The findings could have adverse impact on long-chain omega-3 content in the foetal and infant brain membranes that could play a role in cognitive and visual development during the first years of life.
“Due to the specific low alpha-linolenic acid (ALA) intake in the French general population, this nutritional situation appears different to what is observed in other Western countries,” said the study led by Dr Jessica Tressou, researcher at the University of Paris-Saclay.
“New public health programs might be developed encouraging pregnant and lactating women to consume more vegetable oils and margarines rich in ALA, and fish and oily fish rich in long-chain omega-3 polyunsaturated fatty acids (PUFA).”
LA and ALA
Linoleic acid (LA) is the omega-6 metabolic precursor to the longer-chain arachidonic acid (AA) while ALA is the omega-3 metabolic precursor of longer-chain eicosapentaenoic (EPA) and docosahexaenoic acids (DHA).
Both play roles in the architecture and function of cellular membranes, endogenous mediators of cell signalling and gene expression, and precursors of several enzymatic cascades of lipid mediators and metabolites formed by autoxidation.
As in adult woman, a recommended daily intake (RDI) for DHA is advised at 250 mg/d for optimal infant brain and visual development.
The figure takes into account the low conversion of ALA to DHA in humans and consequently in pregnant and lactating women.
Recommendations reported by the Perinatal Lipid Intake Working Group (PNWG) and the International Society for the Study of Fatty Acids and Lipids (ISSFAL) were similar, notably for the DHA intake (less than 200 mg/d).
However, the European Food Safety Authority (EFSA) set an RDI of 0.5% for ALA and 100–200 mg/d for DHA.
The research team began by determining dietary lipid and PUFA intakes from 28 pregnant and 21 lactating French women.
A seven-day food questionnaire that contained 1305 food items was filled in for which the fat and fatty acid content was available.
This formed part of the National Survey INCA2 performed in 2006 and 2007 and the results were compared with results taken from 742 women of childbearing age.
Main results showed that mean daily intakes of omega-3 PUFA were very low in these populations as no pregnant and lactating women met RDIs.
Moreover, some of them ingested quantities 4 times (ALA) to 10 times (DHA) lower than RDIs. Very similar dietary intakes were observed in women of childbearing age.
PUFA imbalance affects brain function
“Data reported from this INCA2 survey pointed out that our population of French pregnant and lactating women ingest low inadequate quantities of both ALA and omega-3 long-chain PUFA because of low consumption of vegetable oils rich in ALA and fish and sea foods rich in EPA + DHA,” the study noted.
“Such PUFA imbalance in the maternal diet against omega-3 PUFA during perinatal life, i.e. from the beginning of the third trimester of pregnancy up to 2 years of age in human, could alter DHA accretion and function of the developing brain and retina in infant.”
The paper goes on to highlight that new large human studies must be conducted to validate that such low maternal omega-3 PUFA intake has an impact on mothers and their infants due to limited available data.
The low sample of women in the study was also a talking point with a large sample study recommended to find out whether such low omega-3 PUFA intake was representative and generalizable to the French general population of pregnant and lactating women.
Source: Prostaglandins, Leukotrienes and Essential Fatty Acids
Published online: doi.org/10.1016/j.plefa.2018.11.007
“Very low inadequate dietary intakes of essential n-3 polyunsaturated fatty acids (PUFA) in pregnant and lactating French women: The INCA2 survey.”
Authors: Jessica Tressou, Benjamin Buaud, Noëmie Simon, StéphanePasteau, Philippe Guesnet