Optimizing beneficial fats in breastmilk
types of fat consumed by pregnant and lactating women can have
an impact on the quality and availability of important omega
three fatty acids for the growing infant.
Much of the fat present in our food system has been hydrogenated,
i.e., the carbon bonds are saturated with hydrogen molecules.
During the hydrogenation process the configuration of the fat
molecules are changed to trans fatty acids. This
gives the food manufacturer an advantage as products containing
the altered fats have a much longer shelf life and are less likely
to become rancid. Consumption of trans fatty acids has steadily
increased in industrialized countries. In the US and Great Britain
the consumption of total fats as trans has risen to over 6 per
cent of total dietary fats. Until recently
it was assumed that trans fatty acids did not cross the human
placenta; however, this assumption has been proven wrong and
trans fatty acids levels are found to be similar in cord and
maternal plasma lipids.(1) Trans
fatty acids also cross over into breastmilk.(2)
What are the potential side effects of trans fatty acids to the
growing infant pre- and postnatally?
- Impair and limit the production of essential fatty acids,
DHA and arachidonic.
- In newborn mice and rats fed hydrogenated oils, postnatal
weight gain was impaired.
- Lower birth weights in piglets when the sow was fed partially
- In premature infants total trans fatty acids were inversely
correlated to the levels of long chain essential fatty acids
and inversely correlated to birth weight.
What are the effects of reduced essential fatty acids?
- During the last trimester of pregnancy there is a large accumulation
of long chain polyunsaturated fatty acids (DHA, AA) corresponding
with the rapid growth of neural, brain and retinol tissue. Reduced
levels of the essential fatty acids may compromise the full development
of the affected infants.
- Failure to thrive is another potential impact of inadequate
amounts of essential fatty acids.
- Low reserves of essential fatty acids at birth will be further
compromised if the infant is artificially fed (baby milks sold
in Canada have no DHA and AA).
These problems can be easily solved. Pregnant and lactating women
can clear their systems of trans fatty acids in about two weeks
time if they:
- Consume natural fats such as butter and
vegetable oils (non-hydrogenated) as spread, and in cooking and
baking. Avoid margarines.(3)
- Avoid consumption of deep fried foods in fast food restaurants
such as french fries and doughnuts.
- Read labels of commercially prepared foods
and avoid foods containing hydrogenated fats. Commercially baked
goods, frozen french fries, snack foods can be very high in trans
- Consume foods containing essential fatty acids more frequentlyeggs,
fish, liver. Expensive supplements are not necessary.
What can be done to reduce the dumbing down of food
- Informative labelling of the percentage of total fats present
as trans fatty acids should be compulsory so that pregnant and
breastfeeding women can make healthy food choices.
- Better yet, in addition to full disclosure labelling, mandatory
maximum permissible levels in commercially prepared food products
should be set to bring down the extremely high levels that are
- Write to the minister responsible for Health Canada:
The Honourable Allan Rock
House of Commons
Ottawa, ON K1A 0A6
- Tell him you want a safe food system that does not put the
growth and full developmental potential of infants at risk.
1. Koletzko, B. Trans
fatty acids may impair biosynthesis of long-chain polyunsaturateds
and growth in man. Acta Pediatr 81: 302-306, 1992 BACK
2. Chen, Z.Y. et al. Trans
Fatty Acid Isomers in Canadian Human Milk. Lipids 30:15-21, 1995
3. Ratnayake, W.M.N. et
al. Fatty Acids in Canadian margarines. Can Inst Sci Technol
J. 24:81-86, 1991 BACK
4. Ratnayake, W.M.N. et
al. Fatty Acids in Some Common Food Items in Canada. J Am Coll
Nutr. 12:651-660, 1993 BACK