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Higher intakes of omega-3 fatty acids may increase birth weight

March 12, 2014

A new review from China concludes that a higher consumption of omega-3 fatty acids found in fatty fish seems to be associated with a significant reduction in the risk of developing breast cancer.

The meta-analysis included data from 21 prospective cohort studies from the United States, Europe and Asia with a total of 883,585 participants, investigating a potential link between intake of omega-3 fatty acids found in fatty fish (eicosapentaenoic acid, or EPA; docosahexaenoic acid, or DHA; and docosapentaenoic acid, or DPA) or plants (alpha-linolenic acid, or ALA) and breast cancer risk (1). The analysis showed that participants with the highest marine omega-3 fatty acid intakes had a 14% lower risk of breast cancer than participants with the lowest intakes. Further analysis indicated a dose-response relationship: each 0.1 g intake of EPA, DHA and/or DPA per day (corresponding to a consumption of 1 to 2 portions of oily fish per person per week) was associated with a 5% reduction in breast cancer risk. No significant protective association was found for ALA.

The researchers concluded that these findings, together with previous study results, support marine omega-3 fatty acids’ role in preventing the incidence of breast cancer. The risk reduction is lowest in Asian popula-tions, probably because fish intake is much higher in Asia than in Western countries. Studies suggest that a healthy diet and lifestyle is crucial for the prevention of breast cancer, and dietary fat is one of the most intensively studied dietary factors closely related with risk. Omega-3 fatty acids are the most promising types of fat to reduce cancer risk, but results from human studies have been inconsistent.

According to 19 European studies increased intakes of omega-3-fatty-acid-rich fish during pregnancy may lead to infants with a higher birth weight, as well as reducing the risk of pre-term births.

The data analysis included self-reported dietary habits of 151,880 mother-child pairs participating in 19 Euro- pean birth cohort studies (1). The analysis showed that women who ate fish at least three times per week during pregnancy gave birth to babies with birth weight about 15 grams greater than babies of women who ate less than one serving per week. In addition, eating at least one serving of fish per week during preg- nancy was associated with a reduction in the risk of pre-term birth of between 11% and 13%.

Experts commented that although these findings do not show a clear cause-effect-relationship, they support the need for public health advice to promote fish consumption in pregnant women in accordance with coun- try-specific restrictions regarding fish species and items known to have high concentrations of pollutants
(e.g., methyl mercury and dioxins). As the most-pronounced effect on birth weight was observed for fatty fish types, the potential benefit of fish consumption may be linked to the omega-3 fatty acid intakes. Ade- quate intakes of docosahexaenoic acid (DHA) have been linked to a reduced risk of heart disease as well as improved neurological function and several other health benefits in unborn babies (2).

References

  1. Zheng J.-S. et al. Intake of fish and marine n-3 polyunsaturated fatty acids and risk of breast cancer: meta-analysis of data from 21 independent prospective cohort studies. BMJ. 2013; 346:f3706.

References

  1. Leventakou V. et al. Fish intake during pregnancy, fetal growth, and gestational length in 19 European birth cohort studies. American Journal of Clinical Nutrition. 2014; 99(3):506-516.
  2. Larqué E. et al. Omega 3 fatty acids, gestation and pregnancy outcomes. Br J Nutr. 2012; 107(2):S77-S84.