A healthy and proper nutrition during the pregnancy is an essential requirement for maintaining the health of both mother and unborn child. During the gestational period there is in fact a increased need of numerous nutrients that increases the risk of nutritional deficitswhose consequences can affect the health of both mother and child in the short and long term. Also infant feeding is crucial for their health and proper development and the American Academy of Paediatrics (AAP) has emphasised its importance especially in the first 1000 days of a child's life.
Among the various nutrients identified as vital during pregnancy, two have important repercussions on the health of the eye and brain of the unborn child: the choline and thedocosahexaenoic acid (DHA). Both of these nutrients can be synthesised by the body, but their endogenous production is insufficient to meet requirements. A study of American women showed that even the daily intake of these molecules through the diet is inadequate in 95% women of childbearing age, making supplementation through the use of food supplements necessary. Furthermore, some individuals, who present genetic mutations capable of altering the metabolism of choline and DHA, have an even greater need for these two nutrients.
Choline and DHA: essential functions
Choline
The importance of choline is linked to the fact that it is used by our body as precursori.e. starting molecule, for the biosynthesis of important molecules such as phosphatidylcholine, sphingomyelin, acetylcholine and betaine.
These molecules are involved in several vital functions:
-the phosphatidylcholine takes part in lipid transport and represents, together with the sphingomyelinan essential component of cell membranes;
-l'acetylcholine is a neurotransmitter involved in the transmission of nerve impulses;
-the betaine represents an important source of methyl groups, essential for the biosynthesis of numerous organic molecules and for the proper regulation of gene expression.
The role of choline becomes particularly critical during the pregnancy and it has been shown that low levels of choline in maternal blood are associated with an increased risk of defects in the neural tube of the unborn childthe embryonic structure from which various organs originate, including the brain, spinal cord and part of the eye, including the retina. Closure of the neural tube occurs very early in the embryonic development process, so increasing the mother's intake of choline should ideally begin before conception. Choline supplementation can be beneficial to the health of the child not only during pregnancy, but also in the postnatal period, especially in premature infants. In these infants, interruption of the mother's choline supply, which occurs through the placenta during pregnancy, could contribute to impaired neurocognitive development.
DHA
Docosahexaenoic acid (DHA) is a long-chain polyunsaturated fatty acid (LC-PUFA) synthesised by the body from another essential fatty acid, ?-linoleic acid (ALA), belonging to the omega-3 series. DHA performs many useful functions for the general health of the body, but considerable attention has recently been paid to its role in maintaining the health of the nervous system, particularly the brain and eye. The brain, in fact, has among its most important constituents lipids, and among these, DHA is one of the most abundant. At the level of theeyeDHA contributes to the development and functionality of the retinaacting in particular on the photoreceptorsi.e. cells specialised in the perception of light. Photoreceptors are divided into two types, cones and rods, and DHA represents the 50% of fatty acids contained within both cell types. It is assumed that a DHA deficiency can cause damage to specific retinal photoreceptors, the central conesnegatively affecting eye health. This theory is supported by the detection of low serum levels of DHA in individuals with retinal disorders of genetic origin, such as retinitis pigmentosa.
The essential role played by DHA in visual function is also demonstrated by various studies on the development of thevisual acuity of the child in the early stages of growth. These studies claim that ensuring that the child receives the right amount of DHA from the last five weeks of pregnancy until the age of one year, through DHA-rich foods, positively influences its visual acuity.
Synergistic action of choline and DHA
Numerous studies have shown that the simultaneous intake of choline and DHA results in a significant enhancement of the beneficial properties of these two nutrients, significantly greater than the sum of the effects they would have if taken individually. This finding led the authors to assume that the actions of the two molecules are metabolically relatedalthough the exact mechanism of action remains to be elucidated. Proper nutritional intake during pregnancy and in the very early stages of an infant's life can have long-term health benefits for the child, which is why proper nutrition, possibly supported by supplementation of essential nutrients such as choline and DHA, should be a cornerstone of pre- and peri-natal care.
 Sources:
-Purves D. et al., Neuroscience. 2nd edition. Sunderland (MA): Sinauer Associates; 2001. The Retina.
-Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. Development of the Vertebrate Eye.
-Mun JG, et al, Choline and DHA in Maternal and Infant Nutrition: Synergistic Implications in Brain and Eye Health. Nutrients 2019, 11, 1125.
Dr. Carmelo Chines
Direttore responsabile