The pros and cons of the study:

The pros:

1)     The strength of this study is that it is large (27,000 participants), long (16 years) and well designed. The results were statistically very significant.

The cons:

1)     This study only shows associations. It does not prove cause and effect. Having said that, it would be really, really hard to design a placebo controlled study for breakfast versus no breakfast. So cause and effect is almost impossible to prove for this type of comparison.

2)     The study did not ask what kind of breakfast the participants were eating. We don’t know whether the breakfasts were a Danish and coffee, an Egg McMuffin and hash browns  or a high protein smoothie with perhaps some fruit or oatmeal– and, believe me, there is a difference among those three breakfasts!

The Bottom Line:

1)     Eating breakfast is probably a good thing. Yes, the evidence that skipping breakfast increases heart disease risk is circumstantial, but it is also substantial. This is a large, well designed study.

2)     Not all breakfasts are equal. You probably already knew that! I recommend a breakfast with fruit, nuts, whole grains in moderation and lean protein sources.

3)     While this particular study only included men, previous studies suggest that the potential health risks of skipping breakfast are equally strong for women.

4)     Finally, while skipping breakfast grabbed all the headlines, the data suggest that eating late at night is an even stronger predictor of heart disease risk.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Health Tips From The Professor