Several studies have found that the supply of choline in the womb correlates to the cognitive outcome of the baby, and its benefits may continue for years as the child develops.
In one study, pregnant women who had the highest dietary choline intake during the second trimester of pregnancy (from week 13 to week 28) went on to have children who scored higher on a test of short- and long-term memory at the age of seven.
Some research even suggests insufficient choline intake when a woman is pregnant could be linked ADHD behaviours in their offspring.
"We're seeing a lot more ADHD and dyslexia in schools, and some is genetic, but it's also possible that, in utero, they're not getting key nutrients," Derbyshire says. "These very subtle neurodevelopment changes are occurring and impacting them later on. We're treating the aftermath now."
Jiang has studied the relationship between the supply of choline during pregnancy and breastfeeding, and brain development. "In animal findings, when the mum has more choline, the cognitive development of their offspring is better," she says. "We're starting to find similar results in human studies, although, not exactly the same."
Feeding the brain
A 2020 review of 38 animal and 16 human studies concluded that choline supplementation helps brain development. However, only animal studies currently show a strong link between choline and improved cognitive function. The paper doesn't define the ideal amount of supplementation, but says most human studies use supplements providing up to 930mg choline daily – an amount equivalent to the choline in roughly six chicken's eggs – with no adverse effects reported.
There may also be some people that require more choline than the recommended daily amounts, says Øyen – including post-menopausal women, for example, who have lower levels of oestrogen, and people with fatty liver disease.
We also know, Derbyshire says, that, due to the genetic differences from one person to another, some people may have higher requirements for choline. (Derbyshire has previously consulted for and advised The Meat Advisory Panel, Marlow Foods (Quorn), the Health Supplement Information Service and the British Egg Information Service, among other organisations).
When we eat foods containing choline, it's very easily absorbed into our blood, says Jiang, which should go some way to ensuring we're consuming enough choline.
However, several studies show that many of us aren't getting enough. One study found that only 11% of American adults consume the recommended daily amount.
Eggs are one of the most potent dietary sources of choline, and there is some concern that those who choose to follow a vegan diet may not be getting enough of this nutrient – though there are many plant-based sources and choline supplements are widely available in developed countries.
One study found that people who eat eggs have almost twice the usual choline intake compared with those who don't, leading the researchers to conclude that consuming the daily adequate amount of choline was "extremely difficult" without eating eggs or taking a supplement.
But the EFSA's recommendation of 400mg of choline per day is achievable for most people if you plan your diet carefully, says Jiang. Some vegan sources of choline include tofu (28mg of choline per 100g), peanut butter (61-66mg per 100g) and soy beans (120mg per 100g).
Anyone concerned they're not getting enough choline can take a daily supplement, Øyen says. In the meantime, she adds, there needs to be more animal and human research to better understand the mechanisms behind some of choline's health benefits.
However "clinicians are becoming more aware of [choline]", says Derbyshire. While it often seems to be slightly overlooked, she is hopeful that choline will soon start to enjoy the limelight.
