Prenatal DHA Supplement

Written by Dr. Steve Chaney on . Posted in DHA and Pregnancy, Prenatal DHA Supplement

Author: Dr. Stephen Chaney

Is taking a prenatal DHA supplement wise for brain health?

There are lots of reasons to think that DHA supplementation may be important for healthy brain development.

  • DHA is a major component of the myelin sheath that coats every neuron in the brain.
  • Just as the plastic coating on copper wire allows it to conduct an electrical current, the myelin sheath allows neurons to conduct nerve impulses from one end of the neuron to the other. In short, the myelin sheath is absolutely essential for brain function.
  • Unlike many of the other components of the myelin sheath, the body cannot make DHA. It must be provided by the diet.
  • Recent studies have suggested that most women in the United States and Canada do not get sufficient amounts of the omega-3s EPA and DHA in their diet.
  • Animal studies show that DHA deficiency during pregnancy interferes with normal brain and eye development.

With all that circumstantial evidence, it would seem obvious that a prenatal DHA supplement would be important for healthy brain development in infants and children.  However, clinical studies have been all over the map.

Some studies have reported that DHA supplementation during pregnancy improves cognition, attention span, behavior or reading skills in both infants and children.  Other studies have shown no effect of DHA supplementation on those parameters.  There is no consensus on this very important question.

Thus, when I saw a recent study titled “Prenatal Supplementation with DHA Improves Attention At 5 Years Of Age: A Randomized Controlled Trial” (U Ramakrishnan et al, American Journal of Clinical Nutrition, doi: 10.3945/ajcn.114.101071, 2016), I decided to Investigate.

 

Does Taking a Prenatal DHA Supplement Improve Attention Span?

healthy brains for kidsIn this study 1094 Mexican women were randomly assigned to receive either 400 mg of DHA or a placebo containing corn and soy oil starting in the second trimester of pregnancy (a time at which myelination and brain development begins) until delivery. Of the women enrolled in the study, 973 of them gave birth to healthy babies.

The investigators were able to follow up with 797 (82%) of those children at age 5 and conducted tests to measure overall cognitive function, behavior, and attention span.

  • There were no differences in overall cognitive development or behavior between the two groups.
  • The children from mothers who supplemented with DHA performed significantly better in tests of attention span. They were much less likely to be distracted by external stimuli than the children from mothers not supplementing with DHA.
  • In short, this study suggested that supplementation with DHA during pregnancy produced children who were less likely to suffer from attention deficit disorders at age 5.

This study had a number of strengths:

  • It was a fairly large study (797 children).
  • Supplementation was with pure DHA rather than with a mixture of EPA, DHA, and other omega-3 fatty acids.
  • The population was from an urban area of Mexico where omega-3 intake is generally low, so it was likely that many of the women were DHA-deficient at the beginning of the study.

However, it also had some glaring weaknesses:

  • The DHA status of the women was not measured either at baseline or after supplementation.
  • The quality of the child’s learning environment was not measured.

In short, the study was neither better or worse than the many other published studies.

 

Why Is There So Much Confusion?

To try and clear up the confusion I have also analyzed many of the other published studies in this field. There were things not to like about every study, but there was no obvious reason why some studies showed a positive effect of DHA supplementation and others failed to see any benefit. This is not unusual for human nutrition clinical studies, but it is frustrating.

However, when you look at the totality of the studies in this field there is one obvious reason why there is so much confusion. There is no uniformity in experimental design. No two studies are alike.

The published studies differ in:

  • The composition of omega-3s. Some studies are done with pure DHA. Others with mixtures of EPA and DHA and with varying ratios of EPA to DHA.
  • The amount of DHA. Studies range from 100 mg/day to 800 mg/day.
  • When the DHA is given. Some studies give the DHA to the pregnant mothers. Others give DHA to infants or to children of various ages.

Even worse, most of the published studies to date have not measured omega-3 status prior to supplementation, nor have they documented an improvement in omega-3 status with supplementation. Obviously, DHA supplementation is most likely to be beneficial for individuals who were DHA-deficient at the beginning of the study.

Until there is some uniformity in experimental design and DHA status is routinely measured, it is likely that the confusion will continue and this important question will remain unanswered.

 

  Should Pregnant Women Take a Prenatal DHA Supplement?

prenatal dha supplementIf we were to assume that most American women were getting enough omega-3s in their diet, and the consequences of DHA deficiency were relatively minor, this would be merely an academic discussion. We could afford to wait years until scientists were able to come to a consensus.

However, neither of those assumptions are true:

  • One recent study reported that the United States and Canada rated last in the world with respect to omega-3 intake.
  • If any of the reported consequences (short attention span, cognitive deficits, and behavioral problems) of DHA-deficiency during pregnancy and childhood are true and they are preventable with DHA supplementation, this information is of vital importance to every woman during her child bearing years.

In short, inadequate DHA intake is so widespread and the possible consequences of DHA deficiency during pregnancy are so important that, in my opinion, a prenatal DHA supplement only makes sense. Pregnant women can’t afford to wait until we are absolutely sure that DHA supplementation is essential.

The only caveat to this recommendation is to make sure that the DHA you are getting is pure. Our oceans are increasingly polluted. Many fish and some fish oil supplements are contaminated with heavy metals and/or PCBs. Only use omega-3 and/or DHA supplements from manufacturers that use very stringent quality controls to assure their products are pure.

 

The Bottom Line

 

  • A recent study has reported that DHA supplementation during pregnancy improves attention span in children at age 5.
  • Unfortunately, there is no consensus in this field. Some studies have come to similar conclusions while others have seen no effect of DHA supplementation during pregnancy.
  • If we were to assume that omega-3 deficiency was rare in this country and the consequences of DHA deficiency during pregnancy were inconsequential, this would be an academic discussion. Pregnant women could wait for scientists to reach consensus before deciding whether or not to supplement with DHA. However, neither of those studies are true.
  • Studies show that most women in the US and Canada do not get adequate omega-3s during pregnancy.
  • If any of the reported consequences of DHA deficiency during pregnancy are true and they are preventable with DHA supplementation, this information is of vital importance to every woman during her pregnancy.
  • In short, inadequate DHA intake is so widespread and the possible consequences of DHA deficiency during pregnancy are so important that, in my opinion, DHA supplementation during pregnancy only makes sense. Pregnant women can’t afford to wait until we are absolutely sure that DHA supplementation is essential.
  • The only caveat to this recommendation is to make sure that the DHA you are getting is pure. Our oceans are increasingly polluted. Many fish and some fish oil supplements are contaminated with heavy metals and/or PCBs. Only use omega-3 and/or DHA supplements from manufacturers that use very stringent quality controls to assure their products are pure.

 

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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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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