FLAX FACTS OMEGA-3 FATS ARE…

                                  FLAX FACTS
OMEGA-3 FATS ARE ESSENTIAL FOR INFANTS
by Dr. Diane H. Morris
   Infants have a high requirement for essential fats.            eicosanoids, which control the immune system. The
During pregnancy, the mother's diet is the source of              DHA and arachidonic acid derived from essential fatty
essential fats for the developing fetus. After birth,             acids are especially vital, as they are building materials
breast milk or infant formula supplies a variety of               for the structure of nervous tissue, including the brain.1
essential fats for newborn growth.1                               DHA, for example, is laid down rapidly in the grey
                                                                  matter of the brain and in the retina of the eye during
Essential Fats for Infants                                        the last trimester of pregnancy and the first year of
   Two families of fats ­ the omega-3 family and the              life.4 In these tissues, the DHA concentration can
omega-6 family ­ are vital for people of all ages,                exceed 50% of total fatty acids.5
including infants. Alpha-linolenic acid (ALA) is the
parent compound of the omega-3 family. ALA is                     Infants Need Omega-3 Fats to
essential in our diets because the human body cannot              Grow
make it. The human body can convert ALA to the                       After birth, infants obtain omega-3 and omega-6
long-chain omega-3 fatty acids, eicosapentaenoic acid             fatty acids from breast milk or infant formula. Preterm
(EPA) and docosahexaenoic acid (DHA).                             infants, because of their earlier-than-expected births,
   The parent compound of the omega-6 family is                   appear to have a greater need for essential fatty acids
linoleic acid. Like its cousin (ALA), linoleic acid is            than full-term infants.
essential for infants and adults because it cannot be
made in the human body. Linoleic acid can be
converted to a long-chain omega-6 fatty acid that goes              Omega-3 Fats in the Diets of Pregnant Women
by the tongue-twisting name of arachidonic acid.                    Suggested intakes of flax for pregnant and lactating women
                                                                    are described in the Flax Council of Canada's book,
   Although all of these omega-3 and omega-6 fats are
                                                                    Flax ­ A Health and Nutrition Primer, which is available
important in human nutrition, infants have a unique                 on the Council's website at www.flaxcouncil.ca.
need for two of them ­ DHA and arachidonic acid. It
                                                                    Cautions regarding the eating of some species of fish during
is not clear whether ALA has a unique role in infant                pregnancy are posted on the websites of Health Canada
nutrition, other than its recognized role in preventing             (www.hc-sc.gc.ca) and the U.S. Food and Drug Administration
an omega-3 fatty acid deficiency.2 The uncertainty                  (www.fda.gov).27,28
about ALA's unique contribution to infant health may
have arisen because most clinical research over the
past decade has focused on understanding the unique               ALA Is the Main Omega-3 Fat in Breast Milk. ALA
role of DHA in infant nutrition.                                  is the main omega-3 fatty acid in breast milk. ALA
                                                                  constituted 1.2% to 1.9% (% weight of total fatty acids)
                                                                  in breast milk samples taken from women in Canada
  ALA in Infant Nutrition
  · ALA is the essential omega-3 fatty acid, being required in    (1.2%),6 Brazil (1.4%),7 and Nepal (1.9%).8 Breast milk
    our diets because our bodies cannot make it.                  contains 3-10 times more ALA than DHA, depending
  · Infants need ALA to grow and develop properly.                on the mother's diet.6-10 The breast milk of vegetarians
  · ALA is the main omega-3 fatty acid in human breast milk.      contains less DHA than that of omnivores.2
  · A unique role for ALA in infant nutrition, other than being
    needed to prevent an omega-3 fat deficiency, has not been     Breast Milk is Best. Experts agree that breast milk is
    determined, possibly because most research has focused on
    the role of DHA in infant health.
                                                                  best for preterm and term infants. Breast milk provides
                                                                  calories, essential fatty acids, vitamins and other
                                                                  important nutrients.2,11,12
                                                                     Infants who are breast-fed have greater amounts of
Omega-3 Fats Are Needed                                           DHA in their blood, red blood cells and brain tissue
in utero                                                          than formula-fed infants. Some studies found that
   The growing fetus draws its supply of essential fatty          breast-fed infants performed better on tests of vision
acids from the mother through the placenta. For this              and cognitive development than formula-fed ones.13-15
reason, pregnant women must eat a diet containing                 In one study, children born to mothers who took cod
ample amounts of omega-3 and omega-6 fats for her                 liver oil (a source of DHA) during pregnancy and
own needs and also for those of the developing fetus.3            lactation scored higher on IQ tests at 4 years of age
   As the fetus grows in utero, essential fatty acids are         compared with children whose mother's diets were
needed for the production of compounds called                     supplemented with corn oil.16
ALA Content of Infant Formula. In Canada, infant                              optimum mix of essential fatty acids in infant formula?
formula must contain not less than 500 mg of linoleic                         For pregnant and nursing women, which diet pattern
acid. A minimum amount of ALA has not been                                    achieves the best omega-3 fat status in their growing
specified.17 In 2002 Health Canada allowed the use of                         infants? So far, research suggests that infant formula is
an oil blend containing DHA and arachidonic acid in                           not as good for babies as breast milk.26 For pregnant
infant formula.18                                                             women and nursing mothers, the best approach is to
   In the United States, the Life Sciences Research                           eat a varied diet containing ample amounts of ALA,
Office (LSRO) set a range for the ALA content in infant                       DHA and other omega-3 fats.
formula of 1.75% to 4% of total fatty acids. These
levels apply to infant formula for both preterm and                           References
term infants.2,11                                                             1.    Al MDM, et al. Am J Clin Nutr. 2000;71(suppl):285S-291S.
   The LSRO endorsed a ratio of linoleic acid to ALA                          2.    Klein CJ. J Nutr. 2002;132:1395S-1577S.
of not more than 16:1, and not less than 6:1. Upper                           3.    Hornstra G. Am J Clin Nutr. 2000;71(suppl):1262S-1269S.
and lower limits for the ratio were set to prevent                            4.    Innis SM. Placenta 2005;26 (suppl A):S70-S75.
inappropriate combinations of linoleic acid and ALA                           5.    Institute of Medicine. Dietary Reference Intakes, Part I.
that would prevent their conversion to their respective                             Washington, DC: National Academies Press, 2002,
long-chain essential fatty acids.                                                   pp. 8-1 ­ 8-97.
   The source of ALA for most infant formulas is a                            6.    Ratnayake WMN, Chen Z-Y. Lipids. 1996;31:S-279 ­ S-282.
polyunsaturated vegetable oil such as corn oil,                               7.    Silva MHL, et al. Food Chem. 2005;93:297-303.
safflower oil, or soybean oil. Canola oil is a                                8.    Schmeits BL, et al. Nutr Res. 1999;19:1339-1348.
component of some European infant formulas.2                                  9.    Jensen CL, et al. Am J Clin Nutr. 2000;71(suppl):292S-299S.
Canola and soybean oils contain modest amounts                                10.   Sala-Vila, et al. J Nutr. 2004;134:868-873.
of ALA.                                                                       11.   Raiten DJ, et al. J Nutr. 1998;128 (suppl 11S).
DHA Content of Infant Formula. The LSRO                                       12.   American Dietetic Association. Position of the American
recommended a maximum concentration of DHA of                                       Dietetic Association: Promoting and Supporting
0.35% of total fatty acids in preterm infant formula.                               Breastfeeding. JADA. 2005;105:810-818.
LSRO did not specify a minimum DHA content for                                13.   Anderson JW, et al. Am J Clin Nutr. 1999;70:525-535.
preterm infant formula. Egg yolk, fish oils and oils                          14.   Williams C, et al. Am J Clin Nutr. 2001;73:316-322.
produced by single-cell organisms (that is, microalgal                        15.   O'Connor DL, et al. Pediatrics. 2001;108:359-371.
and fungal oils) are sources of DHA and arachidonic                           16.   Helland IB, et al. Pediatrics. 2003;111:e39-e44.
acid in infant formulas.2                                                     17.   Department of Justice Canada. Food and Drug Regulations,
                                                                                    Part 2, section B.25.054. Available at http://laws.justice.gc.ca.
Benefits of Omega-3 Fat-Enriched Infant Formula.                              18.   Health Canada. Letter to Martek Biosciences Corporation,
Some infant formulas have been modified to contain                                  October 2002. Available at
ALA, DHA and other essential fatty acids. As a result,                              www.martekbio.com/images/corporatePages/CanadaPG1.gif.
studies have aimed to determine whether changes in                            19.   Udell T, et al. Lipids. 2005;40:1-11.
infant formula composition improve growth and                                 20.   SanGiovanni JP, et al. Pediatrics. 2000;105:1292-1298.
developmental outcomes in formula-fed preterm and                             21.   Birch EE, et al. Am J Clin Nutr. 2002;75:570-580.
term infants.                                                                 22.   Fewtrell MS, et al. Pediatrics. 2002;110:73-82.
   A recent meta-analysis of clinical studies ­                               23.   Auestad N, et al. Pediatrics. 2001;108:372-381.
5 involving term infants and 3 involving preterm                              24.   Auestad N, et al. Pediatrics. 2003;112:e177-e183.
infants ­ found that infants fed an infant formula                            25.   Makrides M, et al. Pediatrics. 2000;105:32-38.
supplemented with ALA had significantly higher                                26.   Gibson RA, Makrides M. (Comment) Pediatrics.
blood and red blood cell levels of DHA than infants                                 2001;108:465-466.
fed a regular formula without ALA.19 The findings                             27.   Health Canada. Information on mercury levels in fish.
suggest that ALA-supplemented formula improves the                                  Available at http://www.hc-sc.gc.ca/ahc-asc/media/
DHA status of infants.                                                              advisories-avis/2002/2002_41_e.html. Accessed
   The findings related to DHA-supplemented formula                                 September 14, 2005.
are surprisingly mixed. Some studies have shown a                             28.   U.S. Department of Health and Human Services, U.S.
benefit of supplementing formula with DHA in terms                                  Environmental Protection Agency. What you need to
of visual acuity,15,20,21 while others found no evidence                            know about mercury in fish and shell fish. Available at
to support adding DHA to formulas.22-25                                             http://www.cfsan.fda.gov/~dms/admehg3b.html.
                                                                                    Accessed September 10, 2005.
Omega-3 Fats in the Feeding of
Infants
   Many questions about the roles of omega-3 fats in
infant nutrition remain unanswered. What is the
unique role of ALA in infant nutrition? What is the

Flax Council of Canada, 465­167 Lombard Ave., Winnipeg, MB, Canada R3B 0T6, E-mail: flax@flaxcouncil.ca Website: www.flaxcouncil.ca   11.2005ED11.05