Choline: Its Role and Requirements During Pregnancy

Two papers published in August 2019, one by Korsmo et al, and the other by Wallace et al, both highlight the importance of adequate choline intakes during pregnancy. It is known that we produce small amounts of choline by our liver; but that most individuals must consume the nutrient choline through their diet. Each person’s dietary requirement for choline is dependent on various factors, including common genetic variants, folate and one-carbon metabolism. Choline is an essential nutrient that is required for the liver, muscle and brain to function properly.

Choline’s Role During Pregnancy

Choline is vital for a number of physiological processes during pregnancy; including membrane biosynthesis and tissue expansion, neurotransmission and brain development, and methyl group donation and gene expression. The importance of choline intake during pregnancy and whilst breast feeding has been reinforced by both the American Academy of Pediatrics and the American Medical Association. Both have indicated that choline, along with other essential nutrients, is vital during the first 1,000 days after conception. Furthermore, they have stated that inadequate intakes may result in lifelong brain function deficits even with subsequent nutrient repletion.

Choline intake during pregnancy has been shown to influence numerous metabolic and physiologic processes. Choline-derived phospholipids are required in large quantities during foetal development to support rapid cell division, growth and myelination. Acetylcholine is a choline derived neurotransmitter that influences many processes in brain development; including cell survival, gliogenesis, morphology and migration, neurogenesis, progenitor cell proliferation and differentiation and also synaptic plasticity. Acetylcholine also plays an important role in memory function, learning and attention due to supporting the development of the hippocampus during pregnancy. It is well known that the adult hippocampus is densely innervated with cholinergic neurons, mediating the formation of episodic and semantic memory.

1. Choline influences DNA and histone methylation; which regulate gene expression. In humans, choline intakes during pregnancy may influence the stress reactivity of the offspring. It is known that a heightened response to stress can increase the risk of depression, hypertension, type 2 diabetes mellitus and immunological disorders in adulthood, as such children with a decreased stress-reactivity at birth may be less likely to develop mental and cardio-metabolic disorders.

2.  Emerging data from multiple studies are suggesting that choline intakes directly benefit the functioning of the placenta, including its role in angiogenesis, inflammation and macronutrient transport.

3. Further studies have demonstrated an interaction between choline and macronutrient metabolism during pregnancy. Maternal choline supplementation prevented foetal overgrowth during mid-gestation, which is the most common complication of gestational diabetes mellitus.

4. High choline intake during pregnancy in rodents consistently shows that cognitive function is improved in adulthood and prevents old-age memory decline. Further to this, randomised clinical trials are beginning to emerge showing the beneficial effect of prenatal choline in humans on cognitive outcomes.

5. Animal studies show that choline during pregnancy and the first year of life protects the brain from the neuropathological changes associated with Alzheimer’s disease, autism, Down syndrome, foetal alcohol syndrome and early-life iron deficiency. Choline during pregnancy may also protect against the development of congenital malformations of the central nervous system, known as neural tube defects.

Choline Requirements During Pregnancy

Data from human feeding studies has suggested that the choline adequate intake (AI) of 450 mg/day may not be sufficient to meet the demands of pregnancy. During pregnancy circulating levels of choline-derived methyl metabolites are 40-60% lower than in non-pregnant woman. Furthermore, pregnant women who increase their choline intake by doubling it increase the circulating levels of choline-derived methyl metabolites and overcomes some of the metabolic inefficiencies caused by common polymorphisms in folate and choline metabolising genes. Moreover, this higher level of choline intake can lead to improvements in indicators of neonatal stress reactivity, reductions in gestational diabetes mellitus, faster information processing speed among infants and better memory in children at age 7 years.

Conclusion

Data from both animal and human studies during pregnancy highlight the importance of ensuring an adequate choline intake during pregnancy. Supplementing the maternal diet with additional choline has been shown to improve offspring cognition, neurodevelopment, and placental functioning and to protect against neural and metabolic insults.

As such, most pregnant women would likely benefit from increasing their choline intakes through dietary changes and/or supplementation and there is a need to develop better policies and improve consumer education around the importance of this essential nutrient for human health.

Consumption of 450-1000 mg choline/day appears to be an intake level to support foetal development and improve pregnancy outcomes based on the scientific research currently presented. It is imperative that further research into choline requirements during pregnancy is ongoing.

References

Korsmo HW et al (2019). Choline: Exploring the Growing Science on Its Benefits for Moms and Babies. Nutrients. 11(8), 1823.

Wallace TC et al (2019). Choline: The Neurocognitive Essential Nutrient of Interest to Obstetricians and Gynecologists. J Diet Suppl. Aug 6:1-20.