Earlier this month I focused one of my blogs on the apparently beneficial role of fish/omega-3 consumption during pregnancy [1]. The omega-3 fats found abundantly in certain fish have been linked with a variety of potential benefits including better neurological development of the foetus and reduced risk of post-natal depression. Other research has linked inadequate omega-3 intake with an increased risk of low birth weight [2,3]. So, I was interested to read some recent research which has, again, linked omega-3 intake with pregnancy outcome.
This research, published on-line last week in the European Journal of Clinical Nutrition [4], looked at the relationship between fish-eating during pregnancy and birth weight in about 700 Indian women. The women in this study ate, generally speaking, low levels of fish during their pregnancies. The average intake came to only 4 grams of fish per day. This, not surprisingly, meant generally low intake of omega-3 fats too.
The results of the study found that failing to eat fish at all during the final third of pregnancy was associated with an increased risk that the child will be born with low birth weight. The risk increase was about 2.5 fold. Low EPA (EPA is one of the two main omega-3 fats found in fish) intakes during the final third of pregnancy were found to be associated with a 2.75 increased risk of low birth weight.
Such a so-called ‘epidemiological’ study is not proof positive that eating more fish/omega-3 during pregnancy helps reduce the risk of low birth weight. However, it is consistent with this concept. And bearing in mind the other likely benefits of omega-3 consumption during pregnancy, does add some weight to the argument for ensuring adequate omega-3 during gestation.
In the post earlier this month I made the point that it almost certainly worthwhile avoiding omega-3 sources likely to be contaminated with mercury such as swordfish, tuna and marlin. Better options, I think include sardines and mackerel (even tinned).
Options for vegetarians and vegans are obviously more limited. However, I recently came across what is being billed as a vegetarian source of both EPA and DHA (the two main omega-3 fats found in fish and fish oil) at this site: http://www.water4.net/
References:
1. Pregnant mums urged to eat more fish, but what about mercury?
2. Hornstra G. Essential fatty acids in mothers and their neonates. Am J Clin Nutr. 2000 71(5):1262-1269
3. Olsen SF, Secher NJ. 2002. Low consumption of seafood in early pregnancy as a risk factor for preterm delivery: prospective cohort study. BMJ. 324(7335):447
4. Muthayya S, et al. The effect of fish and omega-3 LCPUFA intake on low birth weight in Indian pregnant women. Eur J Clin Nutr, 2007 Oct 24; [Epub ahead of print]
I agree, definitely need my fat in the diet. See Weston A Price Article – diet for Pregnant and Nursing Mums:
http://www.westonaprice.org/children/dietformothers.html
And this – fatty acid requirement for women:
http://www.westonaprice.org/knowyourfats/fatty_acid.html
Dr. Since most of the worlds fish supply comes from waters highly polluted by the huge numbers of chemicals from our industries, why should the need for nutritional oils lead to the conclusion that fish should be a source of those oils? Why risk even low levels of pollutants (mercury etc.) when you say a clean (non-fish) source is available? Unless the alga, flax seed or other sources of omega oils are tainted should they not be first on your list and first in your article instead of last? Or do you have information that low levels of mercury are safe? By inference your article seems to suggest low levels of mercury are preferable over no mercury. Is that my misinterpretation or an unintended conclusion on your part? Or have you unstated reasons to prefer fish oil with some mercury over other oil sources without mercury. (also I have heard that the ratio of fish harvested to fish oil produced, in pounds, is 500 to 1. Considering the destruction of fish supplies and ocean health should we not avoid fish sources for oil?) Thanks for keeping us informed and answering our questions. rm