Do Women Get Enough Omega-3 During Pregnancy?

Written by Dr. Steve Chaney on . Posted in Food and Health, Healthy Living, Nutritiion, Supplements and Health

Should Pregnant Women Take Omega-3 Supplements?

Author: Dr. Stephen Chaney

 

  • omega-3 during pregnancyLong Chain Omega-3 Fatty Acids, Especially DHA, Are Essential For Normal Brain Development

Long chain omega-3 fatty acids, especially DHA, have been shown to be very important during pregnancy, especially during the third trimester when DHA accumulates in the fetal brain at a very high rate. It is during that third trimester that the fetus forms the majority of brain cells that they will have for an entire lifetime.

Inadequate intake of long chain omega-3 during pregnancy and lactation has been shown to be associated with poor neurodevelopmental outcomes. These include poor developmental milestones, problem solving, language development and increased hyperactivity in the children (Coletta et al, Reviews in Obstetrics & Gynecology, 3, 163-171, 2010).

  • The Current Recommendation is 200 mg DHA/day During Pregnancy & Lactation.

In order to support brain development in the fetus, some experts have recommend intake of 300 mg per day of DHA during pregnancy. The best dietary sources of long chain omega-3 fatty acids such as DHA are fish and fish oil supplements. However, because of concerns about seafood contamination with heavy metals and PCBs (both of which are neurotoxins), the FDA recommended in 2004 that pregnant women limit seafood consumption to two servings a week, which amounts to about 200 mg/day of DHA – and this has been subsequently adopted by the American College of Obstetricians and Gynecologists and the European Union as the amount of DHA recommended during pregnancy and lactation (Coletta et al, Reviews in Obstetrics & Gynecology, 3, 163-171, 2010).

Even that recommendation for DHA from seafood could be overly generous. A recent study using the EPA risk assessment protocol concluded that some farmed salmon were so contaminated with PCBs that they should be eaten no more than once a year (Hites et al, Science, 303: 226-229, 2004).

  • Most Pregnant & Lactating Women In The US Are Probably Not Getting The Recommended Amount of DHA In Their Diet

Many pregnant women avoid seafood because of concerns about mercury and PCBs. Unfortunately, the other food sources of omega-3 fatty acids in the American diet, even many omega-3 fortified foods and supplements, are primarily composed of the short chain omega-3 fatty acid linolenic acid (also called alpha-linolenic acid or ALA), and only 1-4% of linolenic acid is converted to DHA in the body (Coletta et al, Reviews in Obstetrics & Gynecology, 3, 163-171, 2010).

Consequently, experts have been concerned for some time that American and Canadian women may not be getting enough DHA during pregnancy and lactation, but it was not clear how serious an issue this was.

Do Women Get Enough Omega-3 During Pregnancy?

women take enough dha omega-3 during pregnancyA group of scientists decided to test the adequacy of DHA intake by comparing DHA intake with the recommended 200 mg/day in a group of 600 pregnant and lactating women enrolled in the Alberta Pregnancy Outcomes and Nutrition study (Jia et al, Applied Physiology, Nutrition & Metabolism, 40: 1-8, 2015). The average age of the women in this study was 31.6. They were primarily Caucasian and married. 92% of them breastfed their infants. Most of them were taking a multivitamin or prenatal supplement on a daily basis. Approximately 1/3 of them were also taking a long chain omega-3 supplement.

The majority of women had completed college and had annual household incomes in excess of $100,000/year. In short, this was a very affluent, well-educated group of women. This is the kind of group one might consider most likely to be getting enough DHA from their diet.

DHA intake was based on 24 hour food recalls and supplement intake questionnaires collected in face-to-face interviews 2-3 times during pregnancy and again 3 months after delivery. The DHA content of the diet was determined from these data using well established methods.

The results were both dramatic and concerning.

  • Only 27% of pregnant women and only 25% of postpartum women who were breastfeeding met the recommendation of 200 mg of DHA/day. In short, nearly three-quarters of the women in the study were not getting enough (DHA) omega-3 during pregnancy and lactation.
  • When the women who were taking DHA-containing supplements were excluded from the data analysis, only 13% of pregnant and lactating women were getting enough DHA from their diet. In short, nearly 90% of the women relying on diet alone were not getting enough DHA.
  • Taking a DHA-containing supplement increased the likelihood of achieving the recommended 200 mg DHA/day by 10.6 fold during pregnancy and 11.1 fold during breastfeeding.
  • Not surprisingly, seafood, fish and seaweed products were the major contributors to the total dietary DHA intake.

The authors concluded “Our results suggest that the majority of participants in the cohort were not meeting the EU recommendations for DHA during pregnancy and lactation, but taking a supplement significantly improved the likelihood that they would meet the recommendations.”

 

The Bottom Line

  • Long chain omega-3 fatty acids, especially DHA, are essential for normal brain development. Inadequate DHA intake during pregnancy and lactation is associated with poor developmental milestones, problem solving, language development and increased hyperactivity in the children.
  • There is no established Daily Value for omega-3 fatty acids. However, the American College of Obstetricians and Gynecologists and the European Union recommend 200 mg DHA/day during pregnancy and lactation.
  • This recommendation is based partly on the amount of DHA needed for brain development and partly on the FDA warning that pregnant women should not consume more than 2 servings of fish/week due to heavy metal and PCB contamination.
  • This recommendation can be met by 1-2 six ounce servings/week of fish or a fish oil supplement containing 550 – 600 mg of omega-3 fatty acids.
  • Many pregnant women avoid fish because of concerns about contamination with heavy metals and PCBs, both of which are neurotoxins. Therefore, the major source of omega-3s in the American and Canadian diets are short chain omega-3 fatty acids that are only inefficiently (1-4%) converted to DHA.
  • Consequently, experts have been concerned for some time that American and Canadian women may not be getting enough DHA during pregnancy and lactation, but it was not clear how serious an issue this was.
  • A recent study done with a group of 600 women enrolled in the Alberta Pregnancy Outcomes and Nutrition study found that:
  • Only 27% of pregnant women and only 25% of postpartum women who were breastfeeding met the recommendation of 200 mg of DHA/day. In short, nearly three-quarters of the women in the study were not getting enough (DHA) omega-3 during pregnancy and lactation.
  • When the women who were taking DHA-containing supplements were excluded from the data analysis, only 13% of pregnant and lactating women were getting enough DHA from their diet. . In short, nearly 90% of the women relying on diet alone were not getting enough DHA.
  • Taking a DHA-containing supplement increased the likelihood of achieving the recommended 200 mg DHA/day by 10.6 fold during pregnancy and 11.1 fold during breastfeeding.
  • This was a very affluent, well-educated group of women. If any women anywhere are getting enough DHA during pregnancy and lactation, this should have been the group that was.
  • The authors concluded “Our results suggest that the majority of participants in the cohort were not meeting the EU recommendations for (DHA) omega-3 during pregnancy and lactation, but taking a supplement significantly improved the likelihood that they would meet the recommendations.”

 

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.

Trackback from your site.

Leave a comment

Recent Videos From Dr. Steve Chaney

READ THE ARTICLE
READ THE ARTICLE

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.

UA-43257393-1