Is Low Omega-3 Intake As Bad For You As Smoking? - Health Tips From The Professor

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

Author: Dr. Stephen Chaney

We already know that smoking is one of the worst things we can do to our bodies. It dramatically increases our risk of cancer, heart disease, diabetes, and lung diseases, including chronic obstructive pulmonary disease (COPD).

It also leads to premature death. People who smoke regularly die 5 years earlier than those who don’t.

That is the bad news. The good news is that smoking is what is called a “modifiable risk factor”. Simply put, that means it is a risk factor we are in control of. The message has been clear for years.

If you don’t smoke, keep it that way.

If you do smoke, stop. If you are a smoker, quitting isn’t easy, but it is worth it. The damage caused by smoking can largely be reversed if you stay off cigarettes long enough.

Obesity and diabetes are also modifiable risk factors that have a huge effect on the risk of both heart disease and premature death. People with diabetes die 4 years earlier than those without diabetes. But obesity and diabetes are harder for most people to reverse than smoking.

Diet is another modifiable risk factor, but, in general, its effect on the risk of heart disease and premature death is not as great as smoking and diabetes. But what if there were one component of diet that had huge effect on both heart disease and premature death?

The long chain omega-3 fatty acids (EPA & DHA) might just fill that bill. We already know they significantly reduce the risk of heart disease (see below), but could they also help us live longer? This study (MI McBurney et al, American Journal of Clinical Nutrition, published online June 16, 2021) was designed to answer that question.

Metabolism 101: What Is The Omega-3 Index And Why Is It Important?

Clinical studies on the benefits of omega-3s have been plagued by the question of how to best measure the omega-3 status of the participants.

You can ask the participants to fill out a dietary survey and calculate how many omega-3-rich foods they are eating, but:

- Dietary recall is notoriously inaccurate. People don’t remember everything they ate and have a hard time estimating portion sizes.

You can measure omega-3 fatty acids in the blood, but:

- Blood levels are transient. Omega-3 fatty acids enter the bloodstream from the intestine and then disappear from blood as they are taken up by the cells.

- Different forms of omega-3s (esters versus acetate, for example) are absorbed from the intestine and taken up by cells at different rates.

You can measure the omega-3 content of cellular membranes. This is the best assay for omega-3 status because:

- The long chain omega-3 fatty acids (EPA and DHA) that have the biggest effect on heart disease risk accumulate in our cell membranes.

- Omega-3 fatty acids are essential (our bodies can’t make them). That means the omega-3 content of our cell membranes reflect the omega-3 content of our diet. This is one of the cases where the saying, “We are what we eat”, is literally true.

- The omega-3 content of our cell membranes is relatively stable. It reflects the omega-3 content of our diet over the last few months.

In theory, you could measure the omega-3 content of cell membranes from any tissues in the body, but red blood cells can easily be obtained by a simple blood draw, so they are the tissue of choice.

A group lead by Dr. William H Harris standardized this measurement by creating something called the Omega-3 Index. Simply put, the Omega-3 Index is the percentage of EPA and DHA in red blood cell membranes.

It turns out that the Omega-3 Index is an excellent indicator of heart disease risk.

An Omega-3 Index of less than 4% is associated with a high risk of heart disease.

An Omega-3 Index of more than 8% is associated with a low risk of heart disease.

But could a low Omega-3 Index also be associated with an increased risk of premature death? This is what the current study was designed to find out.

How Was This Study Done?

The data for this study were obtained from the ongoing Framingham Offspring Heart Study.

To put this statement into perspective, the original Framingham Heart Study began in 1948 in Framingham Massachusetts with the goal of identifying the factors that contributed to heart disease. It was one of the first major studies to identify the role of saturated fats, elevated blood cholesterol, and elevated blood triglycerides on heart disease risk.

The study is continuing today with the second and third generation descendants of the original study participants. It has also been broadened to include other diseases and additional risk factors, such as the Omega-3 Index.

This study selected 2240 participants from the Framingham Offspring study who had no heart disease and also had Omega-3 Index measurements at the beginning of the study. The study then followed them for 11 years. The goal of the study was to compare the Omega-3 Index with the two most potent risk factors for heart disease (smoking and diabetes) in predicting the risk of premature death.

The characteristics of the participants at the beginning of the 11-year study were:

43% male, 57% female.
Average age = 65.
3% were smokers.
8% were diabetic.
Average Omega-3-Index = 5.8%. This is slightly higher than the American average of ~5%.

Is Low Omega-3-Intake As Bad For You As Smoking?

The participants in the study were divided into 5 quintiles based on their Omega-3 Index.

The 20% of the group in the lowest quintile had an Omega-3 Index of <4.2%.

The 20% of the group in the highest quintile had an Omega-3 Index of >6.8%.

First, the scientists running the study did a direct comparison of the top three risk factors on the risk of premature death. Here is what they found.

The group with the lowest average Omega-3 Index died 4.74 years earlier than the group with the highest average Omega-3 Index.

Smokers died 4.73 years earlier than non-smokers.

People with diabetes died 3.90 years earlier than people without diabetes.

That means low omega-3 intake was just as bad for the participants in this study as smoking. Even the authors of the study were surprised by this result. They had expected omega-3 fatty acids to be beneficial, but they had not expected them to be as beneficial as not smoking.

Because omega-3 fatty acid intake and smoking were the two most potent risk factors for premature death, the authors looked at the interaction between the two. They found that the predicted 11-year survival was:

85% for non-smokers with high omega-3 intake.

71% for either…

- Smokers with high omega-3 intake, or…

- Non-smokers with low omega-3 intake.

Only 47% for smokers with low omega-3 intake.

Simply put, this study predicts if you were a 65-year-old smoker with low omega-3 intake, you could almost double your chances of surviving another 11 years by giving up smoking and increasing your omega-3 intake.

In the words of the authors, “Smoking and omega-3 intake seem to be the most easily modified risk factors [for premature death]…Dietary choices that change the Omega-3 index may prolong life.”

The Bottom Line

We know that smoking is deadly, but could low intake of omega-3 fatty acids be just as deadly?

A recent study compared omega-3 intake with the two most potent risk factors (smoking and diabetes) in predicting the risk of premature death. Here is what it found.

The group with the lowest average omega-3 intake died 4.74 years earlier than the group with the highest average omega-3 intake.

Smokers died 4.73 years earlier than non-smokers.

People with diabetes died 3.90 years earlier than people without diabetes.

That means high omega-3 intake was just as beneficial for the participants in this study as not smoking. Even the authors of the study were surprised by this result. They had expected omega-3 fatty acids to be beneficial, but they had not expected them to be as beneficial as not smoking.

85% for non-smokers with high omega-3 intake.

71% for either…

- Smokers with high omega-3 intake, or…

- Non-smokers with low omega-3 intake.

Only 47% for smokers with low omega-3 intake.

In the words of the authors, “Smoking and omega-3 intake seem to be the most easily modified risk factors [for premature death]…Dietary choices that change the Omega-3 index may prolong life.”

For more details about this study, 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.