Why Choline is an Essential Nutrient

Choline is produced by the liver, but not in the amounts required, so choline must also be obtained from the diet^[1]. This makes choline an essential micronutrient. It’s commonly referred to as vitamin B4 but, despite sharing similarities with the B vitamins, it is neither a vitamin or a mineral.

The US Institute of Medicine officially recognised choline as an essential nutrient in 1998^[2]. It was determined that there was insufficient evidence to establish an estimated average requirement (EAR). As a result, adequate intakes (AI) of 550mg/day and 425mg/day were set for men and women respectively^[2]. The AIs for pregnant women (450mg/day) and lactating women (550mg/day) are higher due to their increased needs and loss of choline through breast milk^[3]. Similarly, the European Food Safety Authority (EFSA) established an AI of 400mg/day for adults with higher levels for pregnant and lactating women^[4].

Interestingly, the UK does not recognise choline as an essential nutrient^[5]. Consequently, choline is not included in UK dietary food bases or government recommendations and as such recent calls to the UK government have been made requesting the re-evaluation of their position^[5].

The function of choline

Choline has several important functions in the body. It serves as a source of methyl groups which are needed for numerous steps in metabolism^[6]. Choline is required for making acetylcholine, a neurotransmitter, and phosphatidylcholine which is a vital component of cell membranes^[7]. So, more simply, choline’s functions are involved in nerve transmission, muscle movement and the structure of cells.

Choline is critical during fetal development, namely the brain and spinal cord^[8]. Inadequate intake can result in impaired memory function and neural tube defects^[9].

Folate, also known as vitamin B9, acts as a methyl donor, if a person’s folate intake is low then the requirement for choline increases to compensate^[10]. Choline requirements are also affected by genetics, which is not taken into account by government recommendations^[9].

Dietary sources

Choline can be found in a wide variety of foods. The highest amounts are found in animal foods, particularly eggs, beef and salmon^[7]. Choline can also be found in many plant foods, albeit at lower levels, such as soybeans, quinoa, nuts, cruciferous vegetables and wholegrains^[7].

It has been found that only 11% of US adults meet the AI^[11] – ie 550mg per day – and the same is true for Europe^[7]. As those on a plant-based diet consume foods with a lower amount of choline per serving^[5], it’s important that a balanced and varied diet is eaten to meet the AI.

Choline and NAFLD

Non-alcoholic fatty liver disease (NAFLD) is a disease associated with obesity^[12]. It is characterised by an accumulation of fat in the liver which causes inflammation and can eventually lead to liver failure^[13].

Choline is essential for lipid transport because it helps form the particles that are required for lipids to be carried in the blood^[14]. Therefore, a lack of choline means less fat can be carried out of the liver which allows it to accumulate^[15]. If food consumption is high, as is the case for those with obesity, then choline deficiency could exacerbate the problems that arise^[16]. It’s still unclear the exact role of choline in NAFLD prevention and treatment, but it’s an interesting area of development^[15].

Neurological disorders

Due to the brain being home to an estimated 86 billion neurons^[17] choline plays a major role in the brain’s proper functioning. So, low choline levels have been implicated in neurological diseases such as Alzheimer’s disease^[18]. Alzheimer patients appear to have at least one negative alteration related to choline metabolism^[19]. Furthermore, because of choline’s role in the structural integrity of cells, it’s been suggested it can slow cognitive decline in older adults^[20]. However, clinical trials involving supplementation in this field are mixed^{[21, 22]}.

Choline and Huel

Huel Powders, Hot & Savoury and Ready-to-drink contain between 110-120mg of choline per 400kcal serving or 550-600mg per 2,000kcal, in line with the higher US recommendation. All the choline in Huel products is naturally-occurring from the main ingredients except for Huel Ready-to-drink where additional choline is added in the form of L-choline bitartrate.

Since most people struggle to get enough choline in their diet, Huel is an easy way to ensure your meals contain an adequate amount of choline.

References

1. Zeisel SH, et al. Choline: an essential nutrient for public health. Nutr Rev. 2009; 67(11):615-23.
2. Institute of Medicine Standing Committee on the Scientific Evaluation of Dietary Reference I, et al. The National Academies Collection: Reports funded by National Institutes of Health. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington (DC): National Academies Press (US) National Academy of Sciences.; 1998.
3. NIH. Choline. Date Accessed: 18/10/19. [Available from: https://ods.od.nih.gov/factsheets/Choline-HealthProfessional/]
4. Efsa Panel on Dietetic Products N, et al. Dietary Reference Values for choline. EFSA Journal. 2016; 14(8):e04484.
5. Derbyshire E. Could we be overlooking a potential choline crisis in the United Kingdom? BMJ Nutrition, Prevention & Health. 2019:bmjnph-2019-000037.
6. Zeisel S. Choline, Other Methyl-Donors and Epigenetics. Nutrients. 2017; 9(5):445.
7. Wiedeman AM, et al. Dietary Choline Intake: Current State of Knowledge Across the Life Cycle. Nutrients. 2018; 10(10):1513.
8. Sanders LM, et al. Choline: Dietary Requirements and Role in Brain Development. Nutr Today. 2007; 42(4):181-6.
9. Zeisel SH. Choline: critical role during fetal development and dietary requirements in adults. Annu Rev Nutr. 2006; 26:229-50.
10. Obeid R. The metabolic burden of methyl donor deficiency with focus on the betaine homocysteine methyltransferase pathway. Nutrients. 2013; 5(9):3481-95.
11. Wallace TC, et al. Assessment of Total Choline Intakes in the United States. Journal of the American College of Nutrition. 2016; 35(2):108-12.
12. Fabbrini E, et al. Obesity and nonalcoholic fatty liver disease: biochemical, metabolic, and clinical implications. Hepatology. 2010; 51(2):679-89.
13. Carr RM, et al. Nonalcoholic Fatty Liver Disease: Pathophysiology and Management. Gastroenterol Clin North Am. 2016; 45(4):639-52.
14. Canty DJ, et al. Lecithin and choline in human health and disease. Nutr Rev. 1994; 52(10):327-39.
15. Corbin KD, et al. Choline metabolism provides novel insights into nonalcoholic fatty liver disease and its progression. Curr Opin Gastroenterol. 2012; 28(2):159-65.
16. Zhu J, et al. The effects of choline on hepatic lipid metabolism, mitochondrial function and antioxidative status in human hepatic C3A cells exposed to excessive energy substrates. Nutrients. 2014; 6(7):2552-71.
17. Azevedo FA, et al. Equal numbers of neuronal and nonneuronal cells make the human brain an isometrically scaled-up primate brain. J Comp Neurol. 2009; 513(5):532-41.
18. Michel V, et al. Choline transport for phospholipid synthesis. Exp Biol Med (Maywood). 2006; 231(5):490-504.
19. Ziegler TR, et al. Modern nutrition in health and disease. Wolters Kluwer Health Adis: Philadelphia; 2012.
20. Blusztajn JK, et al. Neuroprotective Actions of Dietary Choline. Nutrients. 2017; 9(8):815.
21. De Jesus Moreno Moreno M. Cognitive improvement in mild to moderate Alzheimer's dementia after treatment with the acetylcholine precursor choline alfoscerate: a multicenter, double-blind, randomized, placebo-controlled trial. Clin Ther. 2003; 25(1):178-93.
22. Higgins JP, et al. Lecithin for dementia and cognitive impairment. Cochrane Database Syst Rev. 2003; (3):Cd001015.