Fact Sheet on PeriLip

The European Commission have recently funded a project on Perinatal Lipid Metabolism (PeriLip) and a project on Early Nutritional Programming (EARNEST, www.metabolic-programming.org). These projects, together with experts representing other groups (1) have recently agreed to a consensus recommendation regarding desirable levels of intake of the omega-3 long chain polyunsaturated fatty acid (n-3 LC-PUFA), docosahexaenoic acid (DHA) for pregnant and lactating women (1).

A coordination committee (Professor Berthold Koletzko (Dr. von Hauner Children´s Hospital, University of Munich, Germany), Professor Irene Cetin (Department for the Health of Woman, Child and Neonate, IRCCS Foundation Po.Ma.Re., University of Milan, Italy) and Professor Thomas Brenna (Division of Nutritional Science, Cornell University, Ithaca, NY, USA) carried out an initial review, identified critical issues and recruited collaborating experts to complete detailed literature reviews. These included toxicological aspects of fish consumption as well as benefits from DHA consumption. An expert workshop was held in September 2005 the results of which led to the unanimous conclusions which are summarised below.

  • Pregnant and nursing women should consume the same levels of fat, as a proportion of overall energy intake, in their diets as the general population (2, 3).
  • Several studies suggest that there is an association between maternal intake of n-3 LC-PUFA when pregnant or lactating, taken either from an oily capsule or from oily fish consumption, and development of vision and cognition in the infant (4-6). The critical period for accretion of DHA in the brain and other tissues is during fetal development and post-natal life (7, 8). Based on these studies, a daily intake of at least 200 mg of DHA should be the target for pregnant and lactating women. Higher intakes (up to 1g per day of DHA and 2.7g per day total LC-PUFA) have been shown in randomised trials to have no significant adverse effects in pregnancy (9, 10).
  • Oily fish is a good source of LC-PUFA in general and one to two portions of sea fish per week would provide the recommended intake of DHA. Such a diet would rarely exceed the tolerable intake of organic contaminants. Large predatory fish are more likely to be contaminated with methyl mercury and a wide range of fish should be consumed (11).
  • Consumption of a precursor of DHA, α-linolenic acid, is considerably less effective than dietary DHA itself in the deposition of DHA in the fetal brain (12).
  • Arachadonic acid (another LC-PUFA) is not required in the diet of women of childbearing age if they have adequate linoleic acid in their diet (13).
  • Maternal intake of fish, fish oil or n-3 LC-PUFA appears to have a further consequence in that it “results in a slightly longer duration of gestation, a somewhat higher birth weight and a reduced risk of preterm delivery” (9, 10, 14). It is unclear what the clinical importance of these effects to the health of the infant is.
  • The consequences of these findings are that pregnant women should be screened to ensure they have adequate nutrition — preferably during the first trimester. Any issues relating to poor dietary habits during pregnancy or lactation can then be addressed by individual counselling.

Further Information

Sources of DHA
  1. Maternal
    While fish and fish oil are considered to be a good source of DHA, intake by pregnant women and women of child-bearing age remain low. In addition to worries over contaminants and taste and flavour issues, perceived or actual fish allergy remains a concern. The Food Standards Agency has noted that “Someone with a fish allergy could have an allergic reaction to fish-oil supplements. It is the protein in the food that triggers an allergic reaction and some fish protein could be present in the supplements, depending on how highly processed and pure they are” (http://www.eatwell.gov.uk/asksam/healthissues/foodintolerance/fishoilsupp/). Most alternative plant derived sources of omega 3 fatty acids (e.g. flaxseed oil, walnuts, linseed oil) contain largely α-linolenic acid which neither has the benefits of DHA nor is bioconverted to it in the body. Some other foods (e.g. eggs) also contain DHA and a list of fresh and prepared foods with typical DHA levels is available (http://www.dietaryfiberfood.com/fats/omega-3-fatty-acids-dha-food-sources.php). Supplements containing DHA are available. Many of these are derived from fish sources. However DHA is also produced by algae which is an alternative, non-fish source and does not contain methyl mercury or any other contaminants. In addition it is often difficult to determine how much of the active principles are present in the supplements due to differences in nomenclature and labelling.
  2. Infants
    The major benefits for infants are in brain and eye development and improved developmental outcomes. Infants can obtain an adequate supply of DHA either from breast milk or from supplemented infant formula. Supplemented formula has been used in many countries for several years and both its safety and benefits from its use have been demonstrated.
  3. References

    1. Koletzko B, Cetin I, Brenna JT; Perinatal Lipid Intake Working Group; Child Health Foundation; Diabetic Pregnancy Study Group; European Association of Perinatal Medicine; European Association of Perinatal Medicine; European Society for Clinical Nutrition and Metabolism; European Society for Paediatric Gastroenterology, Hepatology and Nutrition, Committee on Nutrition; International Federation of Placenta Associations; International Society for the Study of Fatty Acids and Lipids. (2007)
      Br J Nutr. , 98(5):873-7.
      Dietary fat intakes for pregnant and lactating women.
    2. Prentice AM & Goldberg GR (2000)
      Am J Clin Nutr 71, Suppl. 5, 1226S–1232S.
      Energy adaptations in human pregnancy: limits and long-term consequences.
    3. Butte NF & King JC (2005)
      Public Health Nutr 8 (7A), 1010–1027.
      Energy requirements during pregnancy and lactation.
    4. Jensen CL, Voigt RG, Prager TC, et al. (2005).
      Am J Clin Nutr 82, 125–132.
      Effects of maternal docosahexaenoic acid intake on visual function and neurodevelopment in breastfed term infants
    5. Uauy R & Dangour AD (2006)
      Nutr Rev 64 (5 Pt 2),S24–S33.
      Nutrition in brain development and aging: role of essential fatty acids.
    6. Birch EE, Garfield S, Castañeda Y, Hughbanks-Wheaton D, Uauy R, Hoffman D. (2007)
      Early Hum Dev. 83(5):279-84.
      Visual acuity and cognitive outcomes at 4 years of age in a double-blind, randomized trial of long-chain polyunsaturated fatty acid-supplemented infant formula.
    7. Fleith M & Clandinin MT (2005)
      Crit Rev Food Sci Nutr 45, 205–229.
      Dietary PUFA for preterm and term infants: review of clinical studies.
    8. Innis SM (2005)
      Placenta 26, S70–S75.
      Essential fatty acid transfer and fetal development.
    9. Szajewska H, Horvath A & Koletzko B (2006)
      Am J Clin Nutr 83, 1337–1344.
      Effect of n-3 long-chain polyunsaturated fatty acid supplementation of women with low-risk pregnancies on pregnancy outcomes and growth measures at birth: a meta-analysis of randomized controlled trials.
    10. Makrides M, Duley L & Olsen SF (2006)
      Cochrane Database Syst Rev 3, CD003402.
      Marine oil, and other prostaglandin precursor, supplementation for pregnancy uncomplicated by pre-eclampsia or intrauterine growth restriction.
    11. European Food Safety Authority (2007)
      Opinion of the Scientific Panel on Contaminants in the Food Chain on a request from the Commission related to mercury and methylmercury in food
      (Request N8 EFSA-Q-2003-030, adopted on 24 February 2004).
      The EFSA Journal 34, 1–14.
    12. Burdge GC & Calder PC (2005)
      Reprod Nutr Dev 45, 581–597.
      Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults.
    13. Klingler M, Demmelmair H, Larque E & Koletzko B (2003)
      Lipids 38, 561–566.
      Analysis of FA contents in individual lipid fractions from human placental tissue
    14. 1.Horvath A, Koletzko B, Szajewska H. (2007)
      Br J Nutr. 98(2):253-9.
      Effect of supplementation of women in high-risk pregnancies with long-chain polyunsaturated fatty acids on pregnancy outcomes and growth measures at birth: a meta-analysis of randomized controlled trials.