Essential fatty acids: necessary fats during pregnancy and breast-feeding
The essential fatty acids (EFAs) and some of their derivatives are of utmost nutritional importance during pregnancy and lactation (8) . During the last trimester of pregnancy and the first months after birth, major developments in the growth and maturation of the infants central nervous system (CNS) and sensory apparatus, such as the eyes, take place. Rather large amounts of docosahexaenoic acid (DHA), which is ultimately derived from the parent omega-3 fatty acid a -linolenic acid (ALA) or the omega-3 intermediate eicosapentanoic acid (EPA) is needed in the developing infants nervous system (7, 15) . The same goes for arachidonic acid (AA), which is ultimately derived from the parent omega-6 fatty acid linoleic acid (LA): It is also important for proper brain function, although most of the focus has been on DHA. Omega-3 and omega-6 fats are both important, but cannot be interchanged as they are not the same, very much like both vitamin C and E are important vitamins and antioxidants, without one being able to do the job of the other one. Only getting enough of one is better than not getting enough of either, but getting enough of both and in a balanced ratio is the best.
The reason why DHA has been emphasized so much is very likely the general deficiency of omega-3 fatty acids in modern industrial diets and the general imbalance between omega-6 and omega-3 fatty acids. Ideally, it should be no more than 4-5:1, but research estimates that modern diets often contain in excess of 14:1 (24) ; other studies show that the ratio is in between 10:1 to 25:1 (22). Too little of either of these fatty acids can lead to impaired development and functioning of the childs central nervous system (18, 19, 21) with the suspected possibility of lowered IQ and decreased visual acuity (6) .
Animal studies show that severe EFA deficiency during pregnancy leads to more severe deficiencies in mental and sensory capability (20) . There also appears to be a connection between maternal omega-3 status and the length of gestation: The lower the serum levels of omega-3 fatty acids, the greater the chance of giving birth prematurely (22, 25) . Finally, women with postpartum depression lack omega-3 fatty acids compared to women who gave birth without any problems (16) . Since omega-3 fatty acids are known to be lacking in depression and supplementation of benefit (10) , one might wonder if an inadequate intake of omega-3 fatty acids during pregnancy might dispose women for post-partum depression (16, 17) . After giving birth and breastfeeding, it can take quite a while, before omega-3 levels are back to the point they were at before the pregnancy (2, 13, 23) . Supplementing with a good source of omega-3 fatty acids during and after pregnancy could help minimize this drain and facilitate a faster return to normalization of body levels.
The essential fatty acids and derivatives such as DHA and AA are so important to the brain, that it will tenaciously hold on to them (20) . If children or adults whose brain has already been built experience a shortage of DHA and other essential fatty acids, levels decline much slower in the central nervous system than in the rest of the body (20) because they play such an important role there, that the body would rather have other tissues go deficient. Furthermore, the placenta preferentially absorbs EFAs and EFA-derivatives, ALA and DHA in particular, as opposed to other fatty acids from the mothers blood and passes them onto the developing foetus (9, 14) . This is another indication of just how important EFAs and their derivatives are during pregnancy and breastfeeding. If they were not that important, the placenta would not be decidedly active in their preferential absorption and then pass them on to the foetus.
Environmental toxins get into babies
Another issue of no less importance is pollution. We have managed to seriously pollute not only our environment, but also our bodies. Many of the environmental toxins we now find in the human body they are usually called persistent organic pollutants (POPs) are passed on from mother to child either through placental blood or breast milk, and often in very large amounts. Professor Phillip Grandjean and his colleagues from The Institute of Public Health at The University of Southern Denmark have proposed to shorten the recommended period of breastfeeding from 6 months to 4 months because of the excessive amounts of toxins found in breast milk from women living in Western countries. Levels so high that long-term breastfeeding might do more damage than good because the toxicity of the pollutants found in breast milk outweighs the benefits of the nutrients found therein (11) .
A rule of thumb is that the concentration of environmental toxins increases between 10 and 100 times for each step up the food chain. So if a fish lives off plankton with an average contamination with mercury of 1 part per million (ppm), then you would expect the fish in question to contain between 10 and 100 ppm mercury. The feeding of a child by the mother through placental blood or breast milk is also considered a step up in the food chain, so whatever the environmental or dietary load of the mother is, the foetus or child will be subjected to 10-100 times the burden of the mother (3) .
Making matters worse, the developing foetus and small children are much more sensitive to environmental toxins than adults (3) . They also have a much lower capacity for excreting toxins than do adults. The growing foetus is basically incapable of excreting environmental toxins and young children seem to be in the same boat until at least the age of 6 months, when they start synthesizing bile, which is one route of excreting toxins. However, liver function and bile production are not optimal until several years of age .
The developing foetus and young children also have much more body fat. Many of the problematic environmental toxins, such as dioxins, furans and PCBS, are fat-soluble. Thus, the developing foetus and young children also have much more tissue capable of retaining high concentrations of these toxins. The result is that the developing foetus and young children accumulate even greater amounts of whatever environmental toxins they are exposed to than an adult would if subjected to the very same toxins.
In the light of this, it certainly makes sense for women who wish to become pregnant, are pregnant or breast feeding to minimize their exposure to POPs, as their child will be subjected to much higher concentrations than they are exposed to. Some steps that can help minimize POP exposure are:
- Eat organic foods as opposed to conventionally farmed or reared produce, meat, poultry and dairy products. Non-organic vegetables and grains can contain pesticide residues. Non-organic animal products can contain pesticide residues from the grains they are feed and also many of the same POPs found in seafood because they are fed low-grade fish oils with high concentrations of dioxins, furans, PCBs and similar POPs.
- Consider avoiding or limiting seafood, as it can contain organic mercury, dioxins, furans, PCBs and other POPs. Although the EPA and DHA found in seafood are important nutrients, several governments have begun recommending that pregnant and breastfeeding women limit their intake of seafood because of this problem. Be aware that organic vegetable oils can provide the precursor of EPA and DHA in the form of ALA and the precursor for GLA and AA in the form of LA.
- Avoid amalgam fillings in teeth. Amalgam fillings release mercury, which is absorbed by both mother and foetus. Research by the above-mentioned professor Grandjean and colleagues suggests that concentrations of mercury that are below the so-called safe limit adversely affect the neurological development of children exposed during the last trimester of pregnancy and during breastfeeding (12) .
NB: Active detoxification of POPs is not recommended whilst pregnant or breastfeeding. Detoxification by methods such as chelation therapy, liver purges, homeopathy and modified saunas will mobilize POPs lodged in various tissues, thereby temporarily increasing the amounts present in placental blood or breast milk, which in turn increases the toxic burden on the child or developing foetus. Any sort of detoxification to remove stores of POPs should take place before becoming pregnant or after the mother is finished breastfeeding.
References
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widely recognized that modern Western diets often fail to provide adequate levels of micronutrients for optimal functioning (4, 5) . If this is the case with the diets we are ingesting for a single person, then one can only wonder about what sort of deficiencies arise when a woman is pregnant or breastfeeding while eating a modern diet. It has already been documented beyond dispute, that pregnant women in Western countries are not getting enough folate (vitamin B 9 ) during pregnancy and that supplementing with at least 400 g of folate lowers the chance of defective growth of the foetus' spinal cord, which has disastrous consequences if it happens (1) . What about other important nutrients then? Are modern diets providing sufficient amounts of those? 