The Mediterranean Diet For Heart Health

Written by Dr. Steve Chaney on . Posted in Mediterranean diet

Can You Cut Your Heart Disease Risk In Half?

Author: Dr. Stephen Chaney

 

what ifShould you use the Mediterranean diet for heart health?

What if…

  • You could reduce your risk of heart disease by almost 50%…and…
  • It didn’t cost you an extra penny?
  • You didn’t need to lose weight (although you would probably get even better results if you did)?
  • You didn’t need to buy a gym membership and start a workout program (although you would probably get even better results if you did)?
  • There were absolutely no side effects?
  • There were considerable side benefits like reduced risk of type 2 diabetes, high blood pressure, inflammation, and cognitive decline as you aged?

Would you be interested? I’m willing to bet if this were a TV ad, you would be on the edge of your seat. If it were a new “magic” supplement, you might be reaching for your credit card before the ad was over. If it was the latest “miracle” workout machine, you might order it right away.

However, I am not talking about a magic pill or a miracle workout machine. I’m talking about a way of eating called the Mediterranean diet. Recent headlines have claimed that the Mediterranean diet can cut heart disease risk almost in half. This would lead you to believe you could use the Mediterranean diet for heart health.  Let’s look at the evidence behind that claim.

 

How Was The Study Designed?

omega-3 lowers heart disease riskThe study behind the headlines (C-M. Kastorini et al. Atherosclerosis, 246: 87-93, 2016) enrolled 2583 adults, ages 18-89, from the region around Athens, Greece in a 10-year study beginning in 2001-2002.

At the beginning of the study and at the 5 and 10-year mark, participants completed in-depth surveys about their medical records, lifestyle, and dietary habits. These surveys were conducted by trained personnel (cardiologists, general practitioners, dietitians, and nurses). Participants with active cardiovascular disease in the first survey were excluded from the study.

The study evaluated 4 things:

  • Cardiovascular disease risk factors including obesity, high cholesterol, high triglycerides, high blood pressure, diabetes, and inflammation.
  • Adherence to the Mediterranean diet (see below).
  • Heart disease incidence based on heart attacks, stroke, angina, ischemia, cardiac arrhythmias and deaths due to heart disease.
  • Confounding variables such as age, sex, family history of heart disease, smoking, and lack of physical activity. All comparisons were corrected for these confounding variables so that they did not influence the results.

Adherence to the Mediterranean diet was based on a diet analysis scoring system called MedDietScore. The Mediterranean diet is one which emphasizes fresh fruits and vegetables, whole grains, beans, nuts, fish, olive oil, and moderate consumption of red wine.  You can see this might lead you to believe in the Mediterranean diet for heart health.

The MedDietScore gives positive points based on how often these foods are consumed. It gives negative points based on how often meats, meat products, poultry, and full-fat dairy products are consumed. For alcohol, modest consumption is considered a positive, with either no or excess alcohol consumption rating a score of 0. The composite score ranges from 0 to 55, with higher values indicating greater adherence to the Mediterranean diet.

As an aside, you might think that everyone in Greece consumes a Mediterranean diet. Unfortunately, our unhealthy Western diet and our fast foods restaurants are making inroads in the birthplace of the Mediterranean diet.

 

The Mediterranean Diet for Heart Health?

Mediterranean diet for heart healthEven after correcting for confounding variables, the study results were impressive.

  • Each 10% increase in adherence to the Mediterranean diet was associated with a 15% decreased risk of developing heart disease during the 10-year study period.
  • When they compared participants in the upper third for adherence to the Mediterranean diet to those in the lower third, their risk of developing heart disease was decreased by 47%. That’s huge.

However, the results were even more impressive when they looked at the effects of the Mediterranean diet on other risk factors for heart disease.

  • For individuals with low adherence to the Mediterranean diet, each of those risk factors (obesity, high cholesterol, high triglycerides, high blood pressure, diabetes, and inflammation) independently increased the risk of developing heart disease. These results are identical to almost every other published study looking at those risk factors.
  • However, for individuals with high adherence to the Mediterranean diet, those same risk factors had only small, non-significant effects on the risk of developing heart disease. If this finding is verified by future studies, it would suggest that adherence to a Mediterranean diet has the potential to override risk factors like obesity, diabetes, high blood pressure and elevated cholesterol.

Of course, I would not recommend that you ignore obesity and other cardiovascular risk factors and just focus on following a Mediterranean diet. I’m pretty sure you will get even better results if you get your weight, blood sugar, cholesterol, and blood pressure under control in addition to following a Mediterranean diet. Who knows, you might even reduce your risk of heart disease by 75% or more.  So, should we believe in the Mediterranean diet for heart health?

What Does This Mean For You?

If this were the only published study showing that adherence to the Mediterranean diet reduces heart disease risk I would consider it speculative. However, it is only one of several recent studies that have come to a similar conclusion. At this point in time, the evidence is strong that following a Mediterranean-type diet will reduce your heart disease risk.  The Mediterranean diet for heart health seems to be true.

That brings me back to my opening statement. Following a Mediterranean diet:

  • Won’t cost you a penny. You are just spending your food budget on healthier foods.
  • May reduce your risk of heart disease by up to 47% even if you don’t lose weight, but I recommend that you do lose weight.
  • May be as effective as exercise at reducing your heart disease risk. That statement comes from a talk given by one of the authors when he was describing the study.
  • Has no side effects. You could probably achieve a 47% reduction in heart disease using a cardiologist-approved cocktail of 3-5 drugs, but those drugs would come with significant side effects and a considerable cost for someone.
  • Will likely come with side benefits like reduced risk of type 2 diabetes, high blood pressure, inflammation, and cognitive decline.

My question to you is: Now that you know that a simple dietary change could have all those benefits and no downside, are you willing to give it a try? If so, your heart may just thank you for it.

However, I don’t mean to imply that the Mediterranean diet is the only way to reduce your heart disease risk. If your blood pressure is elevated, you might want to try the DASH diet . If you want to reduce heart disease risk and also minimize cognitive decline as you age, you might want to consider the MIND diet .

Those three diets are actually quite similar. They all emphasize fruits, vegetables, whole grains, nuts, seeds, fish, and moderate amounts of healthy fats. They all minimize refined flour, pastries, sweets, red & processed meats. You won’t find a Twinkie or a Big Mac in any of them.

The Mediterranean diet for heart health?  Sure!

The Bottom Line

 

  • A recent study suggests that adherence to a Mediterranean type diet could reduce the risk of developing heart disease by up to 47%.
  • The beneficial effect of the Mediterranean diet was so strong that it overcame other cardiovascular risk factors such as obesity, high cholesterol, high triglycerides, high blood pressure, diabetes, and inflammation.
  • This study is likely to be accurate because it is fully consistent with several other studies looking at the effect of the Mediterranean diet on heart disease risk.
  • To put it into perspective, this simple dietary change.
    • Won’t cost you a penny. You just redirect your food budget.
    • Has zero side effects. You could probably achieve a similar 47% reduction in heart disease risk with a cardiologist-approved cocktail of 3-5 drugs, but that would come with multiple side effects.
    • Has side benefits such as reduced risk of type 2 diabetes, high blood pressure, inflammation, and cognitive decline
  • However, the Mediterranean diet is not the only game in town. Other studies suggest that the DASH diet and MIND diet are also effective at reducing heart disease risk.
  • Those three diet patterns (Mediterranean, DASH & MIND) are actually quite similar. They all emphasize fruits, vegetables, whole grains, nuts, seeds, fish, and moderate amounts of healthy fats. They all minimize refined flour, pastries, sweets, red & processed meats. You won’t find a Twinkie or a Big Mac in any of them.
  • Finally, I am not suggesting that you go on the one of these diets and just throw away your heart medicines without talking to your doctor. However, I would recommend that you talk with your doctor about implementing what the National Institutes of Health calls Therapeutic Lifestyle Change. All three dietary patterns are fully consistent with the NIH-recommended Therapeutic Lifestyle Change. The NIH recommends that Therapeutic Lifestyle Change be tried before considering cholesterol lowering drugs or be used along with cholesterol lowering drugs so that drug dosage can be minimized.

 

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.

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Comments (2)

  • Louise Levesque

    |

    Thank you for your article on the Mediterranean Diet. I suffer from high blood pressure and high cholesterol, so I am a prime candidate for heart disease. These three diets will help me avoid heart disease. Is there anything I can change in my diet to avoid strokes?

    Reply

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Latest Article

Do Omega-3s Lower Blood Pressure in Young, Healthy Adults?

Posted August 14, 2018 by Dr. Steve Chaney

What Is The Omega-3 Index And Why Is It Important?

Author: Dr. Stephen Chaney

 

Do omega-3s lower blood pressure in healthy adults?

omega-3s lower blood pressure young adultsThe literature on the potential health benefits of omega-3s is very confusing. That’s because a lot of bad studies have been published. Many of them never determined the omega-3 status of their subjects prior to omega-3 supplementation. Others relied on dietary recalls of fish consumption, which can be inaccurate.

Fortunately, a much more accurate measure of omega-3 status has been developed and validated in recent years. It’s called the Omega-3 Index. Simply put, the Omega-3 Index is the percentage of EPA and DHA compared to 26 other fatty acids found in cellular membranes. Using modern technology, it can be determined from a single finger prick blood sample. It is a very accurate reflection of omega-3 intake relative to other fats in the diet over the past few months. More importantly, it is a measure of the omega-3 content of your cell membranes, which is a direct measure of your omega-3 nutritional status.

A recent extension of the Framingham Heart Study reported that participants with an Omega-3 Index >6.8% had a 39% lower risk of cardiovascular disease than those with an Omega-3 Index <4.2% (WS Harris et al, Journal of Clinical Lipidology, 12: 718-724, 2018 ). Although more work needs to be done, an Omega-3 Index of 4% or less is generally considered indicative of high cardiovascular risk, while 8% or better is considered indicative of low cardiovascular risk. For reference, the average American has an Omega-3 Index in the 4-5% range. In Japan, where fish consumption is much higher and cardiovascular risk much lower, the Omega-3 Index is in the 9-11% range.

Previous studies have suggested that omega-3 fatty acids lower blood pressure to a modest extent. Thus, it is not surprising that more recent studies have shown an inverse correlation between Omega-3 Index and blood pressure. However, those studies have been done with older populations, many of whom had already developed high blood pressure.

From a public health point of view, it is much more interesting to investigate whether it might be possible to prevent high blood pressure in older adults by optimizing omega-3 intake in a young, healthy population, most of whom had not yet developed high blood pressure. Unfortunately, there were no studies looking at that population. The current study was designed to fill that gap.

 

How Was The Study Done?

omega-3s lower blood pressure young healthy adultsThe current study (M.G. Filipovic et al, Journal of Hypertension, 36: 1548-1554, 2018 ) was based on data collected from 2036 healthy adults, aged 25-41, from Liechtenstein. They were participants in the GAPP (Genetic and Phenotypic Determinants of Blood Pressure) study. Participants were excluded from the study if they had been diagnosed with high blood pressure and were taking medication to lower their blood pressure. They were also excluded if they had heart disease, chronic kidney disease, other severe illnesses, obesity, sleep apnea, or daily use of non-steroidal anti-inflammatory medications.

Blood samples were collected at the time of their enrollment in the study and frozen for subsequent determination of Omega-3 Index. Blood pressure was also measured at their time of enrollment in two different ways. The first was a standard blood pressure measurement in a doctor’s office.

For the second measurement they were given a wearable blood pressure monitor that recorded their blood pressure over 24 hours every 15 minutes during the day and every 30 minutes while they were sleeping. This is considered more accurate than a resting blood pressure measurement in a doctor’s office because it records the variation in blood pressure, while you are sleeping, while you are exercising, and while you go about your everyday activities.

 

Do Omega-3s Lower Blood Pressure In Young, Healthy Adults?

omega-3s lower blood pressure young adults equipmentNone of the participants in the study had significantly elevated blood pressure. The mean systolic and diastolic office blood pressures were 120±13 and 78±9 respectively. The average Omega-3 Index in this population was 4.6%, which is similar to the average Omega-3 Index in the United States.

When they compared the group with the highest Omega-3 Index (average = 5.8%) with the group with the lowest Omega-3 Index (average = 4.6%):

  • The office measurement of systolic and diastolic blood pressure was decreased by 3.3% and 2.6% respectively
  • While those numbers appear small, the differences were highly significant.
  • The 24-hour blood pressure measurements showed a similar decrease.
  • Blood pressure measurements decreased linearly with increasing Omega-3 Index. [In studies of this kind, a linear dose-response is considered an internal validation of the differences observed between the group with the highest Omega-3 Index and the group with the lowest Omega-3 Index.]

The authors concluded: “A higher Omega-3 Index is associated with statistically significant, clinically relevant, lower systolic and diastolic blood pressure in normotensive, young and healthy individuals. Diets rich omega-3 fatty acids may be a strategy for primary prevention of hypertension.”

 

What Does This Mean For You?

omega-3s lower blood pressure young adults questionPerhaps I should first comment on the significance of the relatively small decrease in blood pressure observed in this study.

  • These were young adults, all of whom had normal or near normal blood pressure.
  • The difference in Omega-3 Index was rather small (5.8% to 4.6%). None of the participants in the study were at the 8% or above that is considered optimal.
  • Liechtenstein is a small country located between Switzerland and Spain. Fish consumption is low and omega-3 supplement consumption is rare.

Under these conditions, even a small, but statistically significant, decrease in blood pressure is remarkable.

We should think of this study as the start of the investigation of the relationship between omega-3 status and blood pressure. Its weakness is that it only shows an association between high Omega-3 Index and low blood pressure. It does not prove cause and effect.

Its strength is that it is consistent with many other studies showing omega-3 fatty acids lower blood pressure. Furthermore, it suggests that the effect of omega-3s on blood pressure may also be seen in young, healthy adults who have not yet developed high blood pressure.

Finally, the authors suggested that a diet rich in omega-3s might reduce the incidence of high blood pressure by slowing the age-related increase in blood pressure that most Americans experience. This idea is logical, but speculative at present.

However, the GAPP study is designed to provide the answer to that question. It is a long-term study with follow-up examinations scheduled every 3-5 years. It will be interesting to see whether the author’s prediction holds true, and a higher Omega-3 Index is associated with a slower increase in blood pressure as the participants age.

 

Why Is The Omega-3 Index Important?

 

The authors of this study said: “The Omega-3 Index is very robust to short-term intake of omega-3 fatty acids and reliably reflects an individual’s long-term omega-3 status and tissue omega-3 content. Therefore, the Omega-3 Index has the potential to become a cardiovascular risk factor as much as the HbA1c is for people with diabetes…” That is a bit of an overstatement. HbA1c is a measure of disease progression for diabetes because it is a direct measure of blood sugar control.

In contrast, Omega-3 Index is merely a risk factor for cardiovascular disease. However, if it is further validated by future studies, it is likely to be as important for predicting cardiovascular risk as are cholesterol levels and markers of inflammation.

However, to me the most important role of Omega-3 Index is in the design of future clinical studies. If anyone really wants to determine whether omega-3 supplementation reduces cardiovascular risk, high blood pressure, diabetes or any other health outcome they should:

  • Start with a population group with an Omega-3 Index in the deficient (4-5%) range.
  • Supplement with omega-3 fatty acids in a double blind, placebo-controlled manner.
  • Show that supplementation brought participants up to an optimal Omega-3 Index of 8% or greater.
  • Look at health outcomes such as heart attacks, cardiovascular deaths, hypertension, stroke, or depression.
  • Continue the study long enough for the beneficial effects of omega-3 supplementation to be measurable. For cardiovascular outcomes the American Heart Association has stated that at least two years are required to obtain meaningful results.

These are the kind of experiments that will be required to give definitive, reproducible results and resolve the confusion about the health effects of omega-3 fatty acids.

 

The Bottom Line

 

An accurate measure of omega-3 status has been developed and validated in recent years. It’s called the Omega-3 Index. Simply put, the Omega-3 Index is the percentage of EPA and DHA compared to 26 other fatty acids found in cellular membranes.

Although more work needs to be done, an Omega-3 Index of 4% or less is generally considered indicative of high cardiovascular risk while 8% or better is considered indicative of low cardiovascular risk.

Previous studies have shown an inverse correlation between Omega-3 Index and blood pressure. However, these studies have been done with older populations, many of whom had already developed high blood pressure.

From a public health point of view, it is much more interesting to investigate whether it might be possible to prevent high blood pressure in older adults by optimizing omega-3 intake in a young, healthy population, most of whom had not yet developed high blood pressure. Until now, there have been no studies looking at that population.

The study described in this article was designed to fill that gap. The participants in this study were ages 25-41, were healthy, and none of them had elevated blood pressure.

When the group with the highest Omega-3 Index (average = 5.8%) was compared with the group with the lowest Omega-3 Index (average = 4.6%):

  • Both systolic and diastolic blood pressure were decreased
  • Blood pressure measurements decreased linearly with increasing Omega-3 Index.

The authors concluded: “A higher Omega-3 Index is associated with statistically significant, clinically relevant, lower systolic and diastolic blood pressure in normotensive, young and healthy individuals. Diets rich omega-3 fatty acids may be a strategy for primary prevention of hypertension.”

Let me translate that last sentence into plain English for you. The authors were saying that optimizing omega-3 intake in young adults may slow the age-related increase in blood pressure and reduce the risk of them developing high blood pressure as they age. This may begin to answer the question “Do omega-3s lower blood pressure in young, healthy adults?”

Or even more simply put: Aging is inevitable. Becoming unhealthy is not.

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.

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