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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Is Our Microbiome Affected By Exercise?

Posted November 6, 2018 by Dr. Steve Chaney

Microbiome Mysteries

Author: Dr. Stephen Chaney

is our microbiome affected by exerciseIn a recent post,  What is Your Microbiome and Why is it Important,  of “Health Tips From The Professor” I outlined how our microbiome, especially the bacteria that reside in our intestine, influences our health. That influence can be either good or bad depending on which species of bacteria populate our gut. I also discussed how the species of bacteria that populate our gut are influenced by what we eat and, in turn, influence how the foods we eat are metabolized.

I shared that there is an association between obesity and the species of bacteria that inhabit our gut. At present, this is a “chicken and egg” conundrum. We don’t know whether obesity influences the species of bacteria that inhabit our gut, or whether certain species of gut bacteria cause us to become obese.

Previous studies have shown that there is also an association between exercise and the species of bacteria that inhabit our gut. In particular, exercise is associated with an increase in bacteria that metabolize fiber in our diets to short chain fatty acids such as butyrate. That is potentially important because butyrate is a primary food source for intestinal mucosal cells (the cells that line the intestine). Butyrate helps those cells maintain the integrity of the gut barrier (which helps prevent things like leaky gut syndrome). It also has an anti-inflammatory effect on the immune cells that reside in the gut.

However, associations don’t prove cause and effect. We don’t know whether the differences in gut bacteria were caused by differences in diet or leanness in populations who exercised regularly and those who did not. This is what the present study (JM Allen et al, Medicine & Science In Sports & Exercise, 50: 747-757, 2018 ) was designed to clarify.  Is our microbiome affected by exercise?

 

How Was The Study Designed?

is our microbiome affected by exercise studyThis study was performed at the University of Illinois. Thirty-two previously sedentary subjects (average age = 28) were recruited for the study. Twenty of them were women and 12 were men. Prior to starting the study, the participants filled out a 7-day dietary record. They were asked to follow the same diet throughout the 12-week study. In addition, a dietitian designed a 3-day food menu based on their 7-day recall for the participants to follow prior to each fecal collection to determine species of gut bacteria.

The study included a two-week baseline when their baseline gut bacteria population was measured, and participants were tested for fitness. This was followed by a 6-week exercise intervention consisting of three supervised 30 to 60-minute moderate to vigorous exercise sessions per week. The exercise was adapted to the participant’s initial fitness level, and both the intensity and duration of exercise increased over the 6-week exercise intervention. Following the exercise intervention, all participants were instructed to maintain their diet and refrain from exercise for another 6 weeks. This was referred to as the “washout period.”

VO2max (a measure of fitness) was determined at baseline and at the end of the exercise intervention. Stool samples for determination of gut bacteria and concentrations of short-chain fatty acids were taken at baseline, at the end of the exercise intervention, and again after the washout period.

In short, this study divided participants into lean and obese categories and held diet constant. The only variable was the exercise component.

 

Is Our Microbiome Affected By Exercise?

is our microbiome affected by exercise fitnessThe results of the study were as follows:

  • Fitness, as assessed by VO2max, increased for all the participants, and the increase in fitness was comparable for both lean and obese subjects.
  • Exercise induced a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise increased fecal concentrations of butyrate and other short-chain fatty acids in the lean subjects, but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production were largely reversed once exercise training ceased.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent of diet, and contingent on the sustainment of exercise.” [Note: To be clear, the exercise-induced changes in both gut bacteria and short-chain fatty acid production were independent of diet and contingent on the sustainment of exercise. However, only the production of short-chain fatty acids was dependent on obesity status.]

 

What Does This Study Mean For You?

is our microbiome affected by exercise gut bacteriaThere are two important take home lessons from this study.

  • With respect to our gut bacteria, I have consistently told you that microbiome research is an emerging science. This is a small study, so you should regard it as the beginning of our understanding of the effect of exercise on our microbiome rather than conclusive by itself. It is consistent with previous studies showing an association between exercise and a potentially beneficial shift in the population of gut bacteria.

The strength of the study is that it shows that exercise-induced changes in beneficial gut bacteria are probably independent of diet. However, it is the first study to look at the interaction between obesity, exercise and gut bacteria, so I would interpret those results with caution until they have been replicated in subsequent studies.

  • With respect to exercise, this may be yet another reason to add regular physical activity to your healthy lifestyle program. We already know that exercise is important for cardiovascular health. We also know that exercise increases lean muscle mass which increases metabolic rate and helps prevent obesity. There is also excellent evidence that exercise improves mood and helps prevent cognitive decline as we age.

Exercise is also associated with decreased risk of colon cancer and irritable bowel disease. This effect of exercise has not received much attention because the mechanism of this effect is unclear. This study shows that exercise increases the fecal concentrations of butyrate and other short-chain fatty acids. Perhaps, this provides the mechanism for the interaction between exercise and intestinal health.

 

The Bottom Line

A recent study has reported that:

  • Exercise induces a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise causes an increase in the number of gut bacteria that produce butyrate and other short-chain fatty acids that are beneficial for gut health.
  • These effects are independent of diet, but do not appear to be independent of obesity because they were seen in lean subjects but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production are largely reversed once exercise training ceases.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent on diet, and contingent on the sustainment of exercise.”

For more details and my interpretation of the data, 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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