DHA During Pregnancy; Yes or No?

Written by Dr. Steve Chaney on . Posted in DHA and Pregnancy, Omega-3 Fish Oil Supplements

Are Pregnant Women Deficient In Omega-3s?

Author: Dr. Stephen Chaney

 

dha during pregnancyDo women need DHA during pregnancy?  Most experts agree that omega-3 fatty acids, especially DHA, are essential for fetal development during pregnancy and for brain development through at least the first two years of a child’s life. That’s because DHA is an important component of the myelin sheath that coats and protects our brain neurons.

During the last two trimesters of pregnancy and the first two years of a child’s life, their brains are growing and maturing at a remarkable rate. The need for DHA during this critical period is huge, and most of that DHA comes from the mom. That’s why the mom’s intake of DHA during pregnancy and breastfeeding is so important.

For example, higher intakes of omega-3s during pregnancy and breastfeeding have been associated with:

  • Decreased maternal depression.
  • Increased birth weight.
  • Reduced risk of preterm birth.
  • Reduction in ADHD symptoms.
  • Reduction in allergies and asthma.
  • Improved developmental and cognitive outcomes such as:
    • Increased visual acuity.
    • Better problem-solving skills.

I do wish to acknowledge that there is still debate in the scientific literature about the strength of some of these associations. However, there is enough cumulative evidence for the beneficial effects of omega-3s especially DHA during pregnancy and breastfeeding that virtually all experts agree adequate maternal omega-3 intake is important during this crucial period in a child’s life.

 

How Much DHA During Pregnancy & Breastfeeding Is Needed?

fish oil dha during pregnancyThe National Academies of Science have not yet set a Daily Value for omega-3s. However, a group of experts met in 1999 to recommend adequate dietary intake of omega-3s (Simopoulos et al, Prostaglandins, Leukotrienes & Essential Fatty Acids, 63: 119-121, 2000 ). They concluded that an adequate intake of omega-3 fatty acids in adults was at least 650 mg/day with at least 440 mg/day of that coming from EPA + DHA (220 mg/day each of EPA and DHA). They further recommended that DHA intake in pregnant and lactating women should be at least 300 mg/day.

However, because of concerns about seafood contamination with heavy metals and PCBs (both of which are neurotoxins), the FDA recommended in 2004 that pregnant and lactating women limit seafood consumption to two servings a week, which amounts to about 200 mg/day of DHA. This has been subsequently adopted by the American College of Obstetricians and Gynecologists and the European Union as the recommended amount of DHA during pregnancy and lactation (Coletta et al, Reviews in Obstetrics & Gynecology, 3, 163-171, 2010 ).

How Was The Study Done?

The authors of this study (Nordgren et al, Nutrients, 2017, 9, 197; doi:10.3390/nu9030197 ) utilized a nationwide database called NHANES (National Health and Nutrition Examination Survey). NHANES data are based on an annual survey conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and to track changes over time.

Dietary intake of nutrients is based on two interviewer-administered, 24-hour dietary recalls conducted 3-10 days apart. Omega-3 intake was calculated based on the USDA database of nutrient composition of foods.

The investigators combined NHANES data from the years 2003 to 2012. This included 6478 women of childbearing years (14-45 years old), of which 788 were pregnant at the time of the survey.

Are Pregnant Women Deficient In Omega-3s?

omega3 deficiency in pregnant womenThe results of this study were alarming:

  • Mean EPA + DHA intake was only 89 mg/day with no difference between pregnant and non-pregnant women of childbearing age.
  • This contrasts to the expert committee’s recommendation of at least 440 mg/day for EPA + DHA (220 mg/day each from EPA and DHA).
  • Mean DHA intake was only 66 mg/day in pregnant and 58 mg/day in non-pregnant women of childbearing status.
  • This contrasts to the recommendations of 200 – 300 mg/day for pregnant women.
  • These intakes did not include dietary supplements, but only 1.8% of non-pregnant and 9% of pregnant women in this survey took supplements containing EPA and/or DHA.

The authors concluded “Our results demonstrate that omega-3 fatty acid intake is a concern in pregnant women and women of childbearing age…” They went on to say: ‘Strategies to increase omega-3 fatty acid intake in these populations could have the potential to improve maternal and infant health outcomes.”

What Do Other Studies Show?

This study is not an outlier. In a previous issue  Do Women Get Enough Omega-3 During Pregnancy of “Health Tips From the Professor” I reported on a study showing that 90% of Canadian women were not getting enough DHA in their diet. A similar study in Germany concluded that 97% of middle-aged women had suboptimal omega-3 status (Gellert et al, Prostaglandins, Leukotrienes and Essential Fatty Acids, doi: 10.1016/j.plefa.2017.01.009 ).

More importantly, these omega-3 deficiencies matter. In another issue DHA Supplements During Pregnancy of “Health Tips From the Professor” I reported on a study showing that DHA supplementation significantly reduced preterm births. Based on that effect alone, the authors concluded that DHA supplementation during pregnancy could save the US healthcare system close to $6 billion/year.

Women do need DHA during pregnancy.

The Bottom Line

  • Optimal intake of omega-3s during pregnancy and breastfeeding is associated with:
    • Decreased maternal depression.
    • Increased birth weight.
    • Reduced risk of preterm birth.
    • Reduction in ADHD symptoms.
    • Reduction in allergies and asthma.
    • Improved developmental and cognitive outcomes such as:
      • Increased visual acuity.
      • Better problem-solving skills.
  • In 1999, a panel of experts met to set standards for omega-3 intake. They recommended:
    • At least 650 mg/day for adults with at least 440 mg/day coming from EPA + DHA (220 mg/day each of EPA and DHA).
    • At least 300 mg/day of DHA for pregnant and breastfeeding women.
  • Because of concerns about seafood contamination with heavy metals and PCBs (both of which are neurotoxins), the FDA reduced the recommendation for pregnant and breastfeeding women to 200 mg/day of DHA. That recommendation has been subsequently adopted by the American College of Obstetricians and Gynecologists and the European Union.
  • A recent study has found:
    • Mean EPA + DHA intake was only 89 mg/day with no difference between pregnant and non-pregnant women of childbearing age.
      • This contrasts to the expert committee’s recommendation of at least 440 mg/day (with 220 mg/day each from EPA and DHA).
    • Mean DHA intake was only 66 mg/day in pregnant and 58 mg/day in non-pregnant women of childbearing status.
      • This contrasts to the recommendations of 200 – 300 mg/day for pregnant and breastfeeding women.
    • These intakes did not include dietary supplements, but only 1.8% of non-pregnant and 9% of pregnant women in this survey took supplements containing EPA and/or DHA.
    • This study is in line with recent studies in Canada and Germany. Clearly pregnant and Breastfeeding women in developed countries like the US are getting suboptimal amounts of omega-3s in their diet.
    • This is alarming because these findings come amidst mounting evidence that optimal omega-3 intake during pregnancy and breastfeeding is important for the health of both mother and child.

     

    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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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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