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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Latest Article

Should We Use Supplements For Cardiovascular Health?

Posted July 10, 2018 by Dr. Steve Chaney

Are You Just Wasting Your Money On Supplements?

Author: Dr. Stephen Chaney

 

supplements for cardiovascular health wast moneyYou’ve seen the headlines. “Recent Study Finds Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.”  You are being told that supplements are of no benefit to you. They are a waste of money. You should follow a healthy diet instead. Is all of this true?

If I were like most bloggers, I would give you a simple yes or no answer that would be only partially correct. Instead, I am going to put the study behind these headlines into perspective. I am going to give you a deeper understanding of supplementation, so you can make better choices for your health.

 Should we use supplements for cardiovascular health?

In today’s article I will give you a brief overview of the subject. Here are the topics I will cover today:

  • Is this fake news?
  • Did the study ask the right questions?
  • Is this a question of “Garbage In – Garbage Out?
  • Reducing Heart Disease Risk. What you need to know.

All these topics are covered in much more detail (with references) in my book “Slaying The Supplement Myths”, which will be published this fall.

 

How Was This Study Done?

supplements for cardiovascular healthThis study (D.J.A. Jenkins et al, Journal of the American College Of Cardiology, 71: 2540-2584, 2018 ) was a meta-analysis. Simply put, that means the authors combined the results of many previous studies into a single database to increase the statistical power of their conclusions. This study included 127 randomized control trials published between 2012 and December 2017. These were all studies that included supplementation and looked at cardiovascular end points, cancer end points or overall mortality.

Before looking at the results, it is instructive to look at the strengths and weaknesses of the study. Rather than giving you my interpretation, let me summarize what the authors said about strengths and weaknesses of their own study.

The strengths are obvious. Randomized control trials are considered the gold standard of evidence-based medicine, but they have their weaknesses. Here is what the authors said about the limitations of their study:

  • “Randomized control trials are of shorter duration, whereas longer duration studies might be required to fully capture chronic disease risk.”
  • “Dose-response data were not usually available [from the randomized control studies included in their analysis]. However, larger studies would allow the effect of dose to be assessed.”

There are some other limitations of this study, which I will point out below.

Is This Fake News?

supplements for cardiovascular health fake newsWhen I talk about “fake news” I am referring to the headlines, not to the study behind the headlines. The headlines were definitive: “Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.” However, when you read the study the reality is quite different:

  • In contrast to the negative headlines, the study reported:
    • Folic acid supplementation decreased stroke risk by 20% and overall heart disease risk by 17%.
    • B complex supplements containing folic acid, B6, and B12 decreased stroke risk by 10%.
    • That’s a big deal, but somehow the headlines forgot to mention it.
  • The supplements that had no significant effect on heart disease risk (multivitamins, vitamin D, calcium, and vitamin C) were ones that would not be expected to lower heart disease risk. There was little evidence from previous studies of decreased risk. Furthermore, there is no plausible mechanism for supposing they might decrease heart disease risk.
  • The study did not include vitamin E or omega-3 supplements, which are the ones most likely to prove effective in decreasing heart disease risk when the studies are done properly (see below).

Did The Study Ask The Right Question?

Most of the studies included in this meta-analysis were asking whether a supplement decreased heart disease risk or mortality for everyone. Simply put, the studies started with a group of generally healthy Americans and asked whether supplementation had a significant effect on disease risk for everyone in that population.

That is the wrong question. We should not expect supplementation to benefit everyone equally. Instead, we should be asking who is most likely to benefit from supplementation and design our clinical studies to test whether those people benefit from supplementation.

supplements for cardiovascular health diagramI have created the graphic on the right as a guide to help answer the question of “Who is most likely to benefit from supplementation?”. Let me summarize each of the points using folic acid as the example.

 

Poor Diet: It only makes sense that those people who are deficient in folate from foods are the most likely to benefit from folic acid supplementation. Think about it for a minute. Would you really expect people who are already getting plenty of folate from their diet to obtain additional benefits from folic acid supplementation?

The NIH estimates that around 20% of US women of childbearing age are deficient in folic acid. For other segments of our population, dietary folate insufficiency ranges from 5-10%. Yet, most studies of folic acid supplementation lump everyone together – even though 80-95% of the US population is already getting enough folate through foods, food fortification, and supplementation. It is no wonder most studies fail to find a beneficial effect of folic acid supplementation.

The authors of the meta-analysis I discussed above said that the beneficial effects of folic acid they saw might have been influenced by a very large Chinese study, because a much higher percentage of Chinese are deficient in folic acid. They went on to say that the Chinese study needed to be repeated in this country.

In fact, the US study has already been done. A large study called “The Heart Outcomes Prevention Evaluation (HOPE)” study reported that folic acid supplementation did not reduce heart disease risk in the whole population. However, when the study focused on the subgroup of subjects who were folate-deficient at the beginning of the study, folic acid supplementation significantly decreased their risk of heart attack and cardiovascular death.  This would seem to suggest using supplements for cardiovascular health is a good idea.

Increased Need: There are many factors that increase the need for certain nutrients. However, for the sake of simplicity, let’s only focus on medications. Medications that interfere with folic acid metabolism include anticonvulsants, metformin (used to treat diabetes), methotrexate and sulfasalazine (used to treat severe inflammation), birth control pills, and some diuretics. Use of these medications is not a concern when the diet is adequate. However, when you combine medication use with a folate-deficient diet, health risks are increased and supplementation with folic acid is more likely to be beneficial.

Genetic Predisposition: The best known genetic defect affecting folic acid metabolism is MTHFR. MTHFR deficiency does not mean you have a specific need for methylfolate. However, it does increase your need for folic acid. Again, this is not a concern when the diet is adequate. However, when you combine MTHFR deficiency with a folate-deficient diet, health risks are increased and supplementation with folic acid is more likely to be beneficial. I cover this topic in great detail in my upcoming book, “Slaying The Supplement Myths”. In the meantime, you might wish to view my video, “The Truth About Methyl Folate.”

Diseases: An underlying disease or predisposition to disease often increases the need for one or more nutrients that help reduce disease risk. The best examples of this are two major studies on the effect of vitamin E on heart disease risk in women. Both studies found no effect of vitamin E on heart disease risk in the whole population. However, one study reported that vitamin E reduced heart disease risk in the subgroup of women who were post-menopausal (when the risk of heart disease skyrockets). The other study found that vitamin E reduced heart attack risk in the subgroup of women who had pre-existing heart disease at the beginning of the study.

Finally, if you look at the diagram closely, you will notice a red circle in the middle. When two or three of these factors overlap, that is the “sweet spot” where supplementation is almost certain to make a difference and it may be a good idea to use supplements for cardiovascular health.

Is This A Question Of “Garbage In, Garbage Out”?

supplements for cardiovascular health garbage in outUnfortunately, most clinical studies focus on the “Does everyone benefit from supplementation question?” rather than the “Who benefits from supplementation?” question.

In addition, most clinical studies of supplementation are based on the drug model. They are studying supplementation with a single vitamin or mineral, as if it were a drug. That’s unfortunate, because vitamins and minerals work together synergistically. What we need are more studies of holistic supplementation approaches.

Until these two things change, most supplement studies are doomed to failure. They are doomed to give negative results. In addition, meta-analyses based on these faulty supplement studies will fall victim to what computer programmers refer to as “Garbage In, Garbage Out”. If the data going into the analysis is faulty, the data coming out of the study will be equally faulty. It won’t be worth the paper it is written on. If you are looking for personal guidance on supplementation, this study falls into that category.

 

Should We Use Supplements For Cardiovascular Health?

 

If you want to know whether supplements decrease heart disease risk for everyone, this meta-analysis is clear. Folic acid may decrease the risk of stroke and heart disease. A B complex supplement may decrease the risk of stroke. All the other supplements they included in their analysis did not decrease heart disease risk, but the analysis did not include vitamin E and/or omega-3s.

However, if you want to know whether supplements decrease heart disease risk for you, this study provides no guidance. It did not ask the right questions.

I would be remiss, however, if I failed to point out that we know healthy diets can decrease heart disease risk. In the words of the authors: “The recent science-based report of the U.S. Dietary Guidelines Advisory Committee, also concerned with [heart disease] risk reduction, recommended 3 dietary patterns: 1) a healthy American diet low in saturated fat, trans fat, and meat, but high in fruits and vegetables; 2) a Mediterranean diet; and 3) a vegetarian diet. These diets, with their accompanying recommendations, continue the move towards more plant-based diets…” I cover the effect of diet on heart disease risk in detail in my book, “Slaying The Food Myths”.

 

The Bottom Line

 

You have probably seen the recent headlines proclaiming: “Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.” The study behind the headlines was a meta-analysis of 127 randomized control trials looking at the effect of supplementation on heart disease risk and mortality.

  • The headlines qualify as “fake news” because:
    • The study found that folic acid decreased stroke and heart disease risk, and B vitamins decreased stroke risk. Somehow the headlines forgot to mention that.
    • The study found that multivitamins, vitamin D, calcium, and vitamin C had no effect on heart disease risk. These are nutrients that were unlikely to decrease heart disease risk to begin with.
    • The study did not include vitamin E and omega-3s. These are nutrients that are likely to decrease heart disease risk when the studies are done properly.
  • The authors of the study stated that a major weakness of their study was that that randomized control studies included in their analysis were short term, whereas longer duration studies might be required to fully capture chronic disease risk.
  • The study behind the headlines is of little use for you as an individual because it asked the wrong question.
  • Most clinical studies focus on the “Does everyone benefit from supplementation question?” That is the wrong question. Instead we need more clinical studies focused on the “Who benefits from supplementation?” question. I discuss that question in more detail in the article above.
  • In addition, most clinical studies of supplementation are based on the drug model. They are studying supplementation with a single vitamin or mineral, as if it were a drug. That’s unfortunate, because vitamins and minerals work together synergistically. What we need are more studies of holistic supplementation approaches.
  • Until these two things change, most supplement studies are doomed to failure. They are doomed to give negative results. In addition, meta-analyses based on these faulty supplement studies will fall victim to what computer programmers refer to as “Garbage In, Garbage Out”. If the data going into the analysis is faulty, the data coming out of the study will be equally faulty. It won’t be worth the paper it is written on. If you are looking for personal guidance on supplementation, this study falls into that category.
  • If you want to know whether supplements decrease heart disease risk for everyone, this study is clear. Folic acid may decrease the risk of stroke and heart disease. A B-complex supplement may decrease the risk of stroke. All the other supplements they included in their analysis did not decrease heart disease risk, but they did not include vitamin E and/or omega-3s in their analysis.
  • If you want to know whether supplements decrease heart disease risk for you, this study provides no guidance. It did not ask the right questions.
  • However, we do know that healthy, plant-based diets can decrease heart disease risk. I cover heart healthy diets in detail in my book, “Slaying The Food Myths.”

 

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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