Is Omega-3 Uptake Gender Specific?

Written by Dr. Steve Chaney on . Posted in current health articles, Nutritiion, Supplements and Health

Do We Need To Reexamine Everything We Thought We Knew About Omega-3s?

Author: Dr. Stephen Chaney

is omega-3 uptake gender specific

Some of you may remember the book from a few years ago titled “Men are from Mars, Women are from Venus”. The book proposed that men and women communicate differently (Who would have guessed?), and understanding that fact would help husbands and wives communicate with each other more effectively. I know that some people complained that it was an overly simplistic viewpoint, but I know it sure helped me communicate more effectively with my wife.

I came across a very interesting article recently that suggested the omega-3 fatty acid EPA might be metabolized and utilized differently by men and women. You might say that the statement “Men are from Mars, Women are from Venus” applies to omega-3 utilization as well.

The Science Behind the Study

Now that I’ve captured your interest, perhaps I should fill in a few details. We have known for years that the long chain omega-3 fatty acids EPA and DHA appear to be beneficial at reducing the risk of heart disease. There are several mechanisms for that protective effect:

  1. Omega-3s reduce the stickiness of platelets so that platelet aggregation, a fancy name for blood clotting, occurs less readily. Of course, we want our blood to clot when we cut ourselves, but we don’t want it to clot inside our arteries, because that is the very process that can lead to heart attacks and stroke.
  1. Omega-3s lower triglycerides and reduce inflammation, two important risk factors for heart disease.
  1. Omega-3s help keep the walls of our blood vessels elastic, which enhances blood flow and reduces the risk of hypertension.

However, for any of those things to occur, the omega-3 fatty acids must first be incorporated into our cell membranes. Thus, it is not just how much omega-3s we get in our diet that is important. We need to know how many of those omega-3s are actually incorporated into our membranes.

What if the efficiency of omega-3 uptake into cellular membranes were different for men and women? That would change everything. It would affect the design of omega-3 clinical studies. It would affect omega-3 dietary recommendations for men and women. The implications of gender-specific uptake of omega-3s would be far reaching.

Is Omega-3 Uptake Gender Specific?omega-3

The authors of this week’s study (Pipingas et al., Nutrients, 6, 1956-1970, 2014) hypothesized that efficiency of omega-3 uptake might differ in men and women. They enrolled 160 participants in the study (47% male and 53& female) with an average age of 59 years. The study excluded anybody with pre-existing diabetes or heart disease and anybody who was significantly overweight. The study also excluded anyone taking drugs that might mask the effects of the omega-3 fatty acids and anybody who had previously consumed fish oil supplements or more than two servings of seafood per week.

This was a complex study. In this review I will focus only on the portion of the study relevant to the gender specificity of omega-3 uptake. For that portion of the study, both male and female participants were divided into three groups. The first group received 3 gm of fish oil (240 mg EPA and 240 mg DHA); the second group received 6 gm of fish oil (480 mg EPA and 480 mg of DHA); and the third group received sunflower seed oil as a placebo. The study lasted 16 weeks, and the incorporation of omega-3 fatty acids into red blood cell membranes was measured at the beginning of the study and at the end of 16 weeks.

When they looked at men and women combined, they found:

  • A dose specific increase in EPA incorporation into red cell membranes compared to placebo. That simply means the amount of EPA that ended up in the red blood cell membrane was greater when the participants consumed 6 gm of fish oil than when they consumed 3 gm of fish oil.
  • Very little incorporation of DHA into red blood cell membranes was seen at either dose. This was not unexpected. Previous studies have shown that EPA is preferentially incorporated into red cell membranes. Other tissues, such a neural tissue, preferentially incorporate DHA into their membranes.

When they looked at men and women separately, they found:

  • The efficiency of EPA incorporation into red cell membranes compared to placebo was greater for women than for men. In women increased EPA uptake into red cell membranes was seen with both 3 gm and 6 gm of fish oil. Whereas, with men increased EPA incorporation into red cell membranes was only seen at with 6 gm of fish oil.

What Is The Significance Of These Observations?

The authors concluded “This is an important area for future research because dietary recommendations around long chain omega-3 polyunsaturated fatty acid intake may need to be gender specific.”

However, there are a number of weaknesses of this study:

  1. It was a very small study. Obviously, this study needs to be repeated with a much larger cohort of men and women.
  1. This study was just looking at incorporation of omega-3s into red cell membranes. We don’t yet know whether the specificity of omega-3 uptake will be the same for other tissues. Nor do we know whether there will be gender specificity in the biological effects of omega-3s.
  1. Most importantly, not all previous studies have reported the same gender specificity in omega-3 uptake seen in this study.

So what does this mean for you? Should men be getting more omega-3 fatty acids in their diet than women, as the authors suggested? That is an intriguing idea, but based on the weaknesses I described above, I think it’s premature to make this kind of recommendation until these results have been confirmed by larger studies.

The Bottom Line

  1. A recent study has suggested that women may be more efficient at incorporating the omega-3 fatty acids EPA into their cellular membranes than men. The authors of the study concluded that “…dietary recommendations around long chain omega-3 polyunsaturated fatty acid intake may need to be gender specific.”
  1. However, the study has a number of weaknesses:
  • It was a very small study. Obviously, it needs to be repeated with a much larger cohort of men and women.
  • This study was just looking at incorporation of omega-3s into red cell membranes. We don’t yet know whether the specificity of omega-3 uptake will be the same for other tissues. Nor do we know whether there will be gender specificity in the biological effects of omega-3s.
  • Most importantly, not all previous studies have reported the same gender specificity in omega-3 uptake seen in this study.
  1. The idea that men and women may differ in their needs for omega-3 fatty acids is intriguing, but based on the weaknesses described above, it is premature to make this kind of recommendation until the results of the current study have been confirmed by larger studies.

 

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 (3)

  • kathleen sibbel

    |

    this was very interesting, I find that the more Omegaguard I take the better I feel, less aches and pains (arthritis) still, my Dr. wants to put me on statin drugs, tried them once for about 3wks. and stopped, Told him I would rather die of a stroke than be in the pain those things caused in me.
    Being Diabetic I have to go in regularly for blood work, and it always seems to be a battle. And I am always told I take too much Vita E. I just reply: better to have too much than an amputation (not in my vocabulary and better not be in his) Am anxious to show him the Dr. letter for the new Blood Pressure supplement Shaklee has introduced.
    Thanks for all your articles. so good and informative.

    Reply

  • Sheri Duncan

    |

    That is interesting but only looks at one source of omega 3’s. I’d be interested in one that looks at Flax Seed oil with omega 3,6 & 9 which is what I take. not fair, I’m a subscriber & would like those freebies too. Do you already make them available to us? I don’t check my e-mails often. Thanks Sheri

    Reply

    • Dr. Steve Chaney

      |

      Dear Sherri,
      I usually emphasize sources of long chain omega-3 fatty acids because those are the ones most likely to be missing from the American diet. Most naturally occurring oils contain a mixture of omega-3, omega-6 and omega-9 fatty acids. Vegetable oils other than flaxseed and canola are the best source of omega-6 fatty acids, but also have omega-3 and omega-9. Olive and peanut oil are the best sources of omega-9, but also have omega-3 and omega-6. Flaxseed and canola oil are the best source of omega-3, but also have omega-6 and omega-9.
      Flaxseed oil is not magical, but it is a very healthy oil. What you should know is that vegetable oils such as flaxseed and canola contain short chain omega-3 fatty acids and the efficiency of conversion of those to the beneficial long chain fatty acids is around 10%. That means that you need about 25 grams of flaxseed oil to get the same health benefits that you would experience with 2 or 3 grams of fish oil. That’s OK if you are using a tablespoon or two of flaxseed oil as a salad dressing, but don’t count on much benefit from a flaxseed oil supplement.
      As for the free offers you missed, they were indeed contained in the emails you didn’t read, but I can give you links for each offer. For “Three Things Every Diet Must Do” eBook, click on:
      https://www.healthtipsfromtheprofessor.com/go/thank-you-three-things/
      For the “Myths of the Naysayers” eBook, click on:
      https://www.healthtipsfromtheprofessor.com/go/thank-you-new/
      Dr. Chaney

      Reply

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Latest Article

Can Plant-based Diets Be Unhealthy?

Posted September 10, 2019 by Dr. Steve Chaney

Do Plant-Based Diets Reduce Heart Disease Deaths?

Author: Dr. Stephen Chaney

 

plant-based diets vegetablesPlant-based diets have become the “Golden Boys” of the diet world. They are the diets most often recommended by knowledgeable health and nutrition professionals. I’m not talking about all the “Dr. Strangeloves” who pitch weird diets in books and the internet. I am talking legitimate experts who have spent their life studying the impact of nutrition on our health.

Certainly, there is an overwhelming body of evidence supporting the claim that plant-based diets are healthy. Going on a plant-based diet can help you lower blood pressure, inflammation, cholesterol and triglycerides. People who consume a plant-based diet for a lifetime weigh less and have decreased risk of heart disease, diabetes, and cancer.

But, can a plant-based diet be unhealthy? Some people consider a plant-based diet to simply be the absence of meat and other animal foods. Is just replacing animal foods with plant-based foods enough to make a diet healthy?

Maybe not. After all, sugar and white flour are plant-based food ingredients. Fake meats of all kinds abound in our grocery stores. Some are very wholesome, but others are little more than vegetarian junk food. If you replace animal foods with plant-based sweets, desserts, and junk food, is your diet really healthier?

While the answer to that question seems obvious, very few studies have asked that question. Most studies on the benefits of plant-based diets have compared population groups that eat a strictly plant-based diet (Seventh-Day Adventists, vegans, or vegetarians) with the general public. They have not looked at variations in plant food consumption within the general public. Nor have they compared people who consume healthy and unhealthy plant foods.

This study (H Kim et al, Journal of the American Heart Association, 8:e012865, 2019) was designed to fill that void.

 

How Was The Study Done?

plant-based diets studyThis study used data collected from 12,168 middle aged adults in the ARIC (Atherosclerosis Risk in Communities) study between 1987 and 2016.

The participant’s usual intake of foods and beverages was assessed by trained interviewers using a food frequency questionnaire at the time of entry into the study and again 6 years later.

Participants were asked to indicate the frequency with which they consumed 66 foods and beverages of a defined serving size in the previous year. Visual guides were provided to help participants estimate portion sizes.

The participant’s adherence to a plant-based diet was assessed using four different well-established plant-based diet scores. For the sake of simplicity, I will include 3 of them in this review.

  • The PDI (Plant-Based Diet Index) categorizes foods as either plant foods or animal foods. A high PDI score means that the participant’s diet contains more plant foods than animal foods. A low PDI score means the participant’s diet contains more animal foods than plant foods.
  • The hPDI (healthy plant-based diet index) is based on the PDI but emphasizes “healthy” plant foods. A high hPDI score means that the participant’s diet is high in healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) and low in animal foods.
  • The uPDI (unhealthy plant-based diet index) is based on the PDI but emphasizes “unhealthy” plant foods. A high uPDI score means that the participant’s diet is high in unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) and low in animal foods.

For statistical analysis the scores from the various plant-based diet indices were divided into 5 equal groups. In each case, the group with the highest score consumed the most plant foods and least animal foods. The group with the lowest score consumed the least plant foods and the most animal foods.

The health outcomes measured in this study were heart disease events, heart disease deaths, and all-cause deaths. Again, for the sake of simplicity, I will only include 2 of these outcomes (heart disease deaths and all-cause deaths) in this review. The data on deaths were obtained from state death records and the National Death Index. (Yes, your personal information is available on the web even after you die.)

 

Do Plant-Based Diets Reduce Heart Disease Deaths?

plant-based diets reduce heart deathsThe participants in this study were followed for an average of 25 years.

The investigators looked at heart disease deaths over the 25 years and compared people with the highest intake of plant foods to people with the highest intake of red meat and other animal foods. The results were:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

What Else Did The Study Show?

The investigators made a couple of other interesting observations:

  • The association of the overall diet with heart disease and all-cause deaths was stronger than the association of individual food components. This underscores the importance of looking at the effect of the whole diet on health outcomes rather than the “magic” foods you hear about on Dr. Strangelove’s Health Blog.
  • Diets with the highest amount of healthy plant foods were associated with higher intake of carbohydrates, plant protein, fiber, and micronutrients, including potassium, magnesium, iron, vitamin A, vitamin C, folate, and lower intake of saturated fat and cholesterol.
  • Diets with the highest amount of unhealthy plant foods were associated with higher intake of calories and carbohydrates and lower intake of fiber and micronutrients.

The last two observations may help explain some of the health benefits of plant-based diets.

 

Can Plant-Based Diets Be Unhealthy?

plant-based diets unhealthy cookiesNow, let’s return to the question I asked at the beginning of this article: “Can plant-based diets be unhealthy?” Although some previous studies have suggested that unhealthy plant-based diets might increase the risk of heart disease, this study did not show that.

What this study did show was that an unhealthy plant-based diet was no better for you than a diet containing lots of red meat and other animal foods.

If this were the only conclusion from this study, it might be considered a neutral result. However, this result clearly contrasts with the data from this study and many others showing that both plant-based diets in general and healthy plant-based diets reduce the risk of heart disease deaths and all-cause deaths compared to animal-based diets.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

There is one other subtle message from this study. This study did not compare vegans with the general public. Everyone in the study was the general public. Nobody in the study was consuming a 100% plant-based diet.

For example:

  • The group with the highest intake of plant foods consumed 9 servings per day of plant foods and 3.6 servings per day of animal foods.
  • The group with the lowest intake of plant foods consumed 5.4 servings per day of plant foods and 5.6 servings per day of animal foods.

In other words, you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet.

 

The Bottom Line

A recent study analyzed the effect of consuming plant foods on heart disease deaths and all-cause deaths over a 25-year period.

When the investigators looked at heart disease deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

A more subtle message from the study is that you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet. The people in this study were not following some special diet. The only difference was that some of the people in this study ate more plant foods and others more animal foods.

For more details on the 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.

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